REGENXBIO Inc.

Previous wording

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). 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.

Current wording

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). Sura-vec is currently being evaluated in multiple clinical trials, including two pivotal trials (ATMOSPHERE and ASCENT) where enrollment has been completed, 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 sura-vec in diabetic macular edema (DME). Additionally, we have activated U.S. clinical sites and initiated enrollment of a pivotal trial in DR and expect to dose the first patient in the two-part Phase IIb/III study (NAAVIGATE) in the second quarter of 2026. Sura-vec 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.

Previous wording

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.

Current wording

Sura-vec for Treatment of Wet AMD

Previous wording

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.

Current wording

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, with global regulatory submissions expected in 2027.

Previous wording

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.

Current wording

The ALTITUDE® trial is a multi-center, open label, randomized, controlled, dose-escalation Phase II trial to evaluate the efficacy, safety and tolerability of sura-vec using suprachoroidal delivery for the treatment of DR. In November 2023, we announced data showing sura-vec 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 announced positive 2-year data showing sura-vec was well tolerated in subjects with non-proliferative diabetic retinopathy (NPDR) at dose levels 1, 2, and 3. There were no drug-related serious adverse events and no intraocular inflammation was observed through two years at dose level 3 (1.0x1012 GC/eye) (n = 15) with short-course topical prophylactic steroids. 50% of dose level 3 patients achieved at least a two-step improvement without need for any supplemental treatment.

Previous wording

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).

Current wording

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).

Previous wording

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.

Current wording

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.

Previous wording

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 has 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 has been extended from November 9, 2025 to February 8, 2026.

Current wording

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.

Previous wording

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. 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.

Current wording

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.

Previous wording

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.

Current wording

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.

Previous wording

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.

Current wording

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 in interim results 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.

Previous wording

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 unaudited consolidated financial statements.

Current wording

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 sura-vec (as amended, the AbbVie Collaboration Agreement). Pursuant to the AbbVie Collaboration Agreement, both we and AbbVie are active participants in the development of sura-vec and development expenses are shared between the parties in accordance with the agreement. The Company will lead the manufacturing of sura-vec for clinical development and U.S. commercial supply, and AbbVie will lead the global commercialization of sura-vec. 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 sura-vec in the United States, and we are eligible to receive tiered royalties on net sales by AbbVie of sura-vec 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 unaudited consolidated financial statements.

Previous wording

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.

Current wording

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) in the United States and certain countries in Asia. 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. 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 unaudited consolidated financial statements.

Previous wording

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 September 30, 2025, our NAV Technology Platform was being applied in one commercial product, Zolgensma®, and the preclinical and clinical development of a number of 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.

Current wording

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 March 31, 2026, 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.

Previous wording

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.

Current wording

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, as well as from development and manufacturing services performed under such license and collaboration arrangements. 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.

Previous wording

Royalty revenue to date consists primarily of royalties on net sales of Zolgensma, which is 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 is a licensed product under our license agreement with Novartis Gene Therapies for the development and commercialization of treatments for SMA using the NAV Technology Platform.

Current wording

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 (the Novartis License) for the development and commercialization of treatments for SMA using the NAV Technology Platform.

Previous wording

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 three and nine months ended September 30, 2025 and 2024 (in thousands):

Current wording

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 three months ended March 31, 2026 and 2025 (in thousands):

Previous wording

Direct expenses related to the development of ABBV-RGX-314 include $17.7 million and $49.5 million for the three and nine months ended September 30, 2025, respectively, and $20.1 million and $66.3 million for the three and nine months ended September 30, 2024, respectively, in net cost reimbursement from AbbVie under our eye care collaboration, 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.

Current wording

Direct expenses related to the development of ABBV-RGX-314 include $12.6 million and $14.7 million for the three months ended March 31, 2026 and 2025, respectively, in net cost reimbursement from AbbVie under our eye care collaboration, 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.

Previous wording

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, 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.

Current wording

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.

Previous wording

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/or 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.

Current wording

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.

Previous wording

Interest expense is primarily associated with our royalty monetization liabilities, including our December 2020 Zolgensma 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 unaudited consolidated financial statements.

Current wording

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 unaudited consolidated financial statements.

Previous wording

Our significant accounting policies are fully described in Note 2 to the accompanying unaudited consolidated financial statements and in Note 2 to our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2024. Other than the accounting policies described below, there have been no significant changes in our critical accounting policies and estimates since December 31, 2024.

Current wording

Our significant accounting policies are fully described in Note 2 to the accompanying unaudited consolidated financial statements and in Note 2 to our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2025. There have been no significant changes in our critical accounting policies and estimates since December 31, 2025.

