First FDA-Approved Gene Therapy for Wiskott-Aldrich Syndrome

Waskyra (etuvetidigene autotemcel) is an autologous CD34+ hematopoietic stem-cell-based gene therapy given as a single intravenous infusion after mobilisation, apheresis, and reduced-intensity conditioning. On the US Prescribing Information (revised 07/2026) it is 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.

This is a traditional FDA biologic approval (CBER). The FDA approved STN BL 125846/0 on 9 December 2025. Approval letter issues U.S. License No. 2378 to Fondazione Telethon ETS, Rome, Italy. Associated NCT numbers on the letter: NCT01515462 and NCT03837483. FDA materials describe Orphan Drug designation and a rare pediatric disease Priority Review Voucher.

Distinct path — not this label: Supportive care alone, immunoglobulin replacement, or thrombopoietin-receptor agonists are not this gene-therapy label. Allogeneic HSCT from a suitable HLA-matched related donor is a separate labelled clinical path — Waskyra is for people for whom HSCT is appropriate and no suitable HLA-matched related donor is available. Other primary immunodeficiencies are not this labelled population. Today’s approved US autologous gene-therapy pathway for WAS in that setting is Fondazione Telethon Waskyra STN 125846.

Manufactured for US supply under Fondazione Telethon ETS (U.S. License 2378). Company and foundation materials describe a US commercialisation partnership with Orphan Therapies (Orphan Therapeutics Accelerator) to stand up distribution and patient-support logistics.

Where this is taking place

Approved prescription route today: United States — FDA-labelled Waskyra for WAS ages ≥6 months (and adults) when HSCT is appropriate and no suitable HLA-matched related donor is available, administered only at a qualified treatment centre experienced in stem-cell transplantation / gene therapy after mobilisation with G-CSF + plerixafor, apheresis, collection of a non-transduced back-up graft (≥3×10⁶ CD34+/kg), rituximab (per PI timing), busulfan + fludarabine reduced-intensity conditioning, then one-time IV infusion of the thawed autologous product. Foundation contact on the PI for product issues / suspected infections transmitted by product / malignancy sample instructions: Fondazione Telethon ETS 1-888-212-6928. This is a centre-administered one-time gene therapy conversation — not a retail pharmacy pickup and not a DIY import.

Public foundation / patient-organisation materials around launch described US qualified centres as still being evaluated / stood up with Orphan Therapies. Treat named-centre lists as dynamic. Ask Telethon / Orphan Therapies / an immunology-transplant team for the current referral path. Do not assume every major children’s hospital already infuses Waskyra.

Outside the United States: At the time of writing, no confirmed Health Canada Notice of Compliance / DIN for Waskyra. Do not import on your own. Clinical manufacturing and historical treatment experience at IRCCS Ospedale San Raffaele (Milan) supports the evidence base — that is not the same sentence as a Canadian or other foreign marketing authorisation for your home regulator.

Study 1 — NCT01515462 (ClinicalTrials.gov: completed) and Study 2 — NCT03837483 (ClinicalTrials.gov: active but no longer taking new patients) (plus expanded-access cohorts) — Open-label gene-therapy programs in genetically confirmed WAS without a suitable HLA-matched donor. Letter and PI frame the pooled treated population (N=27 infused; efficacy population N=26). Labelled commercial access is through qualified centres. Completed research cohorts are not walk-in enrolment.

The practical prescription route in the US is a pediatric immunology / bone-marrow transplant / gene-therapy team working with a qualified treatment centre and Telethon / Orphan Therapies logistics to confirm WAS genetics, donor status, organ fitness for conditioning, and payer steps.

Approval matrix

Access by country

• United States: Ask a pediatric immunology / BMT / gene-therapy clinician about referral for FDA-labelled Waskyra. Labelled 9 December 2025. Path: confirm WAS mutation + transplant appropriateness + absence of suitable HLA-matched related donor → mobilise / apherese → bank back-up cells → reduced-intensity conditioning → thaw and IV-infuse autologous product (min 7×10⁶ CD34+/kg; max volume <20% estimated plasma volume; each bag within 2 hours of thaw) → lifelong malignancy surveillance. Product / AE / infection-transmission / malignancy-sample contact on PI: Fondazione Telethon ETS 1-888-212-6928 or FDA MedWatch 1-800-FDA-1088. No list price or copay dollars in this article. This is US labelled supply through qualified centres, not a DIY import.

• Canada: Waskyra authorisation not confirmed. Ask the Canadian immunology / transplant clinic what legal paths exist in Canada when a Canadian Waskyra label does not yet exist.

