A groundbreaking clinical study, published today in Lancet Haematology and coordinated by Professor Alessandro Aiuti—Professor of Pediatrics at Vita‑Salute San Raffaele University and Vice‑Director of the S San Raffaele-Telethon Institute for Gene Therapy (SR-Tiget) in Milan—confirms the efficacy of gene therapy as a treatment for Wiskott–Aldrich Syndrome (WAS), a serious rare genetic disease affecting blood cells.
Launched in 2010, the clinical trial involved eight patients and was made possible through a pioneering alliance between IRCCS Ospedale San Raffaele, Fondazione Telethon, and GlaxoSmithKline (transferred to Orchard Therapeutics in 2018), building on over two decades of cutting-edge research conducted within SR‑Tiget laboratories
Using a lentiviral vector, researchers restored the defective Wiskott‑Aldrich syndrome protein (WASp) gene in patients’ hematopoietic stem cells. This ex vivo gene therapy approach enabled treated patients to produce healthy platelets and immune cells—offering remarkable therapeutic benefits.
WAS results from a mutation in the gene encoding the WAS protein (WASp), which impairs platelet production and immune cell functionality. Patients suffer from chronic bleeding, recurrent infections, heightened risks of tumors, autoimmune and inflammatory diseases, and persistent eczema.
Until now, bone marrow transplantation remained the only available, albeit risky, treatment option—which was not accessible to all patients.
In the clinical protocol, researchers collected patients’ hematopoietic stem cells and restored them by introducing a correct version of the WASp gene using a lentiviral vector—an engineered, inactivated virus. This enabled the stem cells to repopulate the blood with functional platelets and immune cells, demonstrating a significant therapeutic effect.
This milestone underscores Fondazione Telethon’s commitment to advancing gene therapy from laboratory innovation to clinical reality.
