Rocket Pharmaceuticals, Inc. has announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation to RP-L301, the company’s investigational lentiviral-based gene therapy for pyruvate kinase deficiency (PKD).
PKD is a rare blood disorder characterized by severe anemia and excessive red blood cell breakdown.
RMAT designation was granted based on robust safety and efficacy data from the ongoing Phase 1 RP-L301 clinical trial and its potential to cure a life-threatening disease for which no curative therapies currently exist. The designation will provide the benefits of added FDA guidance and expedited review through the program’s development.
“Receiving RMAT designation from the FDA for RP-L301 is a major achievement in our pursuit to bring the first, potentially curative gene therapy treatment to patients living with PKD who have high unmet need. Notably, PKD has an estimated prevalence of up to 8,000 patients in the U.S. and Europe and represents one of the most significant patient opportunities in our LV hematology portfolio,” said Kinnari Patel, president and chief operating officer, Rocket Pharmaceuticals.
“Further, all four Rocket-sponsored programs with clinical data now have received RMAT designation from the FDA across both platforms, a unique showcase of our team’s ability both to select appropriate targets and develop gene therapies for them.”
Patel said results from the RP-L301 program demonstrate robust efficacy in both adult patients for up to 30 months with a highly favorable safety profile and were recently presented at ASGCT.
“The first pediatric patient has shown promising initial results similar to the adults, and enrollment has been completed in the phase 1 study. We look forward to initiating the phase 2 pivotal trial in the fourth quarter of 2023 as we continue to advance our world-class pipeline for patients facing such rare and devastating diseases.”
Established under the 21st Century Cures Act, RMAT designation is designed to expedite the drug development and review processes for promising pipeline products, including gene therapies. A regenerative medicine therapy is eligible for RMAT designation if it is intended to treat, modify, reverse or cure a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug or therapy has the potential to address unmet medical needs for such disease or condition.
In addition to RMAT, RP-L301 has also received Fast Track and Orphan Drug Designation.
About Rocket Pharmaceuticals’ RP-L301 safety profile
Results from the phase 1 program presented recently at the 26th Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT) demonstrate robust and sustained efficacy in both adult patients up to 30 months post-infusion demonstrated by normalized hemoglobin (from baseline levels in the 7.0-7.5 g/dL range), improved hemolysis parameters, red blood cell transfusion independence and improved quality of life with documented improvements via formal quality of life assessments.
The safety profile appears favorable, with no RP-L301-related serious adverse events in either of the adult patients.
The first pediatric patient results suggest efficacy similar to the adult cohort with an initial greater than five-point increase in hemoglobin (from median baseline level of 7.9 g/dL). The infusion was well tolerated, with engraftment achieved at day +15, hospital discharge less than one month following infusion, and no RP-L301-related serious adverse events or red blood cell transfusion requirements following engraftment.
About 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 4,000 to 8,000 patients in the U.S. and Europe. Children are the most commonly and severely affected subgroup of patients. Patients with PKD have a high unmet medical need, as currently available treatments include splenectomy and red blood cell transfusions, which are associated with immune defects and chronic iron overload.
Recently, mitapivat, an oral enzyme activator, was approved for use in adult patients, however its efficacy is limited in more severely-afflicted patients, most notably in those who are splenectomized, transfusion-dependent, or whose disease results from deleterious mutations.
RP-L301 was in-licensed from the Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) and Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz (IIS-FJD).
Earlier this year, Rocket Pharmaceuticals received FDA RMAT designation for its Danon disease gene therapy treatment.