REGENXBIO Inc.

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 has consisted 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. The Company was formed in 2008 in the State of Delaware and is headquartered in Rockville, Maryland.

The Company's lead product candidates include ABBV-RGX-314 (surabgene lomparvovec, sura-vec) for the treatment of wet age-related macular degeneration (wet AMD) and diabetic retinopathy (DR), which is being developed and commercialized in collaboration with AbbVie Global Enterprises Ltd. (AbbVie), a subsidiary of AbbVie Inc., and RGX-202 for the treatment of Duchenne muscular dystrophy. Additional clinical-stage candidates include RGX-121 (clemidsogene lanparvovec) for the treatment of Mucopolysaccharidosis Type II (MPS II) and RGX-111 for the treatment of Mucopolysaccharidosis Type I (MPS I), which are being developed and commercialized in collaboration with Nippon Shinyaku Co., Ltd. (Nippon Shinyaku).

In addition to its internal product development efforts, the Company has also selectively licensed the NAV Technology Platform and other intellectual property rights to other leading biotechnology and pharmaceutical companies (NAV Technology Licensees). As of September 30, 2026, the NAV Technology Platform was being applied by NAV Technology Licensees in two commercial products, Zolgensma®and Itvisma®, and in the preclinical and clinical development of various other licensed products. Additionally, the Company has licensed intellectual property rights to collaborators for the joint development and commercialization of certain product candidates.

Liquidity

The Company has incurred cumulative losses since inception and as of September 30, 2026, had generated an accumulated deficit of$1.23 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.

As of September 30, 2026, the Company had cash, cash equivalents and marketable securities of$251.0 million. In October 2026, the Company received a payment of $39.0 million pursuant to a settlement agreement with Sarepta Therapeutics, Inc. (Sarepta). Please refer to Note 8 for further information regarding the settlement agreement with Sarepta. Management believes the Company's cash, cash equivalents and marketable securities as of September 30, 2026, along with the settlement proceeds received in October 2026, are sufficient to fund operations into the late fourth quarter of 2027. This estimate is based on the Company's current operating plan and excludes the potential effects of any future financings or material milestone payments that may be received under the Company's licensing and collaboration arrangements. The Company has based this estimate on assumptions that may prove to be wrong, and it could exhaust its capital resources sooner than expected. These conditions raise substantial doubt about the Company's ability to continue as a going concern within 12 months from the date these consolidated financial statements were issued. The Company’s ability to continue as a going concern will depend heavily on the successful development, approval and 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.

2. Summary of Significant Accounting Policies

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, 2025 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, which was filed with the SEC on March 5, 2026. 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, 2025, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

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.

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):

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, 2026 and December 31, 2025.

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:

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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.

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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.

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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.

Net Loss Per Share

Basic netloss 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, 2026 and 2025 which had a material impact on the consolidated financial statements.

Recent Accounting Pronouncements Not Yet Adopted

In November 2024, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (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.

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):

As of September 30, 2026, no available-for-sale debt securities had remaining maturities greater than one year. As of December 31, 2025, 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, 2026 and December 31, 2025, 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. Unrealized gain (loss) on available-for-sale securities, net, presented in the statements of operations and comprehensive loss consisted of the following (in thousands):

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):

As of September 30, 2026, available-for-sale debt securities held by the Company in an unrealized loss position consisted of 33 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 didnot record an allowance for credit losses on its available-for-sale debt securities as of September 30, 2026 or December 31, 2025, and no impairment or credit losses on available-for-sale debt securities were recorded during the three and nine months ended September 30, 2026 and 2025.

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):

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 non-current accounts receivable 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, 2026 to determine the present value of these instruments. Accordingly, management estimates that the carrying values of its non-current accounts receivable 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.

5. Property and Equipment, Net

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

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, 2026, total undiscounted future minimum lease payments to be received by the Company over the remaining term of the New York Sublease were $0.3 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, 2026, respectively, and $0.1 million and $0.3 million during the three and nine months ended September 30, 2025, respectively.

