0001193125-25-268095 | 10-Q | XBRL Viewer

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Royalty Monetization Liabilities - Schedule of Royalty Monetization Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Royalty Monetization Liabilities [Line Items]
Royalty monetization liabilities	$ 191,634	$ 59,687
Royalty monetization liabilities	41,718	34,309
Royalty monetization liabilities	149,916	25,378
2020 Royalty Purchase Agreement
Royalty Monetization Liabilities [Line Items]
Royalty monetization liabilities	40,149	59,687
2025 Royalty Bond
Royalty Monetization Liabilities [Line Items]
Royalty monetization liabilities	$ 151,485	$ 0

Royalty Monetization Liabilities

9 Months Ended

Sep. 30, 2025

Royalty Monetization Liabilities [Abstract]

Royalty Monetization Liabilities

7. Royalty Monetization Liabilities

Royalty monetization liabilities are accounted for as debt and consist of the following (in thousands):


	September 30, 2025		December 31, 2024
2020 Royalty Purchase Agreement	$	40,149	$	59,687
2025 Royalty Bond		151,485		—
Total	$	191,634	$	59,687

Current portion of royalty monetization liabilities	$	41,718	$	34,309
Non-current portion of royalty monetization liabilities		149,916		25,378
Total	$	191,634	$	59,687

2020 Royalty Purchase Agreement

In December 2020, the Company entered into a royalty purchase agreement (the 2020 Royalty Purchase Agreement) with entities managed by Healthcare Royalty Management, LLC (collectively and with other affiliated entities, HCR). Under the 2020 Royalty Purchase Agreement, HCR purchased the Company’s rights to a capped amount of Zolgensma royalty payments under the Company’s license agreement with Novartis Gene Therapies (the Novartis License), including $4.0 million of royalty payments received by the Company in the fourth quarter of 2020. In consideration for these rights, HCR paid the Company $200.0 million (the Purchase Price), less $4.0 million representing the payment of the royalties received in the fourth quarter of 2020 to HCR. Beginning upon the effective date of the 2020 Royalty Purchase Agreement, Zolgensma royalty payments, up to a specified threshold, shall be paid to HCR, net of upstream royalties payable by the Company to certain licensors in accordance with existing license agreements.

Pursuant to the 2020 Royalty Purchase Agreement, the total amount of Zolgensma royalty payments to be paid to HCR was subject to an increasing cap (the Cap Amount) equal to (i) $260.0 million applicable for the period from the effective date of the 2020 Royalty Purchase Agreement through November 7, 2024 (the First Cap Amount), and (ii) $300.0 million applicable for the period from November 8, 2024 through the effective date of termination of the Novartis License (the Second Cap Amount). If, on or prior to the defined dates for each Cap Amount, the total amount of Zolgensma royalties paid to HCR equals or exceeds the Cap Amount applicable to such date, the 2020 Royalty Purchase Agreement will automatically terminate. The First Cap Amount was not achieved prior to November 7, 2024, therefore the 2020 Royalty Purchase Agreement will remain in effect until the achievement of the Second Cap Amount or the termination of the Novartis License, if earlier. The Company has no obligation to repay any amounts to HCR under the 2020 Royalty Purchase Agreement if future Zolgensma royalty payments are not sufficient to achieve the applicable Cap Amount prior to the termination of the Novartis License.

The Company has a call option to repurchase its rights to the royalties under the 2020 Royalty Purchase Agreement for a repurchase price equal to, as of the option exercise date, $300.0 million minus the total amount of royalty payments paid to HCR.

The proceeds received from HCR under the 2020 Royalty Purchase Agreement of $196.0 million were recorded as a liability, net of transaction costs of $3.5 million, which is amortized over the estimated life of the arrangement using the effective interest method. In order to determine the amortization of the liability, the Company is required to estimate the total amount of future royalty payments to be paid to HCR, subject to the Cap Amount, over the life of the arrangement. The total amount of royalty payments paid to HCR, less the net proceeds received by the Company of $192.5 million, is recorded as interest expense over the life of the arrangement using the effective interest method. Due to its continuing involvement in the Novartis License, the Company continues to recognize royalty revenue on net sales of Zolgensma and records the royalty payments to HCR as a reduction of the liability when paid. As such payments are made to HCR, the balance of the liability will be effectively repaid over the life of the arrangement.

The Company estimates the effective interest rate used to record interest expense under the 2020 Royalty Purchase Agreement based on its estimate of total Zolgensma royalties to be paid HCR under the arrangement. At each reporting date, the Company reassesses its estimate of total future royalty payments to be paid to HCR at the applicable Cap Amount, and prospectively adjusts the effective interest rate and amortization of the liability as necessary. Over the life of the arrangement, the actual effective interest rate will be affected by the amount and timing of royalty payments actually paid to HCR, which may differ from the Company’s forecasts. The estimated effective interest rate in effect as of September 30, 2025 and December 31, 2024 was 77.1% and 65.5%, respectively, which was based on the amortized balance of the liability and the estimated remaining royalties to be paid to HCR under the arrangement. The estimated interest rate is subject to adjustments in the future based on actual royalties paid to HCR and changes in the royalty forecast. As of September 30, 2025, the estimated effective interest rate over the life of the 2020 Royalty Purchase Agreement, taking into account actual royalties paid to date and the estimated remaining royalties to be paid under the arrangement, was 16.2%.

The following table presents the changes in the royalty monetization liability under the 2020 Royalty Purchase Agreement with HCR (in thousands):


	2020 Royalty
	Purchase Agreement
Balance at December 31, 2024	$	59,687
Zolgensma royalties paid to HCR		(43,384	)
Interest expense recognized		23,846
Balance at September 30, 2025		40,149
Current portion		(38,665	)
Non-current portion	$	1,484

2025 Royalty Bond

In May 2025, the Company entered into a loan agreement with HCR pursuant to which HCR will provide the Company with an aggregate limited recourse loan of up to $250.0 million (the 2025 Royalty Bond). The 2025 Royalty Bond is disbursable to the Company in three tranches, with $150.0 million funded on the closing date in May 2025, $50.0 million available to be funded if sales of a specified product exceed a specified threshold prior to December 31, 2026, and $50.0 million available to be funded if both parties exercise an option in 2027. Loan proceeds under the 2025 Royalty Bond are funded to the Company net of an original issue discount of 2.25% and reimbursement of certain expenses to HCR. Proceeds received by the Company from the initial funding tranche of the 2025 Royalty Bond in May 2025, net of discounts and transaction costs, were $144.5 million.

Prior to the maturity date, interest and principal under the 2025 Royalty Bond shall be paid quarterly to HCR solely using proceeds received from certain specified royalties, milestone payments, license fees and other consideration payable to the Company under specified license agreements (collectively, the Royalty Interest), including (i) the Novartis License for Zolgensma, (ii) the collaboration and license agreement with Nippon Shinyaku for RGX-121 and RGX-111, and (iii) NAV Technology Platform license agreements with Rocket Pharmaceuticals, Inc. and Ultragenyx Pharmaceutical Inc. Zolgensma royalties under the Novartis License shall only be included in the Royalty Interest after full repayment of the applicable Cap Amount under the 2020 Royalty Purchase Agreement with HCR. The Royalty Interest excludes, and the Company retains the rights to, certain other consideration payable under the license agreements including certain milestone payments, license fees and reimbursement of costs as applicable. The Royalty Interest is payable to HCR net of upstream royalty and sublicense fee obligations payable by the Company to applicable licensors. The 2025 Royalty Bond is collateralized by a security interest and lien on the Royalty Interest.

The 2025 Royalty Bond bears interest at a rate of 9.75% plus the 3-month secured overnight financing rate as administered by the Federal Reserve Bank of New York (SOFR), with a minimum interest rate of 14.0%. Interest payments are due quarterly using proceeds received under the Royalty Interest. At each payment date, any proceeds received under the Royalty Interest in excess of the interest payment due will be applied to outstanding principal. If the proceeds received under the Royalty Interest are insufficient to pay the interest due, unpaid interest will accrue to the principal balance.

The 2025 Royalty Bond matures in May 2035, subject to potential extension, unless repaid in full at an earlier date. The maturity date may be extended by two years to May 2037 subject to a potential patent term extension of a specific patent. Upon maturity, the outstanding principal and interest shall be due and payable to HCR. Additionally, upon repayment in full prior to the maturity date, or at the maturity date, the Company shall pay to HCR an additional amount equal to 5.0% of the total outstanding principal as of the applicable determination date. Other than through the payment of proceeds received under the Royalty Interest, the 2025 Royalty Bond may not be prepaid prior to maturity.

In connection with the loan agreement for the 2025 Royalty Bond, the Company also issued HCR warrants to purchase 268,096 shares of its common stock at an exercise price per share of $14.92 (the May 2025 Warrants). The May 2025 Warrants are exercisable upon issuance and expire 10 years from the closing date of the 2025 Royalty Bond. The Company evaluated the May 2025 Warrants and concluded the warrants are indexed to the Company's common stock and meet the criteria to be classified as equity. The net proceeds received by the Company under the loan agreement of $144.5 million were allocated between the 2025 Royalty Bond and the May 2025 Warrants based on their relative fair values. The fair value of the 2025 Royalty Bond was determined based on the carrying amount of the loan on the closing date. The fair value of the May 2025 Warrants was determined using a Black-Scholes option-pricing model on the closing date, resulting in an estimated fair value of the warrants of $1.7 million. Based on the relative fair values of these instruments, $1.6 million of the net proceeds were allocated to the warrants and recorded as additional paid-in capital. The net proceeds allocated to the 2025 Royalty Bond were $142.9 million, resulting in a total debt discount of $7.1 million which is recorded as a reduction of the carrying value of the debt and will be amortized as interest expense over the life of the 2025 Royalty Bond.

The effective interest rate of the 2025 Royalty Bond is partially estimated based on the Company's estimate of future payments under the Royalty Interest to be paid HCR. At each reporting date, the Company reassesses its estimate of total future payments to HCR under the arrangement and prospectively adjusts the effective interest rate and amortization of the debt and associated discount as necessary. Over the life of the arrangement, the actual effective interest rate will be affected by the amount and timing of the actual Royalty Interest payments to HCR and fluctuations in the variable interest rate, which may differ from the Company’s forecasts. The estimated effective interest rate in effect as of September 30, 2025 was 14.9%, which was based on the amortized balance of the liability, the current coupon rate and the estimated remaining payments to HCR under the arrangement.

The following table presents the changes in the royalty monetization liability under the 2025 Royalty Bond with HCR (in thousands):


	2025 Royalty Bond
Balance at December 31, 2024	$	—
Proceeds from royalty bond, net of discount and issuance costs		142,883
Unpaid interest accrued to principal		8,027
Amortization of debt discount and issuance costs		575
Balance at September 30, 2025		151,485
Current portion		(3,053	)
Non-current portion	$	148,432

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current assets
Cash and cash equivalents	$ 58,802	$ 57,526
Marketable securities	215,403	177,161
Accounts receivable	25,347	20,473
Prepaid expenses	12,943	9,067
Other current assets	19,472	13,774
Total current assets	331,967	278,001
Marketable securities	27,838	10,179
Accounts receivable	2,765	474
Property and equipment, net	107,515	117,589
Operating lease right-of-use assets	48,820	53,716
Restricted cash	2,030	2,030
Other assets	4,268	4,000
Total assets	525,203	465,989
Current liabilities
Accounts payable	22,266	22,798
Accrued expenses and other current liabilities	38,316	38,070
Deferred revenue	13,195	115
Operating lease liabilities	9,073	7,902
Royalty monetization liabilities	41,718	34,309
Total current liabilities	124,568	103,194
Deferred revenue	21,186
Operating lease liabilities	67,433	74,131
Royalty monetization liabilities	149,916	25,378
Other liabilities	648	3,635
Total liabilities	363,751	206,338
Stockholders’ equity
Preferred stock; $0.0001 par value; 10,000 shares authorized, no shares issued and outstanding at September 30, 2025 and December 31, 2024
Common stock; $0.0001 par value; 100,000 shares authorized at September 30, 2025 and December 31, 2024; 50,619 and 49,549 shares issued and outstanding at September 30, 2025 and December 31, 2024, respectively	5	5
Additional paid-in capital	1,220,977	1,192,536
Accumulated other comprehensive loss	(652)	(741)
Accumulated deficit	(1,058,878)	(932,149)
Total stockholders’ equity	161,452	259,651
Total liabilities and stockholders’ equity	$ 525,203	$ 465,989

Capitalization - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended		9 Months Ended
	May 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Schedule of Capitalization [Line Items]
Warrants issued						$ 1,610
Percentage of common stock owned			9.99%
Percentage of voting power			9.99%
Maximum [Member]
Schedule of Capitalization [Line Items]
Percentage of common stock owned			19.99%
Minimum [Member]
Schedule of Capitalization [Line Items]
Percentage of common stock owned			4.99%
March 2024 Public Offering [Member]
Schedule of Capitalization [Line Items]
Number of shares sold			4,565,260
Purchase price of share			$ 23
Net proceeds from issuance of common stock			$ 131,100
March 2024 Public Offering [Member] \| March 2024 Pre-funded Warrants [Member]
Schedule of Capitalization [Line Items]
Purchase price of share			$ 22.9999
Number of warrants issued			1,521,740
Exercise price of warrants			$ 0.0001
Warrants remained outstanding				1,125,440		1,125,440
At-the-Market Offering Programs [Member]
Schedule of Capitalization [Line Items]
Aggregate offering price		$ 150,000
2025 Royalty Bond \| HCR [Member] \| May 2025 Warrants [Member]
Schedule of Capitalization [Line Items]
Number of warrants issued	268,096
Exercise price of warrants	$ 14.92
Warrants contractual term	10 years
Warrants issued	$ 1,600
Warrants exercised				0		0
Warrants remained outstanding				268,096		268,096
Common Stock [Member]
Schedule of Capitalization [Line Items]
Number of shares sold							4,565,000
Common Stock [Member] \| March 2024 Public Offering [Member] \| March 2024 Pre-funded Warrants [Member]
Schedule of Capitalization [Line Items]
Number of shares sold				0	0	199,300	197,000

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	50,619,000	49,549,000
Common stock, shares outstanding	50,619,000	49,549,000

Stock-based Compensation - Stock-Based Compensation Expense by Award Type (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 8,998	$ 9,884	$ 26,188	$ 28,921
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	4,777	6,051	14,262	17,969
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	4,051	3,755	11,432	10,536
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 170	$ 78	$ 494	$ 416

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Cash Equivalents and Marketable Securities

The following tables present the fair value of cash equivalents and marketable securities in accordance with the fair value hierarchy discussed in Note 2 (in thousands):


	Level 1		Level 2		Level 3		Total
September 30, 2025
Cash equivalents:
Money market mutual funds	$	—	$	49,384	$	—	$	49,384
Total cash equivalents		—		49,384		—		49,384
Marketable securities:
U.S. government and agency securities		—		123,509		—		123,509
Corporate bonds		—		119,732		—		119,732
Total marketable securities		—		243,241		—		243,241
Total cash equivalents and marketable securities	$	—	$	292,625	$	—	$	292,625


	Level 1		Level 2		Level 3		Total
December 31, 2024
Cash equivalents:
Money market mutual funds	$	—	$	43,895	$	—	$	43,895
U.S. government and agency securities		—		2,498		—		2,498
Total cash equivalents		—		46,393		—		46,393
Marketable securities:
U.S. government and agency securities		—		44,215		—		44,215
Certificates of deposit		—		1,462		—		1,462
Corporate bonds		—		141,663		—		141,663
Total marketable securities		—		187,340		—		187,340
Total cash equivalents and marketable securities	$	—	$	233,733	$	—	$	233,733

Stock-based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 8,998	$ 9,884	$ 26,188	$ 28,921
Research and Development Expense [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	4,245	4,301	12,181	13,893
General and Administrative Expense [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 4,753	$ 5,583	$ 14,007	$ 15,028

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Segment Information - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Revenue, Major Customer [Line Items]
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description			The Company’s CODM, its Chief Executive Officer, views the Company’s operations and manages the business as one operating segment focused on the development and commercialization of gene therapies to treat an array of diseases.
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]			srt:ChiefExecutiveOfficerMember
Cash, Cash Equivalents, and Short-Term Investments, Total	$ 302.0		$ 302.0		$ 244.9
Interest income from investments	$ 3.6	$ 3.3	$ 9.4	$ 9.2

