Phase 2 trial of sirolimus and cyclosporine with post-transplant cyclophosphamide or mycophenolate mofetil as GVHD prophylaxis in unrelated donor HCT

A phase 2 trial at Fred Hutchinson Cancer Center (Seattle, WA) investigated wether sirolimus (SIR) and cyclosporine (CSP) with post-transplantation cyclophosphamide (PTCy) after nonmyeloablative or reduced-intensity conditioning unrelated donor hematopoietic cell transplantation (HCT) would be more effective than SIR, CSP, and mycophenolate mofetil (MMF) in reducing the risk of chronic graft-versus-host disease (cGVHD) without increasing the risk of recurrent malignancy. Estimated 1-year cGVHD-free relapse-free survival rate was 73% with SIR/CSP/PTCy versus 48% with SIR/CSP/MMF (HR 0.46; p=0.005). The authors conclude that the combination of PTCy and SIR/CSP warrants further study.