Abstract 1656: ISM6331, a novel and potent pan-TEAD inhibitor, exhibits strong anti-tumor activity in preclinical models of Hippo pathway-dysregulated cancers

Abstract The Hippo-YAP/TAZ-TEAD signaling pathway plays critical roles in tumorigenesis and tumor progression. Genetic alterations of Hippo pathway regulators, such as NF2 or LATS1/2, have been shown to induce YAP/TAZ-TEAD transcriptional activity, promoting initiation and progression of many solid tumors. In addition, many studies have shown that YAP/TAZ-TEAD activation mediates resistance to multiple targeted therapies, particularly EGFR-KRas-MAPK pathway inhibitors. The TEAD family of transcription factors (TEAD1/2/3/4) share structural similarity and have overlapping functions in tumor development and TEAD auto-palmitoylation is critical for its interaction with YAP/TAZ and its transcriptional function. Therefore, blocking TEAD palmitoylation and allosterically disrupting YAP/TAZ-TEAD-mediated transcriptional regulation, is emerging as a promising approach for the treatment of tumors with Hippo pathway dysregulation. In this work, ISM6331, a novel and potent TEAD inhibitor with excellent inhibition against TEAD1/2/3/4 was identified leveraging an AI generative model. ISM6331 reversibly binds to the TEAD palmitoylation site and significantly suppresses TEAD transcriptional activity. ISM6331 potently and selectively inhibited the growth of many Hippo pathway-dysregulated tumor cells and dose-dependently suppressed the expression of TEAD target genes in vitro. In NF2-deficient or LATS1/2-mutant in vivo mesothelioma models, ISM6331 exhibited promising anti-tumor efficacy as monotherapy in a dose-dependent manner from 3 to 30mg/kg. ISM6331 also showed synergism with EGFR or KRasG12C inhibitors in inhibiting tumor cell growth and overcame drug resistance in in vitro and in vivo models. In addition, ISM6331 showed excellent pharmacokinetic properties in multiple preclinical species and was well-tolerated in GLP-toxicity studies. In summary, ISM6331 has promising potential to treat Hippo pathway-dysregulated tumors as monotherapy as well as in combination with targeted therapies. Citation Format: Qi Li, Jainfei Wan, Jinxin Liu, Jing Shang, Jiaojiao Yu, Wei Zhu, Celia X. -J. Chen, Junwen Qiao, Ling Wang, Man Zhang, Xiao Ding, Supriya Bavadekar, Sujata Rao, Feng Ren, Alex Zhavoronkov. ISM6331, a novel and potent pan-TEAD inhibitor, exhibits strong anti-tumor activity in preclinical models of Hippo pathway-dysregulated 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 1656.