FDA Grants Accelerated Approval to Rocket’s Kresladi Gene Therapy for Rare Pediatric Disorder LAD-I

The U.S. Food and Drug Administration (FDA) has granted accelerated approval to Kresladi (marnetegragene autotemcel) for pediatric patients with severe Leukocyte Adhesion Deficiency Type I (LAD-I) who lack an available human leukocyte antigen (HLA)-matched sibling donor for allogeneic hematopoietic stem cell transplantation.

The therapy, developed by Rocket Pharmaceuticals, becomes the first gene therapy approved for the rare inherited immune disorder. The decision was announced by the FDA, with detailed clinical results from the sponsor not yet publicly released.

Severe LAD-I is caused by mutations in the ITGB2 gene, which prevent white blood cells from effectively adhering to blood vessel walls and migrating to sites of infection. As a result, affected children experience recurrent and often life-threatening bacterial and fungal infections, with significant morbidity and mortality during the first decade of life.

Kresladi is an autologous hematopoietic stem cell (HSC) gene therapy. The treatment uses a patient’s own stem cells, which are genetically modified to introduce functional copies of the ITGB2 gene. After conditioning therapy, the modified cells are infused back into the patient as a single intravenous dose with the aim of restoring immune function.

According to the FDA, the approval was supported by results from an open-label, single-arm, multicenter clinical study (NCT03812263) that evaluated changes in disease-related biomarkers following treatment. Patients receiving the therapy showed increases in neutrophil CD18 and CD11a cell surface expression at 12 months after infusion, with sustained expression through 24 months. These biomarkers indicate improved immune activity and served as surrogate endpoints reasonably likely to predict clinical benefit in LAD-I.

The FDA said the most commonly reported adverse events in the study included anemia, low platelet and white blood cell counts, mouth sores, respiratory and viral infections, fever, febrile neutropenia, nausea, vomiting, skin infections, rash, vascular device-related infections, and elevated liver enzymes.

“Today’s accelerated approval provides a breakthrough treatment for pediatric patients with severe Leukocyte Adhesion Deficiency Type I, the first FDA-approved gene therapy to treat this disease,” said Vinay Prasad, M.D., M.P.H., Chief Medical and Scientific Officer and Director of the FDA’s Center for Biologics Evaluation and Research. He noted that the agency applies regulatory flexibility for rare diseases, considering limited patient populations and multiple sources of evidence while maintaining scientific standards.

Megha Kaushal, M.D., M.S., Acting Deputy Director of the CBER Office of Therapeutic Products, added that the therapy targets the underlying disease mechanism and may help affected children achieve better quality of life.

Kresladi received Orphan Drug, Rare Pediatric Disease, Regenerative Medicine Advanced Therapy (RMAT), and Fast Track designations during development. The FDA also granted Rocket Pharmaceuticals a Rare Pediatric Disease Priority Review Voucher with the approval.

Because the therapy was cleared under the accelerated approval pathway, the company is required to conduct post-marketing studies to verify and describe its clinical benefit. Continued approval may depend on confirmation of benefit in future trials.

Reference

FDA Approves First Gene Therapy for Severe Leukocyte Adhesion Deficiency Type I, 26 March 2026, https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapy-severe-leukocyte-adhesion-deficiency-type-i

A Clinical Trial to Evaluate the Safety and Efficacy of RP-L201 in Subjects With Leukocyte Adhesion Deficiency-I, ClinicalTrials.gov ID NCT03812263, https://clinicaltrials.gov/study/NCT03812263