PTCy-based GvHD prophylaxis in MDS: A GETH-TC multicenter study

Results from a multicenter, retrospective study conducted on behalf of the Grupo Español de Trasplante Hematopoyético y Terapia Celular (GETH-TC), evaluating post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GvHD) prophylaxis in adults with myelodysplastic syndrome (MDS) undergoing first peripheral blood allogeneic hematopoietic stem cell transplantation (allo-HSCT) (N = 291), were published in Transplantation and Cellular Therapy by Salas et al. Outcomes were analyzed in the entire cohort and stratified by age group (>65 years, n = 82; ≤65 years, n = 209).

Key data: Median follow-up was 23.0 months. The cumulative incidence of acute GvHD (aGvHD) by Day +100 was 27.8% (95% confidence interval [CI], 22.8–33.1) for Grade 2–4 and 12.0% (95% CI, 8.6–16.1) for Grade 3–4; at 2 years, moderate-to-severe chronic GvHD (cGvHD) was 20.0% (95% CI, 15.2–25.2). The incidence of GvHD was consistent across age groups. At 3 years, overall survival (OS), cumulative incidence of relapse (CIR), non-relapse mortality (NRM), and GvHD-free/relapse-free survival (GRFS) were 54.6% (95% CI, 48.4–60.4), 21.5% (95% CI, 16.8–26.6), 28.4% (95% CI, 23.2–33.8), and 33.7% (95% CI, 28.0–39.4), respectively. Patients aged >65 years had higher 3-year NRM vs patients aged ≤65 years (35.2% vs 25.7%; p = 0.039), while OS, CIR, GRFS, and infectious complications were comparable. Grade 3–4 aGvHD was independently associated with higher NRM (hazard ratio [HR], 4.20; 95% CI, 2.53–6.91; p < 0.001).

Key learning: PTCy-based GvHD prophylaxis is feasible in patients with MDS undergoing allo-HSCT, including selected older adults; however, further efforts are needed to reduce NRM.