Outcome of adult acute myeloid leukemia patients with extramedullary disease and treatment with venetoclax / hypomethylating agents

Abstract

We evaluated response to VEN/HMA in 46 patients with acute myeloid leukemia (AML) characterized by extramedullary disease (EMD). Median age was 65 (range, 19-81) years. Patients had a median of two EMD sites (range, 1-5) and 35 (76%) patients had concurrent bone marrow involvement. Twenty (43%) patients had highrisk genetic features according to the European Leukemia Net 2022 classification. Twenty-nine (63%) were relapsed or refractory after intensive chemotherapy (CTX) including 13 (28%) with prior allogeneic hematopoietic cell transplantation (allo-HCT). Patients received a median of 2 cycles of VEN/HMA (range, 1-31). Twenty (43%) patients achieved complete remission (CR) or CR with incomplete hematological recovery (CRi) after VEN/HMA and five (11%) achieved a partial remission (PR). Six patients were subsequently consolidated with allo-HCT (CR/CRi, n=4; PR, n=2). Median follow-up was 49.1 months (95%-CI, 26.1 months - not reached) and median overall survival (OS) 6.4 months (95%-CI, 5.1-11 months). One-year and 2-years OS rates were 29.3% (95%-CI, 18.6-46.2%) and 12.3% (95%-CI, 5.5-27.6%), respectively. Age with a cut-off of 60 years had no impact on OS (P=0.90). Relapse occurred in 12 of 20 (60%) patients who achieved CR/CRi after VEN/HMA treatment. Of those, all except one succumbed to their disease. Six (30%) patients were in CR/CRi at last follow-up and 2 (10%) died in CR. In our cohort of patients with AML with EMD with high-risk features, treatment with VEN/HMA resulted in an encouraging ORR of 54% with a CR/CRi rate of 43.5%. However, VEN/HMA alone may not be effective in maintaining disease control.