FDA delays decision on Rocket gene therapy

Feb. 14, 2024

The U.S. FDA has extended the priority review period by three months for Rocket Pharmaceuticals' autologous gene therapy for a rare pediatric immunodeficiency disorder.

The investigational therapy, branded Kresladi (marnetegragene autotemcel), originally had a PDUFA date of March 31 for leukocyte adhesion deficiency-I (LAD-I). The FDA pushed the date to June 30, to allow additional time to review clarifying chemistry, manufacturing and controls information submitted by Rocket in response to the agency's information requests. According to Rocket, the FDA confirmed no advisory committee meeting will be needed.

LAD-1 is caused by mutations in the ITGB2 gene encoding for the beta-2 integrin component CD18, a key protein needed to combat infections. Rocket's Kresladi contains autologous hematopoietic stem cells that have been genetically modified with a lentiviral vector to deliver a functional copy of the ITGB2 gene, which encodes for the beta-2 integrin component CD18.

The NJ-based biotech is hopeful that the therapy has the potential to change the treatment paradigm for patients living with severe LAD-I — one of the most aggressive and highly fatal immunodeficiencies ever characterized. Without a successful bone marrow transplant, mortality in patients with severe LAD-I is 60-75% prior to the age of 2 and survival beyond the age of 5 is uncommon, according to Rocket.

Back in 2022, Rocket revealed promising phase 2 trial results: 3-24 months after Kresladi (then RP-L201) infusion, all nine trial patients sustained stable CD18 expression with no therapy-related serious adverse events. Furthermore, among all participants, the overall survival at one year was 100% — and patients are reporting a statistically significant reduction in all hospitalizations.