7. Royalty Monetization Liabilities

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

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 and Itvisma royalty payments under the Company’s license agreement with Novartis Innovative Technologies Inc. (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 and Itvisma 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 and Itvisma 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 priorto the defined dates for each Cap Amount, the total amount of royalties paid to HCR equals or exceeds the Cap Amount applicable to such date, the 2020 Royalty Purchase Agreement would 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 and Itvisma royalty payments are not sufficient to achieve the Second 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 applicable 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 Itvisma 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 and Itvisma royalties to be paid to 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 as of September 30, 2026 and December 31, 2025 was 38.3% and 85.2%, 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, 2026, 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):

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 inthree 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 and Itvisma, (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 and Itvisma royalties earned under the Novartis License shall only be included in the Royalty Interest after full repayment of the Second 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 the 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 as of September 30, 2026 and December 31, 2025 was 15.0% and 15.1%, respectively, 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):

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.

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

As of September 30, 2026 and December 31, 2025, the Company had recorded $0.9 million and $5.7 million, respectively, payable under the GSK License.

GSK Settlement Agreement

The Company was notified of a dispute with GSK over the amount of sublicense fees paid by the Company to GSK under the GSK License. GSK claimed there had been a significant underpayment by the Company with respect to sublicense fees. In February 2026, the Company and GSK engaged in non-binding mediation regarding the dispute. In March 2026, the Company and GSK entered into a settlement and release agreement to resolve the matter. The settlement agreement provides for the mutual release of all past claims and certain future claims by the parties under the GSK License. Pursuant to the settlement agreement, the Company paid $10.0 million to GSK in March 2026, which was recorded as cost of license and royalty revenues in the first quarter of 2026. Additionally, the Company will continue to pay sublicense fees to GSK on license fees earned under existing sublicense agreements, utilizing the Company's historical allocation methodologies for such sublicense payments.

Sarepta Therapeutics Settlement Agreement

In September 2026, the Company and Penn entered into a settlement agreement with Sarepta and affiliated entities, and Catalent, Inc. to resolve all litigation alleging infringement of certain U.S. patents related to Sarepta's manufacture, use, offer to sell and sale of SRP-9001 (also known as Elevidys®).

Pursuant to the terms of the settlement agreement, Sarepta made a payment of $39.0 million to the Company following the effective date of the agreement. The parties have terminated with prejudice all ongoing patent litigation regarding the asserted patents. The settlement agreement includes the release by the Company and Penn of all current claims of infringement and a covenant not to sue for future patent claims relating to any Sarepta gene therapy product that uses an AAVrh74-based capsid, including Elevidys, based upon certain patents and patent applications. In addition, the Company agreed not to sue Sarepta or its affiliates, licensees or commercial partners over any Company patents or patent applications that cover the existing form of Elevidys or the AAVrh74-based capsid sequence; but this does not extend to patents or patent applications that cover other aspects of gene therapy products.

The Company recorded a gain of $38.0 million in the third quarter of 2026 related to the settlement agreement, which consisted of the $39.0 million settlement payment due from Sarepta, net of proceeds payable to certain licensors as a result of the settlement. The $39.0 million settlement payment was recorded as other current assets on the consolidated balance sheet as of September 30, 2026 and was received in full from Sarepta in October 2026.

Litigation

In February 2026, a putative securities class action complaint was filed by Andre Kuik (Kuik) against the Company and certain of its current officers and directors in the United States District Court for the District of Maryland. The complaint asserted claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder, on behalf of a putative class of persons who purchased or otherwise acquired the Company's securities during the period from February 9, 2022 through January 27, 2026. The complaint alleged that the Company misled investors concerning the viability and safety of RGX-111, and that the Company's stock price declined following the announcement of the clinical hold imposed by the U.S. Food and Drug Administration (FDA) on the Company’s RGX-111 program on January 28, 2026. In August 2026, an amended complaint was filed focusing on interactions with FDA and Company statements prior to the Company’s receipt of a Complete Response Letter for RGX-121 in February 2026. The amended complaint asserts claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder, on behalf of a putative class of persons who purchased or otherwise acquired the Company's securities during the period from February 7, 2024 through March 3, 2026. The plaintiff seeks unspecified compensatory damages, attorneys' fees, expert fees and other costs, and other relief as the court may deem just and proper. The Company believes that it has meritorious defenses to the claims asserted and intends to vigorously defend against them. The Company does not believe that a loss is probable, andno reasonable range of loss is estimable, related to this matter. No liabilities related to this matter were recorded as of September 30, 2026.

