Rocket Pharmaceuticals Presents Promising Preliminary Results from Phase 1 Trial of Commercial-Grade RP-L102 “Process B” for Fanconi Anemia at 61st American Society of Hematology Annual Meeting

Rocket Pharmaceuticals, Inc. (NASDAQ: RCKT) (“Rocket”), a clinical-stage company advancing an integrated and sustainable pipeline of genetic therapies for rare childhood disorders, today announces encouraging preliminary results from its Phase 1 trial of commercial-grade RP-L102 “Process B” for Fanconi Anemia (FA) at the 61st American Society of Hematology (ASH) Annual Meeting. The data are highlighted in a poster presentation by Agnieszka Czechowicz M.D., Ph.D., Assistant Professor of Pediatrics, Division of Stem Cell Transplantation and Regenerative Medicine at the Stanford University School of Medicine, entitled “Changing the Natural History of Fanconi Anemia Complementation Group-A with Gene Therapy: Early Results of U.S. Phase I Study of Lentiviral-Mediated Ex-Vivo FANCA Gene Insertion in Human Stem and Progenitor Cells.”

“The preliminary data presented at ASH provide evidence regarding the potential of our commercial-grade ‘Process B’ product in treating FA,” said Gaurav Shah, M.D., Chief Executive Officer and President of Rocket. “Treatment with ‘Process B’ RP-L102 at four to six months post-infusion showed early signs of engraftment and bone marrow restoration. Further, previously declining blood cell counts appear to have been stabilized or even increased within six months of therapy, providing evidence regarding the potential benefits of treatment with a consistent, commercial-grade product. We are looking forward to presenting additional long-term follow-up data from these patients in the first half of 2020.”

Results presented in the poster highlight preliminary Phase 1 data from two pediatric patients (age 5 and 6 years) who were treated with “Process B” RP-L102 prior to the development of severe bone marrow failure and are in ongoing follow-up. Drug product was successfully manufactured using “Process B” optimization, including transduction enhancers, commercial-grade vector and modified cell processing. “Process B” drug product is manufactured to commercial grade standards, allowing for consistent drug product across patients and a vector copy number (VCN) two to three fold higher than that administered to optimally-treated “Process A” patients. Once transduced, drug product was infused fresh into patients without any prior conditioning regimen. To evaluate transduction efficiency, an analysis of the proportion of the MMC-resistant colony forming cells (CFC’s) was conducted. Both patients exhibited early signs of engraftment based on peripheral blood, VCN and/or MMC-resistance. Preliminary phenotypic correction was also apparent in both patients, as evidenced by stabilization or increases in blood cell lineages. No safety or tolerability issues have been reported.