Supplemental Disclosures (Tables)

9 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

Schedule of Other Current Assets

Other current assets consisted of the following (in thousands):


	September 30, 2025		December 31, 2024
Net cost reimbursement due from AbbVie	$	17,031	$	11,304
Accrued interest on investments		1,120		1,094
Other		1,321		1,376
	$	19,472	$	13,774

Schedules of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	September 30, 2025		December 31, 2024
Accrued personnel costs	$	15,076	$	17,607
Accrued external research and development expenses		11,089		8,998
Accrued sublicense fees and royalties		9,080		8,658
Accrued external general and administrative expenses		2,064		2,002
Accrued purchases of property and equipment		78		156
Other		929		649
	$	38,316	$	38,070

License and Collaboration Agreements - Schedule Of License Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total license and royalty revenue	$ 29,733	$ 24,197	$ 140,104	$ 62,114
Interest income from licensing	19	25	65	91
Novartis Gene Therapies [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total license and royalty revenue	23,586	23,872	59,002	60,849
Interest income from licensing	10	6	31	20
Zolgensma Royalties [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total license and royalty revenue	$ 23,586	$ 23,872	$ 59,002	$ 60,849

- Definition

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (ee)
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-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 7: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
-Paragraph 32
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-4

+ Details

Property and Equipment Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Property Plant And Equipment [Line Items]
Total property and equipment	$ 191,054	$ 189,881
Accumulated depreciation and amortization	(83,539)	(72,292)
Property and equipment, net	107,515	117,589
Laboratory and Manufacturing Equipment [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	78,017	77,141
Computer Equipment and Software [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	4,468	4,244
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	7,036	7,031
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	$ 101,533	$ 101,465

Nature of Business

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Business

1. Nature of Business

REGENXBIO Inc. (the Company) is a clinical-stage biotechnology company seeking to improve lives through the curative potential of gene therapy. The Company's investigational gene therapies use adeno-associated virus (AAV) vectors from its proprietary gene delivery platform (NAV Technology Platform). The NAV® Technology Platform consists of exclusive rights to a large portfolio of proprietary AAV vectors. The Company has developed a broad pipeline of gene therapy product candidates using the NAV Technology Platform as a one-time treatment to address an array of diseases. In addition to its internal product development efforts, the Company also selectively licenses the NAV Technology Platform and other intellectual property rights to other leading biotechnology and pharmaceutical companies (NAV Technology Licensees). As of September 30, 2025, the NAV Technology Platform was being applied by NAV Technology Licensees in one commercial product, Zolgensma®, and in the preclinical and clinical development of a number of other licensed products. Additionally, the Company has licensed intellectual property rights to collaborators for the joint development and commercialization of certain product candidates. The Company was formed in 2008 in the State of Delaware and is headquartered in Rockville, Maryland.

Liquidity

The Company has incurred cumulative losses since inception and as of September 30, 2025, had generated an accumulated deficit of $1.06 billion. The Company's ability to transition to recurring profitability is dependent upon achieving a level of revenues adequate to support its cost structure, which depends heavily on the successful development, approval and commercialization of its product candidates. The Company may never achieve recurring profitability, and unless and until it does, will continue to need to raise additional capital through equity offerings, licensing and collaboration arrangements, or other non-dilutive financings. There is no assurance that the Company will be able to raise sufficient capital or obtain financing on favorable terms, or at all. The Company’s ability to continue as a going concern may be impacted by the development and potential commercialization of its product candidates and its ability to raise additional capital to fund its operations. If the Company is unable to raise capital sufficient to meet its working capital needs in the future, it may be forced to delay expenditures, reduce the scope of its development activities or make other changes to its operating plans. As of September 30, 2025, the Company had cash, cash equivalents and marketable securities of $302.0 million, which management believes is sufficient to fund operations for at least the next 12 months from the date these consolidated financial statements were issued.

Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2025

Stock-Based Compensation Expense by Award Type

The Company’s stock-based compensation expense by award type was as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Stock options	$	4,777	$	6,051	$	14,262	$	17,969
Restricted stock units		4,051		3,755		11,432		10,536
Employee stock purchase plan		170		78		494		416
	$	8,998	$	9,884	$	26,188	$	28,921

Stock-Based Compensation Expense

The Company recorded aggregate stock-based compensation expense in the consolidated statements of operations and comprehensive loss as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Research and development	$	4,245	$	4,301	$	12,181	$	13,893
General and administrative		4,753		5,583		14,007		15,028
	$	8,998	$	9,884	$	26,188	$	28,921

Summary of Unvested RSUs Activity Under Equity Incentive Plans

The following table summarizes restricted stock unit activity under the Company's equity incentive plans (in thousands, except per share data):


				Weighted-average
				Grant Date
	Shares			Fair Value
Unvested balance at December 31, 2024		2,042		$	19.95
Granted		1,696		$	8.56
Vested		(732	)	$	21.34
Forfeited		(102	)	$	15.99
Unvested balance at September 30, 2025		2,904		$	13.09

Equity Incentive Plans [Member]

Summary of Stock Option Activity

The following table summarizes stock option activity under the Company's equity incentive plans (in thousands, except per share data):


						Weighted-
						average
				Weighted-		Remaining
				average		Contractual		Aggregate
				Exercise		Life		Intrinsic
	Shares			Price		(Years)		Value (a)
Outstanding at December 31, 2024		9,994		$	29.48		5.9	$	240
Granted		2,441		$	8.02
Exercised		(61	)	$	3.76
Cancelled or forfeited		(648	)	$	28.73
Outstanding at September 30, 2025		11,726		$	25.19		6.3	$	3,961
Exercisable at September 30, 2025		7,693		$	31.89		5.0	$	125
Vested and expected to vest at September 30, 2025		11,726		$	25.19		6.3	$	3,961

(a)

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money at the dates reported.

License and Collaboration Agreements

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

License and Collaboration Agreements

10. License and Collaboration Agreements

License and Collaboration Revenues

As of September 30, 2025, the Company’s NAV Technology Platform was being applied by NAV Technology Licensees in one commercial product, Zolgensma, and in the development of a number of other licensed products. Additionally, the Company has licensed intellectual property rights to collaborators for the joint development and commercialization of certain product candidates. Consideration payable to the Company under its license and collaboration agreements may include: (i) up-front and annual fees, (ii) milestone payments based on the achievement of certain development and sales-based milestones, (iii) sublicense fees, (iv) royalties on sales of licensed products, (v) fees for services related to the development and manufacturing of licensed products and (vi) other consideration payable upon optional goods and services purchased by licensees and collaborators. Sublicense fees vary by license and range from a mid-single digit percentage to a low-double digit percentage of license fees received by licensees as a result of sublicenses. Royalties on net sales of commercialized products vary by license and range from a mid-single digit percentage to a low double-digit percentage of net sales by licensees.

Revenues earned under license and collaboration agreements consisted of the following (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
License and royalty revenue:
Zolgensma royalties	$	23,586	$	23,872	$	59,002	$	60,849
Nippon Shinyaku licenses		—		—		69,979		—
Other license and royalty revenue		19		110		138		323
Total license and royalty revenue		23,605		23,982		129,119		61,172
Service revenue:
Nippon Shinyaku services		5,932		—		10,426		—
Other service revenue		196		215		559		942
Total service revenue		6,128		215		10,985		942
Total revenues	$	29,733	$	24,197	$	140,104	$	62,114

Outstanding development milestone payments are evaluated each reporting period and are only included in the transaction price of each license to the extent the milestones are considered probable of achievement. Sales-based milestones are excluded from the transaction price of each license agreement and recognized as royalty revenue in the period of achievement. As of September 30, 2025, the Company’s license and collaboration agreements contained unachieved milestones which could result in aggregate milestone payments to the Company of up to $2.18 billion, including (i) $548.2 million upon the commencement of various stages of clinical trials, (ii) $106.3 million upon the submission of regulatory approval filings or upon regulatory approval of licensed products and (iii) $1.53 billion upon the achievement of specified sales targets for licensed products, including milestones payable upon the first commercial sale of licensed products. To the extent the milestone payments are realized by the Company, the Company may be obligated to pay sublicense fees to licensors based on a specified percentage of the fees earned by the Company. The achievement of these milestones is highly dependent on the successful development and commercialization of licensed products and it is at least reasonably possible that some or all of the milestone fees will not be realized by the Company.

Accounts Receivable, Contract Assets and Deferred Revenue

The following table presents the balances of the Company’s accounts receivable, contract assets and deferred revenue, as well as other information regarding revenue recognized, during the periods presented (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Accounts receivable, net, current and non-current:
Beginning of period	$	21,783	$	23,273	$	20,947	$	25,491
End of period	$	28,112	$	24,008	$	28,112	$	24,008

Contract assets:
Beginning of period	$	28	$	194	$	239	$	—
End of period	$	93	$	259	$	93	$	259

Deferred revenue, current and non-current:
Beginning of period	$	37,781	$	21	$	115	$	148
End of period	$	34,381	$	144	$	34,381	$	144

Revenue recognized during the period from:
Amounts included in deferred revenue at beginning of period	$	3,401	$	21	$	115	$	148
Performance obligations satisfied in previous periods	$	23,590	$	23,875	$	59,010	$	60,912

Revenue recognized from performance obligations satisfied in previous periods, as presented in the table above, was primarily attributable to Zolgensma royalties.

As of September 30, 2025, the Company had recorded deferred revenue of $34.4 million which represents consideration received or unconditionally due from licensees and collaboration partners for performance obligations that have not yet been satisfied by the Company. Unsatisfied performance obligations as of September 30, 2025 consisted of (i) development services to be performed related to licensed products, which will be satisfied as the services are performed, and (ii) material rights granted to purchase commercial supply of licensed products, which will be satisfied upon delivery of the commercial supply. As of September 30, 2025, the aggregate transaction price of the Company’s license and collaboration agreements allocated to performance obligations not yet satisfied or partially satisfied was $36.2 million, primarily associated with the Company's collaboration and license agreement with Nippon Shinyaku, the substantial majority of which is expected to be satisfied over a period of approximately five years.

Accounts receivable consisted of the following (in thousands):


	September 30, 2025		December 31, 2024
Current accounts receivable:
Billed to customers	$	20	$	65
Unbilled Zolgensma royalties		22,761		20,106
Unbilled Nippon Shinyaku services		2,494		—
Other unbilled		72		302
Current accounts receivable		25,347		20,473
Non-current accounts receivable:
Unbilled Nippon Shinyaku services		2,292		—
Other unbilled		473		474
Non-current accounts receivable		2,765		474
Total accounts receivable	$	28,112	$	20,947

Zolgensma License with Novartis Gene Therapies

In March 2014, the Company entered into an exclusive license agreement (as amended, the Novartis License) with Novartis Gene Therapies. Under the Novartis License, the Company granted Novartis Gene Therapies an exclusive, worldwide commercial license, with rights to sublicense, to the NAV Technology Platform, as well as other certain rights, for the treatment of SMA in

humans by in vivo gene therapy. In 2019, Novartis Gene Therapies launched commercial sales of Zolgensma, a licensed product under the Novartis License. In accordance with the Novartis License, the Company receives royalties on net sales of Zolgensma.

The Company recognized the following amounts under the Novartis License (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Zolgensma royalties	$	23,586	$	23,872	$	59,002	$	60,849
Total license and royalty revenue	$	23,586	$	23,872	$	59,002	$	60,849

Interest income from licensing	$	10	$	6	$	31	$	20

As of September 30, 2025 and December 31, 2024, the Company had recorded total accounts receivable of $23.1 million and $20.4 million, respectively, from Novartis Gene Therapies under the Novartis License, which consisted primarily of Zolgensma royalties receivable. The Zolgensma royalties receivable recorded as of September 30, 2025 included $16.6 million expected to be paid to HCR in accordance with the 2020 Royalty Purchase Agreement discussed in Note 7. The Company recognizes royalty revenue from net sales of Zolgensma in the period in which the underlying products are sold by Novartis Gene Therapies, which in certain cases may require the Company to estimate royalty revenue for periods of net sales which have not yet been reported to the Company. Estimated royalties are reconciled to actual amounts reported in subsequent periods, and any differences are recognized as an adjustment to royalty revenue in the period the royalties are reported.

Collaboration Agreements

AbbVie Collaboration and License Agreement

In September 2021, the Company entered into a collaboration and license agreement with AbbVie Global Enterprises Ltd. (AbbVie), a subsidiary of AbbVie Inc., to jointly develop and commercialize ABBV-RGX-314, the Company’s product candidate for the treatment of wet age-related macular degeneration (wet AMD), diabetic retinopathy (DR) and other chronic retinal diseases (as amended, the AbbVie Collaboration Agreement). The AbbVie Collaboration Agreement became effective in November 2021.

Pursuant to the AbbVie Collaboration Agreement, the Company granted AbbVie a co-exclusive license to develop and commercialize ABBV-RGX-314 in the United States and an exclusive license to develop and commercialize ABBV-RGX-314 outside the United States. The Company and AbbVie will collaborate to develop ABBV-RGX-314 in the United States, and AbbVie will be responsible for the development of ABBV-RGX-314 in specified markets outside the United States. Global development expenses for ABBV-RGX-314 are shared by the parties in accordance with the AbbVie Collaboration Agreement, with AbbVie being responsible for the majority of total development expenses.

The Company will lead the manufacturing of ABBV-RGX-314 for clinical development and U.S. commercial supply, and AbbVie will lead the manufacturing of ABBV-RGX-314 for commercial supply outside the United States. Manufacturing expenses will be allocated between the parties in accordance with the terms of the AbbVie Collaboration Agreement and mutually agreed supply agreements. If requested by AbbVie, the Company will manufacture up to a specified portion of ABBV-RGX-314 commercial supply for sales outside the United States at a price specified in the agreement. AbbVie will lead the commercialization of ABBV-RGX-314 globally, and the Company will participate in U.S. commercialization efforts as provided under a commercialization plan determined in accordance with the agreement. The Company and AbbVie will share equally in the net profits and net losses associated with the commercialization of ABBV-RGX-314 in the United States. Outside the United States, AbbVie will be responsible, at its sole cost, for the commercialization of ABBV-RGX-314.

In consideration for the rights granted under the AbbVie Collaboration Agreement, AbbVie paid the Company an up-front fee of $370.0 million upon the effective date of the agreement in November 2021 and is required to pay to the Company up to $1.38 billion upon the achievement of specified development and sales-based milestones, of which $562.5 million are based on development milestones and $820.0 million are sales-based milestones. AbbVie is also required to pay to the Company tiered royalties on net sales of ABBV-RGX-314 outside the United States at percentages in the mid-teens to low twenties, subject to specified offsets and reductions.

In August 2025, the Company and AbbVie entered into an amendment to the AbbVie Collaboration Agreement which modified the development plan and milestone payment structure for the ABBV-RGX-314 DR program. Under the amendment, the Company will conduct the first registration enabling trial for DR suprachoroidal (SCS) treatment as a combined Phase IIb/III trial performed in two parts (Part 1 and Part 2), and AbbVie will conduct the second registration enabling trial as a separate, standalone Phase III trial. In

lieu of the $200.0 million development milestone due to the Company under the original AbbVie Collaboration Agreement upon first patient dosed in the first registration enabling trial for DR SCS treatment, AbbVie will pay the Company $100.0 million upon first patient dosed in the Phase IIb/III trial for DR SCS treatment and an additional $100.0 million upon first patient dosed in the subsequent Phase III trial. Also pursuant to the amendment, AbbVie will lead a new Phase III randomized controlled study (the ACHIEVE Study) to assess the injection burden, adverse events, change in disease activity, and long-term preservation of visual acuity of ABBV-RGX-314 in adult participants with neovascular AMD. The Company will be responsible for its development expenses to conduct Part 1 of the Phase IIb/III trial for DR and the parties will share the development expenses related to Part 2 of the Phase IIb/III trial and the subsequent Phase III trial for DR in accordance with the existing terms of the AbbVie Collaboration Agreement. AbbVie will be responsible for all development expenses related to the ACHIEVE Study.