In March 2026, a purported stockholder derivative complaint, as revised, was filed by plaintiff Roberto Medina (Medina) against the Company as nominal defendant and certain of its current officers and directors in the United States District Court for the District of Maryland. The complaint alleges breach of fiduciary duty and claims of unjust enrichment, abuse of control, gross mismanagement, waste of corporate assets, and alleged violations of Sections 10(b), 14(a) and 21D of the Securities Exchange Act of 1934 during the period from February 9, 2022 through January 27, 2026. The complaint alleges that the Company misled investors concerning the viability and safety of RGX-111 and that the Company's stock price declined following the announcement of the clinical hold imposed by the FDA on the Company’s RGX-111 program on January 28, 2026. The complaint seeks, among other relief, damages in favor of the Company, disgorgement of alleged profits, restitution, attorneys' fees, expert fees, corporate governance reforms, and other relief as the court may deem just and proper. In May 2026 a substantially similar suit was filed by plaintiff Matthew Hay (Hay) in the United States District Court for the District of Maryland, containing largely similar factual and legal contentions and requested relief. In June 2026 the Medina and Hay derivative suits were consolidated and stayed through the resolution of the planned motion to dismiss in the Kuik securities suit. The Company believes the claims are procedurally defective. The Company does not believe that a loss is probable, andno reasonable range of loss is estimable, related to this matter. No liabilities related to this matter were recorded as of September 30, 2026.

9. Capitalization

Public Offerings of Common Stock and Pre-funded Warrants

In July 2026, the Company completed a public offering of 11,671,139 shares of its common stock at a price of $9.00 per share and 1,111,111 pre-funded warrants (the July 2026 Pre-funded Warrants) to purchase shares of its common stock at a price of $8.9999 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 $107.8 million, net of underwriting discounts and commissions and offering expenses.

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 March 2024 Pre-funded Warrants and July 2026 Pre-funded Warrants (collectively, the Pre-funded Warrants) have similar terms and conditions, are exercisable at the option of the warrant holder at any time, subject to certain limitations, and do not expire. The Company evaluated the 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. No Pre-funded Warrants were exercised during the nine months ended September 30, 2026. As of September 30, 2026, there were 1,980,714 Pre-funded Warrants 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 ATM Program). During the nine months ended September 30, 2026, the Company sold 2,318,735 shares of common stock under the ATM Program for aggregate net proceeds of $18.9 million after deducting commissions and offering expenses. No shares of common stock were sold under the ATM Program prior to the second quarter of 2026.

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, 2026, no May 2025 Warrants had been exercised.

10. License and Collaboration Agreements

License and Collaboration Revenues

As of September 30, 2026, the Company’s NAV Technology Platform was being applied by NAV Technology Licensees intwo commercial products, Zolgensma and Itvisma, and in the development of various 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):

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, 2026, the Company’s license and collaboration agreements contained unachieved milestones which could result in aggregate milestone payments to the Company of up to$2.06 billion, including (i)$444.0 million upon the commencement of various stages of clinical trials, (ii)$86.5 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 Company realizes the milestone payments, 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):

Revenue recognized from performance obligations satisfied in previous periods, as presented in the table above, was primarily attributable to Zolgensma and Itvisma royalties and changes in the transaction prices of the Company’s license agreements. Changes in transaction prices were primarily attributable to the achievement of development milestones, or the resolution of related uncertainties such that it became probable that a significant reversal of cumulative revenue would not occur if the development milestone consideration was included in the transaction price. These changes were recognized as cumulative catch-up adjustments to revenue. Revenue recognized during the nine months ended September 30, 2026 included $100.0 million in cumulative catch-up adjustments for changes in the probability of achievement of development milestones, which was associated with a $100.0 million development milestone achieved under the Company's collaboration and license agreement with AbbVie. No cumulative catch-up adjustments for development milestones were recorded in revenue during the three months ended September 30, 2026 or during the three and nine months ended September 30, 2025.

As of September 30, 2026, the Company had recorded deferred revenue of $22.2 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, 2026 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, 2026, the aggregate transaction price of the Company’s license and collaboration agreements allocated to performance obligations not yet satisfied or partially satisfied was $23.3 million, primarily associated with development services under 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 four years.

