Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is the only potentially curative therapy for patients with acute lymphoblastic leukemia. However, relapse remains a leading cause for treatment failure after hematopoietic cell transplantation (HCT) in patients, optimization of conditioning regimen can improve prognosis and decrease relapse. Abnormal gene methylation is common in ALL patients. Azacytidine is a DNA methylation transferase inhibitor that can re-express tumor suppressor genes in leukemia cells. Venetoclax is a selective BCL-2 inhibitor, which has antitumor activity against a variety of hematological malignancies. The combination of the two drugs show a synergistic anti-tumor effect. Multiple case reports the efficacy of Venetoclax-based regimens in patients with ALL is encouraging. The objective of this study is to evaluate the feasibility, safety and efficacy of VEN-AZA bridging allogeneic hematopoietic stem cell transplantation in the treatment of high-risk ALL.
The purpose of this prospective, open-label, single-center study is to evaluate the efficacy and safety of VEN-AZA (venetoclax and azacytidine) followed by modified BUCY (busulfan and cyclophosphamide) as conditioning regimen for high-risk or relapsed/refractory acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT).