Rocket Pharmaceuticals highlights FDA-aligned Phase 2 for RP-A501

CRANBURY, N.J.--()--October 07, 2026-- Rocket Pharmaceuticals, Inc. (NASDAQ: RCKT), a fully integrated commercial-stage biotechnology company advancing genetic medicines for rare and life-threatening diseases, highlighted key findings and development milestones presented during its October 6 Danon disease investor webinar. The update outlined a defined path to completing the FDA-aligned pivotal Phase 2 trial, highlighted sustained biological activity in longer-term Phase 1 follow-up and reported encouraging initial safety observations in the first three patients treated under the modified protocol. Key highlights included: -- Pivotal Phase 2 trial: The FDA-aligned pivotal efficacy population includes 12 male patients receiving commercial-grade RP-A501 at the recalibrated dose. The first three patients treated under the modified protocol count toward this population. Trial success requires at least seven patients to meet both response criteria at 12 months: myocardial LAMP2 protein expression of at least Grade 1 and a reduction in left ventricular mass index of at least 10% from baseline. These co-primary endpoints are intended to support a potential accelerated approval pathway. -- Modified protocol: The first three patients treated at the recalibrated dose completed the protocol-specified initial observation period without clinical or laboratory evidence of thrombotic microangiopathy or capillary leak syndrome, as reported during the webinar. Follow-up is ongoing, and these initial observations are preliminary. -- Phase 1 results: At approximately 12 months, all six patients in the principal Phase 1 analysis demonstrated myocardial LAMP2 protein expression and at least a 10% reduction in left ventricular mass index. At follow-up of approximately three to seven years, left ventricular mass index was below baseline in five of six patients, with reductions of at least 10% in four patients. All six patients also had sustained reduction of cardiac biomarkers and improvements of quality of life. -- Original-dose Phase 2 results: Three of four patients with longitudinal efficacy assessments achieved at least a 10% reduction in left ventricular mass index. Safety findings from the original-dose study, including thrombotic microangiopathy and a fatal serious adverse reaction, informed the recalibrated dose, revised immunomodulation regimen and enhanced safety monitoring now in place. -- Patient population: Genetic and clinical analyses converged on a modeled U.S. Danon disease population of approximately 10,000--11,000, including 4,000 males. Rocket's initial focus is males with symptomatic hypertrophic cardiomyopathy. -- Upcoming milestones: Rocket expects to complete pivotal trial dosing by mid-2027, with topline results anticipated mid-2028. A replay of the webinar and the accompanying presentation are available in the Investors section of Rocket's website at ir.rocketpharma.com. About RP-A501 RP-A501 is Rocket's investigational gene therap