Accounts receivable consisted of the following (in thousands):

Zolgensma and Itvisma License with Novartis

In March 2014, the Company entered into an exclusive license agreement (as amended, the Novartis License) with Novartis Innovative Technologies Inc. (formerly, Novartis Gene Therapies, Inc.), a wholly owned subsidiary of Novartis AG (Novartis). Under the Novartis License, the Company granted Novartis an exclusive, worldwide commercial license, with rights to sublicense, to the NAV Technology Platform, as well as other certain rights, for the treatment of spinal muscular atrophy (SMA) in humans byin vivo gene therapy. In 2019, Novartis launched commercial sales of Zolgensma for the treatment of SMA in patients under the age of two years old. In the fourth quarter of 2025, Novartis launched commercial sales of Itvisma for the treatment of SMA in patients two years and older. Zolgensma and Itvisma are licensed products under the Novartis License, pursuant to which the Company receives royalties on certain net sales of the licensed products.

In January 2026, licensed patents for Zolgensma under the Novartis License expired in the United States. The Company is entitled to continued royalties on net sales of Zolgensma in approximately 20 countries where licensed patents remain active. Licensed product made prior to patent expiration but sold after expiration may also be subject to royalties. Licensed patents covering the use of Itvisma have issued in the United States and certain other countries, and the Company is entitled to ongoing royalties on certain net sales of Itvisma in these territories.

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

As of September 30, 2026 and December 31, 2025, the Company had recorded total accounts receivable of $5.5 million and $24.1 million, respectively, from Novartis under the Novartis License, which consisted primarily of Zolgensma and Itvisma royalties receivable. Royalties receivable as of September 30, 2026 included $4.2 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 and Itvisma in the period in which the underlying products are sold by Novartis, 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 to jointly develop and commercialize sura-vec (or ABBV-RGX-314), the Company’s product candidate for the treatment of wet AMD, 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 sura-vec in the United States and an exclusive license to develop and commercialize sura-vec outside the United States. The Company and AbbVie will collaborate to develop sura-vec in the United States, and AbbVie will be responsible for the development of sura-vec in specified markets outside the United States. Global development expenses for sura-vec 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 sura-vec for clinical development and U.S. commercial supply, and AbbVie will lead the manufacturing of sura-vec 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 sura-vec commercial supply for sales outside the United States at a price specified in the agreement. AbbVie will lead the commercialization of sura-vec 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 sura-vec in the United States. Outside the United States, AbbVie will be responsible, at its sole cost, for the commercialization of sura-vec.

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 sura-vec 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 sura-vec 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 (NAAVIGATE) which will be 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 a $200.0 million development milestone payable 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 NAAVIGATE trial (the First DR Milestone) and an additional $100.0 million upon first patient dosed in the subsequent Phase III trial (the Second DR Milestone). Also pursuant to the amendment, AbbVie will lead a new Phase III randomized controlled study (ACHIEVE) to assess the injection burden, adverse events, change in disease activity, and long-term preservation of visual acuity ofsura-vec in adult participants with neovascular AMD. The Company will be responsible for its development expenses to conduct Part 1 of the NAAVIGATE trial and the parties will share the development expenses related to Part 2 of the NAAVIGATE 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.

In June 2026, the Company dosed the first patient in the NAAVIGATE trial, resulting in a $100.0 million milestone payment from AbbVie for achievement of the First DR Milestone.

The Company applied the requirements of ASC 606, Revenue from Contracts with Customers (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 sura-vec 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, 2026, the transaction price of the AbbVie Collaboration Agreement was $470.0 million, which consisted of (i) the $370.0 million up-front payment received from AbbVie in November 2021 and (ii) the $100.0 million development milestone payment earned upon achievement of the First DR Milestone in June 2026 and received from AbbVie in July 2026. As of September 30, 2026, variable consideration excluded from the transaction price of the AbbVie Collaboration Agreement includes $462.5 millionin payments for development milestones that have not yet been achieved and were notconsidered probable of achievement. Additionally, the transaction price excludes sales-based milestone payments of $820.0 million and royalties on net sales ofsura-vec 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. The $470.0 million transaction price of the AbbVie Collaboration Agreement has been fully recognized as license and royalty revenue since the intellectual property licenses were delivered to AbbVie at the inception of the agreement in November 2021. The transaction price of the AbbVie Collaboration Agreement increased by $100.0 million during the nine months ended September 30, 2026 as a result of the achievement of the First DR Milestone in June 2026, as the milestone payment was previously constrained and excluded from the transaction price. The $100.0 million increase in the transaction price was fully recognized as a cumulative catch-up adjustment to revenue upon the achievement of the First DR Milestone in June 2026. There wereno changes in the transaction price of the AbbVie Collaboration Agreement, andno revenue was recognized, during the three months ended September 30, 2026 or the three and nine months ended September 30, 2025.

