Abstract 3081: TEAD inhibition by IAG933 as a novel therapeutic strategy for cholangiocarcinoma

Abstract Background: Cholangiocarcinoma (CCA) is an aggressive hepatobiliary malignancy with marked molecular heterogeneity, limited systemic treatment options, and poor prognosis. Chemoresistance and KRAS mutations remain major therapeutic challenges. Dysregulation of the Hippo pathway, particularly YAP/TAZ hyperactivation, drives CCA progression and resistance. TEAD, the essential transcriptional partner of YAP/TAZ, represents a promising target. IAG933 is a novel oral pan-TEAD inhibitor designed to disrupt YAP/TAZ-TEAD interactions. RMC-6236, a pan-KRAS inhibitor, has also gained attention. Combined TEAD and KRAS inhibition may overcome resistance and improve efficacy in CCA. Methods: We evaluated IAG933 in human (HuCCT1, RBE) and murine (SB1, FAC) CCA cell lines. Cells were treated with IAG933 alone or in combination with GemCis or RMC-6236. Cell viability assays were used to determine IC50 values and calculate combination indexes (CI). TEAD activity was assessed by luciferase reporter and qRT-PCR of YAP/TAZ target genes (CTGF, CYR61, NUAK2). Transcriptomic alterations were analyzed by RNA sequencing. In vivo efficacy was evaluated in syngeneic orthotopic and patient-derived xenograft (PDX) models. Results: IAG933 suppressed TEAD-dependent transcription (IC50 ≈ 500 nM) and downregulated YAP/TAZ target genes. Combination with GemCis or RMC-6236 produced synergistic effects (CI < 1) in all CCA lines. Transcriptomic analysis revealed activation of oxidative stress response pathways, particularly SOD2 upregulation. MitoSOX staining confirmed increased mitochondrial ROS after treatment. In vivo, IAG933 monotherapy suppressed tumor growth similarly to GemCis. Dual TEAD and KRAS inhibition achieved marked tumor regression and significantly delayed tumor regrowth after treatment cessation in KRAS-mutant PDX models. Conclusion: IAG933 effectively suppresses YAP/TAZ-TEAD signaling and inhibits CCA growth. While the combination with GemCis showed limited additional benefit due to strong single-agent efficacy, synergy with RMC-6236 produced durable antitumor effects, particularly in run-out studies, delaying regrowth in KRAS-mutant models. These findings highlight IAG933 as a promising therapeutic candidate targeting the Hippo-TEAD pathway, with potential benefit in KRAS-mutant CCA. Citation Format: Hidemi Nishi,Erik Jessen,Danielle M. Carlson,Amro M. Abdelrahman,Enis H. Ozmert,J. Pedro Fincatto Safi,Brandon A. Wilbanks,Shelby K. Yee,Jack W. Sample,Nathan W. Werneburg,Rory L. Smoot. TEAD inhibition by IAG933 as a novel therapeutic strategy for cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3081.