The Company applied the requirements of ASC 606 to the AbbVie Collaboration Agreement for the units of account in which AbbVie was deemed to be a customer. The Company determined that there is only one material performance obligation under the agreement for the delivery of the intellectual property license to develop and commercialize ABBV-RGX-314 globally. The intellectual property licensed to AbbVie includes the rights to certain patents, data, know-how and other rights developed and owned by the Company, as well as other intellectual property rights exclusively licensed by the Company from various third parties. As of September 30, 2025 and December 31, 2024, the transaction price of the AbbVie Collaboration Agreement was $370.0 million, which consisted solely of the up-front payment received from AbbVie in November 2021. The $370.0 million transaction price was fully recognized as revenue upon the delivery of the license to AbbVie in November 2021. Variable consideration under the AbbVie Collaboration Agreement, which has been excluded from the transaction price, includes $562.5 million in payments for development milestones that have not yet been achieved and were not considered probable of achievement. Additionally, the transaction price excludes sales-based milestone payments of $820.0 million and royalties on net sales of ABBV-RGX-314 outside the United States. Development milestones will be added to the transaction price and recognized as revenue upon achievement, or if deemed probable of achievement. In accordance with the sale- or usage-based royalty exception under ASC 606, royalties on net sales and sales-based milestones will be recognized as revenue in the period the underlying sales occur or milestones are achieved. There were no changes in the transaction price of the AbbVie Collaboration Agreement, and no revenue was recognized, during the three and nine months ended September 30, 2025 and 2024.

The Company applied the requirements of ASC 808 to the AbbVie Collaboration Agreement for the units of account which were deemed to be a collaborative arrangement. Both the Company and AbbVie will perform various activities related to the development, manufacturing and commercialization of ABBV-RGX-314 in the United States. Development costs are shared between the parties in accordance with the terms of the AbbVie Collaboration Agreement, and the parties will share equally in the net profits and losses derived from sales of ABBV-RGX-314 in the United States. The Company accounts for payments to and from AbbVie for the sharing of development and commercialization costs in accordance with its accounting policy for collaborative arrangements. Amounts owed to AbbVie for the Company’s share of development costs or commercialization costs incurred by AbbVie are recorded as research and development expense or general and administrative expense, respectively, in the period the costs are incurred. Amounts owed to the Company for AbbVie’s share of development costs or commercialization costs incurred by the Company are recorded as a reduction of research and development expense or general and administrative expense, respectively, in the period the costs are incurred. At the end of each reporting period, the Company records a net amount due to or from AbbVie as a result of the cost-sharing arrangement. As of September 30, 2025 and December 31, 2024, the Company had recorded $17.0 million and $11.3 million, respectively, due from AbbVie for net reimbursement of costs incurred for activities performed under AbbVie Collaboration Agreement, which was included in other current assets on the consolidated balance sheets.

The Company recognized the following amounts under the AbbVie Collaboration Agreement (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Net cost reimbursement to (from) AbbVie included in:
Research and development expense	$	(17,742	)	$	(20,082	)	$	(49,479	)	$	(66,330	)
General and administrative expense		712			341			1,860			1,168
Total net cost reimbursement to (from) AbbVie	$	(17,030	)	$	(19,741	)	$	(47,619	)	$	(65,162	)

Nippon Shinyaku Collaboration and License Agreement

In January 2025, the Company entered into a collaboration and license agreement with Nippon Shinyaku for the development and commercialization of RGX-121, the Company’s product candidate for the treatment of Mucopolysaccharidosis Type II (MPS II), and RGX-111, the Company's product candidate for the treatment of Mucopolysaccharidosis Type I (MPS I) (the Nippon Shinyaku Collaboration Agreement). The Nippon Shinyaku Collaboration Agreement became effective in March 2025.

Pursuant to the Nippon Shinyaku Collaboration Agreement, the Company granted Nippon Shinyaku a license to develop and exclusively commercialize RGX-121 and RGX-111 in the United States and certain countries in Asia. The Company is responsible for the development of RGX-121 and RGX-111 in the United States, and Nippon Shinyaku is responsible for development in licensed territories outside the United States. The Company is responsible for the manufacturing of RGX-121 and RGX-111 for clinical development and commercial supply, and manufacturing expenses will be allocated between the parties in accordance with the terms of the Nippon Shinyaku Collaboration Agreement and mutually agreed supply agreements. Nippon Shinyaku will be responsible, at its sole cost, for the commercialization of RGX-121 and RGX-111 in the licensed territories. The Company reserves the right to develop and commercialize RGX-121 and RGX-111 in countries outside the licensed territories. The Nippon Shinyaku Collaboration Agreement contains provisions for termination, including termination for convenience by Nippon Shinyaku.

In consideration for the rights granted and services to be performed under the Nippon Shinyaku Collaboration Agreement, Nippon Shinyaku paid the Company an up-front fee of $110.0 million upon the effective date of the agreement in March 2025 and is required to pay to the Company up to $700.0 million upon the achievement of specified development and sales-based milestones, of which $40.0 million are based on development milestones and $660.0 million are sales-based milestones. Nippon Shinyaku is also required to pay to the Company double-digit royalties on net sales of RGX-121 and RGX-111 in the licensed territories, subject to specified offsets and reductions. The Company retains all rights to, and any proceeds related to the sale of, any priority review vouchers that may be issued upon the potential approvals of RGX-121 and RGX-111.

The Company evaluated its various commitments under the Nippon Shinyaku Collaboration Agreement and identified the distinct units of account under the arrangement. For each of the distinct units of account identified, the Company determined whether the transactions should be accounted for as a contract with a customer within the scope of ASC 606 or as a collaborative arrangement within the scope of ASC 808. The Company concluded that each of the distinct units of account identified should be accounted for as revenue under ASC 606, as Nippon Shinyaku is deemed to be a customer for each of the various transactions. The Company identified the following material performance obligations under the agreement: (i) delivery of intellectual property licenses to develop and commercialize RGX-121 and RGX-111 in the United States and Asia territories, (ii) development services for RGX-121 and RGX-111 in the Unites States, including manufacturing of clinical supply and commercial supply prior to regulatory approval, and (iii) material rights granted to Nippon Shinyaku to purchase commercial supply for sales in licensed territories.

The intellectual property licensed to Nippon Shinyaku includes the rights to certain patents, data, know-how and other rights developed and owned by the Company, as well as other intellectual property rights exclusively licensed by the Company from various third parties. In determining the distinct performance obligations under the agreements, the Company concluded that the licenses granted to Nippon Shinyaku to develop and commercialize RGX-121 and RGX-111 are distinct from the other goods and services promised under the agreement, as Nippon Shinyaku can benefit from the license on a standalone basis and, based on the stage of development of the product candidates, the underlying licensed products and know-how are not expected to be significantly modified as a result of other goods and services promised under the agreement. The Company evaluated all options granted to Nippon Shinyaku under the agreement to determine whether the options represent material rights. Management concluded the options to purchase commercial supply convey material rights granted to Nippon Shinyaku, and therefore are accounted for as separate performance obligations under the current arrangement. The Company identified various promises under the Nippon Shinyaku Collaboration Agreement which were determined to be immaterial in the context of the contract and will not be accounted for as separate performance obligations.

As of September 30, 2025, the transaction price of the Nippon Shinyaku Collaboration Agreement included fixed consideration of $110.0 million for the up-front payment and variable consideration of $5.3 million for estimated reimbursable manufacturing costs which are deemed not to be constrained. Variable consideration which has been excluded from the transaction price includes $40.0 million in payments for development milestones that have not yet been achieved and were not considered probable of achievement, and other reimbursable manufacturing costs which are contingent on events occurring that are outside the Company’s control. The transaction price also excludes sales-based milestone payments of $660.0 million and royalties on net sales of RGX-121 and RGX-111 in the United States and Asia territories. Development milestones will be added to the transaction price upon achievement, or if deemed probable of achievement, and other variable consideration may be added to the transaction price in the future as uncertainties regarding payment of the consideration are resolved. In accordance with the sale- or usage-based royalty exception under ASC 606, royalties on net sales and sales-based milestones will be recognized as revenue in the period the underlying sales occur or milestones are achieved. There were no changes in the fixed transaction price of the Nippon Shinyaku Collaboration Agreement between the effective date of the agreement and September 30, 2025.

The fixed transaction price of the Nippon Shinyaku Collaboration Agreement of $110.0 million was allocated to the various performance obligations based on their relative standalone selling prices, which requires significant judgment. The selling prices of the intellectual property licenses were determined based on discounted cash flow models for each of the licensed products in the respective licensed territories and were adjusted for the probability of developmental, regulatory and commercial success. Significant

assumptions and judgments were required to estimate the future cash flows, discount rates and probabilities of success for each of the licensed products and territories. The selling prices of development services and commercial supply were determined based on the expected cost plus a reasonable margin. The selling prices of the material rights to purchase commercial supply were determined based on the incremental discount to the standalone selling prices of the commercial supply and were adjusted to take into account the likelihood of exercise of the material rights. Significant assumptions and judgments were required to estimate the future costs of development and manufacturing, an appropriate margin for such services, and the likelihood of exercise of the material rights to purchase commercial supply based on anticipated demand and risks. The $5.3 million of variable consideration included in the transaction price is allocated directly to performance obligations for development services related to the manufacturing of commercial supply prior to regulatory approval since the consideration is directly associated with reimbursement of such costs. Consideration contingent upon the future exercise of options to purchase commercial supply is excluded from the transaction price until exercised.

The portion of the $110.0 million fixed transaction price allocated to the delivery of the intellectual property licenses was recognized as license and royalty revenue upon the delivery of the license to Nippon Shinyaku in March 2025. The portion of the fixed transaction price allocated to development services will be recognized as service revenue as the services are performed using an input method based on costs incurred versus total estimated costs to perform the services, which is re-assessed at each reporting date. The portion of the fixed transaction price allocated to material rights to purchase commercial supply will be recognized as revenue proportionally with the total expected commercial supply revenue expected to be recognized under the arrangement, which is re-assessed at each reporting date. Commercial supply revenue will be recognized as revenue upon delivery to Nippon Shinyaku, or otherwise upon transfer of control to Nippon Shinyaku as defined in the associated supply agreements.

The Company recognized the following amounts under the Nippon Shinyaku Collaboration Agreement (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
License and royalty revenue	$	—	$	—	$	69,979	$	—
Service revenue		5,932		—		10,426		—
Total revenues	$	5,932	$	—	$	80,405	$	—

As of September 30, 2025, the Company had recorded total accounts receivable of $4.8 million for reimbursement of manufacturing-related development costs and other services under the Nippon Shinyaku Collaboration Agreement, of which $2.5 million was included in current assets and $2.3 million was included in non-current assets. As of September 30, 2025, the Company had recorded total deferred revenue of $34.4 million for development services and material rights which have not yet been satisfied under the Nippon Shinyaku Collaboration Agreement, of which $13.2 million was included in current liabilities and $21.2 million was included in non-current liabilities.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

GlaxoSmithKline

In March 2009, the Company entered into a license agreement, which was amended in April 2009 (as amended, the GSK License), with GlaxoSmithKline LLC (GSK) for exclusive, worldwide rights to certain patents underlying the Company’s NAV Technology Platform which are owned by The Trustees of the University of Pennsylvania (Penn) and exclusively licensed to GSK. Pursuant to the GSK License, the Company is obligated to pay GSK royalties on net sales of licensed products and sublicense fees. Additionally, the Company is obligated to reimburse GSK for certain costs incurred related to the maintenance of the licensed patents. The Company was also obligated to pay $1.5 million to GSK upon the achievement of various milestones, all of which have been achieved and paid.

In March 2022, the Company entered into a letter agreement (the Penn Letter Agreement) with Penn to buy out the Company’s obligation to pay sublicense fees under its license agreement with Penn. In connection with the execution of the Penn Letter Agreement in March 2022, the Company’s royalty obligations under the GSK License were assigned by GSK to Penn. Beginning upon the effective date of the Penn Letter Agreement in March 2022, any royalties payable by the Company under the GSK License shall be paid to Penn rather than GSK. The Company remains obligated to pay GSK sublicense fees and reimbursement of certain patent maintenance costs in accordance with the GSK License.

Expenses incurred by the Company related to the GSK License were recorded as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Cost of license and royalty revenues:
Royalties on net sales of Zolgensma	$	5,709	$	12,330	$	13,495	$	27,168
Other		1		7		244		31
Total cost of license and royalty revenues		5,710		12,337		13,739		27,199
General and administrative		30		70		137		147
	$	5,740	$	12,407	$	13,876	$	27,346

As of September 30, 2025 and December 31, 2024, the Company had recorded $6.4 million and $6.3 million, respectively, payable under the GSK License.

The Company has been notified of a dispute with GSK over the amount of sublicense fees paid by the Company to GSK under the GSK License. GSK claims there has been a significant underpayment by the Company as they are entitled to a sublicense payment on all amounts received by the Company from sublicensees, including royalties, and not just amounts received for GSK's sublicensed patents. The Company disagrees with GSK's interpretation of the GSK License. The Company does not believe that a loss is probable, and no reasonable range of loss is estimable, related to this matter. No liabilities related to this matter were recorded as of September 30, 2025 and December 31, 2024.

License and Collaboration Agreements - Summary of Accounts Receivable, Contract Assets and Deferred Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Accounts receivable, net, current and non-current:
Balance, beginning of period	$ 21,783	$ 23,273	$ 20,947	$ 25,491
Balance, end of period	28,112	24,008	28,112	24,008
Contract assets:
Balance, beginning of period	28	194	239
Balance, end of period	93	259	93	259
Deferred revenue, current and non-current:
Balance, beginning of period	37,781	21	115	148
Balance, end of period	34,381	144	34,381	144
Revenue recognized during the period from:
Amounts included in deferred revenue at beginning of period	3,401	21	115	148
Performance obligations satisfied in previous periods	$ 23,590	$ 23,875	$ 59,010	$ 60,912

Commitments and Contingencies - Summary of Expenses Incurred by Company (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Cost of License and Royalty Revenues [Abstract]
Royalties on net sales of Zolgensma	$ 29,733	$ 24,197	$ 140,104	$ 62,114
Zolgensma Royalties [Member]
Cost of License and Royalty Revenues [Abstract]
Royalties on net sales of Zolgensma	23,586	23,872	59,002	60,849
GlaxoSmithKline LLC [Member]
Other Commitments [Line Items]
Total related party transaction expense	5,740	12,407	13,876	27,346
GlaxoSmithKline LLC [Member] \| Zolgensma Royalties [Member]
Cost of License and Royalty Revenues [Abstract]
Royalties on net sales of Zolgensma	5,709	12,330	13,495	27,168
GlaxoSmithKline LLC [Member] \| Other [Member]
Other Commitments [Line Items]
Total related party transaction expense	1	7	244	31
GlaxoSmithKline LLC [Member] \| Cost of License and Royalty Revenues [Member]
Other Commitments [Line Items]
Total related party transaction expense	5,710	12,337	13,739	27,199
GlaxoSmithKline LLC [Member] \| General and Administrative [Member]
Other Commitments [Line Items]
Total related party transaction expense	$ 30	$ 70	$ 137	$ 147

- Definition

+ References

+ Details

Supplemental Disclosures - Additional Information (Detail) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Supplemental Disclosures of Non-cash Investing and Financing Activities [Line Items]
Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities	$ 200,000	$ 400,000
Increase (decrease) in purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities			$ (200,000)
2025 Royalty Bond
Supplemental Disclosures of Non-cash Investing and Financing Activities [Line Items]
Convertion of accrued interest in to principal balance	$ 8,000,000
Maximum [Member]
Supplemental Disclosures of Non-cash Investing and Financing Activities [Line Items]
Increase (decrease) in purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities				$ (100,000)

Summary of Significant Accounting Policies - Summary of Reconciliation of Cash and Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Accounting Policies [Abstract]
Cash and cash equivalents	$ 58,802	$ 57,526	$ 56,617
Restricted cash	2,030	$ 2,030	2,030
Total cash and cash equivalents and restricted cash	$ 60,832		$ 58,647

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2024	Sep. 30, 2024
Property, Plant and Equipment [Line Items]
Impairment of property and equipment		$ 2,101
Furniture Fixtures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Impairment of property and equipment	$ 700

Nature of Business - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ (1,058,878)	$ (932,149)
Cash, cash equivalents and marketable securities	$ 302,000	$ 244,900

