Abstract A094: Development of selective oxindole-based AMPK inhibitors and their evaluation as single agents and in combination with venetoclax in models of leukemia

Abstract AMP-activated protein kinase (AMPK) acts as a central regulator of metabolism, that is activated in direct response to low cellular ATP levels due to energetic stress. Activated AMPK promotes catabolic activities to maintain cell viability and suppresses anabolic processes to limit ATP consumption. Metabolic dysregulation is a hallmark of cancer and the critical role of AMPK in mediating metabolic and cell-cycle pathways to support catabolism has made AMPK an attractive and yet complex target in cancer. There has been intensive development of small molecule AMPK activators, due to the direct mediation of fatty acid oxidation by AMPK via acetyl-CoA carboxylase 2 (ACC2), for the treatment of metabolic diseases such as diabetes and non-alcoholic fatty liver disease. In cancer, small molecule AMPK inhibitors may be more effective in disrupting catabolic processes that support cancer cell growth and survival; however, there has been little development of AMPK inhibitors and those that have been reported have limitations that prevent clinical evaluation. We have developed a series of 3,5-substitued oxindoles that have demonstrated low nanomolar (<10nM) inhibition of AMPK in a [33P]-ATP activity assay, cellular target engagement by measuring pACC2 by ELISA (>50% reduction in pACC2 at 1µM), and good cytotoxicity profiles with EC50s ranging 0.3-2 µM by MTS and CellTox Green cytotoxicity assays in the leukemic MOLM-13 cell line. Lead compounds were evaluated in a limited kinome screen to gauge selectivity with known oxindole target kinases, and were found to have increased selectivity for AMPK. Additionally, there may be clinical application for disrupting AMPK activity in drug resistant cancers, as AMPK activity has been recognized as an underlying mechanism of venetoclax resistance in acute myeloid leukemia (AML). Studies have shown that venetoclax resistant cells exhibit increased AMPK and oxidative phosphorylation levels to promote cell survival, negating the apoptotic effects of the BCL-2 inhibitor venetoclax. Therefore, the introduction of an AMPK inhibitor may sensitize AML cells to venetoclax, leading to more durable clinical outcomes. Our lead AMPK inhibitor in combination with venetoclax in MOLM-13 cells demonstrated synergy and further preclinical evaluation of this approach is ongoing. In summary, we have developed a series of selective and potent AMPK inhibitors that showed significant reduction in MOLM-13 cell viability and our current lead AMPK inhibitor demonstrated synergy in MOLM-13 cells. Our studies highlight the importance of targeting AMPK as a strategy for the treatment of metabolically driven cancers. Citation Format: Juliet Strang, Philip Reigan, Caleb Chandler, Vu Nguyen, Daniel Astridge. Development of selective oxindole-based AMPK inhibitors and their evaluation as single agents and in combination with venetoclax in models of leukemia [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2025 Oct 22-26; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2025;24(10 Suppl):Abstract nr A094.