A decade of experience using <scp>ATG</scp> and <scp>PTCy</scp> for graft‐versus‐host disease prophylaxis in matched unrelated donor allogeneic haematopoietic cell transplantation
Nihar Desai, Sergio Rodríguez‐Rodríguez, Eshrak Al‐Shaibani, Tommy Alfaro Moya, Arjun Law, Igor Novitzky‐Basso, Ivan Pašić, Fotios V. Michelis, Rajat Kumar, Dennis Dong Hwan Kim, Jonas Mattsson, Auro Viswabandya
Abstract
Anti-thymocyte globulin (ATG) and post-transplant cyclophosphamide (PTCy) are both effective drugs for graft-versus-host disease (GvHD) prophylaxis, but their combined use remains underexplored. We conducted a retrospective analysis of 582 patients with haematological malignancies who underwent unrelated donor transplantation with Status GvHD prophylaxis consisting of low-dose ATG (2 mg/kg) and PTCy over a 10-year period. The median time to neutrophil and platelet engraftment was 18 days (95% CI, 17-19) and 20 days (95% CI, 19-21) respectively. The cumulative incidence of grade III-IV acute Status GvHD at D+100 was 7% (95% CI: 5-9), and the 24-month incidence of moderate-to-severe chronic GvHD was 15.7% (95% CI: 13-19). Clinically significant cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivation by D+180 occurred in 20.4% (95% CI: 17-24) and 22.7% (95% CI: 19-26) respectively. At 24 months, the cumulative incidence of NRM was 16.2% (95% CI: 13-19), and relapse was 21.3% (95% CI: 18-25). Graft-versus-host disease-free, relapse-free survival (GRFS) at 24 months was 49% (95% CI: 44-53), and overall survival (OS) was 68.3% (95% CI: 64-72). Our decade-long experience supports the safety and efficacy of combining low-dose ATG with PTCy for GvHD prophylaxis in unrelated donor transplantation. These findings warrant further validation in prospective studies.