Rocket Pharma's Kresladi Wins First-Ever Gene Therapy Approval for LAD-I
By FieldPulse Editorial · March 26, 2026
Tags: FDA, Rare Disease
The FDA granted accelerated approval to Rocket Pharmaceuticals' Kresladi, the first gene therapy for severe leukocyte adhesion deficiency type I. Only ~25 new US cases are diagnosed per year.
The FDA on March 26 granted accelerated approval to Kresladi (marnetegragene autotemcel) from Rocket Pharmaceuticals , making it the first gene therapy approved for severe leukocyte adhesion deficiency type I (LAD-I) — an ultra-rare genetic disorder that compromises the immune system's ability to fight infections.
The approval came with a Rare Pediatric Disease Priority Review Voucher (PRV), a potentially valuable financial asset that Rocket can sell or use for a future regulatory filing.
Understanding LAD-I and Why This Approval Matters LAD-I is caused by mutations in the ITGB2 gene, which encodes a protein essential for white blood cells to migrate to sites of infection.
Without functional white blood cell adhesion, patients — predominantly infants and young children — suffer recurrent, life-threatening bacterial and fungal infections.
Severe LAD-I has historically been fatal without a bone marrow transplant, and even transplantation carries significant morbidity and mortality risks, particularly when a fully matched donor is unavailable.
Kresladi works by collecting the patient's own hematopoietic stem cells, genetically modifying them ex vivo to express a functional copy of the ITGB2 gene using a lentiviral vector, and then reinfusing the corrected cells after myeloablative conditioning.
The approach is conceptually similar to other approved gene therapies like bluebird bio's Zynteglo and Lyfgenia — autologous ex vivo gene correction followed by reinfusion — but targets a different disease.
The patient population is extraordinarily small.
Approximately 25 new cases of severe LAD-I are diagnosed in the United States each year.
This is ultra-rare even by rare disease standards, placing Kresladi in the same commercial category as other gene therapies that serve tiny populations at premium price points.
The PRV and Its Commercial Significance The Rare Pediatric Disease Priority Review Voucher is, in many cases, the most immediately valuable commercial asset that com.