ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

You should read the following discussion and analysis of our financial condition and results of operations in conjunction with the audited financial statements and the notes thereto included elsewhere in this Annual Report on Form 10-K. In addition, you should read the “Risk Factors” and “Information Regarding Forward-Looking Statements” sections of this Annual Report on Form 10-K for a discussion of important factors that could cause actual results to differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis.

For a full discussion and analysis of financial condition and results of operations for the year ended December 31, 2024, including a year-over-year comparison to the year ended December 31, 2023, please read the “Management's Discussion and Analysis of Financial Condition and Results of Operations” section of our Annual Report on Form 10-K for the year ended December 31, 2024, which we filed with the SEC on March 13, 2025.

Overview

We are a leading clinical-stage biotechnology company seeking to improve lives through the curative potential of gene therapy. Our investigational gene therapies are designed to deliver functional genes to address genetic defects in cells, enabling the production of therapeutic proteins or antibodies that are intended to impact disease. Through a single administration, gene therapy could potentially alter the course of disease significantly and deliver improved patient outcomes with long-lasting effects.

Overview of Product Candidates

We have developed a broad pipeline of gene therapy programs using our proprietary adeno-associated virus (AAV) gene therapy delivery platform (NAV Technology Platform) as a one-time treatment to address an array of diseases. Our lead programs and product candidates are described below:

•

ABBV-RGX-314: We are developing ABBV-RGX-314 (surabgene lomparvovec, sura-vec) in collaboration with AbbVie as a potential one-time treatment for chronic retinal conditions that cause total or partial vision loss, including wet age-related macular degeneration (wet AMD) and diabetic retinopathy (DR). ABBV-RGX-314 is currently being evaluated in multiple clinical trials, including two pivotal trials (ATMOSPHERE and ASCENT), one Phase II bridging study, one long-term follow-up study and a fellow eye sub-study in patients with wet AMD, all utilizing subretinal delivery. Additionally, two Phase II clinical trials in patients with wet AMD (AAVIATE) and DR (ALTITUDE) are ongoing along with two corresponding long-term follow-up studies, all utilizing in-office suprachoroidal delivery. Within the Phase II study in DR, we are also evaluating ABBV-RGX-314 in diabetic macular edema (DME). Additionally, we are planning a Phase IIb/III program in DR and expect to dose the first patient in a two-part Phase IIb/III study (NAAVIGATE) in the second quarter of 2026. ABBV-RGX-314 uses the NAV® AAV8 vector to deliver a gene encoding a therapeutic antibody fragment to inhibit vascular endothelial growth factor (VEGF). We have licensed certain exclusive rights to the SCS Microinjector® from Clearside Biomedical, Inc. (Clearside) to deliver gene therapy treatments to the suprachoroidal space of the eye.

Wet AMD

Subretinal Delivery

Enrollment in the ATMOSPHERE® and ASCENT® pivotal trials for the treatment of patients with wet AMD using subretinal delivery was completed in October 2025. These trials are expected to support global regulatory submissions with the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Topline data from these trials are expected to be shared in the fourth quarter of 2026 in partnership with AbbVie.

Suprachoroidal Delivery

The AAVIATE® trial is a multi-center, open label, randomized, controlled, dose-escalation Phase II trial to evaluate the efficacy, safety and tolerability of suprachoroidal delivery of ABBV-RGX-314 for the treatment of wet AMD.

Based on the favorable safety profile observed as of July 29, 2024, the Phase II AAVIATE trial enrolled a cohort to evaluate ABBV-RGX-314 at dose level 4 (1.5x10e12 GC/eye). Patients in this cohort received short course prophylactic steroid eye drops.

Table of Contents

DR and DME

The ALTITUDE® trial is a multi-center, open label, randomized, controlled, dose-escalation Phase II trial to evaluate the efficacy, safety and tolerability of ABBV-RGX-314 using suprachoroidal delivery for the treatment of DR. In November 2023, we announced data showing ABBV-RGX-314 was well tolerated at dose levels 1 and 2 and positive signals of efficacy, including 20.8% of patients exhibiting > 2-step Diabetic Retinopathy Severity Scale (DRSS) improvement without additional DR treatment at one year.

In August 2025, we and AbbVie executed an amendment to our collaboration agreement and announced plans to initiate a pivotal program consisting of a Phase IIb/III trial (NAAVIGATE) as well as a second Phase III trial. NAAVIGATE is a Phase IIb/III multicenter, randomized, masked, sham-controlled study to evaluate the safety and efficacy of sura-vec in subjects with non-proliferative DR (NPDR) without center-involved diabetic macular edema (CI-DME). The primary endpoint is > 2-step improvement on the diabetic retinopathy severity scale (DRSS) at one year. Following an interim analysis, REGENXBIO and AbbVie will initiate a Phase III expansion, which will include two Phase III trials, including a U.S. trial and a parallel global trial, led by AbbVie. We expect to dose the first patient in NAAVIGATE in the second quarter of 2026.

The ALTITUDE trial includes a new cohort of patients with center-involved DME evaluating ABBV-RGX-314 at dose level 4. Enrollment completed in this cohort in June 2025. DME is a vision-threatening complication of DR; an estimated 34 million people globally have DME. Patients received a one-time, in-office injection of ABBV-RGX-314 at dose level 4 (1.5x10e12 GC/eye) with short course prophylactic steroid eye drops.

•

RGX-202: We are developing RGX-202 as an investigational AAV therapeutic for the treatment of Duchenne muscular dystrophy (Duchenne), using the NAV AAV8 vector to deliver a transgene for a novel microdystrophin that includes the functional elements of the C-Terminal domain as well as a muscle-specific promoter to support a targeted therapy for improved resistance to muscle damage associated with Duchenne. Other differentiating elements of RGX-202 include the proactive immune suppression regimen and in-house, state-of-the-art manufacturing that has demonstrated leading purity levels in Duchenne (>80% full capsids).

AFFINITY DUCHENNE® is a multicenter, open-label Phase I/II/III trial to evaluate the safety, tolerability and clinical efficacy of a one-time intravenous dose of RGX-202 in patients with Duchenne aged one and older. The initiation of the pivotal study was designed to enroll approximately 30 patients in the U.S. and Canada.

In October 2025, we announced that enrollment in the AFFINITY DUCHENNE pivotal trial had completed and that we continue to enroll participants in the planned confirmatory trial. We expect to share topline data in the early second quarter of 2026 and request a pre-Biologics License Application (BLA) meeting with the FDA in mid-2026.

We began manufacturing the first batches of RGX-202 intended for commercial supply at our Manufacturing Innovation Center and completed the Process Performance Qualification (PPQ) campaign in the fourth quarter of 2025. Additional regulatory interactions with the FDA and the EMA are planned for 1H 2026.

We are also recruiting patients in the AFFINITY BEYOND® trial, an observational screening study. The primary objective is to evaluate the prevalence of AAV8 antibodies in patients with Duchenne up to 12 years of age. Information collected in this study may be used to identify potential participants for the AFFINITY DUCHENNE trial and potential future trials of RGX-202.

•

RGX-121: We are developing RGX-121 (clemidsogene lanparvovec) in collaboration with Nippon Shinyaku in the United States and certain countries in Asia as an investigational one-time AAV therapeutic for the treatment of Mucopolysaccharidosis Type II (MPS II), also known as Hunter syndrome, using the NAV AAV9 vector to deliver the gene that encodes the iduronate-2-sulfatase enzyme.

A BLA for RGX-121 seeking accelerated approval was submitted to the FDA in March 2025. The FDA subsequently granted priority review of the BLA and successfully completed mid-cycle meeting, Pre-license inspection (PLI) and Bioresearch monitoring information (BIMO) inspections. The PLI and BIMO inspections were completed with no observations. In August 2025, we announced that the FDA review timeline had been extended following submission of 12-month clinical data for all patients in the pivotal study of RGX-121 (n=13) in response to an FDA information request. The Prescription Drug User Fee Act (PDUFA) goal date was extended from November 9, 2025 to February 8, 2026.

The longer-term data submitted to the FDA were presented at the International Congress of Inborn Errors of Metabolism (ICIEM) in September 2025. These results showed that in the pivotal phase of the CAMPSIITE trial (n=13), participants through one year sustained an 82% median reduction of cerebrospinal fluid (CSF) levels of HS D2S6. These longer-term data were consistent with previously reported topline pivotal results from the CAMPSIITE trial.

Table of Contents

In January 2026, we announced that the FDA placed the RGX-121 program on clinical hold in relation to a serious adverse event in a patient treated in the Phase I/II trial of RGX-111. The FDA cited the similarities in products, study populations, and shared risk between the clinical studies.

In February 2026, we announced that the FDA issued a Complete Response Letter (CRL) for the RGX-121 BLA. The FDA stated in the CRL that it had agreed to the study protocol in principle and outlined several reasons for not approving the gene therapy, including uncertainty regarding the study eligibility criteria to adequately define a population with neuronopathic disease (vs. attenuated disease), the comparability of the natural history external control to the study population, and the appropriateness of CSF HS D2S6 as a surrogate endpoint reasonably likely to predict clinical benefit. The CRL lists several potential paths forward, including a new study, treating additional patients and conducting longer-term follow up, and using an untreated control arm. Throughout active discussions during the BLA process, we believed we had addressed the points raised in the CRL through the submission of additional data and responses to numerous information requests. The FDA did not agree the data set provided substantial evidence of effectiveness to support approval of RGX-121 for the treatment of MPS II. We plan to request a Type A meeting with the FDA.

