Venetoclax-Based Regimen in Refractory or Relapsed Pediatric Acute Lymphoblastic Leukemia

Introduction: This study investigated the efficacy and survival of pediatric refractory or relapsed (R/R) acute lymphoblastic leukemia (ALL) treated with a venetoclax (VEN)-based regimen. Methods: Children with R/R ALL treated with a VEN-based regimen at Peking University People’s Hospital from December 1, 2018, to January 15, 2024, were included in this study. Complete remission (CR) or complete remission with incomplete recovery of blood count (CRi) rates and objective response rates (ORRs) were analyzed. Results: Twenty-two children with R/R ALL were included in this study. The median duration of VEN treatment per cycle was 21 (7–28) days, and the median VEN dose was 100 (50–300) mg/day. Following a cycle of VEN-based therapy, 17 children (77.3%) achieved CR/CRi/morphological leukemia-free state (MLFS), including 8 cases (8/17) with negative MRD. The ORR in the children with B-cell acute lymphoblastic leukemia (B-ALL) (n = 9) and T-cell acute lymphoblastic leukemia (T-ALL) (n = 8) was 75% and 80%, respectively. Patients with early T-cell precursor (ETP) ALL (n = 6) achieved MRD-negative remission, and one KMT2A::USP2-positive child achieved MLFS after receiving a VEN-based regimen. For the relapsed patients, the median overall survival (OS) was 1,371 days. For the refractory patients, the median OS was unreached. For T-ALL patients, the median OS was 1,371 days. For the patients with B-ALL, the median OS was 543 days. All patients had hematologic adverse reactions within an acceptable range. Conclusion: Children with R/R ALL who received the VEN-based regimen achieved a high remission rate with an acceptable safety profile. Significantly, the VEN-based regimen was effective in patients with R/R ETP with MRD-negative results while also proving beneficial for KMT2A-rearranged, highlighting VEN-chemotherapy as a treatment option for remission.