Previous wording

Research and Development Expense. Research and development expenses increased by $1.7 million, from $54.4 million for the three months ended September 30, 2024 to $56.1 million for the three months ended September 30, 2025. The increase was primarily attributable to the following:

Current wording

Research and Development Expense. Research and development expenses increased by $4.3 million, from $53.1 million for the three months ended March 31, 2025 to $57.3 million for the three months ended March 31, 2026. The increase was primarily attributable to the following:

Previous wording

The increase in research and development expenses was partially offset by a decrease of $3.7 million in costs associated with clinical trials and regulatory activities, largely driven by a decrease in clinical trial expenses for ABBV-RGX-314 pivotal trials.

Current wording

an increase of $1.3 million in costs associated with clinical trials and regulatory activities, largely driven by RGX-202 pivotal trials;

Previous wording

an increase of $2.3 million in personnel-related costs due to increased headcount of development personnel, net of a $0.1 million decrease in stock-based compensation expense;

Current wording

an increase of $1.1 million in personnel-related costs due to increased headcount of development personnel, net of a $0.2 million decrease in stock-based compensation expense;

Previous wording

an increase of $1.9 million in manufacturing-related expenses and other clinical supply costs for our lead product candidates, largely driven by manufacturing of RGX-121; and

Current wording

an increase of $0.9 million in manufacturing-related expenses and other clinical supply costs for our lead product candidates; and

Previous wording

an increase of $0.5 million in preclinical activities and other early-stage research and development.

Current wording

an increase of $0.9 million in costs associated with preclinical activities and other early-stage research and development.

Previous wording

General and Administrative Expense. General and administrative expenses increased by $0.8 million, from $19.4 million for the three months ended September 30, 2024 to $20.3 million for the three months ended September 30, 2025. The increase was largely driven by professional services, consulting and other corporate advisory services.

Current wording

General and Administrative Expense. General and administrative expenses increased by $1.0 million, from $20.3 million for the three months ended March 31, 2025 to $21.3 million for the three months ended March 31, 2026. The increase was largely driven by personnel-related costs, consulting and other corporate advisory services.

Previous wording

As of September 30, 2025, we had cash, cash equivalents and marketable securities of $302.0 million, which were primarily derived from the royalty monetization in May 2025 and the up-front payment received under the Nippon Shinyaku Collaboration Agreement in March 2025, each as described below, and the sale of our common stock and pre-funded warrants in March 2024. We expect that our cash, cash equivalents and marketable securities as of September 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements and are sufficient to meet our financial commitments and obligations, for at least the next 12 months from the date of this report based on our current business plan.

Current wording

As of March 31, 2026, we had cash, cash equivalents and marketable securities of $150.5 million, which were primarily derived from our royalty monetization with HCR in May 2025 and the up-front payment received under the Nippon Shinyaku Collaboration Agreement in March 2025.

Previous wording

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 September 30, 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.

Current wording

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 March 31, 2026, no shares of common stock had been sold under the

Previous wording

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 of our product candidates. Additionally, our estimates are based on assumptions that may prove to be wrong, and we may use our available capital resources sooner than we currently expect which could accelerate our liquidity needs.

Current wording

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.

Previous wording

Our net cash used in operating activities for the nine months ended September 30, 2025 decreased by $69.8 million from the nine months ended September 30, 2024, largely as a result of the $110.0 million up-front fee received from Nippon Shinyaku in March 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.

Current wording

Our net cash used in operating activities for the three months ended March 31, 2026 increased by $109.8 million from the three months ended March 31, 2025, largely driven by the $110.0 million up-front fee received from Nippon Shinyaku in March 2025 and an increase in operating expenses in the first quarter of 2026. 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.

Previous wording

For the nine months ended September 30, 2024, our net cash used in operating activities of $141.5 million consisted of a net loss of $175.9 million and unfavorable changes in operating assets and liabilities of $6.1 million, offset by adjustments for non-cash items of $40.5 million. The changes in operating assets and liabilities include a decrease in total accounts payable, accrued expenses and other current liabilities, and other liabilities of $7.5 million, which was driven largely by decreases in accrued personnel costs, sublicense fees payable to licensors and amounts payable to suppliers as of the end of the period. Other changes in operating working capital occurred in the normal course of business. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $28.9 million and depreciation and amortization expense of $12.2 million.

