Fondazione Telethon Announces FDA approval of Waskyra™ (etuvetidigene autotemcel), a Gene Therapy for the Treatment of Wiskott-Aldrich Syndrome

• WAS affects almost exclusively males, with an estimated incidence of 1 in 250,000 live male births.
• The therapy represents a major scientific and clinical achievement, offering new hope for patients affected by this condition.

ROME, Dec. 10, 2025 /PRNewswire/ -- Fondazione Telethon announced today that the U.S. Food and Drug Administration (FDA) has approved the Biologics License Application (BLA) for Waskyra, an ex vivo gene therapy for patients with Wiskott-Aldrich syndrome (WAS), a rare and life-threatening immunodeficiency.

WAS, seen almost exclusively in males, affects blood cells and cells of the immune system (the body's natural defenses). It is caused by abnormalities in the gene that produces the WAS protein found in blood cells and certain immune cells. Because people with the condition lack a functional WAS protein, their immune cells and blood cells do not develop and function normally.

The FDA's approval of the BLA of Waskyra follows a positive opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use for the same product just a few weeks earlier.

Developed through decades of research at the San Raffaele Telethon Institute for Gene Therapy (SR-Tiget) in Milan, Waskyra represents a major scientific and clinical achievement, offering new hope for patients affected by this condition.

"The FDA's approval of Waskyra is an extraordinary achievement – not only for Italian research and for Fondazione Telethon, but for the global rare disease community," said Ilaria Villa, CEO of Fondazione Telethon. "It confirms the value of a patient-centered model that turns research into real treatments, especially where the market fails to act."

"The approval of this gene therapy represents a decisive step forward and a tangible response to the needs of patients," commented Dr. Alessandro Aiuti, Deputy director clinical research at SR-Tiget, Chief of Pediatric Immunohematology at IRCCS Ospedale San Raffaele and Full Professor of Pediatrics at Università Vita-Salute San Raffaele. "Seeing years of scientific research and dedication translate into real therapeutic opportunities for people gives profound meaning to our work."

The clinical trial phase was conducted at IRCCS Ospedale San Raffaele, a center of excellence in gene therapy for WAS and other diseases.

Fondazione Telethon is the first non-profit organization to have successfully led the full pathway of an ex vivo gene therapy from laboratory research to regulatory approval, collaborating with industry partners to bring gene therapies from discovery to patients.

FDA approval further recognizes Fondazione Telethon's excellence in research and strengthens its position as an international leader in rare genetic disease research and the development of advanced therapies.

About Wiskott-Aldrich syndrome (WAS) 

Wiskott-Aldrich syndrome is a rare genetic blood disorder that causes immunodeficiency and low platelet count, resulting from mutations in the WAS gene. The disease manifests from early childhood with recurrent and persistent infections, bleeding episodes and eczema, and is associated with an increased risk of developing autoimmune diseases and lymphomas.
It affects almost exclusively males, with an estimated incidence of 1 in 250,000 live male births. Current treatment options include supportive therapies aimed at managing and preventing clinical manifestations. The only potentially curative option is hematopoietic stem cell transplantation, for which a compatible donor is not always available, and which is not without risks.

About Waskyra™ (etuvetidigene autotemcel) gene therapy for Wiskott-Aldrich syndrome

Waskyra consists of a single administration of autologous CD34+ hematopoietic stem and progenitor cells that have been transduced with a lentiviral vector encoding the WAS gene.
Once corrected, the stem cells are reinfused into the patient, who undergoes chemotherapy beforehand to prepare the bone marrow to receive them. It has been shown that Waskyra reduces the frequency of severe and moderate bleeding events and serious infections in patients with WAS compared with the period prior to treatment. 
In cases where transplantation from a compatible family donor is not possible, a safe and efficacious gene therapy represents a potential therapeutic option for eligible patients.

Indication and Important Safety Information

What is Waskyra?

Waskyra is an autologous hematopoietic stem cell-based gene therapy indicated for the treatment of pediatric patients aged 6 months and older and adults with Wiskott-Aldrich Syndrome (WAS) who have a mutation in the WAS gene for whom hematopoietic stem cell transplantation (HSCT) is appropriate and no suitable human leukocyte antigen (HLA)-matched related stem cell donor is available.

What is the most important information I should know about Waskyra?

During the clinical trials no adverse reactions attributable to Waskyra nor to conditioning regimen were reported. Some side effects are related to pre-treatment and other study procedures.
Treatment with Waskyra is preceded by medical interventions, namely haematopoietic stem cell collection through peripheral blood mobilisation with G-CSF with or without plerixafor followed by apheresis, pre-treatment with rituximab (anti-CD20 monoclonal antibody) and reduced intensity conditioning, which carry their own risks. When assessing the safety of a treatment with Waskyra, the safety profile and product information of the medicinal products used for peripheral blood mobilisation, pre-treatment and reduced intensity conditioning should be considered, in addition to the risks linked to the gene therapy. 

Negative side effects of prescription drugs are encouraged to report to the FDA. Visit www.fda.gov/medwatch, or call 1–800-FDA-1088.

For complete product information, please see the full Prescribing Information at
Site: https://www.fda.gov/vaccines-blood-biologics/waskyra
Package Insert: https://www.fda.gov/media/190096/download?attachment

About Fondazione Telethon

Fondazione Telethon is an Italian non-profit biomedical organization committed to advancing research on rare and complex genetic diseases. For over 35 years, it has supported high-impact science aimed at developing innovative treatments and improving the lives of people affected by these conditions.

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