A novel irreversible TEAD inhibitor, SWTX-143, blocks the Hippo pathway and causes tumor regression in preclinical mesothelioma models [SubQ]

The Hippo pathway and its downstream effectors, the YAP and TAZ transcriptional coactivators, are deregulated in multiple different types of human cancer and are required for cancer cell phenotypes in vitro and in vivo, while largely dispensable for tissue homeostasis in adult mice. YAP/TAZ and their partner transcription factors, the TEAD1-4 factors, are therefore promising anti-cancer targets. Due to frequent YAP/TAZ hyperactivation caused by mutations in the Hippo pathway components NF2 and Lats2, mesothelioma is one of the prime cancer types predicted to be responsive to YAP/TAZ-TEAD inhibitor treatment. Mesothelioma is a devastating disease for which currently no effective treatment options exist. Here, we describe a novel covalent YAP/TAZ-TEAD inhibitor, SWTX-143, that binds to the palmitoylation pocket of all TEAD isoforms. SWTX-143 caused irreversible and specific inhibition of the transcriptional activity of YAP/TAZ-TEAD in Hippo-mutant tumor cell lines. More importantly, YAP/TAZ-TEAD inhibitor treatment caused strong mesothelioma regression in human subcutaneous xenograft models and in an orthotopic mesothelioma mouse model. Finally, SWTX-143 also selectively impaired the growth of NF2-mutant kidney cancer cell lines, suggesting that the exquisite sensitivity of mesothelioma to these YAP/TAZ-TEAD inhibitors can be extended to other tumor types with aberrations in Hippo signaling. In brief, we describe a novel and specific YAP/TAZ-TEAD inhibitor that has great potential to treat multiple Hippo-mutant solid tumor types. NCI-H226 cells were injected subcutaneously into BALB/c nude mice. When tumors reached about 170mm3, mice were randomized into groups and treated once daily with SWTX-143 (10, 25 and 50mg/kg) or vehicle for control group. Samples were extracted either 4h or 24h after the last dose of treatment.