RP-A501

October 7, 2026: Rocket Pharmaceuticals (NASDAQ: RCKT) provided an RP-A501 update for Danon disease following its October 6 investor webinar, outlining an FDA-aligned pivotal Phase 2 path and updated safety/efficacy data. The pivotal efficacy population will include 12 male patients treated with commercial-grade RP-A501 at a recalibrated dose; success requires at least 7 patients to achieve both co-primary endpoints at 12 months: myocardial LAMP2 protein expression of at least Grade 1 and at least a 10% reduction in left ventricular mass index, which the company says could support accelerated approval.

Under the modified protocol, the first 3 patients completed the initial observation period without clinical or laboratory evidence of thrombotic microangiopathy or capillary leak syndrome; follow-up is ongoing and these observations are preliminary.

In Phase 1, all 6 patients in the principal analysis showed myocardial LAMP2 expression and at least a 10% LVMI reduction at about 12 months. At roughly 3 to 7 years follow-up, LVMI remained below baseline in 5 of 6 patients, with reductions of at least 10% in 4 of 6; all 6 also had sustained cardiac biomarker reductions and quality-of-life improvements.

In original-dose Phase 2, 3 of 4 evaluable patients achieved at least a 10% LVMI reduction; prior thrombotic microangiopathy and one fatal serious adverse reaction led to the recalibrated dose, revised immunomodulation, and enhanced monitoring. Rocket expects pivotal dosing completion by mid-2027 and topline results by mid-2028.