Gene therapy to restore immune function in X-linked SCID (SCID‑X1)

Gene therapy for SCID-X1 with low dose busulfan and a SIN-lentiviral vector

NIH-funded research Boston Children's Hospital · NIH-11263682

This treatment uses a child’s own blood stem cells, a safer lentiviral carrier, and a low dose of chemotherapy to help boys with SCID‑X1 rebuild their immune system and make antibodies.

Quick facts

Grant typeU01 cooperative agreement
Study typeNIH-funded research
Funding institutionBoston Children's Hospital NIH-funded
Lab location1 site (Boston, United States)
Project IDNIH-11263682 on NIH RePORTER

What this research studies

If I join, doctors will collect my own CD34+ blood stem cells, add a working IL2RG gene using a self‑inactivating lentiviral vector, and return the corrected cells after a short low‑dose busulfan conditioning. The low‑dose busulfan is intended to make space in the bone marrow so the corrected cells can take hold and produce T, NK, and B cells. The team aims to improve B cell function and reduce safety risks seen with earlier retroviral gene therapies. This is part of a Phase I/II clinical program at Boston Children’s Hospital with ongoing long‑term follow up.

Who could benefit from this research

Good fit: Boys (usually infants or children) with confirmed IL2RG mutations causing SCID‑X1 who lack a suitable allogeneic donor and are medically eligible for stem cell collection and low‑dose busulfan conditioning.

Not a fit: People with other genetic forms of severe immunodeficiency, those unable to tolerate conditioning or stem cell collection, or patients with severe organ dysfunction or uncontrolled infection may not benefit from this protocol.

Why it matters

Potential benefit: If successful, this approach could let boys with SCID‑X1 produce their own antibodies, reduce infections, and avoid or reduce the need for donor transplants or lifelong immune support.

How similar studies have performed: Prior gene therapy trials for SCID‑X1 restored T cells but failed to fix B‑cell function and carried insertional mutagenesis risk, while newer lentiviral vectors and busulfan conditioning have shown encouraging results in related primary immunodeficiencies.

Where this research is happening

Boston, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.