FDA Approves First Gene Therapy Treatment for Wiskott-Aldrich Syndrome

The U.S. Food and Drug Administration (FDA) has approved Waskyra (etuvetidigene autotemcel), the first cell-based gene therapy for the treatment of Wiskott-Aldrich syndrome (WAS). Waskyra is indicated for pediatric patients 6 months and older and adults with WAS who have a mutation in the WAS gene and for whom hematopoietic stem cell transplantation (HSCT) is appropriate and no suitable human leukocyte antigen (HLA)-matched related stem cell donor is available.

The safety and effectiveness of Waskyra was assessed based on two open-label, single-arm, multinational clinical studies and an expanded access program totaling 27 patients with severe WAS, which demonstrate substantial and sustained clinical benefit for patients with severe WAS, with significant reductions in the primary disease manifestations that drive morbidity and mortality.

The rate of severe infections decreased by 93 percent in the six to 18 months post-treatment period compared to the rate 12 months before treatment. Similarly, moderate and severe bleeding events were reduced by 60 percent in the first 12 months post-treatment compared to the year prior to treatment. Most patients did not report moderate to severe bleeding after four years post treatment.

The most common side effects associated with Waskyra include rash, respiratory tract infection, febrile neutropenia, catheter related infection, vomiting, diarrhea, liver injury and petechiae.

“Today’s approval addresses the urgent need in the WAS community, where patients have described living ‘a life of terrifying worry and fear’ without any approved therapies available,” said Vijay Kumar, MD, acting director of the CBER Office of Therapeutic Products. “This action marks significant progress in the development of much-needed treatment options for patients affected by this debilitating and life-threatening disease, enabling them to engage in everyday activities such as going to school or participating in sports.”