NEW YORK – Rocket Pharmaceuticals on Monday said its regulatory application seeking approval for RP-L201 (marnetegragene autotemcel), an investigational gene therapy for severe leukocyte adhesion deficiency-I, has been accepted by the US Food and Drug Administration and is undergoing priority review.
Severe leukocyte adhesion deficiency-I (LAD-I) is a rare, inherited pediatric disease caused by mutations in the ITGB2 gene, which encodes the beta-2 integrin component CD18. This protein plays a key role in deterring infections by enabling leukocyte adhesion and extravasation from blood vessels. Children with LAD-I have frequent life-threatening bacterial and fungal infections, don't respond well to antibiotics, and often end up in the hospital.
Patients can receive bone marrow transplants, but this carries substantial risk of death and often isn't available quickly enough. As such, many LAD-I patients don't survive beyond childhood, Kinnari Patel, Rocket's president and chief operating officer, said in a statement. "Today's acceptance of the BLA by the FDA marks a significant milestone for Rocket towards our goal of delivering a one-time gene therapy to patients facing the devastating effects of severe LAD-I," Patel added.
RP-L201 comprises autologous hematopoietic stem cells that are genetically modified with a lentiviral vector and are designed to deliver a functional copy of the ITGB2 gene. There are between 800 and 1,000 LAD-I patients in the US and in Europe, and regulators in these locations have deemed RP-L201 an orphan drug. The FDA has also granted the gene therapy fast-track and regenerative medicine advanced therapy designations.
In its biologics license application, Rocket submitted data from a global Phase I/II study in which all nine LAD-I patients who received an infusion of RP-L201 were alive one year later. Patients also had much lower rates of significant infections after receiving the gene therapy than they did before treatment. The company also submitted evidence that patients' LAD-I-related skin lesions were healing and that patients were better able to repair wounds. All the patients in the trial also appeared to tolerate RP-L201 very well, Rocket said in a statement, and experienced no treatment-related serious adverse events.
The Cranbury, New Jersey-based firm expects the FDA to issue a decision about its biologics application by March 31, 2024.