Stem cell and bone marrow transplants (BMTs) provide the possibility of a cure for certain types of blood cancer, including many cases of leukemia and lymphoma. But for those transplants that require blood stem cells from a donor — known as allogeneic transplants — it can be hard to find an exact match. This is especially true for patients with certain genetic ancestries, especially African, Latin American, and Asian. Their tissues, or HLA types, are more diverse.
In a new retrospective study, MSK bone marrow transplant specialist and cellular therapist Brian Shaffer, MD, and a multicenter team of investigators demonstrated how to improve transplants in patients who are not able to find fully matched donors. The study was overseen and funded by the National Marrow Donor Program (NMDP). The research confirmed that for patients receiving only partially matched cells, giving chemotherapy shortly after the transplant greatly reduces the chances that the patient will develop graft-versus-host disease (GVHD), a potentially fatal side effect of BMTs that occurs when the donor's immune system attacks the recipient's healthy tissues.
The analysis included data from more than 10,000 BMT recipients, nearly half of whom received cyclophosphamide chemotherapy after their transplant. (The rest received anti-rejection drugs called calcineurin inhibitors, or CNIs.) Patients who received chemotherapy after their transplant had better outcomes than those who received CNIs. In fact, outcomes for patients with partially matched donors who received chemotherapy were almost as good as for those who had fully matched donors. An ongoing clinical trial at MSK is now looking at whether lower doses of chemotherapy are as effective as higher doses at preventing GVHD and whether they reduce the side effects of chemotherapy.
