Haploidentical stem cell transplantation in adults for the treatment of hematologic diseases: Results of a single center (CIC725)

Abstract

Allogeneic HSCT (allo-HSCT) is potentially curative option for a wide variety of malignant and nonmalignant disorders of hematopoiesis. For patients who lack an HLA-matched sibling, HLA-haploidentical related donors (haplo-HSCT) can be considered as alternative sources of donor grafts. The benefits of haplo-HSCT include immediate donor availability for patients who are in urgent need of the transplant. Besides, an availability of a related donor makes post-transplant donor-derived cellular therapy more easily accessible. In addition, the greater HLA mismatch associated with haploidentical HSCT (haplo-HSCT) may potentiate graft-versus-tumor (GVT) effects. The aim of our study was to summarize our single-center experience of haplo-HSCT performed with non-manipulated grafts in adult patients with different malignant diseases. The study included a total of 119 patients with different hematological disorders subjected to haplo-HSCT. At the time of analysis, median follow-up was 371 days (1-2219). Most frequent diagnosis in transplanted patients was acute leukemia. 67 (56%) patients received haplo-HSCT as salvage therapy. Overall survival with an observation term of 2 years was 40.3% for the general group. In particular, the two-year OS in patients transplanted in remissions of ALL and AML was 57% and 46% respectively as compared to 22% and 15% for the patients transplanted in adverse disease status). Two-year event-free survival (EFS) and GVHD-free/relapse-free survival (GRFS) group proved to be 35.7% and 21% respectively. The cumulative incidence of acute GVHD grade II-IV and severe aGVHD grade III-IV was 19% and 10% respectively. The cumulative incidence of chronic GVHD (cGVHD) was 16%. The cumulative incidence of relapse was 21%. The overall transplant-associated mortality was 43% in the studied group. In conclusion, our results show that unmanipulated haplo-HSCT is reasonable treatment option for adult patients with different malignant disorders of hematopoiesis. However, such problems as higher rate graft failure, increased nonrelapse mortality (NRM) and post-transplant relapses remain extremely relevant.