Haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide in the public Chilean national health system: A single center study

Abstract

Introduction  Haploidentical peripheral stem cell transplantation with post-transplant cyclophosphamide is the most common modality in low-and-middle-income countries. This article reports the consecutive adult patients who received this modality of transplant in a single center in Chile between 2016-2021.

Methods  The primary outcome was overall survival. Secondary outcomes were event-free survival, II-IV acute graft-versus-host disease at Day +100, chronic graft-versus-host disease at two years and cumulative incidence of relapse.

Results  The median age was 25 years (Range: 15-51), and 65 % of patients were male. Ninety-four percent had a neoplastic disease (77/82), with the most common diagnosis being acute lymphoblastic leukemia (57 %). Forty-seven percent proceeded to transplant in the first complete response. Conditioning was mostly myeloablative (96 %). Primary graft failure and poor graft function were observed in 1.2 % and 13 %, respectively with five patients (6.1 %) dying before engraftment. Grade II-III acute graft-versus-host disease was seen in 29 % and chronic graft-versus-host disease was 41 % of the patients. With a median follow-up of 33 months (Range: 1-84), the estimated three-year overall survival and event-free survival were 68.3 % (95 % CI: 59-79 %) and 64.6 % (95 % CI: 55-76 %), respectively. The three-year cumulative incidence of relapse was 23 % (95 % CI: 15-33 %).

Conclusion  These results demonstrate encouraging survival outcomes and acceptable rates of graft-versus-host disease following haploidentical peripheral stem cell transplantation with post-transplant cyclophosphamide, suggesting its potential as a feasible option in low-resource settings.

Keywords
Haploidentical transplantation; Peripheral blood stem cell transplantation; Acute graft-versus-host disease; Chronic graft-versus-host disease