Acute GvHD prophylaxis with posttransplant cyclophosphamide after hematopoietic stem cell transplantation (HSCT) for non-malignant disorders

Abstract

Transplantation of allogeneic hematopoietic stem cells (allo-HSCT) is an effective treatment method for non-malignant diseases and inherited disorders. Development of acute graft-versus-host-disease (aGVHD) is a negative factor with adverse effects upon clinical outcomes. Usage of “novel” schedules for drug prophylaxis of this complication using posttransplant cyclophosphamide (PtCy) seems to decrease the GVHD risk. The aim of this study was to assess efficiency of PtCy as a tool for aGVHD prevention in the patients with non-malignant diseases of hematopoiesis and inherited syndromes. Patients and Methods 97 patients with non-malignant blood disorders and metabolic diseases underwent allo-HSCT at the R. Gorbacheva Memorial Institute of Children Oncology and Transplantation over a period of 2005 to 2018. A total of 118 HSCTs were carried out. The aGVHD prophylaxis in 89 cases was performed by a standard schedule (with calcineurin inhibitors). 29 patients were treated according to PtCy regimen, at a dose of 50 mg/kg at days +3 and +4. Cumulative frequency of acute GVHD comprised 32%. Patients treated with PtCy exhibited lower rates of this condition compared to the group with standard prophylaxis schedule (26% vs 47%, р=0.05). Frequency of skin aGVHD was also less common in the PtCy group (23% vs 45%, р=0.046); gastrointestinal aGVHD was observed at equal rates in the both groups. Stem cell engraftment after nonmyeloablative conditioning in HSCT patients with subsequent PtCy administration proved to be sufficiently weaker compared to other patients (86 vs 50%, р=0.004). In conclusion, posttransplant GVHD prevention based on cyclophosphamide prophylaxis is an efficient method which may decrease aGVHD risk. However, one should take into account a higher non-engraftment rate as a potential hazard of HSCT when using non-myeloablative conditioning regimens and Pt-Cy-based GVHD prophylaxis.