RP-A501

Rocket Pharmaceuticals (NASDAQ: RCKT) said the FDA aligned on key elements of the global pivotal Phase 2 trial of RP-A501 in Danon disease, confirming continued enrollment and dosing under the modified protocol, a 12-patient male pivotal efficacy population, and 12-month co-primary endpoints intended to support a potential accelerated approval pathway.

The FDA review included the first three patients treated at the recalibrated dose under the modified protocol. All had at least four weeks of follow-up, were discharged after protocol-specified observation, and showed no clinical or laboratory evidence of thrombotic microangiopathy or capillary leak syndrome. Those three patients will count toward the 12-patient pivotal population, leaving nine more to enroll; Rocket expects to complete dosing by mid-2027.

The confirmed pivotal dose is 3.8 × 10¹³ genome copies/kg using commercial-grade product. The 12-month co-primary endpoints remain myocardial LAMP2 protein expression and a 10% reduction from baseline in left ventricular mass index. The modified protocol includes rituximab, sirolimus, and corticosteroids plus enhanced eligibility, monitoring, and risk-mitigation measures. Rocket also cited nonclinical bridging data supporting pharmacologic activity at the recalibrated dose.

A Danon disease program webinar is planned for October 6, 2026, at 4:30 p.m. ET.