Finding the best busulfan dose for infants with SCID

Clinical and mechanistic studies defining optimal preparative approaches to infants with IL2RG/JAK3/RAG1/RAG2 SCID: a randomized trial of busulfan dosage

NIH-funded research National Marrow Donor Program · NIH-11168867

This project compares lower versus moderate doses of the chemotherapy drug busulfan to help infants with IL2RG-, JAK3-, or RAG1/2-related SCID rebuild their immune systems after a donor bone marrow transplant.

Quick facts

Grant typeU01 cooperative agreement
Study typeNIH-funded research
Funding institutionNational Marrow Donor Program NIH-funded
Lab location1 site (Minneapolis, United States)
Project IDNIH-11168867 on NIH RePORTER

What this research studies

If your baby has one of the listed SCID gene changes, they would be randomly assigned to receive either a lower or a moderate cumulative exposure to busulfan before a donor hematopoietic cell transplant. Some children will also receive additional medicines (rATG, and for RAG1/2 patients may include fludarabine and thiotepa) and can get cells from unrelated or haploidentical family donors. The team will follow immune recovery over time, focusing on T and B cell numbers and antibody function to see if lower dosing gives the same immune benefit with fewer side effects. The trial is running at many transplant centers to enroll enough families and reach clear conclusions.

Who could benefit from this research

Good fit: Ideal candidates are infants or very young children diagnosed with IL2RG-, JAK3-, or RAG1/2-related SCID who are scheduled for an unrelated or haploidentical donor hematopoietic cell transplant.

Not a fit: Children who have matched sibling donors, who have different genetic causes of immune deficiency, or who are not undergoing an allogeneic transplant are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this could allow infants to achieve full immune recovery with less chemotherapy exposure and fewer short- and long-term side effects.

How similar studies have performed: Earlier work under the CSIDE program showed promising results with low, targeted busulfan in SCID, but the randomized head-to-head comparison with moderate dosing is only now being completed and remains partly novel.

Where this research is happening

Minneapolis, 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.