REGENXBIO (NASDAQ:RGNX) outlined a slate of near-term clinical catalysts and provided financial updates during its fourth-quarter and year-end 2025 earnings call, emphasizing what management described as a “pivotal year” ahead as the company advances late-stage programs in Duchenne muscular dystrophy (DMD) and retinal disease. Executives also addressed recent regulatory setbacks in its mucopolysaccharidosis (MPS) programs, including a complete response letter (CRL) and clinical holds, and discussed ongoing interactions with the FDA as the company plans for potential biologics license application (BLA) submissions.
RGX-202 in Duchenne: pivotal readout expected in early Q2
Chief Executive Officer Curran Simpson and Chief Medical Officer Steve Pakola highlighted RGX-202 as the company’s lead program, describing it as a potential “best-in-class” gene therapy for DMD. Management said dosing in the pivotal AFFINITY DUCHENNE trial was completed in October 2025, and that a separate confirmatory study is enrolling robustly.
Pakola pointed to previously disclosed functional results, including what he called a “striking” 7.4 average improvement versus a CTAP model at 18 months in the Phase I/II study. He said the data have shown consistent microdystrophin expression and that most treated patients were 8 years and older—an age when functional decline is typically expected. The company said it expects to have 12-month functional data on the majority of pivotal patients by fall 2026, and noted that the timing and content of functional data included in a BLA will depend on FDA discussions.
On safety, management said it has observed no serious adverse events or adverse events of special interest in the Phase I/II study, including no thrombocytopenia or liver injury. Pakola attributed the profile to a proactive immune suppression regimen, a “novel construct,” and product purity characterized as more than 80% full capsids. Responding to analyst questions about liver enzyme elevations, he said the company has continued to see no cases of liver injury in 13 patients, which he contrasted with a higher rate reported for existing therapy, and said additional safety detail is expected at MDA.
Regulatory strategy: external controls, functional data, and FDA alignment
During the Q&A, management addressed investor concerns about FDA expectations for controlled data in DMD, noting heightened scrutiny across the field. Simpson said the pivotal protocol and statistical plan, including comparisons to external controls, were prospectively reviewed by the FDA and have not been altered mid-study. He argued the company’s functional outcomes to date show a “not narrow” difference versus natural history comparatives, particularly in older patients, and said REGENXBIO does not view a placebo arm as ethical.
Executives also said the confirmatory study was included in the original protocol reviewed by the FDA. Simpson added that rapid confirmatory enrollment could expand the safety exposure database to roughly 50 total patients at the time of filing, versus 30 in the pivotal cohort.
On what data will be included in top-line disclosures, Simpson said the company expects to provide a safety update for the full pivotal cohort (N=30) and biomarker top-line data for the primary endpoint. For functional data at the time of top-line release, he said investors should expect approximately seven patients at 12 months, while additional updates may occur as more patients reach later follow-up.
Management said it has additional FDA interactions planned ahead of the pre-BLA meeting to align on analysis methods and data presentation, with the goal of de-risking the pre-BLA package. On Europe, the company said it is receiving feedback on designs that include a placebo arm that could be feasible outside the U.S., but did not provide a timeline for a European study start.
Retinal franchise with AbbVie: wet AMD readout in Q4, NAVIGATE to start dosing next quarter
REGENXBIO said its ophthalmology partnership with AbbVie continues to advance RGX-314 across wet age-related macular degeneration (wet AMD) and diabetic retinopathy (DR). For wet AMD, the company expects top-line data in Q4 2026 for subretinal delivery in the ATMOSPHERE and ASCENT pivotal studies, which management described as the largest global gene therapy program in the indication. Pakola also referenced durable outcomes through four years in a Phase I/II trial and said recipients in a fellow-eye bilateral dosing study showed a 93% reduction in annualized anti-VEGF injection need at 12 months, with 60% injection-free through that timeframe.
For DR, REGENXBIO said site activation is underway for the pivotal Phase IIb/III NAVIGATE trial using suprachoroidal, in-office delivery of ABBV-RGX-314 at 1e12. First patient dosing is expected next quarter, which management said would trigger a $100 million milestone payment from AbbVie.
