Successful clearance of chemorefractory leptomeningeal disease by craniospinal irradiation followed by venetoclax maintenance in a patient with isolated central nervous system relapsed acute promyelocytic leukemia

Central nervous system (CNS) involvement is a rare but difficult to treat complication of acute promyelocytic leukemia (APML). In patients with relapse disease who are refractory to conventional APML directed therapies such as all trans retinoid acid (ATRA), arsenic trioxide (ATO), anthracyclines, and cytarabine, there is no standard of care. We, hereby, describe a case of 71-year-old male with no known comorbidities, who was diagnosed with high risk APML and was treated with ATRA, ATO, and Daunorubicin-based induction and maintenance therapy and had a medullary relapse (Bone marrow relapse) after 1 year of completion of therapy. He was salvaged by gemtuzumab ozogamicin-based chemotherapy followed by autologous transplant. The patient had a second isolated CNS relapse after 1 year of autologous stem cell transplant and was salvaged by craniospinal irradiation followed by venetoclax maintenance. The patient continued to be in remission on maintenance venetoclax since past 1 year. Craniospinal irradiation is generally efficacious for lymphoblasts. There are very little data on the radiation sensitivity of promyelocytes. This case is being presented to highlight successful clearance of promyelocytes by craniospinal irradiation and maintaining remission on venetoclax since 1 year.