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2025

GlaxoSmithKline LLC [Member]

Summary of Expenses Incurred by Company

Expenses incurred by the Company related to the GSK License were recorded as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Cost of license and royalty revenues:
Royalties on net sales of Zolgensma	$	5,709	$	12,330	$	13,495	$	27,168
Other		1		7		244		31
Total cost of license and royalty revenues		5,710		12,337		13,739		27,199
General and administrative		30		70		137		147
	$	5,740	$	12,407	$	13,876	$	27,346

License and Collaboration Agreements - Additional Information (Detail)	1 Months Ended			3 Months Ended		9 Months Ended
	Aug. 31, 2025 USD ($)	Jan. 31, 2025 USD ($)	Nov. 30, 2021 USD ($)	Sep. 30, 2025 USD ($) ProductCandidate	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) ProductCandidate	Sep. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment upon commencement of clinical trials in humans						$ 548,200,000
Milestone payment upon submission of regulatory approval filings						106,300,000
Milestone payment upon achievement of specified sales targets for licensed products						1,530,000,000
Deferred revenue, current and non-current				$ 34,381,000	$ 144,000	34,381,000	$ 144,000	$ 37,781,000	$ 115,000	$ 21,000	$ 148,000
Contract assets				93,000	259,000	93,000	259,000	28,000	239,000	194,000
Aggregate transaction price of license agreements						$ 36,200,000
Aggregate transaction price of license agreements, expected satisfaction period						5 years
Accounts receivable				28,112,000	24,008,000	$ 28,112,000	24,008,000	$ 21,783,000	20,947,000	$ 23,273,000	$ 25,491,000
Accounts receivable, Current				25,347,000		25,347,000			20,473,000
Accounts receivable, Non current				2,765,000		2,765,000			474,000
Abb Vie Collaboration And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Up-front fee paid			$ 370,000,000
Milestone fee payments upon achievement of various development and commercialization			1,380,000,000
Transaction price of license			370,000,000	370,000,000		370,000,000			370,000,000
Change in transaction price				0	$ 0	0	$ 0
Milestone due	$ 200,000,000
Milestone payment upon first patient dosed in the Phase IIb/III trial	100,000,000
Milestone payment upon first patient dosed in the subsequent Phase III trial	$ 100,000,000
Abb Vie Collaboration And License Agreement \| Other Current Assets [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Due from related parties, current				17,000,000		17,000,000			11,300,000
Nippon Shinyaku Collaboration and License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable				4,800,000		4,800,000
Accounts receivable, Current				2,500,000		2,500,000
Accounts receivable, Non current				2,300,000		2,300,000
Deferred revenue				34,400,000		34,400,000
Deferred revenue, Current				13,200,000		13,200,000
Deferred revenue, Noncurrent				21,200,000		21,200,000
Up-front fee paid		$ 110,000,000
Transaction price of license				110,000,000		110,000,000
Variable consideration				5,300,000		5,300,000
Novartis License Agreement [Member] \| Novartis Gene Therapies [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable				23,100,000		23,100,000			20,400,000
Sales Based Milestones \| Abb Vie Collaboration And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone fee payments upon achievement of various development and commercialization			820,000,000
Transaction price of license				820,000,000		820,000,000			820,000,000
Sales Based Milestones \| Nippon Shinyaku Collaboration and License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone fee received upon achievement of specified development and sales based milestones		660,000,000
Transaction price of license				660,000,000		660,000,000
Development Milestone \| Abb Vie Collaboration And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone fee payments upon achievement of various development and commercialization			$ 562,500,000
Transaction price of license				562,500,000		562,500,000			$ 562,500,000
Development Milestone \| Nippon Shinyaku Collaboration and License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone fee received upon achievement of specified development and sales based milestones		40,000,000
Transaction price of license				$ 40,000,000		40,000,000
Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Aggregate milestone payment for all the targets						$ 2,180,000,000
Maximum [Member] \| Nippon Shinyaku Collaboration and License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone fee received upon achievement of specified development and sales based milestones		$ 700,000,000
N A V Technology Platform [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of commercial product candidates \| ProductCandidate				1		1
HCR [Member] \| Novartis License Agreement [Member] \| Novartis Gene Therapies [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable, current				$ 16,600,000		$ 16,600,000

Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Common Stock [Member] \| Private Placement [Member]
Issuance of Stock, transaction costs	$ 534

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Pay vs Performance Disclosure
Net Income (Loss)	$ (61,941)	$ (59,597)	$ (126,729)	$ (175,916)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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Reference 21: http://www.xbrl.org/2003/role/disclosureRef
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 220
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-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

+ Details

Property and Equipment, Net (Tables)

9 Months Ended

Sep. 30, 2025

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment, net consists of the following (in thousands):


	September 30, 2025			December 31, 2024
Laboratory and manufacturing equipment	$	78,017		$	77,141
Computer equipment and software		4,468			4,244
Furniture and fixtures		7,036			7,031
Leasehold improvements		101,533			101,465
Total property and equipment		191,054			189,881
Accumulated depreciation and amortization		(83,539	)		(72,292	)
Property and equipment, net	$	107,515		$	117,589

Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2025

Earnings Per Share [Abstract]

Schedules for Computation of Diluted Weighted-Average Shares Outstanding


	Three and Nine Months Ended September 30,
	2025		2024
Stock options issued and outstanding		11,726		10,017
Unvested restricted stock units outstanding		2,904		2,035
Employee stock purchase plan		60		47
May 2025 Warrants outstanding		268		—
		14,958		12,099

Income Taxes

9 Months Ended

Sep. 30, 2025

Income Tax Disclosure [Abstract]

Income Taxes

12. Income Taxes

The Company evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets as of September 30, 2025 and December 31, 2024. Based on the Company’s history of operating losses, and other relevant facts and circumstances, the Company concluded that it was more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company provided a full valuation allowance for its net deferred tax assets as of September 30, 2025 and December 31, 2024.

In July 2025, the United States enacted tax reform legislation through the One Big Beautiful Bill Act (OBBBA). The OBBBA amends U.S. tax laws, including extending or making permanent certain provisions of the Tax Cuts and Jobs Act of 2017 and repealing certain clean energy initiatives, in addition to other changes. The Company expects changes to various gross deferred tax assets and liabilities as a result of the enactment of the OBBBA, including changes to its deferred tax assets for net operating loss carryforwards and capitalized research and development costs. However, due to projected taxable losses and a full valuation allowance against its deferred tax assets, the Company expects no material impact to its income tax provision and net deferred tax assets for the year ended December 31, 2025 as a result of the enactment, and there was no impact to the Company's income tax provision for the three and nine months ended September 30, 2025. The Company continues to evaluate the impact the OBBBA will have on its consolidated financial statements in future periods.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
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-Section 50
-Paragraph 1
-Subparagraph (a)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (a)
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
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-Section S99
-Paragraph 1
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (SX 210.4-08(h)(2))
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-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

License and Collaboration Agreements - Schedule of Nippon Shinyaku Collaboration Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 29,733	$ 24,197	$ 140,104	$ 62,114
Nippon Shinyaku Collaboration and License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	5,932		80,405
Nippon Shinyaku Collaboration and License Agreement [Member] \| License and Royalty Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues			69,979
Nippon Shinyaku Collaboration and License Agreement [Member] \| Service Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 5,932		$ 10,426

- Definition

+ References

+ Details

Net Loss Per Share - Schedules for Computation of Diluted Weighted-Average Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted weighted average shares outstanding	14,958	12,099
Stock Options Issued and Outstanding [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted weighted average shares outstanding	11,726	10,017
Unvested Restricted Stock Units Outstanding [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted weighted average shares outstanding	2,904	2,035
Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted weighted average shares outstanding	60	47
May 2025 Warrants Outstanding [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted weighted average shares outstanding	268

Leases

9 Months Ended

Sep. 30, 2025

Leases [Abstract]

Leases

6. Leases

New York Lease and Sublease

In May 2016, the Company entered into an operating lease for office space in New York, New York (the New York Lease), which has since been amended to include additional office space and extend the term of the lease. The lease term commenced in July 2016 and expires in April 2027.

In March 2024, the Company entered into an agreement to sublease its office space under the New York Lease (the New York Sublease) to a third-party subtenant. The sublease term commenced in April 2024 and expires in April 2027 concurrent with the expiration of the New York Lease. Monthly payments under the New York Sublease commenced in July 2024 and escalate annually in accordance with the sublease agreement. As of September 30, 2025, total undiscounted future minimum lease payments to be received by the Company over the term of the New York Sublease were $0.8 million. The Company recognized sublease income under the New York Sublease of $0.1 million and $0.3 million during the three and nine months ended September 30, 2025, respectively, and $0.1 million and $0.2 million during the three and nine months ended September 30, 2024, respectively.

The New York Sublease is classified as an operating lease and the Company was not relieved of its primary obligation under the New York Lease. The Company continues to account for the New York Lease as it did prior to the commencement of the sublease.

As a result of the New York Sublease, the Company determined an impairment indicator was present as of March 31, 2024 related to the long-lived asset group subject to the sublease, which included the right-of-use asset under the New York Lease, leasehold improvements and other property and equipment allocable to the New York Sublease. The Company concluded the carrying value of the asset group as of March 31, 2024 was not recoverable, as it exceeded the sum of the estimated undiscounted cash flows to

be generated by the assets over their remaining lives. The Company estimated the fair value of the asset group as of March 31, 2024 using a discounted cash flow method, which incorporated unobservable inputs including the net identifiable cash flows over the term of the New York Sublease and an estimated borrowing rate of a market participant subtenant. The estimated fair value of the asset group as of March 31, 2024 represents a Level 3 nonrecurring fair value measurement. The Company concluded the carrying value of the asset group of $3.4 million exceeded its estimated fair value of $1.3 million as of March 31, 2024. As such, the Company recognized impairment losses of $2.1 million during the three months ended March 31, 2024 and the nine months ended September 30, 2024 on the long-lived asset group associated with the New York Sublease. The impairment losses were allocated to the various assets within the long-lived asset group based on their relative carrying values and consisted of $1.4 million recorded to the right-of-use assets and $0.7 million recorded to property and equipment. No impairment losses on long-lived assets were recorded during the three and nine months ended September 30, 2025 and the three months ended September 30, 2024.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2025

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

The accompanying consolidated financial statements are unaudited and have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). The interim unaudited consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements as of and for the year ended December 31, 2024 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, which was filed with the SEC on March 13, 2025. Certain information and footnote disclosures required by GAAP, which are normally included in the Company’s annual consolidated financial statements, have been omitted pursuant to SEC rules and regulations for interim reporting. In the opinion of management, the accompanying consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for a fair statement of the results of operations for the periods presented.

The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year, any other interim periods, or any future year or period. These interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2024, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024.

The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities for the periods presented. Management bases its estimates on historical experience and various other factors that it

believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities, and other reported amounts, that are not readily apparent from other sources. Actual results may differ materially from these estimates. Estimates are used in the following areas, among others: revenue recognition, the allowance for credit losses, accrued research and development expenses and other accrued liabilities, stock-based compensation expense, interest expense under royalty monetization liabilities, income taxes and fair value measurements.

Reclassifications

Certain amounts reported in prior periods have been reclassified to conform to current period financial statement presentation, including separate presentation of service revenue in the statements of operations and comprehensive loss. As a result of the Company's collaboration and license agreement with Nippon Shinyaku Co., Ltd. (Nippon Shinyaku) effective in March 2025, the Company has modified the presentation of its revenues and now presents service revenues separately from license and royalty revenues. The modified presentation has been applied retrospectively to all prior periods presented. The reclassifications have no effect on previously reported financial position, results of operations and cash flows.

Restricted Cash

Restricted cash consists of deposits held at financial institutions that are used to collateralize irrevocable letters of credit required under the Company’s lease agreements and certain other agreements with third parties. The following table provides a reconciliation of cash and cash equivalents and restricted cash as reported on the consolidated balance sheets to the total of these amounts as reported at the end of the period in the consolidated statements of cash flows (in thousands):


	As of September 30,
	2025		2024
Cash and cash equivalents	$	58,802	$	56,617
Restricted cash		2,030		2,030
Total cash and cash equivalents and restricted cash	$	60,832	$	58,647

Accounts Receivable

Accounts receivable consist of consideration due to the Company resulting from its agreements with customers. Accounts receivable include amounts invoiced to customers as well as rights to consideration which have not yet been invoiced, including unbilled royalties and services, and for which payment is conditional solely upon the passage of time. If a licensee elects to terminate a license prior to the end of the license term, the licensed intellectual property is returned to the Company and any accounts receivable from the licensee which are not contractually payable to the Company are charged off as a reduction of revenue in the period of the termination. Accounts receivable which are not expected to be received by the Company within 12 months from the reporting date are stated net of a discount to present value and recorded as non-current assets on the consolidated balance sheets. The present value discount is recognized as a reduction of revenue in the period in which the accounts receivable balance is initially recorded and is accreted as interest income from licensing over the term of the receivables.

Accounts receivable are stated net of an allowance for credit losses, if deemed necessary based on the Company’s evaluation of collectability and potential credit losses. Management assesses the collectability of its accounts receivable using the specific identification of account balances and considers the credit quality and financial condition of its significant customers, historical information regarding credit losses and the Company’s evaluation of current and expected future economic conditions. If necessary, an allowance for credit losses is recorded against accounts receivable such that the carrying value of accounts receivable reflects the net amount expected to be collected. Accounts receivable balances are written off against the allowance for credit losses when the potential for collectability is considered remote. The Company did not record an allowance for credit losses on its accounts receivable as of September 30, 2025 and December 31, 2024.

Impairment of Long-lived Assets

The Company's long-lived assets consist primarily of property and equipment and operating lease right-of-use assets. The Company evaluates its long-lived assets for impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to estimated future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. Please refer to Note 5 and Note 6 for further information on impairment of long-lived assets.

Fair Value Measurements

The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. Accounting Standards Codification (ASC) 820, Fair Value Measurements and Disclosures, establishes a hierarchy of inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below:

•

Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

•

Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly.

•

Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable.

To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for assets and liabilities categorized in Level 3. The level within the fair value hierarchy of an asset or liability measured at fair value is based on the lowest level of any input that is significant to the fair value measurement. The fair values of the Company’s Level 2 financial instruments are based on quoted market prices or broker or dealer quotations for similar assets. These investments are initially valued at the transaction price and subsequently valued utilizing third-party pricing providers or other market observable data. Please refer to Note 4 for further information on the Company's fair value measurements.

Revenue Recognition

The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers (ASC 606). ASC 606 requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The following five steps are performed to determine the appropriate revenue recognition for arrangements within the scope of ASC 606: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) the entity satisfies the performance obligations.

The Company applies the five-step model to contracts that are within the scope of ASC 606 only when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, for contracts within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to respective performance obligations when (or as) the respective performance obligations are satisfied.

The Company evaluates its contracts with customers for the presence of significant financing components. If a significant financing component is identified in a contract and provides a financing benefit to the customer, the transaction price for the contract is adjusted to account for the financing portion of the arrangement, which is recognized as interest income over the financing term using the effective interest method. In determining the appropriate interest rates for significant financing components, the Company evaluates the credit profile of the customer and prevailing market interest rates and selects an interest rate in which it believes would be charged to the customer in a separate financing arrangement over a similar financing term.

The Company licenses its NAV Technology Platform and other intellectual property rights to other biotechnology and pharmaceutical companies, including collaborators for the joint development and commercialization of its product candidates. The terms of the licenses vary, and licenses may be exclusive or non-exclusive and may be sublicensable by the licensee. Licenses may grant intellectual property rights for purposes of internal and preclinical research and development only, or may include the rights, or options to obtain future rights, to commercialize drug therapies for specific diseases using the Company’s NAV Technology Platform and other licensed rights. License agreements generally have a term at least equal to the life of the underlying patents, but are terminable at the option of the licensee. Consideration payable to the Company under its license and collaboration agreements may

include: (i) up-front and annual fees, (ii) milestone payments based on the achievement of certain development and sales-based milestones, (iii) sublicense fees, (iv) royalties on sales of licensed products, (v) fees for services related to the development and manufacturing of licensed products and (vi) other consideration payable upon optional goods and services purchased by licensees and collaborators.

