PTCy vs standard GvHD prophylaxis in matched donor allo‑HSCT

Results from a single-center retrospective study, comparing post-transplant cyclophosphamide (PTCy) vs standard (non-PTCy) graft-versus-host disease (GvHD) prophylaxis in matched donor allogeneic hematopoietic stem cell transplantation (allo-HSCT), were published in Transplantation Proceedings by Kim et al. The analysis included patients undergoing matched donor allo-HSCT with tacrolimus-methotrexate-based GvHD prophylaxis treated prior to 2016 (n  =  252) and those transplanted following institutional adoption of PTCy from 2016 onward (n =  99). The primary endpoint was overall survival (OS), with additional analyses including relapse incidence, non-relapse mortality (NRM), and incidence of acute GvHD (aGvHD) and chronic GvHD (cGvHD).

Key data: PTCy demonstrated superior 1‑year OS compared with non-PTCy treatment (90% vs 62%; p < 0.0001), with this benefit maintained at 2  years (82% vs 50%) and 3  years (75% vs 44%). NRM at 1 year was lower with PTCy (7% vs 22%; p = 0.0002), while 1‑year relapse incidence was comparable between groups (19% vs 26%; p = 0.356). The cumulative incidence of Grade  2–4 aGvHD at Day  100 was lower with PTCy (16% vs 33%; p = 0.0013), while 1‑year cumulative incidence of cGvHD was similar between groups (35% vs 42%; p = 0.1235); however, extensive cGvHD occurred less frequently with PTCy (15% vs 29%; p = 0.0078). 

Key learning: PTCy-based GvHD prophylaxis demonstrates superior outcomes in matched donor allo-HSCT compared with standard non-PTCy treatment.