Transplantation from haploidentical donor is not inferior to that from identical sibling donor for patients with chronic myeloid leukemia in blast crisis or chronic phase from blast crisis

Objectives: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for chronic myeloid leukemia (CML) patients in blast crisis (BC), and haploidentical donors (HID) are immediately available for most patients. We compared the outcomes of HID transplantation with those of matched related donor (MRD) transplantation in a cohort study. Patients and Methods: A total of 90 consecutive patients who received allogeneic HSCT because of CML-BC were investigated retrospectively. A total of 67 patients underwent transplantation from HID and 23 from MRD. Survival outcomes were compared between the two cohorts. Results: Of the 90 patients, 86 patients were engrafted. Three-year overall survival (OS) and relapse-free survival (RFS) were comparable between HID and MRD recipients (OS: 60.0% vs 55.3%, respectively, P=.580; RFS: 51.1% vs 47.8%, respectively, P=.512). Three-year incidences of transplant-related mortality (TRM) and relapse did not differ between HID and MRD recipients (relapse: 21.0% vs 26.1%, respectively, P=.626; TRM: 27.9% vs 26.1%, respectively, P=.937). In multivariate analyses, previous chemotherapy history and not achieving CHR before HSCT are independent adverse predictors of OS. Conclusions: For CML-blast crisis or chronic phase from blast crisis patients, HID transplantation achieves comparable survival to MRD transplantation. HID donors can be regarded as regular donors for these special patients at selected centers.