The Company evaluates its agreements with collaboration partners to determine whether they are within the scope of ASC 808, Collaborative Arrangements (ASC 808). For collaboration arrangements within the scope of ASC 808 that contain multiple elements, the Company identifies the various transactions with the counterparty and determines if any unit of account is more reflective of a transaction with a customer and therefore should be accounted for within the scope of ASC 606. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied. For transactions that are accounted for pursuant to ASC 606, the Company applies the five-step model as described in its revenue recognition policies.

The Company’s license and collaboration agreements are accounted for as contracts with customers within the scope of ASC 606, with the exception of transactions for which the counterparty is determined not to be a customer. At the inception of each agreement, the Company determines the contract term for purposes of applying the requirements of ASC 606. Licenses are generally terminable at the option of the licensee with advance notice to the Company. For each license granted, the Company evaluates these termination rights to determine whether a substantive termination penalty would be incurred by the licensee upon termination. If the licensee incurs a substantive termination penalty upon termination, the contract term for revenue recognition purposes is generally equal to the stated term of the license, which is the life of the underlying licensed patents. Alternatively, if the licensee does not incur a substantive termination penalty upon termination, the contract term for revenue recognition purposes may be shorter than the stated term of the license, in which case the termination rights may be accounted for as contract renewal options.

Performance obligations under the Company’s license and collaboration agreements may include (i) the delivery of intellectual property licenses, (ii) development and manufacturing services to be performed by the Company related to licensed products and (iii) options granted to purchase additional goods and services, to the extent the options convey material rights. At the inception of each license agreement which contains performance obligations for development or other services, the Company evaluates whether the license is distinct from the services, which requires judgment. In making this determination, the Company considers, among other things, the stage of development of the licensed products and whether the services will significantly impact further development of the licensed products. If it is determined that the license is not distinct from the services, the license is combined with the services into a single performance obligation. Agreements may provide licensees and collaborators with options to purchase additional goods or other services, including options to purchase commercial supply of licensed products. Options are evaluated at the inception of the agreement to determine whether they provide material rights to the customer. In making this determination, the Company considers whether the options are priced at an incremental discount to the standalone selling price of the underlying goods or services, in which case the option is considered to be a material right. Material rights are accounted for as separate performance obligations under the current arrangement.

The Company evaluates the transaction price of its license and collaboration agreements at contract inception and at each reporting date. The transaction price includes the fixed consideration payable to the Company over the contract term, as well as any variable consideration to the extent that it is probable that a significant reversal of revenue will not occur in the future. Fixed consideration under the agreements may include up-front and annual fees payable over the contract term and fixed fees for development and other services performed by the Company. Variable consideration under the agreements may include development and sales-based milestone payments, payments for development and other services performed by the Company, sublicense fees and royalties on sales of licensed products. Consideration contingent upon the exercise of options by the customer is excluded from the transaction price and not accounted for as part of the arrangement until the option is exercised.

The transaction price of the Company's license and collaboration arrangements is allocated to the underlying performance obligations based on their relative standalone selling prices and recognized as revenue when (or as) the performance obligations are satisfied. Variable consideration payable based on services performed by the Company is allocated directly to the performance obligation for such services. Consideration allocated to performance obligations for the delivery of intellectual property licenses is recognized as license and royalty revenue in full upon the delivery of the license. Consideration allocated to performance obligations for development and manufacturing services is recognized as service revenue as the services are performed by the Company. Consideration allocated to performance obligations for material rights to purchase additional goods and services is recognized as revenue upon the satisfaction of the performance obligations underlying the optional goods and services purchased by the customer. Service revenue is recognized using a measure of progress that best reflects the pattern of satisfaction of the performance obligations. At each reporting date, the Company re-evaluates the measure of progress and adjusts service revenue on a cumulative catch-up basis to reflect its best estimate of the services performed to date versus the total services to be performed under the arrangement.

Development milestone payments are payable to the Company upon the achievement of specified development milestones. At the inception of each license agreement that contains development milestone payments, the Company evaluates whether the milestones are probable of achievement and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal will not occur in the future, milestone payments are included in the transaction price. Milestone payments contingent on the achievement of development milestones that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved and are excluded from the transaction price until the milestone is achieved. At each reporting date, the Company re-evaluates the probability of achievement of each outstanding development milestone and, if necessary, adjusts the transaction price for any milestones for which the probability of achievement has changed due to current facts and circumstances. The increase to the transaction price as a result of any such adjustments is then allocated to the underlying performance obligations in a manner similar to the allocation of the initial transaction price and, to the extent the performance obligations are satisfied, recognized as revenue on a cumulative catch-up basis in the period of the adjustment.

Royalties on sales of licensed products, sales-based milestone payments, including milestones payable upon first commercial sales of licensed products, and sublicense fees based on the receipt of certain fees by licensees from any sublicensees are excluded from the transaction price of each license and recognized as license and royalty revenue in the period that the related sales or sublicenses occur, provided that the associated license has been delivered to the licensee.

Royalty revenue to date consists primarily of royalties on net sales of Zolgensma, which is a licensed product under the Company’s license agreement with Novartis Gene Therapies, Inc. (Novartis Gene Therapies), a wholly owned subsidiary of Novartis AG (Novartis), for the development and commercialization of treatments for spinal muscular atrophy (SMA). The Company recognizes royalty revenue from net sales of Zolgensma in the period in which the underlying products are sold by Novartis Gene Therapies, which in certain cases may require the Company to estimate royalty revenue for periods of net sales which have not yet been reported to the Company. Estimated royalties are reconciled to actual amounts reported in subsequent periods, and any differences are recognized as an adjustment to royalty revenue in the period the royalties are reported.

The Company receives payments from licensees and collaborators based on the billing schedules established in the associated agreements. Amounts recognized as revenue which have not yet been received from the customer are recorded as accounts receivable when the Company’s rights to the consideration are conditional solely upon the passage of time. Amounts recognized as revenue which have not yet been received from customers are recorded as contract assets when the Company’s rights to the consideration are not unconditional. Contract assets are recorded as other current assets on the consolidated balance sheets if the consideration is expected to be realized within 12 months from the reporting date, or as other assets if the consideration is expected to be realized in periods beyond 12 months from the reporting date. If a licensee elects to terminate a license prior to the end of the license term, the licensed intellectual property is returned to the Company and any consideration recorded as accounts receivable or contract assets which is not contractually payable by the licensee is charged off as a reduction of revenue in the period of the termination. Amounts received by the Company prior to the delivery of underlying performance obligations are deferred and recognized as revenue upon the satisfaction of the performance obligations by the Company. Deferred revenue which is not expected to be recognized within 12 months from the reporting date is recorded as non-current on the consolidated balance sheets.

Net Income (Loss) Per Share

Net Loss Per Share

Basic net loss per share is calculated by dividing net loss applicable to common stockholders by the weighted-average common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by adjusting the weighted-average common shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of computing both basic and diluted net loss per share, pre-funded warrants are considered outstanding shares upon issuance because the underlying shares may be issued for nominal consideration and are exercisable after the original issuance date. Contingently convertible shares in which conversion is based on non-market-priced contingencies are excluded from the calculations of both basic and diluted net loss per share until the contingency has been fully met. For purposes of the diluted net loss per share calculation, common stock equivalents are excluded from the calculation of diluted net loss per share if their effect would be anti-dilutive.

Recent Accounting Pronouncements

Recently Adopted Accounting Pronouncements

The Company did not adopt any new accounting standards during the three and nine months ended September 30, 2025 and 2024 which had a material impact on the consolidated financial statements.

Recent Accounting Pronouncements Not Yet Adopted

In December 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances the disclosure of an entity's effective tax rate reconciliation and requires the disclosure of income taxes paid to be disaggregated by jurisdiction. The standard is effective for the Company for annual periods beginning January 1, 2025. The Company is currently in the process of evaluating the impact of this standard on its consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement – Reporting Comprehensive Income – Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. The new standard requires disclosures about specific types of expenses included in the expense captions presented on the face of the income statement as well as disclosures about selling expenses. In January 2025, the FASB issued ASU 2025-01, which clarifies the effective date of ASU 2024-03 with respect to interim periods. The standard is effective for the Company for annual periods beginning January 1, 2027 and interim periods beginning January 1, 2028, with early adoption permitted. The standard may be applied either prospectively to financial statements issued for reporting periods after the effective date or retrospectively to any or all prior periods presented in the financial statements. The Company is currently in the process of evaluating the impact of this standard on its consolidated financial statements and related disclosures.

Fair Value Measurements - Schedule of Fair Value of Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Marketable securities:
Fair Value	$ 243,241	$ 187,340
Cash Equivalents and Marketable Securities [Member]
Marketable securities:
Total cash equivalents and marketable securities	292,625	233,733
Corporate Bonds [Member]
Marketable securities:
Fair Value	119,732	141,663
Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	49,384	46,393
US Government and Agency Securities [Member]
Cash equivalents:
Total cash equivalents		2,498
Marketable securities:
Fair Value	123,509	44,215
Certificates of Deposit [Member]
Marketable securities:
Fair Value		1,462
Money Market Mutual Funds [Member] \| Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	49,384	43,895
Level 2
Marketable securities:
Fair Value	243,241	187,340
Level 2 \| Cash Equivalents and Marketable Securities [Member]
Marketable securities:
Total cash equivalents and marketable securities	292,625	233,733
Level 2 \| Corporate Bonds [Member]
Marketable securities:
Fair Value	119,732	141,663
Level 2 \| Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	49,384	46,393
Level 2 \| US Government and Agency Securities [Member]
Cash equivalents:
Total cash equivalents		2,498
Marketable securities:
Fair Value	123,509	44,215
Level 2 \| Certificates of Deposit [Member]
Marketable securities:
Fair Value		1,462
Level 2 \| Money Market Mutual Funds [Member] \| Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	$ 49,384	$ 43,895

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2025

Accounting Policies [Abstract]

Summary of Reconciliation of Cash and Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash and cash equivalents and restricted cash as reported on the consolidated balance sheets to the total of these amounts as reported at the end of the period in the consolidated statements of cash flows (in thousands):


	As of September 30,
	2025		2024
Cash and cash equivalents	$	58,802	$	56,617
Restricted cash		2,030		2,030
Total cash and cash equivalents and restricted cash	$	60,832	$	58,647

Segment Information - Schedule of Information about Company's Segment Revenues, Significant Segment Expenses Regularly Provided to CODM, Other Segment Items and Consolidated Net Income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Revenues	$ 29,733	$ 24,197	$ 140,104	$ 62,114
Less:
Cost of license and royalty revenues	5,725	12,387	14,370	27,249
Total research and development expense	56,101	54,429	168,688	158,142
Total general and administrative expense	20,253	19,422	60,483	56,568
Other segment items	(9,595)	2,444	(23,292)	3,929
Net loss	(61,941)	(59,597)	(126,729)	(175,916)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	29,733	24,197	140,104	62,114
Less:
Cost of license and royalty revenues	5,725	12,387	14,370	27,249
Total research and development expense	56,101	54,429	168,688	158,142
Total general and administrative expense	20,253	19,422	60,483	56,568
Operating Segments [Member] \| Personnel
Less:
Total research and development expense	18,464	16,367	55,153	49,467
Total general and administrative expense	5,567	5,512	17,055	15,905
Operating Segments [Member] \| Direct development and support
Less:
Total research and development expense	26,800	27,306	81,860	74,664
Operating Segments [Member] \| Other general and administrative
Less:
Total general and administrative expense	8,331	6,839	24,751	21,301
Operating Segments [Member] \| Facilities
Less:
Total research and development expense	2,946	2,742	8,467	8,672
Total general and administrative expense	1,362	1,240	3,951	3,588
Operating Segments [Member] \| Stock-based compensation
Less:
Total research and development expense	4,245	4,301	12,181	13,893
Total general and administrative expense	4,753	5,583	14,007	15,028
Operating Segments [Member] \| Depreciation and amortization
Less:
Total research and development expense	3,646	3,713	11,027	11,446
Total general and administrative expense	$ 240	$ 248	$ 719	$ 746

Royalty Monetization Liabilities - Additional Information (Details)	1 Months Ended	9 Months Ended
	May 31, 2025 USD ($) Tranche $ / shares shares	Sep. 30, 2025 USD ($)	Dec. 31, 2024
Royalty Monetization Liabilities [Line Items]
Warrants issued		$ 1,610,000
2020 Royalty Purchase Agreement
Royalty Monetization Liabilities [Line Items]
Repurchase of call option amount		$ 300,000,000
Interest Rate, Effective Percentage		16.20%
HCR [Member] \| 2020 Royalty Purchase Agreement
Royalty Monetization Liabilities [Line Items]
Proceeds from Royalties Received		$ 4,000,000.0
Purchase Agreement		200,000,000.0
Proceeds from sale of future royalties		196,000,000
Deferred Transaction Cost		3,500,000
Interest expense		$ 192,500,000
Interest Rate, Effective Percentage		77.10%	65.50%
HCR [Member] \| 2020 Royalty Purchase Agreement \| November 7, 2024
Royalty Monetization Liabilities [Line Items]
Royalty Payment Cap Amount		$ 260,000,000.0
HCR [Member] \| 2020 Royalty Purchase Agreement \| November 8, 2024
Royalty Monetization Liabilities [Line Items]
Royalty Payment Cap Amount		$ 300,000,000.0
HCR [Member] \| 2025 Royalty Bond
Royalty Monetization Liabilities [Line Items]
Interest Rate, Effective Percentage	9.75%	14.90%
Number of tranches of debt disbursal \| Tranche	3
Description of debt disbursal		The 2025 Royalty Bond is disbursable to the Company in three tranches, with $150.0 million funded on the closing date in May 2025, $50.0 million available to be funded if sales of a specified product exceed a specified threshold prior to December 31, 2026, and $50.0 million available to be funded if both parties exercise an option in 2027.
First disbursal of loan amount	$ 150,000,000
Second disbursal of loan amount	50,000,000
Third disbursal of loan amount	$ 50,000,000
Debt issuance discount percentage	2.25%
Proceeds received, net of discounts and transaction costs	$ 144,500,000
Interest rate terms		The 2025 Royalty Bond bears interest at a rate of 9.75% plus the 3-month secured overnight financing rate as administered by the Federal Reserve Bank of New York (SOFR), with a minimum interest rate of 14.0%. Interest payments are due quarterly using proceeds received under the Royalty Interest.
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Debt instrument, maturity date	May 31, 2035
Debt instrument extended maturity date	May 31, 2037
Additional percentage of amount payable upon repayment of debt	5.00%
Net proceeds allocated to Royalty Bond		$ 142,883,000
HCR [Member] \| 2025 Royalty Bond \| May 2025 Warrants [Member]
Royalty Monetization Liabilities [Line Items]
Proceeds received, net of discounts and transaction costs	$ 144,500,000
Number of warrants issued \| shares	268,096
Exercise price of warrants \| $ / shares	$ 14.92
Warrants contractual term	10 years
Estimated fair value of warrants	$ 1,700,000
Warrants issued	1,600,000
Net proceeds allocated to Royalty Bond	142,900,000
Debt discount	7,100,000
HCR [Member] \| 2025 Royalty Bond \| Maximum
Royalty Monetization Liabilities [Line Items]
Aggregate amount	$ 250,000,000
HCR [Member] \| 2025 Royalty Bond \| Minimum
Royalty Monetization Liabilities [Line Items]
Interest Rate, Effective Percentage	14.00%

Royalty Monetization Liabilities (Tables)

9 Months Ended

Sep. 30, 2025

Royalty Monetization Liabilities [Line Items]

Schedule of Royalty Monetization Liabilities

Royalty monetization liabilities are accounted for as debt and consist of the following (in thousands):


	September 30, 2025		December 31, 2024
2020 Royalty Purchase Agreement	$	40,149	$	59,687
2025 Royalty Bond		151,485		—
Total	$	191,634	$	59,687

Current portion of royalty monetization liabilities	$	41,718	$	34,309
Non-current portion of royalty monetization liabilities		149,916		25,378
Total	$	191,634	$	59,687

2020 Royalty Purchase Agreement

Royalty Monetization Liabilities [Line Items]

Schedule of Changes in Royalty Monetization Liability

The following table presents the changes in the royalty monetization liability under the 2020 Royalty Purchase Agreement with HCR (in thousands):