Current wording

For the three months ended March 31, 2026, our net cash used in operating activities of $76.2 million consisted of a net loss of $90.1 million and unfavorable changes in operating assets and liabilities of $1.5 million, offset by adjustments for non-cash items of $15.4 million. The changes in operating assets and liabilities include a decrease in accrued expenses and other current liabilities of $16.7 million, which was driven largely by decreases in accrued personnel-related expenses, royalties and sublicense fees, and external research and development services. The unfavorable changes in operating assets and liabilities were partially offset by a decrease in accounts receivable of $18.2 million, which was driven largely by royalties receivable on net sales of Zolgensma. Other changes in operating working capital occurred in the normal course of business. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $8.6 million, depreciation and amortization expense of $3.9 million and non-cash interest expense of $3.8 million.

Previous wording

For the nine months ended September 30, 2025, our net cash used in operating activities of $71.7 million consisted of a net loss of $126.7 million, offset by adjustments for non-cash items of $41.5 million and favorable changes in operating assets and liabilities of $13.6 million. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $26.2 million and depreciation and amortization expense of $11.7 million. The changes in operating assets and liabilities include an increase in deferred revenue of $34.3 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 prepaid expenses and other current assets of $9.5 million, which was largely driven by an increase in net cost reimbursement due from AbbVie under our ABBV-RGX-314 collaboration, and an increase in accounts receivable of $7.1 million, which was driven largely by reimbursable costs due from Nippon Shinyaku under our collaboration for RGX-121 and RGX-111. Other changes in operating working capital occurred in the normal course of business.

Current wording

For the three months ended March 31, 2025, our net cash provided by operating activities of $33.6 million consisted of net income of $6.1 million, adjustments for non-cash items of $11.1 million and favorable changes in operating assets and liabilities of $16.4 million. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $8.5 million and depreciation and amortization expense of $4.0 million, partially offset by the accretion of discounts on marketable debt securities during the period. The changes in operating assets and liabilities include an increase of $39.8 million in deferred revenue, which was driven primarily by 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 a decrease in total accounts payable and accrued expenses and other current liabilities of $18.1 million, which was driven largely by decreases in accrued personnel-related expenses, royalties and external research and development services, as well as a total increase in prepaid expenses and other current assets of $4.3 million, which was driven primarily by increases in prepaid software licenses and net cost reimbursement due from AbbVie under our ABBV-RGX-314 collaboration. Other changes in operating working capital occurred in the normal course of business.

Previous wording

For the nine months ended September 30, 2024, our net cash provided by investing activities consisted of $238.4 million in maturities of marketable debt securities, offset by $173.9 million used to purchase marketable debt securities and $1.4 million used to purchase property and equipment.

Current wording

For the three months ended March 31, 2026, our net cash provided by investing activities consisted of $81.7 million in maturities of marketable debt securities, offset by $9.8 million used to purchase marketable debt securities and $1.2 million used to purchase property and equipment.

Previous wording

For the nine months ended September 30, 2025, our net cash used in investing activities primarily consisted of $269.8 million used to purchase marketable debt securities and $1.9 million used to purchase property and equipment, partially offset by $218.3 million in maturities of marketable debt securities.

Current wording

For the three months ended March 31, 2025, our net cash provided by investing activities consisted of $64.9 million in maturities of marketable debt securities, offset by $19.2 million used to purchase marketable debt securities and $1.0 million used to purchase property and equipment.

Previous wording

For the nine months ended September 30, 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 $18.4 million of royalties paid, net of interest, under our royalty monetization liabilities.

Current wording

For the three months ended March 31, 2026, our net cash used in financing activities primarily consisted of $13.4 million of royalties paid, net of interest, under our royalty monetization liabilities.

Previous wording

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 liabilities. Our material commitments and obligations are further described in Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” of our Annual Report on Form 10-K for the year ended December 31, 2024, and in the notes to the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2024. Other than the changes described in the notes to the unaudited consolidated financial statements accompanying this Quarterly Report on Form 10-Q, including Note 7, "Royalty Monetization Liabilities," and Note 8, “Commitments and Contingencies,” there have been no material changes to our commitments and obligations since December 31, 2024.

Current wording

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. Our material commitments and obligations are further described in Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” of our Annual Report on Form 10-K for the year ended December 31, 2025, and in the notes to the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2025. Other than the changes described in the notes to the unaudited consolidated financial statements accompanying this Quarterly Report on Form 10-Q, including Note 8, “Commitments and Contingencies,” there have been no material changes to our commitments and obligations since December 31, 2025.

Previous wording

We have incurred cumulative losses since our inception and had an accumulated deficit of $1.06 billion as of September 30, 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 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.

Current wording

We have incurred cumulative losses since our inception and had an accumulated deficit of $1.22 billion as of March 31, 2026. 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 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.

Previous wording

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

Current wording

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

Previous wording

the timing and amount of Zolgensma royalties and other specified royalties, milestones and consideration under our license agreements and collaborations paid to HCR under our royalty monetization agreements;

Current wording

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;