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 GVHD is a negative factor for outcomes. Using «novel» strategies for drug prophylaxis, such as posttransplant cyclophosphamide (PtCy) allows to decrease the GVHD risk. The aim of this study: to assess efficiency of PtCy as a prophylaxis aGVHDin the patients with non-malignant diseases of hematopoiesis and inherited syndromes. 97 patients with non-malignant blood disorders and metabolic diseases received 118 underwent allo-HSCT at the R. Gorbacheva Memorial Institute of Children Oncology and Transplantation. 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, +4. Cumulative incidence (CI) of aGVHD 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). CI 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). Conclusions: aGVHD prophylaxis based on posttransplant PtCy 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 PtCy-based GVHD prophylaxis.