Chronic graft-versus-host-disease treatment in Brazil: analyses of failure-free survival.

Failure-free survival (FFS), defined as the absence of new systemic treatment, recurrence of original malignancy and mortality not associated with recurrence after allogeneic hematopoietic stem cell transplantation (HCT), is a robust clinical measure to interpret results of initial systemic treatment of chronic graft-versus-host disease (cGVHD). We evaluate FFS after initial treatment of cGVHD in a mixed-race cohort from a resource-constrained country. This retrospective study included 354 consecutive patients after their first HCT between January 2014 and August 2020, who received initial systemic treatment for moderate or severe cGVHD at 13 Brazilian centers. Cox regression models were used to identify risk factors for treatment failure. The overall median follow-up among survivors was 28 months (range 1-71) after initial treatment. FFS was 89% at 6 months, 71% at 1 year and 52% at 2 years. New systemic treatment was the major cause of failure. In multivariable models, prior grades II-IV acute GVHD, a National Institutes of Health severity score of 3 in liver, gastrointestinal tract or lung involvement, and onset of initial treatment of cGVHD within 12 months after transplantation were all associated with an increased risk of treatment failure. Our results could serve as a benchmark for the design of future clinical trials evaluating initial treatment of cGVHD in resource-constrained locations.