Rocket Pharmaceuticals Presents Clinical Data From Company’s Lentiviral Gene Therapies For Treatment Of Fanconi Anemia, LAD-I And PKD At ASH 2021 Meeting

Rocket Pharmaceuticals, Inc. (NASDAQ:RCKT), a clinical-stage company advancing an integrated and sustainable pipeline of genetic therapies for rare childhood disorders, today announces positive clinical updates from

Rocket Pharmaceuticals, Inc. (NASDAQ:RCKT), a clinical-stage company advancing an integrated and sustainable pipeline of genetic therapies for rare childhood disorders, today announces positive clinical updates from its ongoing Phase 2 registrational trials for Fanconi Anemia (FA) and Leukocyte Adhesion Deficiency-I (LAD-I) and its ongoing Phase 1 trial for Pyruvate Kinase Deficiency (PKD) at the 63rd American Society of Hematology (ASH) Annual Meeting.

"The positive updates presented across our Fanconi Anemia, LAD-I and PKD programs highlight the continued progress and importance of our lentiviral platform in providing potentially curative therapies for rare and devastating bone marrow-derived diseases," said Gaurav Shah, M.D., Chief Executive Officer of Rocket Pharma. "We have now dosed 11 Fanconi Anemia patients and have at least 12-months of follow-up on eight of these patients in our clinical trial of RP-L102. In six of these eight patients, we see evidence of engraftment and bone marrow mitomycin-C, or MMC, resistance ranging from 16% to 63% measured at least at one timepoint. MMC resistance is a key indicator of the ability of bone marrow stem cells to resist DNA damage, a process that is impaired in Fanconi Anemia. As a reminder, a minimum of five patients with increased MMC resistance greater than or equal to 10% above baseline at two or more timepoints and evidence of clinical stabilization will be required for statistical significance. The increasing MMC resistance in these six patients is encouraging as we move closer toward potential topline readout."

Dr. Shah continued, "We are equally pleased to have completed enrollment of all nine patients in the Phase 1/2 trial of RP-L201 for LAD-I and that evidence of meaningful clinical activity has been observed in the first eight patients for whom there is at least three months of follow-up. Notably, four patients have follow-up of at least 12-months, and none of these patients have had serious infections or required hospitalization following treatment with RP-L201. Finally, the updated data from our global Phase 1 PKD study showed doubling of baseline hemoglobin to normal-range levels, improved hemolysis parameters and red blood cell transfusion independence following engraftment in the two adult patients with severe PKD who were treated with RP-L301. Taken together, I am very pleased about the strong progress of our LVV programs and our team's focus on consistent and reliable execution."

Gene Therapy for Fanconi Anemia (Group A): Preliminary Results of Ongoing RP-L102 Clinical Trials

The ASH poster presentation included preliminary data from 11 pediatric patients who were treated as of the Nov. 1, 2021, cut-off date with RP-L102, Rocket's ex-vivo lentiviral gene therapy candidate for FA. The tolerability profile of RP-L102 appears favorable and all patients were treated without conditioning. As previously reported, one patient experienced a Grade 2 transient infusion-related reaction.

Evidence of engraftment has been observed in six of eight patients with at least 12-months of follow-up. Sustained peripheral blood vector copy number (VCN) levels were seen in six of seven patients with at least 12-months of follow-up. As previously reported, Patient 2, who was further along in bone marrow failure and had complications due to a previously disclosed influenza B infection contracted during the months subsequent to treatment, was withdrawn from the trial at 18-months post-treatment.

*Patient 1, 24-months post-treatment, demonstrated a 16% BM progenitor resistance to 10 nM MMC and had modest decline in blood counts with potential stabilization at approximately 21-months and no transfusions required

**Assessment was not performed at study's centralized laboratories

A Phase 1/2 Study of Lentiviral-Mediated Ex-Vivo Gene Therapy for Pediatric Patients with Severe Leukocyte Adhesion Deficiency-I (LAD-I): Interim Results

The ASH oral presentation included preliminary data from eight of nine severe LAD-I patients, as defined by CD18 expression of less than 2%, who received RP-L201 treatment as of the Nov. 8, 2021, data cut-off date. Eight patients had follow-up data of at least three months, and four of the eight patients had been followed for 12-months or longer. One patient recently received RP-L201 infusion after the data cut-off date.

All infusions of RP-L201 were well tolerated and no drug product-related serious adverse events (SAEs) were reported. Evidence of preliminary efficacy was observed in all eight evaluable patients. All eight patients demonstrated durable neutrophil CD18 expression that exceeded the 4-10% threshold associated with survival into adulthood and consistent with reversal of the severe LAD-I phenotype. Peripheral blood VCN levels have been stable and in the 0.54 – 2.94 copies per genome range. No patients had LAD-I related infections requiring hospitalization after hematopoietic reconstitution post-RP-L201.

Lentiviral Mediated Gene Therapy for Pyruvate Kinase Deficiency: Updated Results of a Global Phase 1 Study for Adult and Pediatric Patients

The ASH poster presentation included preliminary data from two adult patients with significant anemia and transfusion requirements who were treated as of the Nov. 3, 2021, cut-off date with RP-L301, Rocket's ex-vivo lentiviral gene therapy candidate for PKD. RP-L301 continues to be well tolerated, with no drug product related SAEs or infusion-related complications observed through 12-months post-treatment.

Preliminary clinical activity was observed in both patients at 12-months post-RP-L301 infusion. Both patients have reported improved quality of life following treatment.

• Patient 1 received a CD34+ cell dose of 3.9×106 cells/kilogram (kg). At 12-months post-treatment the patient had sustained improvement in hemoglobin levels of 13.3 grams (g)/deciliter (dL), compared to an average pre-treatment baseline of ~7.4 g/dL.
  • Patient 2 received a CD34+ cell dose of 2.4×106 cells/kg. At approximately 12-months post-treatment the patient had normalized hemoglobin levels of 14.8 g/dL, compared to a pre-treatment baseline of ~7.0 g/dL.