Abstract / Summary
ABSTRACT Background Graft‐versus‐host disease (GvHD) remains one of the most significant complications of hematopoietic stem cell transplantation (HSCT). Abatacept, a selective T‐cell costimulation modulator, is a relatively novel prophylactic agent, though pediatric data remain limited. Procedure A systematic review and meta‐analysis was conducted to evaluate the efficacy and safety of abatacept for GvHD prophylaxis in pediatric HSCT. Results Fifteen cohort studies were identified (eight comparative and seven single‐arm). Studies included abatacept as adjunctive agent to traditional regimens. Pooled analyses demonstrated that abatacept‐inclusive regimens significantly reduced the risk of Grade II–IV acute GvHD (aGvHD) (risk ratio [RR] 0.31, 95% confidence interval [CI] 0.14–0.65) and severe Grade III–IV aGvHD (RR 0.14, 95% CI 0.05–0.37). Abatacept administration was not associated with decreased moderate‐to‐severe chronic GvHD incidence, although extended regimens were associated with reduced risk (RR 0.25, 95% CI 0.08–0.78). Abatacept‐inclusive GvHD prophylaxis was not associated with compromised immune reconstitution or increased viral reactivations, whereas it was associated with a reduced incidence of bacterial infections (RR 0.39, 95% CI 0.21–0.74) and improved overall survival (RR 1.18, 95% CI 1.03–1.34). Conclusions Despite limitations inherent to retrospective study designs and cohort heterogeneity, these findings indicate that abatacept is an efficacious and safe addition to GvHD prophylaxis in pediatric HSCT.