The Company applied the requirements of ASC 808, Collaborative Arrangements(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 sura-vec 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 sura-vec 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, 2026 and December 31, 2025, the Company had recorded $7.5 million and $10.9 million, respectively, due from AbbVie for net reimbursement of costs incurred for activities performed under the 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):

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 MPS II, and RGX-111, the Company's product candidate for the treatment of 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.

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 concluded that each of the distinct units of account identified under the Nippon Shinyaku Collaboration Agreement 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 United 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.

As of September 30, 2026, the transaction price of the Nippon Shinyaku Collaboration Agreement included fixed consideration of $110.0 million for the up-front payment and estimated variable consideration of $5.6 million for reimbursable costs of manufacturing and other services 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 reimbursable costs of manufacturing and other services which are contingent on events occurring that are outside the Company’s control and are deemed to be constrained. 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 for manufacturing and other services 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 wereno changes in the fixed transaction price of the Nippon Shinyaku Collaboration Agreement during the three and nine months ended September 30, 2026 and 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 $5.6 million of estimated variable consideration included in the transaction price is allocated directly to performance obligations for the manufacturing of commercial supply prior to regulatory approval and other service obligations since the consideration is directly associated with the performance of such services and reimbursement of applicable 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 licenses 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 of commercial supply to Nippon Shinyaku as defined in the associated supply agreements.

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

As of September 30, 2026 and December 31, 2025, the Company had recorded total accounts receivable of $2.5 million and $4.1 million, respectively, for reimbursement of manufacturing-related development costs and other services under the Nippon Shinyaku Collaboration Agreement.

As of September 30, 2026, the Company had recorded total deferred revenue of $22.2 million for development services and material rights which have not yet been satisfied under the Nippon Shinyaku Collaboration Agreement, of which $6.0 million was included in current liabilities and $16.2 million was included in non-current liabilities. As of December 31, 2025, the Company had recorded total deferred revenue of $29.4 million for development services and material rights which have not yet been satisfied under the Nippon Shinyaku Collaboration Agreement, of which $10.5 million was included in current liabilities and $18.9 million was included in non-current liabilities.

11. Stock-based Compensation

The total number of shares of common stock authorized for issuance under the 2025 Equity Incentive Plan (the 2025 Plan) upon its adoption in May 2025 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 Equity Incentive Plan (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, including an exchange of the award (to the extent that surrendered awards exceed newly issued awards in such exchange). 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, 2026, the total number of shares of common stock reserved for issuance under the 2025 Plan and 2015 Plan was 18,732,094, of which 4,985,411 remained available for future grants under the 2025 Plan.

The Company's equity incentive plans 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. As of September 30, 2026, the Company has issued only stock options, restricted stock units (RSUs) and performance stock units (PSUs) under its equity plans. Stock options generally expire 10 years following the date of grant and typically vest over afour-year service period, but contractual terms and 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. RSUs typically vest over afour-year service period, but vesting provisions can vary by award based on the discretion of the Board of Directors. In January 2026, the Company granted PSUs to certain executive employees. PSUs have similar terms and conditions as RSUs, except that vesting is contingent upon the achievement of specified performance conditions in addition to service conditions over a period ofone year. Upon vesting, RSUs and PSUs are settled in common stock of the Company. Awards granted under the 2025 Plan generally have a minimum vesting requirement ofone year from the grant date.

Stock-based Compensation Expense

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

As of September 30, 2026, the Company had$45.8 million of unrecognized stock-based compensation expense related to stock options, RSUs, PSUs 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):

Stock Options

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

(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.

The weighted-average grant date fair value per share of options granted during the nine months ended September 30, 2026, excluding options granted under the stock option exchange program as discussed below, was$6.87. During the nine months ended September 30, 2026, the total number of stock options exercised was 325,339, resulting in total proceeds of$0.8 million. The number of stock options exercised during the period includes shares withheld to cover option cost and taxes. The total intrinsic value of options exercised during the nine months ended September 30, 2026 was$0.5 million.