As of March 2026, we plan to work with the FDA to address the clinical hold and CRL, and discuss potential paths forward for the program, Potential approval of the BLA for RGX-121 could result in receipt of a Rare Pediatric Disease Priority Review Voucher (PRV), assuming the statutory criteria are met. If approved, RGX-121 would be the first approved gene therapy and one-time treatment for MPS II.

•

RGX-111: We are developing RGX-111 in collaboration with Nippon Shinyaku in the United States and certain countries in Asia as an investigational one-time AAV therapeutic for the treatment of Mucopolysaccharidosis Type I (MPS I), also known as Hurler syndrome, using the NAV AAV9 vector to deliver the IDUA gene.

In November 2023, future development of RGX-111 was halted as a result of a strategic pipeline prioritization and corporate restructuring. Prior to that announcement, RGX-111 demonstrated to be well tolerated and indicated encouraging biomarker and neurodevelopmental results in a Phase I/II study. Efforts to continue development of RGX-111 as part of the strategic partnership with Nippon Shinyaku are ongoing.

In January 2026, we announced that the FDA placed the RGX-111 program on clinical hold following preliminary analysis of a single case of neoplasm (intraventricular CNS tumor) in a participant treated in the Phase I/II study. The case was identified during a routine brain MRI of an asymptomatic five-year-old participant who received intracisternal RGX-111 four years prior. Preliminary genetic analysis of the resected tumor detected an AAV vector genome integration event associated with overexpression of a proto-oncogene (PLAG1), which is known to be susceptible to chromosomal rearrangements. Final analysis of the resected tumor was conducted by an independent third-party lab, and, as previously reported, detected an AAV vector genome integration event associated with overexpression of a PLAG1. Clonal integration of AAV vector elements into the PLAG1 gene was detected in the tumor tissue. Analyses supported classification as a PLAG1‐family neuroepithelial tumor and are consistent with the hypothesis that AAV vector integration at the PLAG1 site contributed to tumor formation. Of note, this participant had a background of factors that could have contributed to risk of oncogenic transformation. This child underwent unsuccessful stem cell transplant at 4 months of age, with loss of donor chimerism, and he received chemotherapeutics that may have contributed to DNA damage. The report concludes, based on formal neuropsychologic testing and developmental pediatrician assessment, that the patient’s neurocognitive development is above average, which indicates mitigation of MPS I disease, and the patient continues to do well. We anticipate the analysis will be published in a peer-reviewed journal this year.

AbbVie Collaboration for ABBV-RGX-314

In September 2021, we 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 (as amended, the AbbVie Collaboration Agreement). Pursuant to the AbbVie Collaboration Agreement, both we and AbbVie are active participants in the development of ABBV-RGX-314 and development expenses are shared between the parties in accordance with the agreement. The Company will lead the manufacturing of ABBV-RGX-314 for clinical development and U.S. commercial supply, and AbbVie will lead the global commercialization of ABBV-RGX-314. We received an up-front fee of $370.0 million from AbbVie upon the effective date of the AbbVie Collaboration Agreement in November 2021, and we are eligible to receive up to $1.38 billion from AbbVie upon the achievement of specified development and sales-based milestones. Additionally, the parties will share equally in the net profits and net losses associated with the commercialization of ABBV-RGX-314 in the United States, and we are eligible to receive tiered royalties on net sales by AbbVie of ABBV-RGX-314 outside the United States. For additional information regarding the AbbVie Collaboration Agreement, please refer to Note 10, “License and Collaboration Agreements—AbbVie Collaboration and License Agreement” to the accompanying audited consolidated financial statements.

Table of Contents

In August 2025, we 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, we 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 the $200.0 million milestone due to us under the original AbbVie Collaboration Agreement upon first patient dosed in the first registration enabling trial for DR SCS treatment, AbbVie will pay us $100.0 million upon first patient dosed in the NAAVIGATE trial 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 (ACHIEVE) 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. We will be responsible for our 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.

Nippon Shinyaku Collaboration for RGX-121 and RGX-111

In January 2025, we entered into a collaboration and license agreement with Nippon Shinyaku Co., Ltd. (Nippon Shinyaku) for the development and commercialization of RGX-121 and RGX-111 (the Nippon Shinyaku Collaboration Agreement). Pursuant to the Nippon Shinyaku Collaboration Agreement, we are 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. We are 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. Nippon Shinyaku is responsible, at its sole cost, for the commercialization of RGX-121 and RGX-111 in the licensed territories. Under the terms of the Nippon Shinyaku Collaboration Agreement, we received an up-front payment of $110.0 million from Nippon Shinyaku following the effective date of the agreement in March 2025 and are eligible to receive up to $700.0 million from Nippon Shinyaku upon the achievement of specified development and sales-based milestones. We are also eligible to receive double-digit royalties on net sales of RGX-121 and RGX-111 by Nippon Shinyaku, subject to specified offsets and reductions. We retain 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.

We recognized $84.7 million of revenue under the Nippon Shinyaku Collaboration Agreement during the year ended December 31, 2025. For additional information regarding the Nippon Shinyaku Collaboration Agreement, please refer to Note 10, “License and Collaboration Agreements—Nippon Shinyaku Collaboration and License Agreement” to the accompanying audited consolidated financial statements.

In May 2025, we entered into a loan agreement with entities managed by Healthcare Royalty Management, LLC (collectively and with other affiliated entities, HCR). Pursuant to the terms of the loan agreement, future royalties, sales-based milestone payments and certain development milestone payments earned under the Nippon Shinyaku Collaboration Agreement, along with consideration earned under various other NAV Technology Platform license agreements, shall be used to repay principal and interest owed to HCR. For additional information regarding the May 2025 loan agreement with HCR, please refer to Note 7, “Royalty Monetization Liabilities—2025 Royalty Bond” to the accompanying audited consolidated financial statements.

NAV Technology Licensing Platform

In addition to our internal product development efforts, we also selectively license the NAV Technology Platform and other intellectual property rights to other leading biotechnology and pharmaceutical companies, which we refer to as NAV Technology Licensees. As of December 31, 2025, our NAV Technology Platform was being applied in two commercial products, Zolgensma® and Itvisma®, and the preclinical and clinical development of various other licensed products. Licensing the NAV Technology Platform allows us to maintain our internal product development focus on our core disease indications and therapeutic areas while still expanding the NAV gene therapy pipeline, developing a greater breadth of treatments for patients, providing additional technological and potential clinical proof-of-concept for our NAV Technology Platform and creating additional revenue opportunities.

Financial Overview

Revenues

Our revenues to date have been primarily generated from the licensing of our NAV Technology Platform and other intellectual property rights to NAV Technology Licensees and collaborators. We have not generated any revenues from commercial sales of our own products. If we fail to complete the development of our product candidates in a timely manner or obtain regulatory approval and adequate labeling, our ability to generate future revenues will be materially compromised.

Table of Contents

We license our NAV Technology Platform and other intellectual property rights to other biotechnology and pharmaceutical companies, including collaborators for the joint development and commercialization of our 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 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 us under our 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.

Future revenues under our license and collaboration arrangements are dependent on the successful development and commercialization of licensed products, which is uncertain, and revenues may fluctuate significantly from period to period. Additionally, we may never receive consideration under our license or collaboration agreements that is contemplated on optional goods and services, development and sales-based milestones, royalties on sales of licensed products or sublicense fees, given the contingent nature of these payments. Our revenues are concentrated among a low number of licensees and collaborators and the arrangements are terminable at the option of the counterparty. The termination of our license and collaborations arrangements may materially impact the amount of revenue we recognize in future periods. Please refer to Note 16, “Segment and Geographical Information” to the accompanying audited consolidated financial statements for a description of segment and geographical information regarding our revenues.

Zolgensma and Itvisma Royalties

Royalty revenue to date consists primarily of royalties on net sales of Zolgensma and Itvisma, which are marketed by Novartis Gene Therapies, Inc. (Novartis Gene Therapies), a wholly owned subsidiary of Novartis AG (Novartis), for the treatment of spinal muscular atrophy (SMA). Zolgensma and Itvisma are licensed products under our license agreement with Novartis Gene Therapies for the development and commercialization of treatments for SMA using the NAV Technology Platform.

Operating Expenses

Our operating expenses consist primarily of cost of license and royalty revenues, research and development expenses and general and administrative expenses. Personnel costs including salaries, wages, benefits, bonuses and stock-based compensation expense, comprise a significant component of research and development and general and administrative expenses. We allocate indirect expenses associated with our facilities, information technology costs, depreciation and other overhead costs between research and development and general and administrative categories based on employee headcount and the nature of work performed by each employee or using other reasonable allocation methodologies.

Cost of License and Royalty Revenues

Our cost of license and royalty revenues consists primarily of upstream fees due to our licensors as a result of revenue generated from the licensing of our NAV Technology Platform and other intellectual property rights, including sublicense fees and royalties on net sales of licensed products. Sublicense fees are based on a percentage of license fees received by us from licensees and are recognized in the period that the underlying license revenue is recognized. Royalties are based on a percentage of net sales of licensed products by licensees and are recognized in the period that the underlying sales occur. Future costs of revenues are uncertain due to the nature of our license agreements and significant fluctuations in cost of license and royalty revenues may occur from period to period.

Research and Development Expense

Our research and development expenses consist primarily of:

•

salaries, wages and personnel-related costs, including benefits, travel and stock-based compensation, for our scientific personnel and others performing research and development activities;

•

costs related to executing preclinical studies and clinical trials;

•

costs related to acquiring, developing and manufacturing materials for preclinical studies and clinical trials;

Table of Contents

•

fees paid to consultants and other third parties who support our product candidate development;

•

other costs in seeking regulatory approval of our product candidates; and

•

direct costs and allocated costs related to laboratories and facilities, depreciation expense, information technology and other overhead.

