Overview
- Researchers reported in Nature Medicine that a Washington University–led Phase I/II trial tested donor stem cells edited to delete CD33 in adults with high‑risk acute myeloid leukemia or myelodysplastic syndromes.
- All 30 patients engrafted by day 28 with platelet recovery around day 16, which matched timelines seen with standard, non‑edited transplants.
- Patients who received gemtuzumab ozogamicin, a CD33‑targeting antibody‑drug, kept stable blood counts across doses, pointing to protection of healthy myeloid cells.
- Average survival in the study was just over 14 months, and a separate donor‑derived CD33 CAR‑T case after relapse achieved a complete remission lasting more than a year.
- The multicenter effort across the U.S. and Canada provides proof of concept for pairing edited grafts with CD33‑targeted therapies, though larger studies with longer follow‑up are needed to confirm safety and relapse prevention.