Stock Option Exchange Program

On June 3, 2026, the Company commenced an offer to exchange (the Offer to Exchange) certain eligible stock options held by eligible non-executive employees for replacement stock options under a voluntary stock option exchange program (the Stock Option Exchange Program). Under the Stock Option Exchange Program, eligible employees were offered the opportunity to exchange outstanding stock options granted under the 2015 Plan that have an exercise price equal to or greater than $18.00 per share (Eligible Options), for a lesser number of replacement stock options to be granted under the 2025 Plan (Replacement Options). The number of Replacement Options granted in exchange for Eligible Options surrendered was calculated based on specified exchange ratios which vary based on the grant date and exercise price of the Eligible Options. The exchange ratios were established in order to result in a fair value of the Replacement Options that was generally equal, on an aggregate basis, to the fair value of the Eligible Options surrendered.

The Offer to Exchange expired on July 1, 2026. Pursuant to the terms and conditions of the Offer to Exchange, a total of 184 eligible employees elected to exchange a total of 1,940,394 Eligible Options with a weighted-average exercise price of $35.13 per share, representing approximately 67.0% of the total Eligible Options outstanding. On July 2, 2026, all Eligible Options that were tendered were cancelled and, in exchange therefor, the Company granted Replacement Options to purchase 775,401 shares of common stock with an exercise price of $13.28 per share, which was the closing price of the Company's common stock on July 2, 2026. The Replacement Options expire eight years from the grant date and are subject to new vesting schedules based on continued service over a period oftwo years from the grant date.

The exchange of stock options under the Stock Option Exchange Program was accounted for as a modification of the awards in accordance with ASC 718, Compensation—Stock Compensation(ASC 718). The total incremental stock-based compensation expense resulting from the modification of the awards was immaterial and was measured based on the excess fair value of the modified awards over the fair value of the original awards immediately before the modification, calculated using a Black-Scholes option-pricing model. The incremental stock-based compensation expense will be recognized together with any unrecognized compensation cost remaining on the exchanged options over the two-year requisite service period of the Replacement Options granted.

Restricted Stock Units

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

The total intrinsic value of RSUs vested during the nine months ended September 30, 2026 was$12.6 million.

Performance Stock Units

In January 2026, the Company granted PSUs to certain executive employees. Vesting of the PSUs is contingent upon the achievement of specified performance conditions pre-determined by the Board of Directors, as well as service conditions over a requisite service period. The performance conditions are based on certain specified business objectives and are non-market based. As determined by the Board of Directors, each performance condition that is achieved during the applicable performance period will result in the vesting of a specified number of PSUs one year from the grant date, subject to the grantee's continued service through the vesting date.

Stock-based compensation expense for PSUs is measured based on the grant date fair value of the award, which is determined based on the fair value of the Company's stock on the grant date, and is recognized over the requisite service period beginning in the period it is probable that the performance conditions will be achieved. As of September 30, 2026, certain specified performance conditions were achieved or deemed probable of achievement but vesting of the associated PSUs remains subject to continued service conditions. No PSUs vested during the nine months ended September 30, 2026.

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

Employee Stock Purchase Plan

As of September 30, 2026, the total number of shares of common stock authorized for issuance under the 2015 ESPP was 1,426,994, of which 574,699 remained available for future issuance. During the nine months ended September 30, 2026,180,607 shares of common stock were issued under the 2015 ESPP.

12. Income Taxes

The Company evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets as of September 30, 2026 and December 31, 2025. 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 deferred tax assets as of September 30, 2026 and December 31, 2025.

13. Net Loss Per Share

Since the Company incurred net losses for the three and nine months ended September 30, 2026 and 2025, 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):

In addition to the common stock equivalents in the table above, the computations of weighted-average diluted common shares for the three and nine months ended September 30, 2026 exclude 122,565 unvested PSUs as of September 30, 2026 for which vesting is contingent upon the future achievement of performance conditions.

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, 2026 and December 31, 2025, the Company’s cash, cash equivalents and marketable securities were$251.0 million and $240.9 million, respectively.

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 loss (in thousands):

(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, commercialization expenses, commercial cost reimbursement to and from collaborators and other corporate overhead expenses.

(c)

Other segment items include gain on litigation settlement, other operating expenses (income), 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 $2.3 million and $5.5 million during the three and nine months ended September 30, 2026, respectively, and $3.6 million and $9.4 million during the three and nine months ended September 30, 2025, 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.

15. Supplemental Disclosures

Other Current Assets

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

Accrued Expenses and Other Current Liabilities

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