Up-front fees incurred in obtaining technology licenses for research and development activities, as well as associated milestone payments, are charged to research and development expense as incurred if the technology licensed has no alternative future use.

We expect to continue to incur significant research and development expenses for the foreseeable future as we continue the development of our product candidates and engage in early research and development for prospective product candidates and new technologies. The following table summarizes our research and development expenses incurred during the years ended December 31, 2025 and 2024 (in thousands):

Years Ended December 31,

Direct Expenses

Unallocated Expenses

Direct expenses related to the development of ABBV-RGX-314 for the years ended December 31, 2025 and 2024 include net cost reimbursement from AbbVie under our eye care collaboration of $60.2 million and $78.3 million, respectively, which were recorded as a reduction of research and development expenses. In addition to reimbursement of direct development expenses, net cost reimbursement from AbbVie includes reimbursement of personnel and overhead costs attributable to the development of ABBV-RGX-314, the underlying costs of which are reported as unallocated expenses in the table above. We typically utilize our employee and infrastructure resources across our development programs. As a result, we generally do not allocate personnel and other internal costs, such as facilities and other overhead costs, to specific product candidates or development programs.

Platform and early research reported in the table above includes direct costs not identifiable with a specific lead product candidate, including costs associated with our research and development platform used across programs, manufacturing support, process and analytical development, early research and development for prospective product candidates and new technologies, and other costs in support of research and development activities.

General and Administrative Expense

Our general and administrative expenses consist primarily of salaries, wages and personnel-related costs, including benefits, travel and stock-based compensation, for employees performing functions other than research and development. This includes certain personnel in executive, commercial, corporate development, finance, legal, human resources, information technology, facilities and administrative support functions. Additionally, general and administrative expenses include costs associated with accounting, legal, commercial and other corporate advisory services, obtaining and maintaining patents, insurance, information systems and other general corporate activities, as well as facility-related costs and other corporate overhead costs not otherwise allocated to research and development expense. We expect that our general and administrative expenses will increase as we continue to develop, and potentially commercialize, our product candidates. Specifically, we expect general and administrative costs associated with the potential commercialization of our product candidates to increase in future periods as we and our commercial partners prepare for and carry out product launch efforts, in particular for the potential commercialization of our RGX-202 and ABBV-RGX-314 product candidates.

Table of Contents

Other Income (Expense)

Interest Income from Licensing

In accordance with our revenue recognition policy, interest income from licensing consists of imputed interest recognized from significant financing components identified in our license agreements with NAV Technology Licensees.

Investment Income

Investment income consists of interest income earned and gains and losses realized from our cash equivalents, marketable securities and non-marketable equity securities. Cash equivalents are comprised of money market mutual funds and highly liquid debt securities with original maturities of 90 days or less at acquisition. Marketable securities are comprised of available-for-sale debt securities.

Interest Expense

Interest expense is primarily associated with our royalty monetization liabilities, including our December 2020 royalty purchase agreement (2020 Royalty Purchase Agreement) and May 2025 loan agreement (2025 Royalty Bond) with HCR. For further information regarding our royalty monetization liabilities and associated interest expense, please refer to Note 7, “Royalty Monetization Liabilities” to the accompanying audited consolidated financial statements.

Critical Accounting Policies and Estimates

This Management’s Discussion and Analysis of Financial Condition and Results of Operations is based on our consolidated financial statements, which we have prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The preparation of financial statements in conformity with GAAP requires us 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. We base our estimates on historical experience and on various other factors that we believe 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 under different assumptions or conditions.

Our significant accounting policies are fully described in Note 2, “Summary of Significant Accounting Policies” to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. We believe the following accounting policies are critical to the process of making significant judgments and estimates in the preparation of our financial statements and understanding and evaluating our reported financial results.

Revenue Recognition

We recognize revenue in accordance with Accounting Standards Codification (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.

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

We evaluate our 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, we evaluate the credit profile of the customer and prevailing market interest rates and select an interest rate in which we believe would be charged to the customer in a separate financing arrangement over a similar financing term.

Table of Contents

We evaluate our 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, we identify the various transactions with the counterparty and determine 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 606, we apply the five-step model as described in our revenue recognition policies. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied in accordance with our accounting policies for collaborative arrangements.

Our 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, we determine 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 us. For each license granted, we evaluate 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 our license and collaboration agreements may include (i) the delivery of intellectual property licenses, (ii) development and manufacturing services to be performed by us 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, manufacturing or other services, we evaluate whether the license is distinct from the services, which requires judgment. In making this determination, we consider, 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, we consider 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.

We evaluate the transaction price of our license and collaboration agreements at contract inception and at each reporting date. The transaction price includes the fixed consideration payable to us 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 to us over the contract term and fixed fees for development, manufacturing and other services. Variable consideration under the agreements may include development and sales-based milestone payments, payments for development, manufacturing and other services, 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 our 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 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, manufacturing and other services is recognized as service revenue as we perform the services. 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

Table of Contents

best reflects the pattern of satisfaction of the performance obligations. At each reporting date, we re-evaluate the measure of progress and adjust service revenue on a cumulative catch-up basis to reflect our best estimate of the services performed to date versus the total services to be performed under the arrangement.

Development milestone payments are payable to us upon the achievement of specified development milestones. At the inception of each license agreement that contains development milestone payments, we evaluate whether the milestones are probable of achievement and estimate 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 our control or the control of 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, we re-evaluate the probability of achievement of each outstanding development milestone and, if necessary, adjust 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 and Itvisma, which are licensed products under our license agreement with Novartis Gene Therapies for the development and commercialization of treatments for SMA. We recognize royalty revenue from net sales of Zolgensma and Itvisma in the period in which the underlying products are sold by Novartis Gene Therapies, which in certain cases may require us to estimate royalty revenue for periods of net sales which have not yet been reported to us. 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.

We receive 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 our 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 our 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 us 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 us prior to the delivery of underlying performance obligations are deferred and recognized as revenue upon the satisfaction of the performance obligations. 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.

Collaborative Arrangements

We evaluate our agreements with collaboration partners to determine whether they are within the scope of ASC 808. Such arrangements are within the scope of ASC 808 if they involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This evaluation is performed throughout the life of the arrangement based on any changes in the roles and responsibilities of the parties under the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, we identify the various transactions with the counterparty and determine 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 606, we apply the five-step model as described in our revenue recognition policies. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied.

For additional information regarding our collaborative arrangements, including our collaborations with AbbVie and Nippon Shinyaku, refer to Note 10, “License and Collaboration Agreements” to the accompanying audited consolidated financial statements.

Table of Contents

Accrued Research and Development Expenses

We estimate our accrued research and development expenses as of each balance sheet date. This process involves reviewing contracts and purchase orders with service providers, identifying services that have been performed on our behalf and estimating the level of service performed, the expected remaining period of performance and the associated expenses incurred for the service when we have not yet been invoiced or otherwise notified of actual cost. Depending on the timing of payments to the service providers and the estimated expenses incurred, we may record net prepaid or accrued research and development expenses relating to these costs.

Examples of estimated accrued research and development expenses include fees paid to:

•

Contract research organizations (CROs) and other vendors in connection with preclinical development and clinical studies;

•

Contract manufacturing organizations (CMOs) and other vendors related to process development and manufacturing of materials for use in preclinical development and clinical studies; and

•

service providers for professional service fees such as consulting and other research and development related services.

Our understanding of the status and timing of services performed relative to the actual status and timing may vary and may result in us reporting changes in estimates in any particular period. To date, there have been no material differences from our estimates to the amount actually incurred.

Stock-based Compensation

We account for our stock-based compensation awards in accordance with ASC 718, Compensation—Stock Compensation (ASC 718). ASC 718 requires all stock-based awards to employees and nonemployees to be recognized as expense based on the grant date fair value of the awards. Our stock-based awards include stock options and restricted stock units granted to employees and nonemployees and shares issued to employees under our employee stock purchase plan.

Our stock-based awards may be subject to either service or performance-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the estimated grant date fair value over the requisite service period of the award, which is generally the vesting term. Compensation expense related to awards with performance-based vesting conditions is recognized based on the estimated grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable.

We have elected to not estimate forfeitures of stock-based awards and account for forfeitures as they occur.

We estimate the fair value of our stock option awards using the Black-Scholes option-pricing model, which requires the input of subjective assumptions, including (i) the fair value of the underlying common stock, (ii) the expected stock price volatility, (iii) the expected term of the award, (iv) the risk-free interest rate and (v) expected dividends. The fair value of our common stock, as used as an input to determine the fair value of our stock option awards, is based on the closing price of our common stock on the date of the grant. We estimate expected stock price volatility based on the historical volatility of our common stock over a period of time commensurate with the expected term of our stock option awards. Due to the lack of sufficient historical data, we estimate the expected term of our employee stock options using the “simplified” method, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. For stock options granted to nonemployees, we use the contractual term of the award rather than expected term to estimate the fair value of the award. We estimate the risk-free interest rates for periods within the expected term of its options based on the rates of U.S. Treasury securities with maturity dates commensurate with the expected term of the associated awards. We assume a dividend yield of zero for our common stock as we have never paid dividends and do not expect to pay dividends for the foreseeable future.

We estimate the fair value of our restricted stock units based on the closing price of our common stock on the date of the grant.

