Posttransplantation Cyclophosphamide- and Sirolimus-Based Graft-Versus-Host-Disease Prophylaxis in Allogeneic Stem Cell Transplant
Raffaella Greco, Francesca Lorentino, Serena Albanese, Maria Teresa Lupo Stanghellini, Fabio Giglio, Simona Piemontese, Daniela Clerici, Lorenzo Lazzari, Magda Marcatti, Sara Mastaglio, Elisabetta Xue, Francesca Farina, Francesca Pavesi, Andrea Assanelli, Matteo Giovanni Carrabba, Sarah Marktel, Luca Vago, Chiara Bonini, Consuelo Corti, Massimo Bernardi, Fabio Ciceri, Jacopo Peccatori
Abstract
Post-transplantation cyclophosphamide (PTCy) has emerged as a promising graft-versus-host-disease (GVHD) prophylaxis in the setting of allogeneic hematopoietic stem cell transplantation (HSCT) from haploidentical donors and more recently in matched donor transplants. Herein, we describe our real-life experience on 249 adult patients undergoing allogeneic HSCT, from HLA-matched related (MRD), HLA-matched unrelated (MUD), or mismatched related donors (MMRD). Patients received unmanipulated peripheral blood stem cells (PBSCs), using a GVHD prophylaxis with PTCy and sirolimus. Mycophenolate mofetil was added in MUD or MMRD. In the HLA-matched donor group (MRD, n = 48, MUD, n = 50), the cumulative incidence of grades II-IV and III-IV acute GvHD was 23% and 9% at 100 days, respectively. The cumulative incidence of chronic GvHD was 25% at 2 years, severe only for 5% of the patients. The cumulative incidences of relapse and transplant-related mortality (TRM) were 31% and 9% at 2 years, respectively. The 2-year overall survival (OS) was 72% and progression-free survival (PFS) 60%; the composite endpoint of GvHD/relapse-free survival (GRFS) was 52% at 2 years. In the haploidentical donor group (n = 151), we documented a cumulative incidence of grades II-IV and III-IV acute GVHD of 35% and 20% at 100 days, respectively, and a cumulative incidence of chronic GvHD of 39% at 2 years. We observed severe chronic GVHD in 15% of the patients. The cumulative incidence of relapse and TRM was 32% and 25% at 2 years, respectively. The 2-year OS was 48%, whereas PFS was 43%; GRFS was 28% at 2 years. However, more patients in the haploidentical group presented high/very high disease risk index (DRI) and higher HCT-comorbidity index. In patients classified in the low-intermediate DRI, 2-year GRFS was 53% in MRD, 65% in MUD, and 46% in haploidentical HSCT (P = .33). Sirolimus-PTCy platform deserves further investigation as an alternative to calcineurin-inhibitor-based GVHD prophylaxis for all donor sources. In patients presenting a low-intermediate DRI, this strategy translates in relevant survival independently from the transplant source.