Gene therapy for haemophilia A: a CMC trial in five patients
3 Oct 2026
A CMC team treated five people with severe haemophilia A using their own stem cells carrying a factor VIII gene, and none had a bleed during follow-up. The results were published in the New England Journal of Medicine.
What the work is
Severe haemophilia A is managed with factor VIII replacement or other products that stop or prevent bleeding. At CMC, the Department of Haematology and the Centre for Stem Cell Research, with Emory University in the United States, tested a different approach in five participants aged 22 to 41 with severe haemophilia A and no factor VIII inhibitors. Each person's own blood stem cells were taken, given a factor VIII gene using a lentiviral vector, and returned after conditioning.
What it found
- Factor VIII levels were sustained, and rose with the amount of vector in the blood.
- In the three participants in the second group, median factor VIII activity ranged from about 19 to 40 IU per decilitre.
- Across all five participants, the annualised bleeding rate was zero over a cumulative 81 months of follow-up (median 14 months).
- The study was a small single-centre trial funded by the Government of India's Ministry of Science and Technology and others. It does not yet show how long the effect lasts.
Source: Srivastava A, et al. Lentiviral gene therapy with CD34+ haematopoietic cells for haemophilia A. N Engl J Med 2025;392:450-457. doi:10.1056/NEJMoa2410597
The full author list is in the paper.