Venetoclax‐Based Therapy as a Bridge to Hematopoietic Stem Cell Transplantation in Relapsed or Refractory Pediatric Acute Leukemia

ABSTRACT Relapsed and/or refractory (R/R) pediatric acute leukemia carries a dismal prognosis, largely driven by chemoresistance to conventional salvage therapy. The BH3‐mimetic venetoclax, combined with chemotherapy or hypomethylating agents, has demonstrated efficacy in small clinical trials. However, data on its role as a bridge to hematopoietic stem cell transplantation (HSCT) and on re‐challenge in previously exposed patients remain limited. We report outcomes from 21 children treated with 26 episodes of venetoclax‐based regimens as a bridge to HSCT, including five after prior venetoclax exposure. Overall response rate was 75% (15/20) after initial treatment and 100% (5/5) after re‐treatment. Overall, 62% (16/26) of all patient‐episodes facilitated immediate HSCT, and for another 12% (3/26), venetoclax‐based therapy eradicated disease, and the patient transitioned to surveillance rather than HSCT. As such, venetoclax may represent an effective bridging strategy in R/R pediatric leukemia.