Primary Citation of Related Structures:   3VNT, 4DBN
PubMed Abstract: 
To develop RAF/VEGFR2 inhibitors that bind to the inactive DFG-out conformation, we conducted structure-based drug design using the X-ray cocrystal structures of BRAF, starting from an imidazo[1,2-b]pyridazine derivative. We designed various [5,6]-fused bicyclic scaffolds (ring A, 1-6) possessing an anilide group that forms two hydrogen bond interactions with Cys532 ...
To develop RAF/VEGFR2 inhibitors that bind to the inactive DFG-out conformation, we conducted structure-based drug design using the X-ray cocrystal structures of BRAF, starting from an imidazo[1,2-b]pyridazine derivative. We designed various [5,6]-fused bicyclic scaffolds (ring A, 1-6) possessing an anilide group that forms two hydrogen bond interactions with Cys532. Stabilizing the planarity of this anilide and the nitrogen atom on the six-membered ring of the scaffold was critical for enhancing BRAF inhibition. The selected [1,3]thiazolo[5,4-b]pyridine derivative 6d showed potent inhibitory activity in both BRAF and VEGFR2. Solid dispersion formulation of 6d (6d-SD) maximized its oral absorption in rats and showed significant suppression of ERK1/2 phosphorylation in an A375 melanoma xenograft model in rats by single administration. Tumor regression (T/C = -7.0%) in twice-daily repetitive studies at a dose of 50 mg/kg in rats confirmed that 6d is a promising RAF/VEGFR2 inhibitor showing potent anticancer activity.
Organizational Affiliation: 
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan. masanori.okaniwa@takeda.com
2-chloro-3-(1-cyanocyclopropyl)-N-[5-({2-[(cyclopropylcarbonyl)amino][1,3]thiazolo[5,4-b]pyridin-5-yl}oxy)-2-fluorophenyl]benzamide C27 H19 Cl F N5 O3 S MDPMAXSABUPRJI-UHFFFAOYSA-N