Rocket Pharmaceuticals Announces Completion of Enrollment in Phase 2 Pivotal Trial of RP-A501 for the Treatment of Danon Disease

Rocket Pharmaceuticals, Inc. (NASDAQ: RCKT), a fully integrated, late-stage biotechnology company advancing a sustainable pipeline of genetic therapies for rare disorders with high unmet need, today announced that all patients have been enrolled in the global, pivotal Phase 2 clinical trial evaluating RP-A501 to treat male patients with Danon disease.

After the two-patient safety run-in, followed by harmonized global site activations, the remaining 10 patients were enrolled across the United States (U.S.) and European Union within three months. Given the prevalence of Danon disease across regions, the Company plans to pursue regulatory filings concomitantly in the U.S. and ex-U.S.

“From a clinical perspective, the important thing is that we are moving closer to the goal of having a treatment for patients with Danon disease,” said Barry H. Greenberg, MD, FHFSA, Director of the Advanced Heart Failure Treatment Program and Distinguished Professor of Medicine at UC San Diego Health. “I can attest to the excitement and anticipation within the Danon patient community for this novel, one-time treatment designed to improve cardiac abnormalities associated with Danon disease and help preserve normal cardiac function by delivering functional LAMP2B genes to the heart tissue. The rapid recruitment of the Phase 2 trial signifies the positive views of the study clinicians regarding this investigational therapy.”

RP-A501 Phase 2 Pivotal Trial Overview

The global, single-arm, multi-center Phase 2 pivotal trial evaluates the efficacy and safety of RP-A501 in 12 patients with Danon disease, including a pediatric safety run-in (n=2), and a dose level of 6.7 x 10¹³ GC/kg.

• To support accelerated approval, the study assesses the efficacy of RP-A501 as measured by the biomarker-based co-primary endpoint consisting of improvements in LAMP2 protein expression, and reductions in left ventricular mass.
• Key secondary endpoint is change in troponin. Additional secondary endpoints include natriuretic peptides, Kansas City Cardiomyopathy Questionnaire, New York Heart Association class, event free survival to 24 months and treatment emergent safety events. These endpoints could support full approval with longer-term follow-up.
• A global natural history study is running concurrently with the Phase 2 pivotal trial.
• The pediatric run-in enrolled two patients in a sequential manner with a minimum three-month follow-up prior to subsequent enrollment. In addition, all patients enrolled in the trial are required to have a three-months observational pre-treatment run-in to enable an assessment of troponin (and other biomarker) trajectories to optimally assess this key secondary endpoint.

Details about the Phase 2 study can be found at www.clinicaltrials.gov under NCT identifier NCT06092034.