Abstract 6589: Discovery of potent and selective pan-TEAD autopalmitoylation inhibitors for the treatment of Hippo-pathway altered cancers

Abstract TEAD1-4 are DNA bound transcription factors regulated by the Hippo tumor suppressor pathway that bind the coactivators YAP/TAZ to activate oncogenic gene expression programs involved in cell survival, proliferation, and drug resistance. TEAD-dependent transcription is activated in many tumor types through a variety of mechanisms including LOF Hippo pathway mutations (e. g. NF2, LATS) and YAP/TAZ amplification, and also as an adaptive resistance mechanism, for example in response to EGFR TKI and KRAS inhibition. Here, we report the initial characterization of a novel pan-TEAD inhibitor, AZ4331, which was identified following a structure-guided drug design campaign. AZ4331 disrupts the post-translational palmitoylation of TEAD proteins through covalent binding to a conserved cysteine residue resulting in inhibition of TEAD-dependent transcriptional output. AZ4331 inhibited the proliferation of NF2m NCI-H226 cells (GI50: 92 nM) while having no effect on Hippo-wild type NCI-H2452 (GI50: undetermined). Cell-based metabolic labeling studies demonstrated the ability of AZ4331 to inhibit palmitoylation of all four TEAD paralogs and led to disruption of the YAP/TEAD complex assessed by immunoprecipitation resulting in reduced TEAD transcriptional output as assessed by qPCR. Furthermore, in vivo profiling showed AZ4331 achieved sufficient exposures (plasma free Cmax: 2. 7 µM) and robust target engagement as measured through reduction of multiple canonical TEAD target genes (CTGF IC50: 0. 127 µM, ANKRD1, AMOTL2 and CYR61) in Hippo-altered mesothelioma xenograft tumors. This target engagement in turn drove inhibition of tumor proliferation in xenograft models representing common Hippo-alterations. AZ4331 treatment of NF2m NCI-H226 and LATS1/2 loss MSTO-211H mesothelioma xenografts drove 50% and 93% regression of tumors, respectively. While treatment of head and neck squamous cell carcinoma FAT1m FaDu and YAP1amp Detroit562 xenografts lead to 58% tumor growth inhibition and 35% tumor regression, respectively. These findings identify AZ4331 as a potent inhibitor of the TEAD transcription factor family and further validate the inhibition of TEAD in Hippo-altered cancers as a potential therapeutic strategy. Citation Format: Jacob A. Gordon, Jolanta Dubauskaite, Michelle DuPont, Nin Guan, Geoff Holdgate, Scott Mlynarski, Neil Umbreit, Danielle Sanchez, Abhishek Srivastava, Janek Suski, Nancy Su, Ryan Richards, Sabina Cosulich, Corinne Reimer, James Brownell. Discovery of potent and selective pan-TEAD autopalmitoylation inhibitors for the treatment of Hippo-pathway altered cancers abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 6589.