FDA Lifts Clinical Hold on Rocket Pharmaceuticals Phase 2 Danon Disease Trial

The FDA has lifted the clinical hold on Rocket Pharmaceuticals' pivotal Phase 2 trial of RP-A501 for treating Danon disease, allowing the trial to resume with a recalibrated dose of 3.8 x 10¹³ GC/kg. This decision came less than three months after the hold was imposed, reflecting the FDA's satisfaction with Rocket's safety measures and revised immunomodulatory regimen, which now excludes prophylactic use of a C3 complement inhibitor while maintaining sirolimus, rituximab, and steroids. Six patients have been treated so far at a higher dose, and the trial will continue with three additional patients under the adjusted dosing protocol, with a minimum four-week interval between treatments. RP-A501 is an investigational gene therapy designed to restore cardiac function by delivering a functional LAMP2B gene, targeting the rare and often fatal Danon disease that currently lacks effective treatments beyond heart transplantation. Despite Rocket Pharmaceuticals' stock decline, the company maintains a strong financial position and anticipates further updates after reviewing new patient data. The global, multi-center trial aims to confirm RP-A501's safety and efficacy, which holds multiple FDA designations including RMAT, Fast Track, Rare Pediatric, and Orphan Drug status.