Discovery of P3971 an Orally Efficacious Novel Anticancer Agent Targeting HIF-1α and STAT3 Pathways

Hypoxia-inducible factor-1 alpha (HIF-1 alpha) and signal transducer and activator of transcription 3 (STAT3) are transcription factors and are activated in response to hypoxia. Both HIF-1 alpha and STAT3 regulate various aspects of cancer biology such as cell survival, proliferation, angiogenesis etc. and are constitutively expressed in a wide range of human cancers. In the last decade, over expression of HIF-1 alpha and STAT3 has been demonstrated in many common human cancers, thereby emerging as highly compelling anticancer targets for drug discovery. We herein report the design and synthesis of new imidazopyridine based potent dual inhibitors of HIF-1 alpha and STAT3 pathways. The lead compound of this series P3971 has been identified as a potent inhibitor of HIF-1 alpha (200 nM) and STAT3 (350 nM) with significant antiproliferative activity against various cancer cell lines. Moreover, P3971 was also found to be orally efficacious in HCT116 (colon cancer) and H460 (lung cancer) xenograft mice models.