Rocket Pharmaceuticals (RCKT) Status update summary

Clinical evidence

• Phase I showed durable myocardial LAMP2 expression through 7.1 years; at latest imaging, LVMI remained below baseline in 5 of 6 evaluable patients, with reductions of ≥10% in 4. All Phase I patients met both pivotal endpoints at ~12 months.

• At latest follow-up, NT-proBNP and troponin were below baseline in all 6 evaluable patients; 5 were NYHA class I and 1 class II, and all reported KCCQ improvement of ≥5 points.

• Phase I overall survival was 100%; 5 of 6 evaluable patients remained transplant-free. Estimated transplant-free survival was 80% at 58.05 months, with median not reached; one patient underwent transplant ~4.8 years after infusion.

• In the initial 4 Phase II patients at the original dose, 3 had LVMI reductions of ≥10% (30%-36%) and 1 had an ~9% increase; preliminary Phase II findings through 36 months showed improvement or stabilization across cardiac and symptom measures.

Safety and dose changes

• TMA occurred in 2 of the initial 4 Phase II patients; both patients treated with a C3-inhibitor regimen had serious adverse events including capillary leak syndrome, and one patient died. Cohort 3 was discontinued.

• Revised protocol removed C3 inhibition, recalibrated commercial-grade dose from 6.7E13 to 3.8E13 GC/kg, increased rituximab to 3 doses, and added enhanced TMA/CLS monitoring and eligibility screening.

• The first 3 Cohort 4 patients had no TMA, capillary leak or other severe complement-mediated toxicity through 3 months; one Grade 3, RP-A501-related GGT increase resolved, and all were discharged within 1–2 weeks. FDA and IDMC allowed dosing to continue.

• Product full-capsid proportion improved from below 50% to above 70%; clinical, preclinical and manufacturing data supported biological activity at the recalibrated dose.

Pivotal study and financing

• FDA-aligned pivotal global, single-arm Phase II targets 12 male pediatric and adult/adolescent patients at 3.8 × 10¹³ GC/kg with rituximab, steroid and sirolimus; co-primary endpoints at 12 months are LAMP2 expression improvement ≥Grade 1 and LVMI reduction ≥10%.

• Prespecified success target is at least 7 of 12 responders meeting both endpoints; the first 3 Cohort 4 patients count toward the pivotal population, leaving 9 to dose.

• Dosing completion is targeted for mid-2027; topline efficacy readout is targeted for mid-2028, pending alignment with dosing completion and 12-month follow-up, and BLA filing is targeted for late 2028. Potential pathway includes accelerated approval and priority review.

• Cohort 4 is the pivotal analysis population; Phase I and other Phase II results are supportive, and natural history data support design assumptions but are not an external comparator.

• A $35 million initial draw under a Hercules facility, alongside existing resources and the operating plan, is expected to fund operations into Q3 2028; additional borrowing could extend runway into 2029, subject to conditions and future draws.