	2020 Royalty
	Purchase Agreement
Balance at December 31, 2024	$	59,687
Zolgensma royalties paid to HCR		(43,384	)
Interest expense recognized		23,846
Balance at September 30, 2025		40,149
Current portion		(38,665	)
Non-current portion	$	1,484

2025 Royalty Bond

Royalty Monetization Liabilities [Line Items]

Schedule of Changes in Royalty Monetization Liability

The following table presents the changes in the royalty monetization liability under the 2025 Royalty Bond with HCR (in thousands):


	2025 Royalty Bond
Balance at December 31, 2024	$	—
Proceeds from royalty bond, net of discount and issuance costs		142,883
Unpaid interest accrued to principal		8,027
Amortization of debt discount and issuance costs		575
Balance at September 30, 2025		151,485
Current portion		(3,053	)
Non-current portion	$	148,432

Net Loss Per Share

9 Months Ended

Sep. 30, 2025

Earnings Per Share [Abstract]

Net Loss Per Share

13. Net Loss Per Share

Since the Company incurred net losses for the three and nine months ended September 30, 2025 and 2024, common stock equivalents were excluded from the calculation of diluted net loss per share for such periods as their effect would be anti-dilutive. Accordingly, basic and diluted net loss per share were the same for such periods. The weighted-average number of common shares outstanding used in the basic and diluted net loss per share calculations includes the weighted-average effect of pre-funded warrants to purchase shares of the Company's common stock, as the pre-funded warrants are exercisable at any time for nominal cash consideration. The following potentially dilutive common stock equivalents outstanding at the end of the period were excluded from the computations of weighted-average diluted common shares for the periods indicated as their effects would be anti-dilutive (in thousands):


	Three and Nine Months Ended September 30,
	2025		2024
Stock options issued and outstanding		11,726		10,017
Unvested restricted stock units outstanding		2,904		2,035
Employee stock purchase plan		60		47
May 2025 Warrants outstanding		268		—
		14,958		12,099

License and Collaboration Agreements - Schedule Of Revenues Earned Under License and Collaboration Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 29,733	$ 24,197	$ 140,104	$ 62,114
Other license and royalty revenue	19	110	138	323
Total license and royalty revenue	23,605	23,982	129,119	61,172
Zolgensma Royalties [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	23,586	23,872	59,002	60,849
Nippon Shinyaku Licenses [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues			69,979
Nippon Shinyaku Services [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	5,932		10,426
Other Service Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	196	215	559	942
Total Service Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 6,128	$ 215	$ 10,985	$ 942

- Definition

+ References

+ Details

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2025

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

Use of Estimates

Reclassifications

Restricted Cash


	As of September 30,
	2025		2024
Cash and cash equivalents	$	58,802	$	56,617
Restricted cash		2,030		2,030
Total cash and cash equivalents and restricted cash	$	60,832	$	58,647

Accounts Receivable

Impairment of Long-lived Assets

Fair Value Measurements

•

Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

•

Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly.

•

Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable.

Revenue Recognition

Net Loss Per Share

Recent Accounting Pronouncements

Recently Adopted Accounting Pronouncements

The Company did not adopt any new accounting standards during the three and nine months ended September 30, 2025 and 2024 which had a material impact on the consolidated financial statements.

Recent Accounting Pronouncements Not Yet Adopted

License and Collaboration Agreements -Schedule of AbbVie Collaboration Agreement (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net cost reimbursement to (from) AbbVie included in:
Total net cost reimbursement to (from) AbbVie	$ (17,030)	$ (19,741)	$ (47,619)	$ (65,162)
Abb Vie Collaboration And License Agreement \| Research and Development Expense [Member]
Net cost reimbursement to (from) AbbVie included in:
Total net cost reimbursement to (from) AbbVie	(17,742)	(20,082)	(49,479)	(66,330)
Abb Vie Collaboration And License Agreement \| General and Administrative Expense [Member]
Net cost reimbursement to (from) AbbVie included in:
Total net cost reimbursement to (from) AbbVie	$ 712	$ 341	$ 1,860	$ 1,168

Stock-based Compensation - Summary of Stock Option Activity (Detail) - Equity Incentive Plans [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Shares Outstanding, Beginning Balance	9,994
Shares, Granted	2,441
Shares, Exercised	(61)
Shares, Cancelled or forfeited	(648)
Shares Outstanding, Ending Balance	11,726	9,994
Shares, Exercisable	7,693
Shares, Vested and expected to vest	11,726
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-average Exercise Price Outstanding, Beginning Balance	$ 29.48
Weighted-average Exercise Price, Granted	8.02
Weighted-average Exercise Price, Exercised	3.76
Weighted-average Exercise Price, Cancelled or forfeited	28.73
Weighted-average Exercise Price, Outstanding, Ending Balance	25.19	$ 29.48
Weighted-average Exercise Price, Exercisable	31.89
Weighted-average Exercise Price, Vested and expected to vest	$ 25.19
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-average Remaining Contractual Life (Years) Outstanding	6 years 3 months 18 days	5 years 10 months 24 days
Weighted-average Remaining Contractual Life (Years), Exercisable	5 years
Weighted-average Remaining Contractual Life (Years), Vested and expected to vest	6 years 3 months 18 days
Aggregate Intrinsic Value Outstanding	$ 3,961	$ 240
Aggregate Intrinsic Value, Exercisable	125
Aggregate Intrinsic Value, Vested and expected to vest	$ 3,961

Supplemental Disclosures

9 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

Supplemental Disclosures

15. Supplemental Disclosures

Other Current Assets

Other current assets consisted of the following (in thousands):


	September 30, 2025		December 31, 2024
Net cost reimbursement due from AbbVie	$	17,031	$	11,304
Accrued interest on investments		1,120		1,094
Other		1,321		1,376
	$	19,472	$	13,774

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	September 30, 2025		December 31, 2024
Accrued personnel costs	$	15,076	$	17,607
Accrued external research and development expenses		11,089		8,998
Accrued sublicense fees and royalties		9,080		8,658
Accrued external general and administrative expenses		2,064		2,002
Accrued purchases of property and equipment		78		156
Other		929		649
	$	38,316	$	38,070

Supplemental Disclosures of Non-cash Investing and Financing Activities

Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities were $0.2 million as of September 30, 2025, a net decrease of $0.2 million from December 31, 2024, and $0.4 million as of September 30, 2024, a net decrease of less than $0.1 million from December 31, 2023.

During the nine months ended September 30, 2025, accrued interest of $8.0 million was converted to principal balance under the 2025 Royalty Bond.

Marketable Securities - Summary of Fair Values and Unrealized Losses of Marketable Securities Held by the Company in an Unrealized Loss Position for Less Than 12 months and 12 Months or Greater (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 45,720	$ 21,317
Less than 12 Months, Unrealized Losses	(16)	(45)
12 Months or Greater, Fair Value	0	24,138
12 Months or Greater, Unrealized Losses	0	(81)
Total, Fair Value	45,720	45,455
Total, Unrealized Losses	(16)	(126)
U.S. Government and Agency Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	11,485	0
Less than 12 Months, Unrealized Losses	(1)	0
12 Months or Greater, Fair Value	0	22,917
12 Months or Greater, Unrealized Losses	0	(77)
Total, Fair Value	11,485	22,917
Total, Unrealized Losses	(1)	(77)
Certificates of Deposit [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value		0
Less than 12 Months, Unrealized Losses		0
12 Months or Greater, Fair Value		1,221
12 Months or Greater, Unrealized Losses		(4)
Total, Fair Value		1,221
Total, Unrealized Losses		(4)
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	34,235	21,317
Less than 12 Months, Unrealized Losses	(15)	(45)
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Unrealized Losses	0	0
Total, Fair Value	34,235	21,317
Total, Unrealized Losses	$ (15)	$ (45)

Fair Value Measurements

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

Financial instruments reported at fair value on a recurring basis include cash equivalents and marketable securities. The following tables present the fair value of cash equivalents and marketable securities in accordance with the fair value hierarchy discussed in Note 2 (in thousands):


	Level 1		Level 2		Level 3		Total
September 30, 2025
Cash equivalents:
Money market mutual funds	$	—	$	49,384	$	—	$	49,384
Total cash equivalents		—		49,384		—		49,384
Marketable securities:
U.S. government and agency securities		—		123,509		—		123,509
Corporate bonds		—		119,732		—		119,732
Total marketable securities		—		243,241		—		243,241
Total cash equivalents and marketable securities	$	—	$	292,625	$	—	$	292,625


	Level 1		Level 2		Level 3		Total
December 31, 2024
Cash equivalents:
Money market mutual funds	$	—	$	43,895	$	—	$	43,895
U.S. government and agency securities		—		2,498		—		2,498
Total cash equivalents		—		46,393		—		46,393
Marketable securities:
U.S. government and agency securities		—		44,215		—		44,215
Certificates of deposit		—		1,462		—		1,462
Corporate bonds		—		141,663		—		141,663
Total marketable securities		—		187,340		—		187,340
Total cash equivalents and marketable securities	$	—	$	233,733	$	—	$	233,733

Management estimates that the carrying values of its current accounts receivable, other current assets, accounts payable, accrued expenses and other current liabilities approximate fair value due to the short-term nature of those instruments. Certain accounts receivable which contain non-current portions and certain non-current payables reported as other liabilities are recorded at their present values using a discount rate that is based on prevailing market rates on the date the amounts were initially recorded. Management does not believe there have been any significant changes in market conditions or credit quality that would cause the discount rates initially used to be materially different from those that would be used as of September 30, 2025 to determine the present value of these instruments. Accordingly, management estimates that the carrying values of its non-current accounts receivable and other liabilities approximate the fair value of those instruments. Management estimates that the carrying values of its royalty monetization liabilities approximate fair value. As discussed in Note 7, the carrying values of royalty monetization liabilities are based on the Company’s estimate of future royalties, milestones and other consideration to be paid over the life of the arrangement, which are considered Level 3 inputs, as well as any remaining repayment obligations upon maturity of the instruments.

Long-lived assets, if determined to be impaired, are measured at fair value on a nonrecurring basis using Level 3 inputs. Please refer to Note 6 for further information on nonrecurring fair value measurements of long-lived assets during the three and nine months ended September 30, 2025 and 2024.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 107
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-107

Reference 3: http://www.xbrl.org/2003/role/exampleRef
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-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (c)(3)
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

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-Subparagraph (h)
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (e)
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-URI https://asc.fasb.org/1943274/2147478119/940-820-50-1

+ Details

Marketable Securities - Additional Information (Detail)	3 Months Ended		9 Months Ended
Marketable Securities - Additional Information (Detail)	Sep. 30, 2025 USD ($) Security	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) Security	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Investments, Debt and Equity Securities [Abstract]
Available for sale debt securities remaining maturities greater than three years	$ 0		$ 0		$ 0
Number of investment grade fixed income debt security \| Security	11		11
Allowance for credit loss	$ 0		$ 0		$ 0
Realized gains or losses on available-for-sales securities	$ 0	$ 0	$ 0	$ 0

Commitments and Contingencies - Additional Information (Detail) - GlaxoSmithKline LLC [Member] - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Mar. 31, 2009
Other Commitments [Line Items]
Milestone payment obligation			$ 1.5
Accrued expeses	$ 6.4	$ 6.3

Supplemental Disclosures - Schedules of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Payables and Accruals [Abstract]
Accrued personnel costs	$ 15,076	$ 17,607
Accrued external research and development expenses	11,089	8,998
Accrued sublicense fees and royalties	9,080	8,658
Accrued external general and administrative expenses	2,064	2,002
Accrued purchases of property and equipment	78	156
Other	929	649
Accrued expenses and other current liabilities	$ 38,316	$ 38,070

Marketable Securities - Summary of Company Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost / Cost	$ 243,033	$ 187,221
Unrealized Gains	224	245
Unrealized Losses	(16)	(126)
Fair Value	243,241	187,340
U.S. Government and Agency Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost / Cost	123,444	44,281
Unrealized Gains	66	11
Unrealized Losses	(1)	(77)
Fair Value	123,509	44,215
Certificates of Deposit [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost / Cost		1,466
Unrealized Losses		(4)
Fair Value		1,462
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost / Cost	119,589	141,474
Unrealized Gains	158	234
Unrealized Losses	(15)	(45)
Fair Value	$ 119,732	$ 141,663

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
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Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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+ Details

Leases - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended			9 Months Ended
Leases - Additional Information (Detail) - USD ($)	Mar. 31, 2024	May 31, 2016	Sep. 30, 2025	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024
Other Commitments [Line Items]
Impairment losses of long-lived assets							$ 2,101,000
400 Madison Avenue [Member] \| 400 Madison Lease [Member]
Other Commitments [Line Items]
Operating Lease Commencement Year		2016-07
Lease expiration date		Apr. 30, 2027
New York Sublease [Member]
Other Commitments [Line Items]
Total undiscounted payments			$ 800,000			$ 800,000
Sublease income			100,000	$ 100,000		300,000	200,000
Operating Lease Commencement Year	2024-04
Lease expiration date	Apr. 30, 2027
Carrying value of the asset	$ 3,400,000				$ 3,400,000
Estimated fair value of asset	$ 1,300,000				1,300,000
Impairment losses of long-lived assets			$ 0	$ 0	2,100,000	$ 0	2,100,000
Impairment losses recorded to right-of-use assets					1,400,000		1,400,000
Impairment losses recorded to property and equipment					$ 700,000		$ 700,000

License and Collaboration Agreements - Summary of Accounts Receivables (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current accounts receivable:
Billed to customers	$ 20	$ 65
Other unbilled	72	302
Current accounts receivable, net	25,347	20,473
Non-current accounts receivable:
Unbilled	473	474
Non-current accounts receivable	2,765	474
Total accounts receivable	28,112	20,947
Zolgensma Royalties [Member]
Current accounts receivable:
Unbilled	22,761	$ 20,106
Nippon Shinyaku Services [Member]
Current accounts receivable:
Unbilled	2,494
Non-current accounts receivable:
Unbilled	$ 2,292

Stock-based Compensation - Summary of Unvested RSUs Activity Under Equity Incentive Plans (Detail) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2025 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested balance at December 31, 2024 \| shares	2,042,000
Shares, Granted \| shares	1,696,000
Vested \| shares	(732,000)
Forfeited \| shares	(102,000)
Unvested balance at September 30, 2025 \| shares	2,904,000
Weighted-average Grant Date Fair Value, Unvested Beginning Balance \| $ / shares	$ 19.95
Weighted-average Grant Date Fair Value, Granted \| $ / shares	8.56
Weighted-average Grant Date Fair Value, Vested \| $ / shares	21.34
Weighted-average Grant Date Fair Value, Forfeited \| $ / shares	15.99
Weighted-average Grant Date Fair Value, Unvested Ending Balance \| $ / shares	$ 13.09

Royalty Monetization Liabilities - Schedule of Changes in Royalty Monetization Liability (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Royalty Monetization Liabilities [Line Items]
Beginning balance	$ 59,687
Ending balance	191,634
Current portion	(41,718)	$ (34,309)
Non-current portion	149,916	$ 25,378
2020 Royalty Purchase Agreement
Royalty Monetization Liabilities [Line Items]
Beginning balance	59,687
Ending balance	40,149
2020 Royalty Purchase Agreement \| HCR
Royalty Monetization Liabilities [Line Items]
Beginning balance	59,687
Zolgensma royalties paid to HCR	(43,384)
Interest expense recognized	23,846
Ending balance	40,149
Current portion	(38,665)
Non-current portion	1,484
2025 Royalty Bond
Royalty Monetization Liabilities [Line Items]
Beginning balance	0
Ending balance	151,485
2025 Royalty Bond \| HCR
Royalty Monetization Liabilities [Line Items]
Beginning balance	0
Proceeds from royalty bond, net of discount and issuance costs	142,883
Unpaid interest accrued to principal	8,027
Amortization of debt discount and issuance costs	575
Ending balance	151,485
Current portion	(3,053)
Non-current portion	$ 148,432

Stock-based Compensation

9 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation

11. Stock-based Compensation

Effective in January 2025, an additional 1,981,975 shares were authorized for issuance under the 2015 Equity Incentive Plan (the 2015 Plan). The 2015 Plan expired in June 2025, upon which no further awards may be issued under the plan. Any awards outstanding under the 2015 Plan as of its expiration shall remain outstanding and effective pursuant to the contractual terms of the awards. Additionally, as of September 30, 2025, no awards remained outstanding or available for issuance under the 2014 Stock Plan (the 2014 Plan), the predecessor plan to the 2015 Plan.