Royalty Monetization Liabilities

Net proceeds received under our royalty monetization agreements with HCR are recorded as liabilities and accounted for as debt. The liabilities are amortized over the estimated life of the arrangements using the effective interest method. For arrangements in which there is no stated interest rate, the total amount of royalty and other payments paid to HCR under the arrangement, less the net proceeds we received from HCR, is recorded as interest expense over the life of the arrangement. We estimate the effective interest rates of our royalty monetization liabilities based on our estimate of total payments to be paid to HCR under the arrangement. We reassess these estimates at each reporting date and adjust the effective interest rate and amortization of the liabilities on a prospective basis as necessary.

Table of Contents

Income Taxes

We account for income taxes in accordance with ASC 740, Income Taxes, which provides for deferred taxes using an asset and liability approach. We recognize deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

As of December 31, 2025, we had federal net operating loss (NOL) carryforwards of $754.4 million, U.S. state NOL carryforwards of $394.9 million and federal and state research and development tax credit carryforwards of $95.1 million which may be available to offset future income tax liabilities. Our federal NOL carryforwards and a portion of our state NOL carryforwards as of December 31, 2025 may be carried forward indefinitely. The remaining portion of our state NOL carryforwards and our federal and state credit carryforwards as of December 31, 2025 expire at various dates between 2029 and 2045.

We have evaluated the positive and negative evidence bearing upon the realizability of our deferred tax assets, including our NOL and credit carryforwards. Based on our history of operating losses, and other relevant facts and circumstances, we concluded that it is more likely than not that the benefit of our deferred tax assets will not be realized. Accordingly, we provided a full valuation allowance for our net deferred tax assets as of December 31, 2025 and 2024.

Results of Operations

Our consolidated results of operations were as follows (in thousands):

Years Ended December 31,

Revenues

Operating Expenses

Credit losses (recoveries) — (5,000 ) 5,000

Impairment of long-lived assets — 2,101 (2,101 )

Other Income (Expense)

Interest income from licensing 83 174 (91 )

Comparison of the Years Ended December 31, 2025 and 2024

License and Royalty Revenue. License and royalty revenue increased by $74.3 million, from $82.0 million for the year ended December 31, 2024 to $156.3 million for the year ended December 31, 2025. The increase was primarily attributable to $72.9 million of up-front license revenue recognized under our collaboration with Nippon Shinyaku in 2025, as well as an increase in royalty revenues for Zolgensma and Itvisma. Total royalty revenues for Zolgensma and Itvisma increased by $1.7 million, from $81.5 million in 2024 to $83.2 million in 2025. Novartis reported combined Zolgensma and Itvisma sales of $1.23 billion in 2025, as compared to $1.21 billion in 2024. As reported by Novartis, the increase reflects continued strong demand for Zolgensma in the incident SMA population, and was partially driven by the approval and launch of Itvisma in the fourth quarter of 2025. Zolgensma and Itvisma royalty revenues for 2025 were $82.5 million and $0.6 million, respectively. Itvisma royalties for 2025 reflect a product launch in the late fourth quarter of 2025.

Table of Contents

Service Revenue. Service revenue increased by $12.8 million, from $1.4 million for the year ended December 31, 2024 to $14.2 million for the year ended December 31, 2025. The increase was primarily attributable to $11.8 million of service revenue recognized under our collaboration with Nippon Shinyaku in 2025, largely driven by the performance of RGX-121 development and manufacturing services.

Cost of License and Royalty Revenues. Cost of license and royalty revenues decreased by $13.3 million, from $33.6 million for the year ended December 31, 2024 to $20.3 million for the year ended December 31, 2025. The decrease was largely driven by a reduction in upstream Zolgensma royalties payable to licensors for net sales in certain territories outside the United States.

Research and Development Expense. Research and development expenses increased by $19.8 million, from $208.5 million for the year ended December 31, 2024 to $228.3 million for the year ended December 31, 2025. The increase was primarily attributable to the following:

•

an increase of $8.1 million in manufacturing-related expenses and other clinical supply costs for our lead product candidates, largely driven by manufacturing costs for ABBV-RGX-314, RGX-202 and RGX-121;

•

an increase of $5.8 million in personnel-related costs due to increased headcount of development personnel, net of a $2.0 million decrease in stock-based compensation expense; and

•

an increase of $5.7 million in costs associated with clinical trials and regulatory activities, largely driven by clinical trial expenses for RGX-202 pivotal trials.

General and Administrative Expense. General and administrative expenses increased by $6.2 million, from $76.6 million for the year ended December 31, 2024 to $82.9 million for the year ended December 31, 2025. The increase was largely driven by professional services, consulting and other corporate advisory services.

Credit Losses (Recoveries). We recognized credit recoveries of $5.0 million during the year ended December 31, 2024 upon the full collection of amounts due under our settlement agreement with Abeona Therapeutics Inc. (Abeona), for which we had previously recorded an allowance for credit losses. For further information regarding the settlement agreement with Abeona and the allowance for credit losses, please refer to Note 10, “License and Collaboration Agreements—Settlement Agreement with Abeona Therapeutics” to the accompanying audited consolidated financial statements. We did not record any credit losses or recoveries during the year ended December 31, 2025.

Investment Income. Investment income decreased by $6.5 million, from $18.7 million for the year ended December 31, 2024 to $12.2 million for the year ended December 31, 2025. The decrease was primarily attributable to the achievement of milestones associated with the July 2021 acquisition of our non-marketable equity securities of Corlieve Therapeutics SAS (Corlieve) by uniQure N.V. (uniQure). We recognized realized gains of $6.6 million upon the achievement of such milestones during 2024. No such milestones were achieved during 2025 and no gains were realized during the period.

Interest Expense. Interest expense increased by $32.3 million, from $12.7 million for the year ended December 31, 2024 to $45.0 million for the year ended December 31, 2025. The increase was primarily attributable to interest expense under our royalty monetization liabilities, driven largely by an increase in forecasted Zolgensma and Itvisma royalties expected to be paid to HCR under the 2020 Royalty Purchase Agreement and interest expense incurred to date under the 2025 Royalty Bond issued in May 2025.

Liquidity and Capital Resources

Sources of Liquidity

As of December 31, 2025, we had cash, cash equivalents and marketable securities of $240.9 million, which were primarily derived from the royalty monetization in May 2025, the up-front payment received under the Nippon Shinyaku Collaboration Agreement in March 2025 and the sale of our common stock and pre-funded warrants in March 2024, each as described below:

•

In May 2025, we entered into a loan agreement with HCR pursuant to which HCR will provide us with an aggregate limited recourse loan of up to $250.0 million (the 2025 Royalty Bond). The 2025 Royalty Bond is disbursable to us 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 sales threshold prior to December 31, 2026, and $50.0 million available to be funded if both parties exercise an option in 2027. Proceeds received from the initial funding tranche of the 2025 Royalty Bond in May 2025, net of discounts and transaction costs, were $144.5 million. The 2025 Royalty Bond matures in 2035, subject to potential extension, and 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%. Prior to the maturity date, interest and principal under the 2025 Royalty Bond will be paid quarterly to HCR solely using proceeds

Table of Contents

received, net of upstream obligations to licensors, from certain specified royalties, milestone payments, license fees and other consideration payable to us under the Zolgensma and Itvisma license with Novartis Gene Therapies, the Nippon Shinyaku Collaboration Agreement and certain other NAV Technology Platform license agreements.

•

In January 2025, we entered into the Nippon Shinyaku Collaboration Agreement for the development and commercialization of RGX-121 and RGX-111 in the United States and certain countries in Asia. Pursuant the Nippon Shinyaku Collaboration Agreement, we received an up-front payment of $110.0 million following the effective date of the agreement in March 2025 and are eligible to receive up to $700.0 million upon the achievement of specified development and sales-based milestones. We are also eligible to receive double-digit royalties on net sales of RGX-121 and RGX-111 by Nippon Shinyaku, subject to specified offsets and reductions.

•

In March 2024, we completed a public offering of 4,565,260 shares of our common stock at a price of $23.00 per share and 1,521,740 pre-funded warrants to purchase shares of our 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 from the offering were $131.1 million, net of underwriting discounts and commissions and offering expenses.

At-the-Market Offering Program

In December 2024, we entered into a Sales Agreement with Leerink Partners LLC (Leerink) pursuant to which we may offer and sell shares of our common stock having an aggregate offering price of up to $150.0 million from time to time through Leerink, acting as our sales agent (the Leerink ATM Program). As of December 31, 2025, no shares of common stock had been sold under the Leerink ATM Program. We intend to use proceeds obtained from the sale of shares under the Leerink ATM Program, if any, for general corporate purposes.

Future Liquidity and Ability to Continue as a Going Concern

We intend to devote the majority of our current capital to preclinical research, clinical development, seeking regulatory approval of our product candidates and, if approved, commercialization of our product candidates, as well as additional capital expenditures needed to support these activities. Because of the numerous risks and uncertainties associated with the development and commercialization of gene therapy product candidates, we are unable to estimate the total amount of operating expenditures and capital outlays necessary to complete the development and commercialization of our product candidates.

We expect that our cash, cash equivalents and marketable securities of $240.9 million as of December 31, 2025 will enable us to fund our operating expenses and capital expenditure requirements, and are sufficient to meet our financial commitments and obligations into early 2027. This estimate is based on our current operating plan, and excludes the potential effects of any future financings or material milestone payments that may be received under our licensing and collaboration arrangements. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our capital resources sooner than expected. These conditions raise substantial doubt about our ability to continue as a going concern within 12 months from the issuance date of our consolidated financial statements for the year ended December 31, 2025, which accompany this Annual Report on Form 10-K. Our ability to continue as a going concern will depend heavily on the successful development, approval and commercialization of our product candidates and our ability to raise additional capital to fund operations. If we are unable to raise capital sufficient to meet our working capital needs in the future, we may be forced to delay expenditures, reduce the scope of our development activities or make other changes to our operating plans.

