FDA

First gene therapy OK’d for Wiskott-Aldrich syndrome

December 12, 2025

Brand name: Waskyra

Generic name: etuvetidigene autotemcel

Manufacturer: Fondazione Telethon

Approval date: December 9, 2025

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 of age 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.

Waskyra consists of the patient’s own hematopoietic stem cells (HSCs), which have been genetically modified to include functional copies of the WAS gene. Following reduced-intensity conditioning, the gene-corrected cells are infused intravenously to restore blood cell production. Waskyra restores functional WAS protein expression in affected cells, addressing the underlying cause of the disease.

WAS is a rare, life-threatening genetic disease caused by mutations in the WAS gene. The condition is characterized by bleeding, eczema, recurrent infections, and increased susceptibility to autoimmunity and lymphoreticular malignancies.

Efficacy and safety

The safety and effectiveness of Waskyra was assessed based on two open-label, single-arm, multinational clinical studies (Study 1: NCT01515462; Study 2: NCT03837483) and an expanded access program totaling 27 patients with severe WAS, which demonstrate substantial and sustained clinical benefit for patients with severe disease, with significant reductions in the primary disease manifestations that drive morbidity and mortality.

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

The most common adverse reactions (≥20%) are catheter-related infections, bacterial and viral infections, diarrhea, vomiting, stomatitis, liver injury, head injury, rhinitis, cough, rash, petechiae, hypersensitivity, anemia, febrile neutropenia, epistaxis, pyrexia, catheter site complications.

Sources:

FDA approves first gene therapy treatment for Wiskott-Aldrich syndrome. [News release]. 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapy-treatment-wiskott-aldrich-syndrome

Waskyra (etuvetidigene autotemcel) [package insert]. Food and Drug Administration. https://www.fda.gov/media/190096/download Revised December 2025. Accessed December 11, 2025.

Fondazione Telethon announces FDA approval of Waskyra™ (etuvetidigene autotemcel), a gene therapy for the treatment of Wiskott-Aldrich syndrome. [News release]. 2025. https://www.fondazionetelethon.it/en/stories-and-news/news/from-telethon-foundation/fondazione-telethon-announces-fda-approval-of-waskyra-etuvetidigene-autotemcel-a-gene-therapy-for-the-treatment-of-wiskott-aldrich-syndrome/