The Clinical Tumor Lysis Syndrome in a Patient with Mixed Phenotype Acute Leukemia Undergoing Induction with Venetoclax and Azacitidine: A Case Report

Abstract A combination of azacitidine and venetoclax (AZA-VEN) has been approved for the treatment of adult treatment-naïve acute myeloid leukemia (AML) patients, ineligible for intensive chemotherapy. The protocol may also constitute an alternative for the treatment of patients with mixed phenotype acute leukemia (MPAL), for which no established treatment guidelines exist. It may be anticipated, that alike in AML or chronic lymphocytic leukemia, the treatment of MPAL may be complicated by the tumor lysis syndrome (TLS). No case of TLS in MPAL after VEN has been however reported so far. Here, we present a case of a patient with MPAL, who received AZA-VEN. The patient had a substantial bulk of disease with generalized lymphadenopathy and increased white blood cell count. Despite preventive measures, the patient developed the clinical TLS, which was successfully treated. Based on the current case and other published cases, the incidence of TLS after AZA-VEN was established at 17%.