Safer Stem Cell Transplants — without Chemotherapy or Radiation | Stanford Medicine

Why It Matters

Eliminating chemo and radiation reduces life‑threatening DNA damage, making curative transplants viable for fragile patients and opening a safer paradigm for future stem‑cell therapies.

Key Takeaways

• Stanford uses antibody Briquilimab to replace chemo in stem cell transplants.
• Targeting CD117 depletes native stem cells, facilitating donor engraftment.
• Early trial shows >95% donor chimerism without radiation or chemo.
• Patients with Fanconi anemia avoid DNA‑damage from traditional conditioning.
• Ongoing study aims for fully chemo‑free, radiation‑free transplant protocol.

Summary

Stanford Medicine researchers have introduced a novel conditioning regimen that replaces traditional chemotherapy and radiation with an antibody, Briquilimab, for bone‑marrow transplants in patients with Fanconi anemia—a disorder marked by defective DNA repair. The approach targets the CD117 receptor on hematopoietic stem and progenitor cells, blocking stem‑cell factor signaling and temporarily depleting the patient’s own stem cells, thereby creating space for donor cells to engraft without the DNA‑damaging effects of chemo‑radiation.

Early clinical data demonstrate that the antibody‑based protocol can achieve donor chimerism exceeding 95 % after transplant, with patients experiencing minimal infections and no severe toxicities. Researchers reported a case where a child, previously facing a high risk of leukemia, remained largely healthy for two years post‑transplant, underscoring the regimen’s efficacy and safety.

The team highlighted the emotional burden on families, noting a physician’s promise to “not give radiation” and the careful monitoring of donor cell percentages as low as 1 % to confirm engraftment. Ongoing trial amendments aim to enroll additional patients and test whether the antibody alone suffices for conditioning.

If successful, this chemo‑free, radiation‑free strategy could redefine transplant standards for DNA‑repair disorders and potentially extend to broader hematologic applications, offering a safer, more tolerable pathway to curative therapy.

Original Description

Can a life-saving stem cell transplant be done without chemotherapy or radiation?

At Stanford Medicine, scientists are pioneering a new antibody-based approach for Fanconi anemia—a rare condition that causes bone marrow failure and increases cancer risk over time.

Built on decades of discovery, this method replaces traditional toxic conditioning with a targeted therapy that safely makes room for healthy donor cells. The goal: restore blood and immune function while reducing long-term harm.

Early clinical results are promising—bringing safer stem cell transplants without chemotherapy or radiation closer to reality, and opening new possibilities for treating rare genetic diseases.

Learn more about this research:

https://stan.md/4mYUIEa

https://stan.md/4ebOA9d

This work is led by Stanford Medicine researchers in collaboration with:

Stanford Institute for Stem Cell Biology and Regenerative Medicine: https://stemcell.stanford.edu

Center for Definitive and Curative Medicine: https://cdcm.stanford.edu

Lucile Packard Children’s Hospital Stanford: https://www.stanfordchildrens.org

Bass Center for Childhood Cancer and Blood Diseases: https://www.stanfordchildrens.org/en/service/cancer

#FanconiAnemia #RareDisease #StanfordMedicine

.

.

.

Stanford Medicine advances human health through world-class biomedical research, education and patient care. Bringing together the resources of Stanford University School of Medicine, Stanford Health Care and Lucile Packard Children's Hospital, Stanford Medicine is committed to training future leaders in biomedicine and translating the latest discoveries into new ways to prevent, diagnose and treat disease.

The Stanford Medicine YouTube channel is a curated collection of contributions from our School of Medicine departments, divisions, students, and the community. Our diverse content includes coverage of events, presentations, lectures, and associated stories about the people of Stanford Medicine.