Treatment of central nervous system relapse in PLZF::RARA-positive acute promyelocytic leukemia by venetoclax combined with arubicin and cytarabine: a case report

Background: Patients with refractory acute promyelocytic leukemia and central nervous system relapse often have a poor prognosis. Among them, patients with the PLZF RARA rearrangement have a poor response to all-trans retinoic acid and conventional chemotherapy. Venetoclax, a selective inhibitor of B-cell lymphoma-2 (BCL-2), can cross the blood–brain barrier and has been widely used in the treatment of acute myeloid leukemia in recent years. Case presentation We report a case of central nervous system relapse in a patient with acute promyelocytic leukemia with PLZF RARA rearrangement who achieved complete remission after treatment with anthracycline cytotoxic chemotherapy in combination with venetoclax. The concentration of venetoclax in the cerebrospinal fluid (CSF) was found to be approximately 1/1000 of that in the plasma based on liquid chromatography–tandem mass spectrometry. After the first treatment course, the PLZF RARA test result for the patient’s marrow fluid sample turned negative. After the third treatment course, abnormal promyelocytic leukemia cells in the CSF were not detected using flow cytometry, and the PLZF RARA test in the CSF remained negative. Conclusion: This case report highlights a new approach to the treatment of central nervous system relapse in patients with PLZF RARA -positive acute promyelocytic leukemia.