Isoquinoline-based biaryls as a robust scaffold for microtubule inhibitors

We here report the discovery of isoquinoline-based biaryls as a new scaffold for colchicine domain tubulin inhibitors. Colchicinoid inhibitors offer highly desirable cytotoxic and vascular disrupting bioactivities, but their further development requires improving in vivo robustness and tolerability: properties that both depend on the scaffold structure employed. We have developed isoquinoline-based biaryls as a novel scaffold for high-potency tubulin inhibitors, with excellent robustness, druglikeness, and facile late-stage structural diversification, accessible through a tolerant synthetic route. We confirmed their bioactivity mechanism in vitro, developed soluble prodrugs, and established safe in vivo dosing in mice. By addressing several problems facing the current families of inhibitors, we expect that this new scaffold will find a range of in vivo applications towards translational use in cancer therapy.