FDA Approves Kresladi Gene Therapy for Severe Immune Disorder

The U.S. Food and Drug Administration (FDA) has approved Kresladi, a gene therapy for severe leukocyte adhesion deficiency-I (LAD-I). This rare genetic disorder leaves children vulnerable to life-threatening infections, and the approval, announced on November 10, 2026, follows more than 30 years of research by Dr. Donald Kohn. Dr. Kohn has focused much of his career on developing gene therapies for pediatric immune disorders, and this milestone marks a significant development for the field and for families affected by the condition.

Severe LAD-I is caused by mutations in the ITGB2 gene, which disrupt the proteins necessary for a functioning immune response. Without effective treatment, children are highly susceptible to bacterial and fungal infections that often lead to early mortality. During a clinical trial led by UCLA, nine patients between the ages of 5 months and 9 years were treated with the therapy. All nine participants survived the trial and showed restored immune function.

Kresladi is a one-time treatment that uses a patient’s own blood stem cells. A functional copy of the ITGB2 gene is introduced into these cells before they are returned to the patient to begin producing healthy immune cells. By using the patient's own genetic material, the therapy avoids the complications often associated with traditional bone marrow transplants, such as graft-versus-host disease. Trial results showed a sharp decline in severe infections, with no reports of immune rejection or graft failure.

This approval represents a landmark for Dr. Kohn and his team, as well as for the California Institute for Regenerative Medicine (CIRM), which co-funded the clinical trials. Since its founding in 2004, CIRM has worked to accelerate the development of various stem cell therapies. The success of Kresladi is expected to encourage broader research and investment into gene therapies for other rare diseases, potentially opening doors for treatments where medical options have historically been limited.

Looking ahead, Dr. Kohn remains hopeful that this milestone will drive further support for therapies targeting rare immune disorders. He is currently overseeing clinical trials for another severe condition, ADA-SCID, which have also yielded promising results. The approval of Kresladi serves as a practical demonstration of how gene therapy can change the trajectory for children born with rare genetic diseases, offering a new approach to managing these complex conditions.