FDA approves Rocket's Kresladi as the first gene therapy for severe leukocyte adhesion deficiency-I

The FDA on March 26, 2026 granted accelerated approval to Rocket Pharmaceuticals' Kresladi (marnetegragene autotemcel), the first gene therapy for severe leukocyte adhesion deficiency type I (LAD-I). The one-time treatment is indicated for paediatric patients with biallelic ITGB2 variants who lack an HLA-matched sibling donor for allogeneic haematopoietic stem cell transplant.

LAD-I is an ultra-rare genetic immune disorder—fewer than 400 cases reported worldwide—caused by mutations in the ITGB2 gene that encodes the CD18 integrin subunit essential for white blood cell migration. Without treatment, the severe form (CD18 expression <1 %) is near-uniformly fatal in early childhood due to recurrent bacterial infections. The previous standard of care, allogeneic bone marrow transplant, carries transplant-related mortality of approximately 19 % and requires a matched donor many patients lack.

Kresladi uses the patient's own haematopoietic stem cells, which are collected and transduced ex vivo with a lentiviral vector encoding a functional ITGB2 copy. Modified cells are reinfused after conditioning chemotherapy. In the Phase 1/2 open-label trial (9 children, median follow-up 4.2 years), HSCT-free survival was 100 %. All evaluable patients showed sustained neutrophil CD18 expression through at least month 42, with a substantial reduction in infection incidence and restored wound-healing capability.

The safety profile was consistent with the conditioning regimen; no treatment-related serious adverse events were reported. Kresladi received Orphan Drug, Rare Paediatric Disease, RMAT, and Fast Track designations, and Rocket was awarded a Priority Review Voucher.

Sources: FDA Press Announcement; Rocket Pharmaceuticals.