Rocket Pharmaceuticals Presents Positive Clinical Data from Danon Disease, Fanconi Anemia and Pyruvate Kinase Deficiency Programs at the 25th Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT)

Rocket Pharmaceuticals, Inc. (NASDAQ: RCKT), a leading late-stage, clinical biotechnology company advancing an integrated and sustainable pipeline of genetic therapies for rare childhood disorders with high unmet need, today announces positive clinical updates from its Phase 2 pivotal trial for Fanconi Anemia (FA) and Phase 1 trials for Danon Disease and Pyruvate Kinase Deficiency (PKD) at the 25^th Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT).

“We are highly encouraged by the initial safety data from the two pediatric patients in the Phase 1 Danon Disease trial that suggest RP-A501 was well-tolerated,” said Gaurav Shah, M.D., Chief Executive Officer of Rocket Pharma. “These two patients had markedly reduced complement activation and no complement-related adverse events. They received preventative therapy with a modified immunosuppressive regimen. We believe today’s results represent an important step forward in optimizing the safety of AAV9-based gene therapy for Danon Disease and the Danon patient community. Updated data are anticipated in the third quarter, and we believe that the totality of data from seven patients treated in Phase 1 will support a rapid advance toward a Phase 2 pivotal study.”

“In our Phase 2 pivotal study in Fanconi Anemia, five of nine patients sustained increasing bone marrow cell resistance to mitomycin-C (MMC) confirmed over two consecutive timepoints,” said Dr. Shah. “In these patients, MMC-resistance increased to 51%-94% at 18 to 21 months, up from 21%-42% at 12 to 18 months. The increase in MMC resistance was accompanied by concomitant genetic markings and hematologic stabilization. Addressing the hematologic aspects of Fanconi Anemia is essential because this devastating disorder leads to bone marrow failure in the first decade of life. With these results, we have reached our primary endpoint as defined in the trial protocol and are initiating dialogue with health authorities on next steps forward.”

Dr. Shah continued, “Today’s positive updates from a subset of our world-class gene therapy pipeline highlight the momentum of our targeted and multi-platform approach toward developing potential cures for these rare, devastating bone marrow-derived and cardiovascular diseases for which viable treatment options are extremely limited.”

Extended Results From First-In-Human Clinical Trial of RP-A501 (AAV9:LAMP2B) Gene Therapy Treatment for Danon Disease

The data described in this oral presentation are from the ongoing first-in-human Phase 1 clinical trial evaluating a single intravenous infusion of RP-A501, the Company’s investigational gene therapy for the treatment of Danon Disease. The presentation includes previously disclosed safety and efficacy data from patients in the low-dose (6.7 x 10¹³ GC/kg; n=3) and high-dose (1.1 x 10¹⁴ GC/kg; n=2) young adult and adolescent cohort and new initial safety data from the low-dose (6.7 x 10¹³GC/kg; n=2) pediatric cohort.