Rocket Pharmaceuticals Announces Positive Preliminary Clinical Data from Phase 1 Trial of RP-L301 for the Treatment of Pyruvate Kinase Deficiency at the 62nd American Society of Hematology Annual Meeting

Dec. 6, 2020 15:00 UTC

• Preliminary Data from First Patient Demonstrates Initial Safety and Tolerability of RP-L301, Near Doubling of Hemoglobin to Normal Range and Additional Normalization of Hemolysis Markers
• Rocket’s Largest Lentiviral Pipeline Program Aims to Address Unmet Need for up to 8,000 PKD Patients in the U.S. and Europe

NEW YORK--(BUSINESS WIRE)-- 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 preliminary clinical data from its Phase 1 clinical trial of RP-L301 for the treatment of Pyruvate Kinase Deficiency (PKD), showing significant improvement in hemoglobin levels and transfusion independence over the initial 3-months following therapy. These results were presented virtually at the 62^nd American Society of Hematology (ASH) Annual Meeting in a poster presentation.

“The positive preliminary clinical results for RP-L301 point to a potential path to transform the management of PKD using an approach that addresses the root cause of the disease for the first time at the genetic level,” said Gaurav Shah, M.D., Chief Executive Officer and President of Rocket. “RP-L301 has the potential to normalize hemoglobin levels, as demonstrated by an increase from an average of 7.4 g/dL (at baseline) to 14.3 g/dL (at 3-months post-treatment) with no transfusion requirements after hematopoietic reconstitution in the first patient treated. This patient exhibited a peripheral blood VCN of 2.21 at 1-month post-treatment, suggesting robust and rapid engraftment. Circulating bilirubin and other markers of hemolysis also normalized. We look forward to progressing the study and presenting longer-term data in the second half of 2021. We remain focused on our mission of relieving suffering for PKD patients who are frequently transfusion-dependent and debilitated from the disease and its treatments.”

Key findings from the poster presentation are highlighted below. To access the presentation please visit: https://www.rocketpharma.com/ash-presentations/

Lentiviral Mediated Gene Therapy for Pyruvate Kinase Deficiency: A Global Phase 1 Study for Adult and Pediatric Patients

The data presented in the poster presentation are from two adult patients with significant anemia and transfusion requirement. Patient L301-006-1001 was treated with RP-L301, Rocket’s ex vivo lentiviral gene therapy candidate for PKD. Patient L301-006-1001 was 31-years old at the time of enrollment and had been followed for 3-months post treatment at the time of data cutoff. Patient L301-001-1002 was 47-years old at the time of enrollment and was recently treated. Key highlights from the presentation include:

• RP-L301 was well tolerated, with no serious safety issues or infusion-related complications observed 3-months post treatment
• Patient L301-006-1001 received a cell dose of 3.9x10⁶ cells/kilogram (kg) with a drug product mean vector copy number (VCN) of 2.73
  • Hematopoietic reconstitution in less than 2 weeks
  • Peripheral blood VCN of 2.21 at 1-month, normalized hemoglobin (Hb) and hemolysis markers (baseline Hb ~7.4 grams (g)/deciliter (dL); Hb 14.3 g/dL at 3-months post treatment with RP-L301)
  • No red blood cell transfusion requirements following engraftment
    • In the two years prior to enrollment, the patient underwent approximately 14 transfusion episodes
  • Normalization of bilirubin, lactate dehydrogenase (LDH) and erythropoietin levels at 3-months post treatment, each of which had been substantially elevated prior to study enrollment
• Patient L301-006-1002 was recently treated with RP-L301
  • The patient received a cell dose of 2.4x10⁶ cells/kg with a mean drug product VCN of 2.08

Aspects of the RP-L301 pre-clinical data package, including phenotypic reversal in the murine PKD knockout model, were also reviewed.

Conference Call Details Rocket management will host a conference call and webcast on December 7, at 6:00 p.m. EST. To access the call and webcast, please click here. The webcast replay will be available on the Rocket website following the completion of the call.

Investors may listen to the call by dialing (866) 866-1333 from locations in the United States or +1 (404) 260-1421 from outside the United States. Please refer to conference ID number 50038102.