In May 2025, the Company adopted the 2025 Equity Incentive Plan (the 2025 Plan), which replaced the 2015 Plan upon its expiration in June 2025. The total number of shares of common stock authorized for issuance under the 2025 Plan upon its adoption was 5,500,000. The number of shares authorized for issuance under the 2025 Plan shall automatically increase for any shares of common stock underlying awards outstanding under the 2015 Plan, as of the adoption date of the 2025 Plan, which are not issued due to forfeiture, expiration, termination or cancellation of the award. Shares of common stock that are withheld, tendered, or otherwise not issued in connection with the settlement of awards outstanding under the 2015 Plan do not increase the number of shares authorized for issuance under the 2025 Plan. As of September 30, 2025, the total number of shares of common stock reserved for issuance under the 2025 Plan and the 2015 Plan was 20,167,367, of which 5,537,889 remained available for future grants under the 2025 Plan.

The 2025 Plan and 2015 Plan provide for the issuance of stock options, stock appreciation rights, restricted and unrestricted stock and unit awards, and performance cash awards to employees, members of the Board of Directors and consultants of the Company. Stock options generally expire 10 years following the date of grant. Options typically vest over a four-year period, but vesting provisions can vary by award based on the discretion of the Board of Directors. Stock options have an exercise price at least equal to the estimated fair value of the Company’s common stock on the date of grant. Restricted stock units typically vest over a four-year period, but vesting provisions can vary by award based on the discretion of the Board of Directors. Upon vesting, restricted stock units are settled in common stock of the Company. Awards granted under the 2025 Plan generally have a minimum vesting requirement of one year from the grant date.

Shares of common stock underlying awards granted under the 2025 Plan which are not issued due to forfeiture, expiration, termination or cancellation of the award are added to the number of shares of common stock available for issuance under the 2025 Plan, except for shares that are withheld, tendered or otherwise not issued in connection with the settlement of the award. Shares available for issuance under the 2025 Plan and 2015 Plan may be either authorized but unissued shares of the Company’s common stock or common stock reacquired by the Company and held in treasury. The 2025 Plan expires in May 2035, 10 years from its adoption date, unless earlier terminated.

Stock-based Compensation Expense

The Company’s stock-based compensation expense by award type was as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Stock options	$	4,777	$	6,051	$	14,262	$	17,969
Restricted stock units		4,051		3,755		11,432		10,536
Employee stock purchase plan		170		78		494		416
	$	8,998	$	9,884	$	26,188	$	28,921

As of September 30, 2025, the Company had $57.2 million of unrecognized stock-based compensation expense related to stock options, restricted stock units and the 2015 Employee Stock Purchase Plan (the 2015 ESPP), which is expected to be recognized over a weighted-average period of 2.3 years.

The Company recorded aggregate stock-based compensation expense in the consolidated statements of operations and comprehensive loss as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Research and development	$	4,245	$	4,301	$	12,181	$	13,893
General and administrative		4,753		5,583		14,007		15,028
	$	8,998	$	9,884	$	26,188	$	28,921

Stock Options

The following table summarizes stock option activity under the Company's equity incentive plans (in thousands, except per share data):


						Weighted-
						average
				Weighted-		Remaining
				average		Contractual		Aggregate
				Exercise		Life		Intrinsic
	Shares			Price		(Years)		Value (a)
Outstanding at December 31, 2024		9,994		$	29.48		5.9	$	240
Granted		2,441		$	8.02
Exercised		(61	)	$	3.76
Cancelled or forfeited		(648	)	$	28.73
Outstanding at September 30, 2025		11,726		$	25.19		6.3	$	3,961
Exercisable at September 30, 2025		7,693		$	31.89		5.0	$	125
Vested and expected to vest at September 30, 2025		11,726		$	25.19		6.3	$	3,961

(a)

The weighted-average grant date fair value per share of options granted during the nine months ended September 30, 2025 was $4.96. During the nine months ended September 30, 2025, the total number of stock options exercised was 60,554, resulting in total proceeds of $0.2 million. The total intrinsic value of options exercised during the nine months ended September 30, 2025 was $0.3 million.

Restricted Stock Units

The following table summarizes restricted stock unit activity under the Company's equity incentive plans (in thousands, except per share data):


				Weighted-average
				Grant Date
	Shares			Fair Value
Unvested balance at December 31, 2024		2,042		$	19.95
Granted		1,696		$	8.56
Vested		(732	)	$	21.34
Forfeited		(102	)	$	15.99
Unvested balance at September 30, 2025		2,904		$	13.09

The total intrinsic value of restricted stock units vested during the nine months ended September 30, 2025 was $5.9 million.

Employee Stock Purchase Plan

As of September 30, 2025, the total number of shares of common stock authorized for issuance under the 2015 ESPP was 1,426,994, of which 755,306 remained available for future issuance. During the nine months ended September 30, 2025, 157,658 shares of common stock were issued under the 2015 ESPP.

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional paid in capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Balances at Dec. 31, 2023	$ 311,742	$ 4	$ 1,021,214	$ (4,429)	$ (705,047)
Balances (Shares) at Dec. 31, 2023		44,046
Vesting of restricted stock units, net of tax	(910)		(910)
Vesting of restricted stock units, net of tax, shares		340
Exercise of stock options, net of tax	1,474		1,474
Exercise of stock options, net of tax, shares		281
Exercise of pre-funded warrants		197
Issuance of common stock under employee stock purchase plan	1,191		1,191
Issuance of common stock under employee stock purchase plan, shares		105
Issuance of common stock and pre-funded warrants	131,067		131,066
Issuance of common stock and pre-funded warrants, shares		4,565
Stock-based compensation expense	28,921		28,921
Unrealized gain on available-for-sale securities, net	3,847			3,847
Net loss	(175,916)				(175,916)
Balances at Sep. 30, 2024	301,416	$ 5	1,182,956	(582)	(880,963)
Balances (Shares) at Sep. 30, 2024		49,534
Balances at Jun. 30, 2024	348,267	$ 5	1,171,894	(2,266)	(821,366)
Balances (Shares) at Jun. 30, 2024		49,317
Vesting of restricted stock units, net of tax, shares		31
Exercise of stock options, net of tax	398		398
Exercise of stock options, net of tax, shares		108
Issuance of common stock under employee stock purchase plan	780		780
Issuance of common stock under employee stock purchase plan, shares		78
Stock-based compensation expense	9,884		9,884
Unrealized gain on available-for-sale securities, net	1,684			1,684
Net loss	(59,597)				(59,597)
Balances at Sep. 30, 2024	301,416	$ 5	1,182,956	(582)	(880,963)
Balances (Shares) at Sep. 30, 2024		49,534
Balances at Dec. 31, 2024	259,651	$ 5	1,192,536	(741)	(932,149)
Balances (Shares) at Dec. 31, 2024		49,549
Vesting of restricted stock units, net of tax	(633)		(633)
Vesting of restricted stock units, net of tax, shares		652
Exercise of stock options, net of tax	228		228
Exercise of stock options, net of tax, shares		61
Issuance of warrants, net of transaction costs	1,610		1,610
Exercise of pre-funded warrants		199
Issuance of common stock under employee stock purchase plan	1,048		1,048
Issuance of common stock under employee stock purchase plan, shares		158
Stock-based compensation expense	26,188		26,188
Unrealized gain on available-for-sale securities, net	89			89
Net loss	(126,729)				(126,729)
Balances at Sep. 30, 2025	161,452	$ 5	1,220,977	(652)	(1,058,878)
Balances (Shares) at Sep. 30, 2025		50,619
Balances at Jun. 30, 2025	213,679	$ 5	1,211,361	(750)	(996,937)
Balances (Shares) at Jun. 30, 2025		50,389
Vesting of restricted stock units, net of tax	(123)		(123)
Vesting of restricted stock units, net of tax, shares		119
Issuance of common stock under employee stock purchase plan	741		741
Issuance of common stock under employee stock purchase plan, shares		111
Stock-based compensation expense	8,998		8,998
Unrealized gain on available-for-sale securities, net	98			98
Net loss	(61,941)				(61,941)
Balances at Sep. 30, 2025	$ 161,452	$ 5	$ 1,220,977	$ (652)	$ (1,058,878)
Balances (Shares) at Sep. 30, 2025		50,619

License and Collaboration Agreements (Tables)

9 Months Ended

Sep. 30, 2025

Schedule Of Revenues Earned Under License and Collaboration Agreements

Revenues earned under license and collaboration agreements consisted of the following (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
License and royalty revenue:
Zolgensma royalties	$	23,586	$	23,872	$	59,002	$	60,849
Nippon Shinyaku licenses		—		—		69,979		—
Other license and royalty revenue		19		110		138		323
Total license and royalty revenue		23,605		23,982		129,119		61,172
Service revenue:
Nippon Shinyaku services		5,932		—		10,426		—
Other service revenue		196		215		559		942
Total service revenue		6,128		215		10,985		942
Total revenues	$	29,733	$	24,197	$	140,104	$	62,114

Summary of Accounts Receivable, Contract Assets and Deferred Revenue


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Accounts receivable, net, current and non-current:
Beginning of period	$	21,783	$	23,273	$	20,947	$	25,491
End of period	$	28,112	$	24,008	$	28,112	$	24,008

Contract assets:
Beginning of period	$	28	$	194	$	239	$	—
End of period	$	93	$	259	$	93	$	259

Deferred revenue, current and non-current:
Beginning of period	$	37,781	$	21	$	115	$	148
End of period	$	34,381	$	144	$	34,381	$	144

Revenue recognized during the period from:
Amounts included in deferred revenue at beginning of period	$	3,401	$	21	$	115	$	148
Performance obligations satisfied in previous periods	$	23,590	$	23,875	$	59,010	$	60,912

Summary of Accounts Receivables

Accounts receivable consisted of the following (in thousands):


	September 30, 2025		December 31, 2024
Current accounts receivable:
Billed to customers	$	20	$	65
Unbilled Zolgensma royalties		22,761		20,106
Unbilled Nippon Shinyaku services		2,494		—
Other unbilled		72		302
Current accounts receivable		25,347		20,473
Non-current accounts receivable:
Unbilled Nippon Shinyaku services		2,292		—
Other unbilled		473		474
Non-current accounts receivable		2,765		474
Total accounts receivable	$	28,112	$	20,947

Novartis Gene Therapies [Member]

Schedule Of Revenues Earned Under License and Collaboration Agreements

The Company recognized the following amounts under the Novartis License (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Zolgensma royalties	$	23,586	$	23,872	$	59,002	$	60,849
Total license and royalty revenue	$	23,586	$	23,872	$	59,002	$	60,849

Interest income from licensing	$	10	$	6	$	31	$	20

Abb Vie Collaboration And License Agreement [Member]

Schedule of Collaboration Agreement

The Company recognized the following amounts under the AbbVie Collaboration Agreement (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Net cost reimbursement to (from) AbbVie included in:
Research and development expense	$	(17,742	)	$	(20,082	)	$	(49,479	)	$	(66,330	)
General and administrative expense		712			341			1,860			1,168
Total net cost reimbursement to (from) AbbVie	$	(17,030	)	$	(19,741	)	$	(47,619	)	$	(65,162	)

Nippon Shinyaku Collaboration and License Agreement [Member]

Schedule of Collaboration Agreement

The Company recognized the following amounts under the Nippon Shinyaku Collaboration Agreement (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
License and royalty revenue	$	—	$	—	$	69,979	$	—
Service revenue		5,932		—		10,426		—
Total revenues	$	5,932	$	—	$	80,405	$	—

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Cash flows from operating activities
Net loss	$ (126,729)	$ (175,916)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	26,188	28,921
Depreciation and amortization	11,746	12,192
Net accretion of discounts on marketable debt securities	(4,250)	(3,027)
Net realized gain on investments	(62)
Impairment of long-lived assets		2,101
Non-cash interest expense	7,795	412
Other non-cash adjustments	60	(60)
Changes in operating assets and liabilities
Accounts receivable	(7,100)	1,574
Prepaid expenses	(3,876)	3,518
Other current assets	(5,586)	(2,804)
Operating lease right-of-use assets	4,989	4,586
Other assets	(268)	475
Accounts payable	(423)	(3,330)
Accrued expenses and other current liabilities	184	(1,448)
Deferred revenue	34,266	(4)
Operating lease liabilities	(5,620)	(6,021)
Other liabilities	(2,987)	(2,670)
Net cash used in operating activities	(71,673)	(141,501)
Cash flows from investing activities
Purchases of marketable debt securities	(269,819)	(173,916)
Maturities of marketable debt securities	218,257	238,446
Sales of equity securities	62
Purchases of property and equipment	(1,906)	(1,357)
Net cash provided by (used in) investing activities	(53,406)	63,173
Cash flows from financing activities
Proceeds from exercise of stock options	228	1,474
Taxes paid related to net settlement of stock-based awards	(633)	(910)
Proceeds from issuance of common stock under employee stock purchase plan	1,048	1,191
Proceeds from public offering of common stock and pre-funded warrants, net of issuance costs		131,067
Offering expenses related to at-the-market offering program	(334)	(158)
Proceeds from issuance of royalty bond and warrants, net of transaction costs	144,493
Repayments under royalty monetization liabilities, net of interest	(18,447)	(32,241)
Net cash provided by financing activities	126,355	100,423
Net increase in cash and cash equivalents and restricted cash	1,276	22,095
Cash and cash equivalents and restricted cash
Beginning of period	59,556	36,552
End of period	$ 60,832	$ 58,647

Capitalization

9 Months Ended

Sep. 30, 2025

Equity [Abstract]

Capitalization

9. Capitalization

March 2024 Public Offering and Pre-funded Warrants

In March 2024, the Company completed a public offering of 4,565,260 shares of its common stock at a price of $23.00 per share and 1,521,740 pre-funded warrants (the March 2024 Pre-funded Warrants) to purchase shares of its common stock at a price of $22.9999 per pre-funded warrant, which equaled the public offering price per share of the common stock less the $0.0001 exercise price of each pre-funded warrant. The aggregate net proceeds received by the Company from the offering were $131.1 million, net of underwriting discounts and commissions and offering expenses.

The rights and privileges of the March 2024 Pre-funded Warrants are set forth in the warrant agreement between the Company and each of the respective warrant holders. The March 2024 Pre-funded Warrants are exercisable at the option of the warrant holder at any time and do not expire. However, as set forth in the warrant agreements with each holder, the number of pre-funded warrants that may be exercised at any given time may be limited if, upon exercise, the warrant holder and any of its affiliates would beneficially own more than 9.99% of the Company’s common stock, or have voting power of more than 9.99% of the Company's common stock. The limitation threshold may be increased or decreased by the warrant holder, with advance notice to the Company, to any other percentage not less than 4.99% nor in excess of 19.99%. The March 2024 Pre-funded Warrants do not provide any of the rights or privileges provided by the Company's common stock, including any voting rights, until the pre-funded warrants are exercised and settled in underlying shares of common stock.

The Company evaluated the March 2024 Pre-funded Warrants and concluded the warrants are indexed to the Company's common stock, meet the criteria to be classified as equity and are not subject to remeasurement. The proceeds received from the issuance of the pre-funded warrants were recorded as additional paid-in capital. The Company issued 199,300 shares of common stock upon the exercise of March 2024 Pre-funded Warrants during the nine months ended September 30, 2025, and there were no exercises of March 2024 Pre-funded Warrants during the three months ended September 30, 2025. The Company issued 197,000 shares of common stock upon the exercise of March 2024 Pre-funded Warrants during the nine months ended September 30, 2024, and there were no exercises of March 2024 Pre-funded Warrants during the three months ended September 30, 2024. As of September 30, 2025, 1,125,440 of the March 2024 Pre-funded Warrants remained outstanding.