Cash Flows

Our consolidated cash flows were as follows (in thousands):

Years Ended December 31,

Net cash used in operating activities $ (123,963 ) $ (173,125 )

Net cash provided by (used in) investing activities (15,868 ) 103,446

Net cash provided by financing activities 116,771 92,683

Table of Contents

Cash Flows from Operating Activities

Our net cash used in operating activities for the year ended December 31, 2025 decreased by $49.2 million from the year ended December 31, 2024, largely as a result of the $110.0 million up-front fee received from Nippon Shinyaku in March 2025, partially offset by an increase in operating expenses in 2025. We expect to continue to incur regular net cash outflows from operations for the foreseeable future as we continue the development and advancement of our product candidates and other research programs.

For the year ended December 31, 2025, our net cash used in operating activities of $124.0 million consisted of a net loss of $193.9 million, offset by adjustments for non-cash items of $58.1 million and favorable changes in operating assets and liabilities of $11.8 million. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $34.6 million, depreciation and amortization expense of $15.6 million, and non-cash interest expense of $12.9 million. The changes in operating assets and liabilities include an increase in deferred revenue of $29.3 million, which was primarily attributable to the deferred portion of the $110.0 million up-front payment received under our collaboration with Nippon Shinyaku in the first quarter of 2025. The favorable changes in operating assets and liabilities were partially offset by an increase in accounts receivable of $7.7 million, which was driven largely by reimbursable costs due from Nippon Shinyaku under our collaboration for RGX-121 and RGX-111 and royalties receivable on net sales of Zolgensma and Itvisma. Other changes in operating working capital occurred in the normal course of business.

For the year ended December 31, 2024, our net cash used in operating activities of $173.1 million consisted of a net loss of $227.1 million, offset by adjustments for non-cash items of $48.4 million and favorable changes in operating assets and liabilities of $5.5 million. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $38.5 million and depreciation and amortization expense of $16.2 million, partially offset by realized gains on investments, credit recoveries and the accretion of discounts on marketable debt securities during the period. The changes in operating assets and liabilities include a decrease in total accounts receivable of $9.7 million, which was driven largely by a decrease in Zolgensma royalties receivable and the full collection of amounts due under our settlement agreement with Abeona, for which we recorded a $5.0 million credit recovery during the period. The changes in operating assets and liabilities also include a total decrease in prepaid expenses and other current assets of $12.0 million, which was driven primarily by decreases in prepaid fees to CROs and net cost reimbursement due from AbbVie under our ABBV-RGX-314 collaboration. The favorable changes in operating assets and liabilities were partially offset by a decrease in accrued expenses and other current liabilities of $12.1 million, which was driven primarily by decreases in accruals for external research and development services and sublicense and royalties due to licensors. Other changes in operating working capital occurred in the normal course of business.

Cash Flows from Investing Activities

For the year ended December 31, 2025, our net cash used in investing activities primarily consisted of $332.6 million used to purchase marketable debt securities and $2.4 million used to purchase property and equipment, partially offset by $319.1 million in maturities of marketable debt securities.

For the year ended December 31, 2024, our net cash provided by investing activities consisted of $290.2 million in maturities of marketable debt securities and $5.8 million in proceeds received from uniQure upon the achievement of milestones associated with their acquisition of Corlieve, offset by $190.1 million used to purchase marketable debt securities and $2.4 million used to purchase property and equipment.

Cash Flows from Financing Activities

For the year ended December 31, 2025, our net cash provided by financing activities primarily consisted of $144.5 million in proceeds received from the issuance of the 2025 Royalty Bond and warrants to HCR in May 2025, net of discounts and transaction costs paid during the period, and was partially offset by $28.1 million of royalties paid, net of interest, under our royalty monetization liabilities.

For the year ended December 31, 2024, our net cash provided by financing activities primarily consisted of $131.1 million in proceeds received from the public offering of common stock and pre-funded warrants completed in March 2024, net of underwriting discounts and commissions and other offering expenses paid during the period, and $2.7 million in proceeds received from the exercise of stock options and issuance of common stock under our employee stock purchase plan. Our net cash provided by financing activities was partially offset by $39.9 million of royalties paid, net of interest, under our royalty monetization liabilities.

Table of Contents

Additional Capital Requirements

Our material capital requirements from known contractual and other obligations primarily relate to our vendor service contracts and purchase commitments, in-license agreements, operating lease agreements and royalty monetization agreements.

In the normal course of business, we enter into services agreements with CROs, CMOs and other third parties. Generally, these agreements provide for termination upon notice, with specified amounts due upon termination based on the timing of termination and the terms of the agreement. The amounts and timing of payments under these agreements are uncertain and contingent upon the initiation and completion of the services to be provided.

Obligations to licensors under our in-license agreements may include sublicense fees, milestones fees, royalties and reimbursement of patent maintenance costs. Sublicense fees are payable to licensors when we sublicense underlying intellectual property to third parties; the fees are based on a percentage of the license fees we receive from sublicensees. Milestone fees are payable to licensors upon our future achievement of certain development, regulatory and commercial milestones. Royalties are payable to licensors based on a percentage of net sales of licensed products. Patent maintenance costs are payable to licensors as reimbursement for the cost of maintaining licensed patents. Due to the contingent nature of the payments, the amounts and timing of payments to licensors under our in-license agreements are uncertain and may fluctuate significantly from period to period.

In March 2022, we entered into a letter agreement (the Penn Letter Agreement) with The Trustees of the University of Pennsylvania (Penn) to buy out our obligation to pay sublicense fees under our license agreement with Penn (the Penn License). Pursuant to the letter agreement, we are obligated to pay Penn a total of $12.0 million to satisfy any other past or future obligations to pay sublicense fees under the Penn License, which is payable in four equal annual installments of $3.0 million beginning in March 2023. We are no longer obligated to pay sublicense fees to Penn under the license agreement, but remain obligated to pay Penn royalties on net sales of licensed products, milestone fees and reimbursement of certain patent maintenance costs in accordance with the Penn License. As of December 31, 2025, we had $3.0 million remaining payable to Penn under the Penn Letter Agreement, in addition to other amounts payable under the Penn License.

We have entered into a number of long-term operating leases for office, laboratory and manufacturing space in Rockville, Maryland, Washington, D.C. and New York, New York, as well as a number of laboratory and other equipment leases. As of December 31, 2025, we had recorded total lease liabilities of $73.5 million under our operating leases. Please refer to Note 6, “Leases” to the accompanying consolidated financial statements for further information regarding our lease commitments.

Under the terms of the 2020 Royalty Purchase Agreement, our Zolgensma and Itvisma royalties, less amounts payable by us to certain licensors, are payable to HCR up to a specified capped amount. As of December 31, 2025, the total amount of future royalties payable to HCR under the 2020 Royalty Purchase Agreement was $35.5 million. We have no obligation to repay any amounts to HCR if total future Zolgensma and Itvisma royalty payments from Novartis are not sufficient to repay these amounts. Upon full repayment of our obligation under the 2020 Royalty Purchase Agreement, future Zolgensma and Itvisma royalties shall be included in the royalty interest payable to HCR under the 2025 Royalty Bond.

Under the terms of the 2025 Royalty Bond, interest and principal shall be paid quarterly to HCR solely using proceeds received, net of upstream obligations to licensors, from certain specified royalties, milestone payments, license fees and other consideration payable to us under the Zolgensma and Itvisma license with Novartis Gene Therapies, the Nippon Shinyaku Collaboration Agreement and certain other NAV Technology Platform license agreements. If the proceeds received under the specified license agreements are insufficient to pay the quarterly interest due to HCR, 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. Upon maturity, the outstanding principal and interest shall be due and payable to HCR. Other than through the payment of proceeds received under the specified license agreements, the 2025 Royalty Bond may not be prepaid prior to maturity. The 2025 Royalty Bond is collateralized by a security interest and lien on the specified royalties and license fees. As of December 31, 2025, the principal balance outstanding under the 2025 Royalty Bond was $163.4 million.

Future Funding Requirements

We have incurred cumulative losses since our inception and had an accumulated deficit of $1.13 billion as of December 31, 2025. Our transition to recurring profitability is dependent upon achieving a level of revenues adequate to support our cost structure, which depends heavily on the successful development, approval and commercialization of our product candidates. We do not expect to achieve such revenues, and expect to continue to incur losses, for at least the next several years. We expect to continue to incur significant research and development and general and administrative expenses for the foreseeable future as we continue the development of, and seek regulatory approval for, our product candidates. Subject to obtaining regulatory approval for our product

Table of Contents

candidates, we expect to incur significant commercialization expenses for product sales, marketing, manufacturing and distribution. Additionally, we expect to continue to incur capital expenditures associated with building out additional laboratory and manufacturing capacity to further support the development of our product candidates and potential commercialization efforts. As a result, we will need significant additional capital to fund our operations, which we may obtain through one or more equity offerings, debt financings or other third-party funding, including potential strategic alliances and licensing or collaboration arrangements.

