Design, synthesis and evaluation of derivatives based on pyrimidine scaffold as potent Pan-Raf inhibitors to overcome resistance

Abstract Simutaneous targeting all Raf isoforms offers the prospect of enhanced efficacy as well as reduced potential for resistance. Described herein is the discovery and characterization of a series of pyrimidine scaffold with DFG-out conformation as potent Pan-Raf inhibitors. Among them, I-41 with excellent Pan-Raf potency demonstrates inhibitory activity against BRaf WT phenotypic melanoma and BRaf V600E phenotypic colon cells. The western blot results for the Erk inhibition in human melanoma SK-Mel-2 cell lines showed I-41 inhibited the proliferation of SK-Mel-2 cell lines without paradoxical activation of Erk, which supported I-41 may become a good candidate compound to overcome the resistance of melanoma against the current BRaf V600E inhibitor therapy. I-41 also have a favorable pharmacokinetic profile in rat. Synthesis, SAR, lead selection, and evaluation of the key compounds studies are described.