About Pyruvate Kinase Deficiency

Pyruvate kinase deficiency (PKD) is a rare, monogenic red blood cell disorder resulting from a mutation in the PKLR gene encoding for the pyruvate kinase enzyme, a key component of the red blood cell glycolytic pathway. Mutations in the PKLR gene result in increased red blood cell destruction and the disorder ranges from mild to life-threatening anemia. PKD has an estimated prevalence of 3,000 to 8,000 patients in the United States and the European Union. Children are the most commonly and severely affected subgroup of patients. Currently available treatments include splenectomy and red blood cell transfusions, which are associated with immune defects and chronic iron overload.

RP-L301 was in-licensed from the Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER) and Instituto de Investigacion Sanitaria Fundacion Jimenez Diaz (IIS-FJD).

About Rocket Pharmaceuticals, Inc.

Rocket Pharmaceuticals, Inc. (NASDAQ: RCKT) (“Rocket”) is advancing an integrated and sustainable pipeline of genetic therapies that correct the root cause of complex and rare childhood disorders. The company’s platform-agnostic approach enables it to design the best therapy for each indication, creating potentially transformative options for patients afflicted with rare genetic diseases. Rocket's clinical programs using lentiviral vector (LVV)-based gene therapy are for the treatment of Fanconi Anemia (FA), a difficult to treat genetic disease that leads to bone marrow failure and potentially cancer, Leukocyte Adhesion Deficiency-I (LAD-I), a severe pediatric genetic disorder that causes recurrent and life-threatening infections which are frequently fatal, Pyruvate Kinase Deficiency (PKD) a rare, monogenic red blood cell disorder resulting in increased red cell destruction and mild to life-threatening anemia and Infantile Malignant Osteopetrosis (IMO), a bone marrow-derived disorder. Rocket’s first clinical program using adeno-associated virus (AAV)-based gene therapy is for Danon disease, a devastating, pediatric heart failure condition. For more information about Rocket, please visit www.rocketpharma.com.

Rocket Cautionary Statement Regarding Forward-Looking Statements

Various statements in this release concerning Rocket's future expectations, plans and prospects, including without limitation, Rocket's expectations regarding its guidance for 2020 in light of COVID-19, the safety, effectiveness and timing of product candidates that Rocket may develop, to treat Fanconi Anemia (FA), Leukocyte Adhesion Deficiency-I (LAD-I), Pyruvate Kinase Deficiency (PKD), Infantile Malignant Osteopetrosis (IMO) and Danon Disease, and the safety, effectiveness and timing of related pre-clinical studies and clinical trials, may constitute forward-looking statements for the purposes of the safe harbor provisions under the Private Securities Litigation Reform Act of 1995 and other federal securities laws and are subject to substantial risks, uncertainties and assumptions. You should not place reliance on these forward-looking statements, which often include words such as "believe," "expect," "anticipate," "intend," "plan," "will give," "estimate," "seek," "will," "may," "suggest" or similar terms, variations of such terms or the negative of those terms. Although Rocket believes that the expectations reflected in the forward-looking statements are reasonable, Rocket cannot guarantee such outcomes. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including, without limitation, Rocket's ability to monitor the impact of COVID-19 on its business operations and take steps to ensure the safety of patients, families and employees, the interest from patients and families for participation in each of Rocket’s ongoing trials, our expectations regarding when clinical trial sites will resume normal business operations, our expectations regarding the delays and impact of COVID-19 on clinical sites, patient enrollment, trial timelines and data readouts, our expectations regarding our drug supply for our ongoing and anticipated trials, actions of regulatory agencies, which may affect the initiation, timing and progress of pre-clinical studies and clinical trials of its product candidates, Rocket's dependence on third parties for development, manufacture, marketing, sales and distribution of product candidates, the outcome of litigation, and unexpected expenditures, as well as those risks more fully discussed in the section entitled "Risk Factors" in Rocket's Quarterly Report on Form 10-Q for the quarter ended September 30, 2020, filed November 6, 2020 with the SEC. Accordingly, you should not place undue reliance on these forward-looking statements. All such statements speak only as of the date made, and Rocket undertakes no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

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