Pakola described NAVIGATE as a double-masked, sham-controlled trial. The Phase IIb portion is expected to enroll 136 patients with non-proliferative DR, with a primary endpoint of at least a 2-step improvement on the diabetic retinopathy severity scale (DRSS) at one year. He also summarized Phase II ALTITUDE results at dose level 3, including that no intraocular inflammation was observed with a short course of prophylactic topical steroids, and said 50% achieved at least a 2-step improvement without additional DR treatment. The company added it will have flexibility to evaluate alternative endpoint approaches, including consideration of ordinal DRSS assessments, as data accumulate.
MPS programs: CRL and clinical holds; tumor integration analysis disclosed
REGENXBIO said it received a CRL for RGX-121 two weeks prior to the call and also received clinical hold letters for both RGX-111 and RGX-121. The company said it believes the requirements to remove the holds are addressable and that it had already been working on them. Management said it is preparing a CRL response and working toward a Type A meeting with the goal of resubmitting the BLA.
Pakola provided an update on the serious adverse event in the RGX-111 study, stating the company received a final genetic analysis from an independent third-party lab on a resected tumor. According to the company, the analysis detected an AAV vector genome integration event associated with overexpression of proto-oncogene PLAG1, with clonal integration into the PLAG1 gene detected in tumor tissue. Pakola said findings were consistent with the hypothesis that AAV integration at the PLAG1 site contributed to tumor formation, while also noting the participant had a background of risk factors including an unsuccessful stem cell transplant in infancy and prior exposure to chemotherapeutics that may have contributed to DNA damage. He said the report concluded the patient’s neurocognitive development was above average, indicating mitigation of MPS I disease, and that the analysis is expected to be published in a peer-reviewed journal this year.
On regulatory questions related to biomarkers for Hunter syndrome, management said it is watching upcoming regulatory decisions for other programs and discussed the relationship between D2S6 and heparan sulfate. Executives said they measure heparan sulfate and have assays available if needed, and that the company plans to provide additional detail in its CRL response.
Financial position and runway into early 2027
Chief Financial Officer Vithesh Taneja reported cash, cash equivalents, and marketable securities of $241 million as of December 31, 2025, compared with $245 million a year earlier. He said the year-end cash balance reflected a $110 million upfront payment from Nippon Shinyaku received in the first quarter of 2025 and $145 million in net proceeds from a royalty monetization transaction with HealthCare Royalty Partners in the second quarter, offset by operating cash use.
For 2025, R&D expense was $228 million, up from $209 million in 2024, which management attributed largely to pivotal trial execution and manufacturing for RGX-202 and “Sirvac.” Total annual revenue was $170 million, which included upfront license revenue under the Nippon Shinyaku collaboration and increased royalty revenue for Zolgensma and Evrysdi, both included in the royalty monetization agreement.
Taneja said the company expects its December 31 cash balance to fund operations into early 2027. He added that guidance does not include the expected $100 million AbbVie milestone upon first patient dosing in NAVIGATE or any additional funds from the May 2025 HealthCare Royalty agreement, which he said could extend runway into the second half of 2027. The company also noted the guidance does not include any future revenue from its MPS programs.
About REGENXBIO (NASDAQ:RGNX)
REGENXBIO Inc is a clinical‐stage biotechnology company specializing in the development of gene therapies using its proprietary NAV® AAV (adeno‐associated virus) platform. The company engineers next‐generation AAV vectors designed to deliver functional genes to targeted cells, aiming to address a range of rare genetic diseases and ocular, metabolic and neurologic disorders. REGENXBIO’s pipeline features several product candidates in various stages of preclinical and clinical development, including RGX-314 for wet age‐related macular degeneration, RGX-121 for mucopolysaccharidosis II (Hunter syndrome) and RGX-121 for other rare lysosomal storage diseases.
In addition to its internally funded programs, REGENXBIO has established partnerships with major biopharmaceutical companies to advance its NAV technology.
