Effect of acute and chronic GVHD on relapse and survival after reduced-intensity conditioning allogeneic transplantation for myeloma

We evaluated the effect of acute and chronic graft-versus-host disease (GVHD) on relapse and survival after allogeneic haematopoietic stem cell transplantation (HSCT) for multiple myeloma (MM) using non-myeloablative conditioning (NMA) and reduced-intensity conditioning (RIC). The outcomes of 177 HLA-identical sibling HSCT recipients between 1997 and 2005 following NMA (n=98) or RIC (n=79) were analyzed. In 105 patients, autografting was followed by planned NMA/RIC allogeneic transplantation. The impact of GVHD was assessed as a time-dependent covariate using Cox models. The incidence of acute GVHD (grades I–IV) was 42% (95% confidence interval (CI) 35 – 49%) and of chronic GVHD at five years was 59% (95% CI 49 – 69%), with 70% developing extensive chronic GVHD. In multivariate analysis, acute GVHD (≥ grade I) was associated with an increased risk of TRM (relative risk (RR)=2.42; p=0.016), whereas limited chronic GVHD significantly decreased the risk of myeloma relapse (RR=0.35, p=0.035) and was associated with superior event-free survival (RR=0.40, p=0.027). Acute GVHD had a detrimental effect on survival, especially in those receiving autologous followed by allogeneic HSCT (RR=3.52; p=0.001). The reduction in relapse risk associated with chronic GVHD is consistent with a beneficial graft-versus-myeloma effect, but this did not translate into a survival advantage.