Venetoclax Resistance in Acute Myeloid Leukemia

Simple Summary Venetoclax-azacitidine is a new standard for elderly or unfit acute myeloid leukemia patients. Nevertheless, resistance remains a matter of concern. The main genetic alterations associated with venetoclax sensitivity are IDH mutations, whereas TP53, signaling mutations, and BAX mutations are associated with venetoclax resistance. Non-genetic resistance mechanisms have also been described, including changes in apoptotic proteins, differentiation states, metabolic status, and mitochondrial machinery. Venetoclax-based triplet therapies including IDH and FLT3 inhibitors or innovative therapies are under investigation to target resistances.Abstract Venetoclax is a BH3-mimetics agent interacting with the anti-apoptotic protein BCL2, facilitating cytochrome c release from mitochondria, subsequent caspases activation, and cell death. Venetoclax combined with azacitidine (VEN-AZA) has become a new standard treatment for AML patients unfit for intensive chemotherapy. In the phase III VIALE-A study, VEN-AZA showed a 65% overall response rate and 14.7 months overall survival in comparison with 22% and 8 months in the azacitidine monotherapy control arm. Despite these promising results, relapses and primary resistance to venetoclax are frequent and remain an unmet clinical need. Clinical and preclinical studies have been conducted to identify factors driving resistance. Among them, the most documented are molecular alterations including IDH, FLT3, TP53, and the newly described BAX mutations. Several non-genetic factors are also described such as metabolic plasticity, changes in anti-apoptotic protein expression, and dependencies, as well as monocytic differentiation status. Strategies to overcome venetoclax resistance are being developed in clinical trials, including triplet therapies with targeted agents targeting IDH, FLT3, as well as the recently developed menin inhibitors or immunotherapies such as antibody-drug conjugated or monoclonal antibodies. A better understanding of the molecular factors driving venetoclax resistance by single-cell analyses will help the discovery of new therapeutic strategies in the future.