Our future capital requirements will depend on many factors, including:

•

the timing of enrollment, commencement and completion of our clinical trials;

•

the results of our clinical trials;

•

the results of our preclinical studies for our product candidates and any subsequent clinical trials;

•

the scope, progress, results and costs of drug discovery, laboratory testing, preclinical development and clinical trials for our product candidates;

•

delays or costs due to a clinical hold or CRL, including BLA resubmission;

•

whether we receive a PRV and are able to monetize or otherwise realize any potential value associated with such a voucher;

•

the value of any PRV received diminishes including any decreases due to demand for these vouchers;

•

the costs associated with building out additional laboratory and manufacturing capacity;

•

the costs, timing and outcome of regulatory review of our product candidates;

•

the impact of any government-imposed tariffs on cost of goods and services, particularly related to partnered product candidates;

•

the costs of future product sales, medical affairs, marketing, manufacturing and distribution activities for any of our product candidates for which we receive marketing approval;

•

revenue, if any, received from commercial sales of our products, should any of our product candidates receive marketing approval;

•

revenue received from commercial sales of Zolgensma and Itvisma, and the timing and amount of Zolgensma and Itvisma royalties paid to HCR under our royalty monetization agreements;

•

revenue received from other commercial sales of our licensees’ and collaborators’ products, should any of their product candidates receive marketing approval, other revenue received under our licensing agreements and collaborations, and the timing and amount of any such revenues payable to HCR under our royalty monetization agreements;

•

the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights including against Sarepta and defending any intellectual property-related claims;

•

our current licensing agreements or collaborations remaining in effect, including the AbbVie Collaboration Agreement relating to ABBV-RGX-314 and the Nippon Shinyaku Collaboration Agreement relating to RGX-121 and RGX-111, and our ability to timely achieve any milestones set forth in such agreements or collaborations;

•

our ability to establish and maintain additional licensing agreements or collaborations on favorable terms, if at all; and

•

the extent to which we acquire or in-license other product candidates and technologies.

The issuance of additional securities, whether equity or debt, by us, including through our at-the-market program, or the possibility of such issuance, may cause the market price of our common stock to decline. Adequate additional financing may not be available to us on acceptable terms, or at all. We also could be required to seek funds through arrangements with partners or otherwise that may require us to relinquish rights to our intellectual property, our product candidates or otherwise agree to terms unfavorable to us.

Off-Balance Sheet Arrangements

We did not have any off-balance sheet arrangements during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined in the rules and regulations of the SEC.

Table of Contents

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Interest Rate Risk

We are exposed to market risk related to changes in interest rates. Our primary exposure to interest rate risk results from the cash equivalents and marketable securities in our investment portfolio. Our primary objectives in managing our investment portfolio are to preserve principal, maintain proper liquidity to meet operating needs and maximize yields. At any time, significant changes in interest rates can affect the fair value of the investment portfolio and its interest earnings. Currently, we do not hedge these interest rate exposures. As of December 31, 2025 and 2024, we had cash, cash equivalents and marketable securities of $240.9 million and $244.9 million, respectively. Our cash equivalents and marketable securities as of December 31, 2025 consisted of money market mutual funds, U.S. government and agency securities and corporate bonds. If market interest rates were to increase immediately and uniformly by 100 basis points, or one percentage point, from levels at December 31, 2025, we estimate that the increase would have resulted in a hypothetical decline of $0.8 million in the net fair value of our interest-sensitive securities as of December 31, 2025. A similar increase in market interest rates as of December 31, 2024 would have resulted in an estimated hypothetical decline of $0.8 million in the net fair value of our interest-sensitive securities as of December 31, 2024.

Foreign Currency Exchange Rate Risk

We are exposed to foreign currency exchange rate risk as a result of entering into transactions denominated in currencies other than U.S. dollars, primarily including euros and British pounds. All foreign currency transactions settle on the applicable spot exchange basis at the time such payments are made. Accordingly, an adverse movement in foreign exchange rates between the U.S. dollar and the aforementioned currencies could impact our results of operations and cash flows. Currently, we do not hedge these foreign currency exchange rate exposures. The effect of a hypothetical 10% change in foreign currency exchange rates applicable to our business would not materially harm our business, financial condition or results of operations.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

The financial statements and related financial statement schedules required to be filed are listed in the Index to Consolidated Financial Statements and are incorporated herein.

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE

None.

ITEM 9A. CONTROLS AND PROCEDURES

Conclusion Regarding the Effectiveness of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and our Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2025. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the Exchange Act), means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure.

Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that, as of December 31, 2025, our disclosure controls and procedures were effective at a reasonable assurance level.

Table of Contents

Management’s Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rules 13a-15(f) and 15d-15(f) promulgated under the Exchange Act as a process designed by, or under the supervision of, our principal executive and principal financial officers and effected by our Board of Directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that:

•

pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of our assets;

•

provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that our receipts and expenditures are being made only in accordance with authorizations of our management and directors; and

•

provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on the financial statements.

Under the supervision and with the participation of management, including our principal executive and financial officers, we assessed our internal control over financial reporting as of December 31, 2025, based on criteria for effective internal control over financial reporting established in Internal Control — Integrated Framework (2013), issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our management’s opinion, we have maintained effective internal control over financial reporting as of December 31, 2025, based on criteria established in the COSO 2013 framework.

As a non-accelerated filer as defined in Rule 12b-2 under the Exchange Act, our independent registered public accounting firm is not required to issue an attestation report on our internal control over financial reporting and no such report is included in this Annual Report on Form 10-K.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the quarter ended December 31, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Limitations on the Effectiveness of Controls

Control systems, no matter how well conceived and operated, are designed to provide a reasonable, but not an absolute, level of assurance that the objectives of the control system are met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, have been detected. Because of the inherent limitations in any control system, misstatements due to error or fraud may occur and not be detected.

Table of Contents

ITEM 9B. OTHER INFORMATION

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 December 31, 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)

(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 December 31, 2025, none of our directors or Section 16 reporting officersadopted 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).

Amendment to Bylaws

On March 4, 2026, the Board of Directors amended and restated the Company’s bylaws (as so amended and restated, the Amended and Restated Bylaws), effective immediately. The Amended and Restated Bylaws modify the Company’s prior bylaws to (i) revise the procedures and disclosure requirements governing stockholder nominations of director candidates, including to require compliance with Rule 14a-19 under the Exchange Act, (ii) update procedures and rules relating to stockholder meetings, (iii) make certain changes to conform to recent amendments to the Delaware General Corporation Law and (iv) make certain other ministerial and conforming changes. The foregoing summary is not, nor is it intended to be, a complete or comprehensive summary of all of the changes reflected in Amended and Restated Bylaws. The foregoing summary is qualified in its entirety by the full text of the Amended and Restated Bylaws, a copy of which is filed as Exhibit 3.2 hereto and incorporated herein by reference.

ITEM 9C. DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS

Not applicable.

Table of Contents

PART III

ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

The information required by this item will be included in our proxy statement for the 2026 annual meeting of stockholders to be filed with the SEC within 120 days of the fiscal year ended December 31, 2025 (2026 Proxy Statement) under the headings “Election of Directors,” “Information about our Executive Officers” and “Corporate Governance” and is incorporated herein by reference.

We maintain a code of business conduct and ethics that qualifies as a “code of ethics” under Item 406 of the SEC’s Regulation S-K and applies to each of our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer and controller, or persons performing similar functions. The code of business conduct and ethics is available in the corporate governance section of our corporate website at www.regenxbio.com. Any amendment or waiver of the “code of ethics” provisions of the code of business conduct and ethics for an executive officer or director may be granted only by our Board of Directors or a committee thereof and must be timely disclosed as required by applicable law. We intend to satisfy the disclosure requirements regarding any such amendment or waiver applicable to any principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, in a current report filed with the SEC on Form 8-K or on our corporate website at www.regenxbio.com.

ITEM 11. EXECUTIVE COMPENSATION

The information required by this item will be included in our 2026 Proxy Statement under the headings “Corporate Governance,” “Director Compensation” and “Executive Compensation” and is incorporated herein by reference.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS

The information required by this item will be included in our 2026 Proxy Statement under the headings “Executive Compensation” and “Security Ownership of Certain Beneficial Owners and Management” and is incorporated herein by reference.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE

The information required by this item will be included in our 2026 Proxy Statement under the headings “Certain Relationships and Related Party Transactions” and “Corporate Governance” and is incorporated herein by reference.

ITEM 14. PRINCIPAL ACCOUNTANT FEES AND SERVICES

The information required by this item will be included in our 2026 Proxy Statement under the heading “Ratification of Appointment of Independent Registered Public Accounting Firm” and is incorporated herein by reference.

Table of Contents

PART IV

ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES

(a)

The following documents are filed as part of, or incorporated by reference into, this Annual Report on Form 10-K:

Financial Statements. See Index to Consolidated Financial Statements under Item 8 of this Annual Report on Form 10-K.

Financial Statement Schedules. All schedules have been omitted because the information required to be presented in them is not applicable or is shown in the financial statements or related notes.

Exhibits. We have filed, or incorporated into this Annual Report on Form 10-K by reference, the exhibits listed on the accompanying Exhibit Index immediately following the financial statements in this Annual Report on Form 10-K.

(b)

Exhibits. See Item 15(a)(3) above.

(c)

Financial Statement Schedules. See Item 15(a)(2) above.

ITEM 16. FORM 10-K SUMMARY

Not applicable.

Table of Contents

REGENXBIO INC.

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID: 238) 94

Consolidated Financial Statements:

Consolidated Balance Sheets 96

Consolidated Statements of Operations and Comprehensive Loss 97

Consolidated Statements of Stockholders’ Equity 98

Consolidated Statements of Cash Flows 99

Notes to Consolidated Financial Statements 100

Table of Contents

Report of Independent Registered Public Accounting Firm

To the Board of Directors and Stockholders of REGENXBIO Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of REGENXBIO Inc. and its subsidiaries (the "Company") as of December 31, 2025 and 2024, and the related consolidated statements of operations and comprehensive loss, of stockholders’ equity and of cash flows for the years then ended, including the related notes (collectively referred to as the "consolidated financial statements"). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for the years then ended in conformity with accounting principles generally accepted in the United States of America.

