CRISPR-edited donor stem cells shield healthy blood cells during CD33-targeted leukaemia treatment
A 30-patient trial found that removing CD33 from donor haematopoietic stem cells allowed a CD33-directed cancer therapy to attack leukaemia whilst leaving the engrafted healthy cells intact.
Researchers have reported results from a 30-patient clinical trial in which CRISPR gene editing was used to delete the CD33 surface protein from donor haematopoietic stem and progenitor cells before transplantation into patients with aggressive blood cancers. CD33 is a target of gemtuzumab ozogamicin and similar antibody-drug conjugates used to kill leukaemic blasts; the problem has historically been that these drugs also destroy healthy myeloid cells, limiting their utility after stem-cell transplantation.
By removing CD33 from the donor cells prior to infusion, the trial aimed to create a population of engrafted blood-forming cells that are invisible to the CD33-targeted therapy. According to the ScienceDaily report, the edited cells successfully engrafted and appeared to confer protection to the reconstituting blood-cell population whilst the cancer treatment remained active against the CD33-expressing tumour cells.
The approach is an example of an 'epitope editing' strategy — modifying the very target of a drug on normal cells so that the drug can be deployed with greater specificity. The source reporting does not name the specific institution, principal investigators, or journal at this stage, and full peer-reviewed data have not yet been cited. Genetic Current will update this cluster when primary publication details become available.
This trial-stage finding is of interest to researchers working in haematological malignancy, genome editing, and transplant biology, and to oncologists following developments in leukaemia treatment approaches.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
Scientists have reported early results from a trial in people with aggressive blood cancers. They used a gene-editing technology called CRISPR to modify donor blood stem cells before transplanting them into patients. The modification removed a protein called CD33 from the surface of those donor cells. A cancer drug that targets CD33 could then be given to attack the leukaemia, while the transplanted healthy cells — which no longer carry CD33 — were protected from that same drug. In the 30 people in the trial, the modified cells appeared to take hold successfully and to provide this protective effect. This is early-stage research and further study is needed before the approach could become widely available. Researchers say the result may help doctors think about new ways to treat blood cancers in future.
This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
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Primary source ScienceDaily · 2026-09-25CRISPR could help doctors attack blood cancer without destroying healthy cells