Dynamic Graft-versus-Host Disease-Free, Relapse-Free Survival: Multistate Modeling of the Morbidity and Mortality of Allotransplantation

Abstract

Graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) represents complete, ideal recovery after allogeneic hematopoietic cell transplantation (HCT). However, as originally proposed, this composite endpoint does not account for the possibility that HCT complications may improve after treatment. To more accurately estimate survival with response to GVHD and relapse after HCT, we developed a dynamic multistate GRFS (dGRFS) model with outcomes data from 949 patients undergoing their first allogeneic HCT for hematologic malignancy at the University of Minnesota. Because some patients were successfully treated for GVHD and relapse, dGRFS was higher than the originally defined time-to-event GRFS at 1 year (37.0 versus 27.6%) through 4 years (37.4% versus 22.2%). Mean survival without failure events was .52 years (95% confidence interval, .45 to .58 year) greater in dGRFS compared with the originally defined GRFS. Patient age (P< .001), disease risk (P < .001), conditioning intensity (P = .007), and donor type (P = .003) all significantly influenced dGRFS. The multistate model of dGRFS closely estimates the continuing and prevalent severe morbidity and mortality of allogeneic HCT. To serve the greater HCT community in more accurately modeling recovery from transplantation, we provide our R code for determination of dGRFS with annotations in Supplementary Materials.

Keywords: Allogeneic hematopoietic cell transplantation; GRFS; Graft-versus-host disease; Multistate modeling; Relapse.