May 2025 Warrants

In May 2025, in connection with issuance of the 2025 Royalty Bond, the Company issued to HCR the May 2025 Warrants to purchase 268,096 shares of its common stock at an exercise price per share of $14.92. The May 2025 Warrants are exercisable upon issuance and have a contractual term of 10 years. The Company evaluated the May 2025 Warrants and concluded the warrants are indexed to the Company's common stock, meet the criteria to be classified as equity and are not subject to remeasurement. The Company allocated $1.6 million of the net proceeds from the 2025 Royalty Bond to the issuance of the May 2025 Warrants, which were recorded as additional paid-in capital. Please refer to Note 7 for further information on the May 2025 Warrants issued in connection with the 2025 Royalty Bond. As of September 30, 2025, none of the May 2025 Warrants had been exercised and 268,096 of the May 2025 Warrants remained outstanding.

At-the-Market Offering Program

In December 2024, the Company entered into a Sales Agreement with Leerink Partners LLC (Leerink) pursuant to which the Company may offer and sell shares of its common stock having an aggregate offering price of up to $150.0 million from time to time through Leerink, acting as the Company's sales agent (the Leerink ATM Program). As of September 30, 2025, no shares of common stock had been sold under the Leerink ATM Program.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Section 50
-Paragraph 13
-Subparagraph (b)
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Paragraph 13
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 14
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
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-Section 50
-Paragraph 6
-Subparagraph (a)
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-URI https://asc.fasb.org/1943274/2147480237/815-40-50-6

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

Stock-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Jan. 31, 2025	Sep. 30, 2025	Sep. 30, 2024	May 31, 2025
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense		$ 57,200
Unrecognized stock-based compensation, weighted-average period		2 years 3 months 18 days
Proceeds from exercise of stock options		$ 228	$ 1,474
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units vested		732,000
Total intrinsic values vested		$ 5,900
2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional shares to be issued	1,981,975
Stock plan expiration date		2025-06
Common stock reserved for issuance		20,167,367
Stock options expiration term		10 years
2015 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance		1,426,994
Shares available for future grants		755,306
Common stock shares issued to participants		157,658
2014 Stock Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards remained outstanding		0
Shares available for future grants		0
2025 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock plan expiration date		2035-05
Common stock shares authorized for issuance				5,500,000
Shares available for future grants		5,537,889
Stock options expiration term		10 years
Vesting period		1 year
Weighted-average fair values of options granted		$ 4.96
Exercise of stock options, net of tax, shares		60,554
Proceeds from exercise of stock options		$ 200
Total intrinsic value of options exercised		$ 300

Insider Trading Arrangements

3 Months Ended

Sep. 30, 2025

Trading Arrangements, by Individual

Material Terms of Trading Arrangement

Rule 10b5-1 Trading Plans

The adoption or termination of contracts, instructions or written plans for the purchase or sale of our securities by our Section 16 officers and directors for the three months ended September 30, 2025, each of which is intended to satisfy the affirmative defense of Rule 10b5-1(c) (Rule 10b5-1 Plan), were as follows:

        
       Rule 10b5-1 Trading Plan

       Aggregate # of

        
       Provides for

       Securities to be

       Name

       Title

       Action

       Date Adopted

       Expiration Date

       Purchase/Sale

       Purchased/Sold (a)

       Mitchell Chan

       Chief Financial Officer

       Adoption

       8/12/2025

       8/11/2026

       Sale

       156,401

(a)

The aggregate number of shares in this column includes shares that may be forfeited or withheld to satisfy exercise price and/or tax withholding obligations at the time of vesting.

Other than as described above, during the three months ended September 30, 2025, none of our directors or Section 16 reporting officers adopted or terminated any Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement (as such terms are defined in Item 408 of the SEC's Regulation S-K).

Mitchell Chan [Member]

Trading Arrangements, by Individual

Name

Mitchell Chan

Title

Chief Financial Officer

Rule 10b5-1 Arrangement Adopted

true

Adoption Date

8/12/2025

Expiration Date

8/11/2026

Aggregate Available

156,401

Directors or Section 16 Reporting Officers [Member]

Trading Arrangements, by Individual

Title

directors or Section 16 reporting officers

Rule 10b5-1 Arrangement Adopted

false

Non-Rule 10b5-1 Arrangement Adopted

false

Rule 10b5-1 Arrangement Terminated

false

Non-Rule 10b5-1 Arrangement Terminated

false

Supplemental Disclosures - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Other Current Assets [Line Items]
Other Assets, Current, Total	$ 19,472	$ 13,774
Other Current Assets [Member]
Other Current Assets [Line Items]
Accrued Interest on Investments	1,120	1,094
Other	1,321	1,376
Other Current Assets [Member] \| Related Party [Member]
Other Current Assets [Line Items]
Due from related parties, current	$ 17,031	$ 11,304

Segment Information (Tables)

9 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Segment Information

The following table presents information about the Company's segment revenues, significant segment expenses regularly provided to the CODM, other segment items and consolidated net income (loss) (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Revenues	$	29,733		$	24,197		$	140,104		$	62,114
Less:
Cost of license and royalty revenues		5,725			12,387			14,370			27,249
Research and development expense
Personnel		18,464			16,367			55,153			49,467
Direct development and support (a)		26,800			27,306			81,860			74,664
Facilities		2,946			2,742			8,467			8,672
Stock-based compensation		4,245			4,301			12,181			13,893
Depreciation and amortization		3,646			3,713			11,027			11,446
Total research and development expense		56,101			54,429			168,688			158,142
General and administrative expense
Personnel		5,567			5,512			17,055			15,905
Other general and administrative (b)		8,331			6,839			24,751			21,301
Facilities		1,362			1,240			3,951			3,588
Stock-based compensation		4,753			5,583			14,007			15,028
Depreciation and amortization		240			248			719			746
Total general and administrative expense		20,253			19,422			60,483			56,568
Other segment items (c)		(9,595	)		2,444			(23,292	)		3,929
Net loss	$	(61,941	)	$	(59,597	)	$	(126,729	)	$	(175,916	)

(a)

Direct development and support includes external goods and services for the development of product candidates and early-stage research activities, laboratory costs, consulting, development cost reimbursement to and from collaborators and other expenses in support of research and development activities.

(b)

Other general and administrative expenses include professional and administrative services, consulting, commercial cost reimbursement to and from collaborators and other corporate overhead expenses.

(c)

Other segment items include impairment of long-lived assets, other operating expenses, interest income from licensing, investment income and interest expense.

Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenues
Revenues	$ 29,733	$ 24,197	$ 140,104	$ 62,114
Operating Expenses
Cost of license and royalty revenues	5,725	12,387	14,370	27,249
Research and development	56,101	54,429	168,688	158,142
General and administrative	20,253	19,422	60,483	56,568
Impairment of long-lived assets				2,101
Other operating expenses	65	37	125	32
Total operating expenses	82,144	86,275	243,666	244,092
Loss from operations	(52,411)	(62,078)	(103,562)	(181,978)
Other Income (Expense)
Interest income from licensing	19	25	65	91
Investment income	3,620	3,276	9,500	9,213
Interest expense	(13,169)	(820)	(32,732)	(3,242)
Total other income (expense)	(9,530)	2,481	(23,167)	6,062
Net loss	(61,941)	(59,597)	(126,729)	(175,916)
Other Comprehensive Income
Unrealized gain on available-for-sale securities, net	98	1,684	89	3,847
Total other comprehensive income	98	1,684	89	3,847
Comprehensive loss	$ (61,843)	$ (57,913)	$ (126,640)	$ (172,069)
Net loss per share, basic	$ (1.2)	$ (1.17)	$ (2.46)	$ (3.59)
Net loss per share, diluted	$ (1.2)	$ (1.17)	$ (2.46)	$ (3.59)
Weighted-average common shares outstanding, basic	51,689	50,800	51,513	49,051
Weighted-average common shares outstanding, diluted	51,689	50,800	51,513	49,051
License and royalty [Member]
Revenues
Revenues	$ 23,605	$ 23,982	$ 129,119	$ 61,172
Service [Member]
Revenues
Revenues	$ 6,128	$ 215	$ 10,985	$ 942

Segment Information

9 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Segment Information

14. Segment Information

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker (CODM), or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s CODM, its Chief Executive Officer, views the Company’s operations and manages the business as one operating segment focused on the development and commercialization of gene therapies to treat an array of diseases. The determination of a single operating segment is consistent with the consolidated financial information regularly provided to the CODM

The CODM reviews and evaluates consolidated net income (loss) for purposes of assessing performance, making operating decisions and allocating resources. The CODM uses net income (loss) to assess performance versus operating budgets and in the preparation of near-term and long-range operating plans to inform decisions on resource and capital allocation. The CODM reviews consolidated cash, cash equivalents and marketable securities as a measure of segment assets. As of September 30, 2025 and December 31, 2024, the Company’s cash, cash equivalents and marketable securities were $302.0 million and $244.9 million, respectively.


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Revenues	$	29,733		$	24,197		$	140,104		$	62,114
Less:
Cost of license and royalty revenues		5,725			12,387			14,370			27,249
Research and development expense
Personnel		18,464			16,367			55,153			49,467
Direct development and support (a)		26,800			27,306			81,860			74,664
Facilities		2,946			2,742			8,467			8,672
Stock-based compensation		4,245			4,301			12,181			13,893
Depreciation and amortization		3,646			3,713			11,027			11,446
Total research and development expense		56,101			54,429			168,688			158,142
General and administrative expense
Personnel		5,567			5,512			17,055			15,905
Other general and administrative (b)		8,331			6,839			24,751			21,301
Facilities		1,362			1,240			3,951			3,588
Stock-based compensation		4,753			5,583			14,007			15,028
Depreciation and amortization		240			248			719			746
Total general and administrative expense		20,253			19,422			60,483			56,568
Other segment items (c)		(9,595	)		2,444			(23,292	)		3,929
Net loss	$	(61,941	)	$	(59,597	)	$	(126,729	)	$	(175,916	)

(a)

(b)

Other general and administrative expenses include professional and administrative services, consulting, commercial cost reimbursement to and from collaborators and other corporate overhead expenses.

(c)

Other segment items include impairment of long-lived assets, other operating expenses, interest income from licensing, investment income and interest expense.

The Company’s interest income included interest income from licensing as presented in the consolidated statements of operations and comprehensive loss, as well as interest income from investments of $3.6 million and $9.4 million during the three and nine months ended September 30, 2025, respectively, and $3.3 million and $9.2 million during the three and nine months ended September 30, 2024, respectively, which is included within investment income in the consolidated statements of operations and comprehensive loss.

The substantial majority of the Company’s assets reside in the United States.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2025	Oct. 31, 2025
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2025
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q3
Trading Symbol	RGNX
Entity Registrant Name	REGENXBIO Inc.
Entity Central Index Key	0001590877
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-37553
Entity Tax Identification Number	47-1851754
Entity Address, Address Line One	9804 Medical Center Drive
Entity Address, City or Town	Rockville
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20850
City Area Code	240
Local Phone Number	552-8181
Entity Common Stock, Shares Outstanding		50,623,086
Document Transition Report	false
Document Quarterly Report	true
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Entity Incorporation, State or Country Code	DE

Marketable Securities

9 Months Ended

Sep. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

3. Marketable Securities

The following tables present a summary of the Company’s marketable securities, which consist solely of available-for-sale debt securities (in thousands):


	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
September 30, 2025
U.S. government and agency securities	$	123,444	$	66	$	(1	)	$	123,509
Corporate bonds		119,589		158		(15	)		119,732
	$	243,033	$	224	$	(16	)	$	243,241


	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2024
U.S. government and agency securities	$	44,281	$	11	$	(77	)	$	44,215
Certificates of deposit		1,466		—		(4	)		1,462
Corporate bonds		141,474		234		(45	)		141,663
	$	187,221	$	245	$	(126	)	$	187,340

As of September 30, 2025 and December 31, 2024, no available-for-sale debt securities had remaining maturities greater than two years. The amortized cost of marketable debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, or to the earliest call date for callable debt securities purchased at a premium.

As of September 30, 2025 and December 31, 2024, the balance in accumulated other comprehensive loss consisted solely of unrealized gains and losses on available-for-sale debt securities, net of reclassification adjustments for realized gains and losses and income tax effects. The Company uses the aggregate portfolio approach to release the tax effects of unrealized gains and losses on available-for-sale debt securities in accumulated other comprehensive loss. Realized gains and losses from the sale or maturity of marketable securities are based on the specific identification method and are included in results of operations as investment income. The Company did not recognize any realized gains or losses on available-for-sales securities during the three and nine months ended September 30, 2025 and 2024, and no income tax effects or reclassification adjustments were recorded in accumulated other comprehensive loss during the periods.

The following tables present the fair values and unrealized losses of available-for-sale debt securities held by the Company in an unrealized loss position for less than 12 months and 12 months or greater (in thousands):


	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
September 30, 2025
U.S. government and agency securities	$	11,485	$	(1	)	$	—	$	—	$	11,485	$	(1	)
Corporate bonds		34,235		(15	)		—		—		34,235		(15	)
	$	45,720	$	(16	)	$	—	$	—	$	45,720	$	(16	)


	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
December 31, 2024
U.S. government and agency securities	$	—	$	—		$	22,917	$	(77	)	$	22,917	$	(77	)
Certificates of deposit		—		—			1,221		(4	)		1,221		(4	)
Corporate bonds		21,317		(45	)		—		—			21,317		(45	)
	$	21,317	$	(45	)	$	24,138	$	(81	)	$	45,455	$	(126	)

As of September 30, 2025, available-for-sale debt securities held by the Company which were in an unrealized loss position consisted of 11 investment grade security positions. The Company has the intent and ability to hold such securities until recovery, and based on the credit quality of the issuers and low severity of each unrealized loss position relative to its amortized cost basis, the Company did not identify any credit losses associated with its available-for-sale debt securities. The Company did not record an allowance for credit losses on its available-for-sale debt securities as of September 30, 2025 or December 31, 2024, and no impairment or credit losses on available-for-sale debt securities were recorded during the three and nine months ended September 30, 2025 and 2024.

Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Summary of Company Marketable Securities

The following tables present a summary of the Company’s marketable securities, which consist solely of available-for-sale debt securities (in thousands):


	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
September 30, 2025
U.S. government and agency securities	$	123,444	$	66	$	(1	)	$	123,509
Corporate bonds		119,589		158		(15	)		119,732
	$	243,033	$	224	$	(16	)	$	243,241


	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2024
U.S. government and agency securities	$	44,281	$	11	$	(77	)	$	44,215
Certificates of deposit		1,466		—		(4	)		1,462
Corporate bonds		141,474		234		(45	)		141,663
	$	187,221	$	245	$	(126	)	$	187,340

Summary of Fair Values and Unrealized Losses of Marketable Securities Held by the Company in an Unrealized Loss Position for Less Than 12 months and 12 Months or Greater


	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
September 30, 2025
U.S. government and agency securities	$	11,485	$	(1	)	$	—	$	—	$	11,485	$	(1	)
Corporate bonds		34,235		(15	)		—		—		34,235		(15	)
	$	45,720	$	(16	)	$	—	$	—	$	45,720	$	(16	)


	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
December 31, 2024
U.S. government and agency securities	$	—	$	—		$	22,917	$	(77	)	$	22,917	$	(77	)
Certificates of deposit		—		—			1,221		(4	)		1,221		(4	)
Corporate bonds		21,317		(45	)		—		—			21,317		(45	)
	$	21,317	$	(45	)	$	24,138	$	(81	)	$	45,455	$	(126	)

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-9

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

+ Details

Property and Equipment, Net

9 Months Ended

Sep. 30, 2025

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

5. Property and Equipment, Net

Property and equipment, net consists of the following (in thousands):


	September 30, 2025			December 31, 2024
Laboratory and manufacturing equipment	$	78,017		$	77,141
Computer equipment and software		4,468			4,244
Furniture and fixtures		7,036			7,031
Leasehold improvements		101,533			101,465
Total property and equipment		191,054			189,881
Accumulated depreciation and amortization		(83,539	)		(72,292	)
Property and equipment, net	$	107,515		$	117,589

In March 2024, the Company entered into an agreement to sublease its office facilities in New York, New York. In connection with the sublease, the Company recorded impairment of property and equipment of $0.7 million in the first quarter of 2024 related to furniture and fixtures and leasehold improvements located at the subleased facility. Please refer to Note 6 for further information regarding the sublease agreement and associated impairment of long-lived assets.