Belvarafenib

Biochemically assayed for over 120 kinases, HM95573 shows the high selectivity toward BRAF mutant and CRAF kinases. The half maximal inhibition concentrations (IC50) of HM95573 against BRAFWT, BRAFV600E and CRAF kinases are 41nM, 7nM and 2nM, respectively. The strongly inhibited kinases subsequent to RAF kinases appear to be CSF1R (44nM), DDR1 (77nM) and DDR2 (182 nM). HM95573 potently inhibits the growth of mutant BRAF melanoma cell lines such as A375 (IC50: 57 nM) and SK-MEL-28 (69 nM) and of mutant NRAS melanoma cell lines such as SK-MEL-2 (53 nM) and SK-MEL-30 (24 nM). In addition, the phosphorylations of MEK and ERK downstream kinases associated with cell proliferation are effectively inhibited with treatment of HM95573 in mutant BRAF and mutant NRAS melanoma cells. HM95573 inhibits the downstream signaling in melanoma cells even in the presence of HGF which is known to mediate innate resistance to RAF inhibitors^[1].

SUM-159 cells were treated with the pan-Raf inhibitor, belvarafenib, for 48 h

HM95573 shows the excellent antitumor activity in mouse models xenografted with both of BRAF mutation cell lines (e.g. A375 and SK-MEL-28) and NRAS mutation cell lines (such as SK-MEL-2 and SK-MEL-30)^[1].