Rocket Pharmaceuticals Quick Take on RP-A501 FDA Alignment

Research evidence excerpt

J P M O R G A N

North America Equity Research

15 September 2026

Rocket Pharmaceuticals

Quick Take on RP-A501 FDA Alignment

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RCKT, RCKT US

Price (15 Sep 26):$3.41

SMid Biotechnology

We view the announcement this morning that it has aligned with the FDA on continued

enrollment, dosing, and key elements of the pivotal phase 2 trial of RP-A501 for the

treatment of Danon disease as a positive step and an important milestone for Rocket.

The announcement follows an FDA review of the available safety data, enabling

continued enrollment and dosing under the modified protocol at the recalibrated dose

(3.8E13 GC/kg); recall, the three patients treated under the modified protocol had

completed at least 4wk of follow-up and had been discharged following protocolspecified observation and no clinical or laboratory evidence of thrombotic

microangiopathy or capillary leak syndrome had been observed (see our prior note

here). Importantly, the three patients treated under the modified protocol count toward

the 12-patient pivotal population, meaning that only nine additional patients need to

be enrolled and treated; Rocket expects to complete dosing of the remaining patients

by mid 2027. Additionally, the co-primary endpoints – myocardial LAMP2 protein

expression and a 10% reduction from baseline in left ventricular mass index (LVMI)

(primary assessment will occur at 12mo) – are preserved. Looking ahead, Rocket

expects to provide a comprehensive update on the Danon disease program during a

webinar on Oct. 6, 2026, at 4:30pm ET. Net-net, we see Rocket making positive steps

on this lead program but at the same time wonder what the market will need to gain

more conviction around the asset and support the stock, and if that will indeed include

complete data from the pivotal phase 2 trial.