Substantial Doubt about the Company's Ability to Continue as a Going Concern

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As discussed in Note 1 to the consolidated financial statements, the Company has incurred cumulative losses from operations since inception, an accumulated deficit of $1.13 billion and cash outflows from operating activities that raise substantial doubt about its ability to continue as a going concern. Management's plans in regard to these matters are also described in Note 1. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits of these consolidated financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Table of Contents

Revenue Recognition – Determination of the Standalone Selling Price of the RGX-121 Intellectual Property License for the United States Under the Nippon Shinyaku Collaboration Agreement

As described in Notes 2 and 10 to the consolidated financial statements, the Company’s license 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. The transaction price for each license agreement 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. In January 2025, the Company entered into a collaboration and license agreement with Nippon Shinyaku Co., Ltd. (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). Management identified the following 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. The selling prices of 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, including the addressable market, sales price per unit, discount rates and probabilities of success for each of the licensed products and territories. For the year ended December 31, 2025, the Company recognized total revenues of $84.7 million related to the Nippon Shinyaku Collaboration Agreement, of which a majority related to the RGX-121 intellectual property license for the United States.

The principal considerations for our determination that performing procedures relating to the determination of the standalone selling price of the RGX-121 intellectual property license for the United States under the Nippon Shinyaku Collaboration Agreement is a critical audit matter are (i) the significant judgment by management when determining the standalone selling price of the RGX-121 intellectual property license for the United States; (ii) a high degree of auditor judgment, subjectivity, and effort in performing procedures and evaluating management’s significant assumptions related to the addressable market, sales price per unit, discount rate and probability of success; and (iii) the audit effort involved the use of professionals with specialized skill and knowledge.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included, among others (i) reading the contractual terms of the Nippon Shinyaku Collaboration Agreement; (ii) testing management’s process for determining the standalone selling price of the RGX-121 intellectual property license for the United States; (iii) evaluating the appropriateness of the discounted cash flow model; and (iv) evaluating the reasonableness of the significant assumptions used by management related to the addressable market, sales price per unit, discount rate and probability of success. Evaluating the reasonableness of management’s assumptions related to the addressable market, sales price per unit, and the probability of success involved considering (i) the consistency with external market and industry data and (ii) whether the assumptions were consistent with evidence obtained in other areas of the audit. Professionals with specialized skill and knowledge were used to assist in evaluating (i) the appropriateness of the discounted cash flow model and (ii) the reasonableness of the discount rate assumption.

/s/ PricewaterhouseCoopers LLP

Washington, District of Columbia

March 5, 2026

We have served as the Company’s auditor since 2015.

Table of Contents

REGENXBIO INC.

CONSOLIDATED BALANCE SHEETS

(in thousands, except per share data)

As of December 31,

Assets

Current assets

Liabilities and Stockholders’ Equity

Current liabilities

Accrued expenses and other current liabilities 38,390 38,070

Commitments and contingencies (Note 8)

Stockholders’ equity

Accumulated other comprehensive loss (687 ) (741 )

Total liabilities and stockholders’ equity $ 453,032 $ 465,989

The accompanying notes are an integral part of these consolidated financial statements.

Table of Contents

REGENXBIO INC.

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

(in thousands, except per share data)

Years Ended December 31,

Revenues

Operating Expenses

Credit losses (recoveries) — (5,000 )

Impairment of long-lived assets — 2,101

Other operating expenses 179 865

Other Income (Expense)

Interest income from licensing 83 174

Other Comprehensive Income

Unrealized gain on available-for-sale securities, net 54 3,688

Total other comprehensive income 54 3,688

Net loss per share, basic and diluted $ (3.76 ) $ (4.59 )

Weighted-average common shares outstanding, basic and diluted 51,573 49,509

The accompanying notes are an integral part of these consolidated financial statements.

Table of Contents

REGENXBIO INC.

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(in thousands)

Accumulated

Additional Other Total

Common Stock Paid-in Comprehensive Accumulated Stockholders’

Shares Amount Capital Loss Deficit Equity

Vesting of restricted stock units, net of tax 345 — (910 ) — — (910 )

Exercise of stock options, net of tax 291 — 1,512 — — 1,512

Exercise of pre-funded warrants 197 — — — — —

Stock-based compensation expense — — 38,463 — — 38,463

Unrealized gain on available-for-sale securities, net — — — 3,688 — 3,688

Vesting of restricted stock units, net of tax 662 — (633 ) — — (633 )

Exercise of stock options, net of tax 68 — 318 — — 318

Issuance of warrants, net of transaction costs — — 1,610 — — 1,610

Exercise of pre-funded warrants 455 — — — — —

Stock-based compensation expense — — 34,563 — — 34,563

Unrealized gain on available-for-sale securities, net — — — 54 — 54

The accompanying notes are an integral part of these consolidated financial statements.

Table of Contents

REGENXBIO INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(in thousands)

Years Ended December 31,

Cash flows from operating activities

Adjustments to reconcile net loss to net cash used in operating activities

Provision for credit losses (recoveries) — (5,000 )

Net accretion of discounts on marketable debt securities (5,479 ) (4,144 )

Net realized gain on investments (62 ) (6,616 )

Impairment of long-lived assets — 2,101

Other non-cash adjustments 597 1,324

Changes in operating assets and liabilities

Operating lease right-of-use assets 6,653 6,196

Accrued expenses and other current liabilities 229 (12,124 )

Operating lease liabilities (8,625 ) (8,083 )

Cash flows from investing activities

Purchases of marketable debt securities (332,630 ) (190,139 )

Sales of equity securities 62 5,783

Purchases of property and equipment (2,414 ) (2,436 )

Net cash provided by (used in) investing activities (15,868 ) 103,446

Cash flows from financing activities

Proceeds from exercise of stock options 318 1,512

Taxes paid related to net settlement of stock-based awards (633 ) (910 )

Expenses related to at-the-market offering programs (357 ) (323 )

Net cash provided by financing activities 116,771 92,683

Cash and cash equivalents and restricted cash

Supplemental cash flow information

Cash paid (received) for income taxes $ 285 $ (72 )

Cash paid for interest under royalty monetization liabilities $ 32,107 $ 6,559

Supplemental disclosures of non-cash investing and financing information

Deferred equity offering costs reclassified $ 499 $ 628

The accompanying notes are an integral part of these consolidated financial statements.

Table of Contents

REGENXBIO INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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's lead product candidates include ABBV-RGX-314 for the treatment of wet age-related macular degeneration (wet AMD) and diabetic retinopathy (DR), RGX-202 for the treatment of Duchenne muscular dystrophy, RGX-121 for the treatment of Mucopolysaccharidosis Type II (MPS II) and RGX-111 for the treatment of Mucopolysaccharidosis Type I (MPS I). 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 December 31, 2025, 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. 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 December 31, 2025, had generated an accumulated deficit of $1.13 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 December 31, 2025, the Company had cash, cash equivalents and marketable securities of $240.9 million, which management believes is sufficient to fund operations into early 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 have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Foreign Currency Transactions

The functional currency of the Company and its consolidated subsidiaries is the U.S. dollar. Transaction gains and losses that arise from exchange rate fluctuations on transactions denominated in currencies other than the U.S. dollar are included in results of operations as incurred. During the years ended December 31, 2025 and 2024, the Company recorded aggregate net foreign currency transaction losses of $0.1 million and$0.9 million, respectively, which are included in other operating expenses in the consolidated statements of operations and comprehensive loss.

100

Table of Contents

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) which became 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.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents.

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 December 31,

Total cash and cash equivalents and restricted cash $ 36,496 $ 59,556

Marketable Securities

Marketable securities consist of available-for-sale debt securities and are carried at fair value. Marketable debt securities with remaining maturity dates exceeding 12 months which are not intended to be sold prior to maturity for use in current operations are classified as non-current assets. Unrealized gains and losses on available-for-sale debt securities, net of any related tax effects, are excluded from results of operations and are included in other comprehensive income and reported as a separate component of stockholders’ equity until realized. 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. Purchase premiums and discounts on marketable debt securities are amortized or accreted into the cost basis over the life of the related security as adjustments to the yield using the effective-interest method. Interest income is recognized when earned. 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.

At each reporting date, the Company evaluates available-for-sale debt securities which have an amortized cost basis in excess of the fair value of the security to determine if the unrealized loss or any potential credit losses should be recognized in results of operations. If the Company does not have the intent and ability to hold the security until recovery of the unrealized loss, the difference between the fair value and amortized cost basis of the security is charged to results of operations resulting in a new amortized cost basis of the security. If the Company has the intent and ability to hold the security until recovery of the unrealized loss, the security is evaluated for potential credit losses. If a credit loss is deemed to exist, the credit loss is recognized in results of operations and an allowance for credit losses is recorded against the amortized cost basis of the security. In determining whether a credit loss exists related to impaired available-for-sale debt securities, the Company considers, among other factors, the extent of the unrealized loss relative to the amortized cost basis, the credit rating of the issuer and any recent changes thereto, current and expected future

101

Table of Contents

economic conditions, and any adverse events or other changes in circumstances that have occurred which may indicate a potential credit loss. The Company did not record an allowance for credit losses on its available-for-sale debt securities as of December 31, 2025 or 2024.

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 December 31, 2025 or 2024.