• European Union / United Kingdom / Australia / Japan / other countries: Confirm your local regulator’s current status with the treating centre. A US bag is not a foreign pack. Do not import on your own.

• If your regulator has not authorised it: do not import on your own. Ask the local clinician about documented special-access / named-patient rules, referral to a centre in a labelled country, or waiting.

Who is eligible (from the US label)

This is an autologous gene-modified stem-cell conversation on the Prescribing Information — not a matched-related-donor allogeneic transplant label, and not established under 6 months of age.

United States (USPI, revised July 2026):

• Indication: Pediatric patients ≥6 months and adults with WAS (WAS gene mutation) for whom HSCT is appropriate and no suitable HLA-matched related stem-cell donor is available.
• Minimum recommended dose: 7×10⁶ CD34+ cells/kg (actual dose on Lot Information Sheet; treated range in studies about 7–31×10⁶/kg, median about 16.9×10⁶/kg).
• Contraindications: Hypersensitivity to active substance or excipients; prior HSCT within 6 months or residual donor cells; prior hematopoietic stem-cell gene therapy; contraindications to mobilisation / conditioning.
• Warnings: Hypersensitivity / infusion reactions (DMSO); engraftment failure; cytopenias (≥8 weeks monitoring); serious infections; infectious-agent transmission; hepatic VOD; lifelong insertional oncogenesis / secondary malignancy risk; PCR-based HIV false positives; no future blood / organ / tissue / cell donation.
• Most common adverse reactions (≥20% on PI): 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.
• Pediatrics: Established ≥6 months; not established <6 months.

Not labelled on the sources checked for this article:

• Use when a suitable HLA-matched related donor is available (that remains an allogeneic HSCT conversation).
• Children younger than 6 months.
• Canadian (and several other) marketing authorisations (not confirmed here).
• Treating completed research enrolment as open commercial trial recruitment.

What the pivotal evidence showed (USPI)

Use the USPI for a prescription conversation. Journals are supportive reading.

Pooled Study 1 / Study 2 / EAP (USPI §14):

• 27 patients received a single Waskyra infusion; 26 in efficacy analyses (one mobilisation failure excluded).
• Median age 2.6 years (range 1–35); all male in the reported cohort.
• Severe-infection rate: 2.0 (95% CI 1.50–2.61) per patient-year pre-treatment → 0.2 (95% CI 0.04–0.40) per patient-year at 6–18 months post-gene therapy.
• Moderate/severe bleeding rate: 2.0 (95% CI 1.50–2.61) per patient-year pre-treatment → 0.8 (95% CI 0.49–1.22) per patient-year in the 12 months after treatment.
• Median follow-up about 5.67 years (range about 0.37–13.26 years) in the safety description.

How to talk with a doctor

Bring this page and ask an immunology / BMT / gene-therapy clinician:

1. “We have genetically confirmed Wiskott-Aldrich syndrome. Do we have a suitable HLA-matched related donor, or is labelled US Waskyra the path to discuss?”
2. “Which qualified treatment centre are you referring to, and what is the current Telethon / Orphan Therapies intake step?”
3. “What are the conditioning, infection-prophylaxis, and lifelong cancer-surveillance plans?”
4. “How should we bank the back-up non-transduced stem cells before conditioning?”
5. If outside the US: “Has our regulator authorised Waskyra, or what legal special-access options exist?”

Who is involved (from primary sources)

• License holder / manufacturer: Fondazione Telethon ETS, Via Varese 16/B, 00185 Rome, Italy — U.S. License 2378 (approval letter / USPI).
• US commercialisation partner (company/foundation materials): Orphan Therapies / Orphan Therapeutics Accelerator — distribution, centre engagement, patient-support build-out (confirm current phone/URL with the treating centre; contacts beyond the PI Telethon line are omitted here).
• Pivotal programs: Study 1 NCT01515462; Study 2 NCT03837483; expanded-access cohorts described on USPI.
• Product / AE contact on USPI: Fondazione Telethon ETS 1-888-212-6928.

Names and roles above are limited to what appears on the primary sources cited. Contacts not listed on those sources are omitted.

Sources

• FDA approval letter STN BL 125846/0, 9 Dec 2025
• FDA Waskyra product page / Package Insert Rev 07/2026
• ClinicalTrials.gov NCT01515462, NCT03837483
• Fondazione Telethon / Orphan Therapeutics Accelerator public materials on US access model (centre network still standing up — stated as such)

Authorized is not funded. Not medical advice.