Sequential Combination of FLAM and Venetoclax plus Azacitidine to Bridge to Cord Blood Transplantation in a Patient with Primary Induction Failure Acute Myeloid Leukemia

Venetoclax (VEN) is an oral B-cell lymphoma-2 (BCL-2) inhibitor that has been widely used to treat various hematological disorders. Recent studies have demonstrated that VEN in combination with fludarabine-enhanced high-dose cytarabine (FLA) is effective for treating relapsed or refractory acute myeloid leukemia (AML). In the combination therapy, salvage chemotherapy and VEN are basically concurrently administrated; however, further optimization may enable the treatment to apply to larger numbers of patients with various clinical backgrounds. Here, we describe a case of refractory AML treated with a sequential combination of the intensive chemotherapy (fludarabine, cytarabine, and mitoxantrone; FLAM) and VEN/AZA to bridge to an unrelated cord blood transplantation (uCBT). By continuously adding VEN/AZA after FLAM, the patient achieved morphologic leukemia free state with only minor toxicities. Blood cell counts did not recover until the time of transplantation because of the deep myelosuppression caused by the treatment sequence, but the infection risk was safely managed during this period. After engraftment, maintenance therapy with VEN/AZA was performed, and the patient has survived without disease recurrence for over 9 months after transplantation. Our case suggests that bridging therapy with VEN and AZA from the time of the last chemotherapy to allogeneic transplantation may provide an effective and tolerable treatment strategy for refractory AML. Further studies of larger numbers of cases are needed to validate the effectiveness of this treatment.