Concentrations of Credit Risk and Off-balance Sheet Risk

Cash and cash equivalents, marketable debt securities and accounts receivable are financial instruments that are potentially subject to concentrations of credit risk. The Company’s cash and cash equivalents are deposited in accounts at multiple financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. The Company’s marketable debt securities consist of investment grade securities and may be subject to concentrations of credit risk. The Company has adopted an investment policy which limits potential concentrations of investments and establishes minimum acceptable credit ratings, thereby reducing credit risk exposure. As of December 31, 2025, the Company believes that it is not exposed to significant credit risk related to accounts receivable due to the credit quality and history of collections from its significant customers, and the Company is unaware of any concentrations of credit risk related to accounts receivable from significant customers with deteriorated credit quality. The Company has no financial instruments with off-balance sheet risk of loss.

The following table summarizes those customers who represented at least 10% of revenues or total net accounts receivable for the periods presented:

Revenues Accounts Receivable

Years Ended December 31, As of December 31,

Customer B 50 % — 14 % —

Leases

The Company accounts for its lease arrangements in accordance with Accounting Standards Codification (ASC) 842, Leases (ASC 842). Under ASC 842, the Company classifies its leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the Company. Lease classification is evaluated at the inception of the lease agreement. Regardless of classification, the Company records a right-of-use asset and a lease liability for all leases with a term greater than 12 months. All of the Company’s leases are classified as operating leases. Operating lease expense is recognized on a straight-line basis over the term of the lease, with the exception of variable lease expenses which are recognized as incurred.

102

Table of Contents

The Company identifies leases in its contracts if the contract conveys the right to control the use of identified property, plant or equipment for a period of time in exchange for consideration. The Company does not allocate lease consideration between lease and nonlease components and records a lease liability equal to the present value of the remaining fixed consideration under the lease. The interest rates implicit in the Company’s leases are generally not readily determinable. Accordingly, the Company uses its estimated incremental borrowing rate at the commencement date of the lease to determine the present value discount of the lease liability. The Company estimates its incremental borrowing rate for each lease based on an evaluation of its expected credit rating and the prevailing market rates for collateralized debt in a similar economic environment with similar payment terms and maturity dates commensurate with the term of the lease. The right-of-use asset for each lease is equal to the lease liability, adjusted for unamortized initial direct costs and lease incentives and prepaid or accrued rent. Initial direct costs of entering into a lease are included in the right-of-use asset and amortized as lease expense over the term of the lease. Lease incentives, such as tenant improvement allowances, are recorded as a reduction of the right-of-use asset and amortized as a reduction of lease expense over the term of the lease. The Company excludes options to extend or terminate leases from the calculation of the lease liability unless it is reasonably certain the option will be exercised.

The Company evaluates its right-of-use assets for impairment in accordance with its policy for long-lived assets. To the extent an impairment of a right-of-use asset is recognized, the remaining carrying value of the asset is subsequently amortized as lease expense on a straight-line basis from the date of impairment to the earlier of the end of the right-of-use asset’s useful life or the end of the lease term.

The Company determines the classification of subleases at the inception of the sublease, as well as whether the Company has been relieved of its primary obligation under the original lease. All of the Company's subleases are classified as operating leases and, in each case, the Company has not been relieved of its primary obligation under the original lease and continues to account for the original lease as it did prior to the commencement of the sublease. Sublease income is recognized on a straight-line basis over the term of the sublease as a reduction of the related lease expense of the original lease. Initial direct costs of entering into a sublease are deferred and amortized on a straight-line basis over the term of the sublease as a reduction of sublease income.

Property and Equipment

Property and equipment is stated at cost less accumulated depreciation and amortization. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Upon disposal, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows:

Estimated Useful Life

Computer equipment and software 3 years

Furniture and fixtures 5 years

Laboratory and manufacturing equipment 5 to 15 years

Leasehold improvements Shorter of lease term or estimated useful life

Cloud Computing Arrangements

The Company capitalizes certain costs associated with the implementation of cloud computing arrangements that are accounted for as service contracts. Once implementation activities are substantially complete and the cloud-based application is ready for its intended use, capitalization ceases and amounts capitalized are amortized on a straight-line basis over the term of the hosting arrangement. Capitalized implementation costs for cloud-based applications and associated amortization are classified on the consolidated balance sheets and statements of operations and comprehensive loss in the same manner as the costs of the associated hosting arrangement. As of December 31, 2025 and 2024, the Company had recorded capitalized costs, net of amounts amortized, of $0.1 million and less than $0.1 million, respectively, related to the implementation of cloud-based software applications, which were included in prepaid expenses and other assets on the consolidated balance sheets. Amortization of capitalized implementation costs for cloud-based applications recorded for the years ended December 31, 2025 and 2024 was less than $0.1 million and $1.0 million, respectively, and was included in general and administrative expenses in the consolidated statements of operations and comprehensive loss.

103

Table of Contents

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.

Non-marketable Equity Securities

Non-marketable equity securities consist of equity investments in other entities in which the Company’s ownership interest is below 20% and the Company does not have significant influence over the operations of the entity, or for which the equity securities are not common stock or in-substance common stock. The Company’s non-marketable equity securities do not have readily determinable fair values and are measured at cost less impairment, adjusted for observable price changes for identical or similar investments of the same issuer. Please refer to Note 3 for further information on non-marketable equity securities.

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. 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.

Royalty Monetization Liabilities

As discussed in Note 7, the Company has entered into multiple royalty monetization arrangements with entities managed by Healthcare Royalty Management, LLC (collectively and with other affiliated entities, HCR). Net proceeds received by the Company under these arrangements are recorded as liabilities and accounted for as debt since the return to HCR is explicitly capped under the agreements. The liabilities are amortized over the estimated life of the arrangements using the effective interest method. For arrangements in which there is no stated interest rate, the total amount of royalty and other payments paid to HCR under the arrangement, less the net proceeds received by the Company, is recorded as interest expense over the life of the arrangement. The Company estimates the effective interest rates of its royalty monetization liabilities based on its estimate of total payments to be paid to HCR under the arrangements. The Company reassesses these estimates at each reporting date and adjusts the effective interest rate and amortization of the liabilities on a prospective basis as necessary.

104

Table of Contents

Due to its continuing involvement in the license and collaboration agreements underlying the royalty monetization arrangements with HCR, the Company continues to recognize license and royalty revenues under these license and collaboration agreements and records any payments to HCR as a reduction of the associated royalty monetization liability when paid. As such payments are made to HCR, the balance of the liability will be effectively repaid over the life of the royalty monetization agreement. The portion of royalty monetization liabilities representing principal that is expected to be paid within 12 months of the reporting date is recorded as a current liability, with the remaining portion of the liabilities recorded as non-current.

Warrants

Warrants are accounted for based on the specific terms of the warrant agreements. The Company's warrants, including pre-funded warrants, are indexed to the Company's common stock and meet the criteria to be classified as equity. Net proceeds received from the issuance of warrants are recorded within additional paid-in capital and are not subject to remeasurement. Please refer to Note 9 for further information regarding warrants issued by the Company.

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 606, the Company applies the five-step model as described in its revenue recognition policies. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied in accordance with the Company's accounting policies for collaborative arrangements.

105

Table of Contents

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, manufacturing 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, manufacturing and other services performed by the Company. Variable consideration under the agreements may include development and sales-based milestone payments, payments for development, manufacturing 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, manufacturing and other 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.

106

Table of Contents

Royalty revenue to date consists primarily of royalties on net sales of Zolgensma and Itvisma, which are licensed products 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 and Itvisma 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.

Collaborative Arrangements

The Company evaluates its agreements with collaboration partners to determine whether they are within the scope of ASC 808. Such arrangements are within the scope of ASC 808 if they involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This evaluation is performed throughout the life of the arrangement based on any changes in the roles and responsibilities of the parties under the arrangement. 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 606, the Company applies the five-step model as described in its revenue recognition policies. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied.

For transactions accounted for as collaborative arrangements under ASC 808, payments to and from collaboration partners associated with multiple activities in a collaboration arrangement are classified based on the nature of each separate activity. Payments associated with development activities performed are recorded as research and development expense when owed to collaboration partners, or as a reduction of research and development expense when due from collaboration partners. Payments associated with commercialization activities performed are recorded as general and administrative expense when owed to collaboration partners, or as a reduction of general and administrative expense when due from collaboration partners. At the end of each reporting period, the Company records a net amount due to or from collaboration partners for activities performed by the parties under the collaboration.

Cost of License and Royalty Revenues

Cost of license and royalty revenues consists primarily of sublicense fees and royalties on net sales of licensed products as specified in the Company’s agreements with its licensors. Sublicense fees are based on a percentage of license fees received by the Company from licensees and are recognized in the period that the underlying revenue is recognized. Royalties are based on a percentage of net sales of licensed products by licensees and are recognized in the period that the underlying sales occur. Amounts which are payable to licensors in periods beyond 12 months from the reporting date are recorded as non-current liabilities on the consolidated balance sheets.

107

Table of Contents

Research and Development Expenses

RGNX US Equity

RGNX · 10-K · period ended 2025-12-31

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE

ITEM 9A. CONTROLS AND PROCEDURES

ITEM 9B. OTHER INFORMATION

ITEM 9C. DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS

ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

ITEM 11. EXECUTIVE COMPENSATION

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE

ITEM 14. PRINCIPAL ACCOUNTANT FEES AND SERVICES

ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES

ITEM 16. FORM 10-K SUMMARY

RGNX US Equity☆

RGNX · 10-K · period ended 2025-12-31

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE

ITEM 9A. CONTROLS AND PROCEDURES

ITEM 9B. OTHER INFORMATION

ITEM 9C. DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS

ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

ITEM 11. EXECUTIVE COMPENSATION

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE

ITEM 14. PRINCIPAL ACCOUNTANT FEES AND SERVICES

ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES

ITEM 16. FORM 10-K SUMMARY

RGNX US Equity