TAK-632 is a potent pan-Raf inhibitor with IC50 of 8.3 nM and 1.4 nM for B-Raf(wt) and C-Raf, respectively, showing less or no inhibition against other tested kinases.
TAK-632 inhibits phosphorylation of MEK and ERK in melanoma A375 cells (BRAFV600E) with IC50 of 12 nM and 16 nM, respectively. In human melanoma HMVII cells (NRASQ61K/BRAFG469V), TAK-632 also shows strong inhibition of pMEK and pERK with IC50 of 49 nM and 50 nM, respectively. Moreover, TAK-632 also exhibits antiproliferative activity in both A375 and HMVII cells with GI50 of 66 nM and 200 nM, respectively.TAK-632 induces RAF dimerization but inhibits the kinase activity of the RAF dimer because of its slow dissociation from RAF. The combination of TAK-632 and TAK-733 exhibits synergistic antiproliferative effects in BRAF- and NRAS-mutated melanoma cells.
TAK-632 shows superior oral bioavailability in both rats and dogs. TAK-632 (3.9–24.1 mg/kg, p.o.) exhibits dose-dependent antitumor efficacy without severe body weight reduction in a melanoma A375 (BRAFV600E) xenograft model and a human melanoma HMVII (NRASQ61K/BRAFG469V) xenograft in rats.In NRAS-mutant melanoma SK-MEL-2 xenograft model, TAK-632 (60 or 120 mg/kg, p.o.) also exhibits potent antitumor efficacy without severe toxicity. |
