Cobimetinib

Cobimetinib (GDC-0973, XL-518) is a potent, selective MEK inhibitor with IC50 of 4.2 nM for MEK1; shows excellent selectivity against mTOR, DNA-dependent protein kinase (DNA-PK), and a panel of more than 228 kinases; shows strong cellular potency in a broad panel of tumor types, particularly in BRAF or KRAS mutant cancer cell lines, triggers robust apoptosis and tumor growth inhibition in vivo combined with PI3K inhibitor GDC-0941.Skin Cancer Approved (In Vitro) :The EC50 values of Cobimetinib (GDC-0973) for 888MEL and A2058 cells are 0.2 μM, 10 μM, respectivelly. Melanoma cells are treated with EC50 concentration of MEK and PI3K inhibitors for 24 hours (888MEL: 0.05 μM GDC-0973, 2.5 μM GDC-0941; A2058: 2.5 μM GDC-0973, 2.5 μM GDC-0941) . Mitochondrial OXPHOS limits cell death induced by cobimetinib (100 nM) in melanoma with constitutive MAPK activation in A375 cells. (In Vivo) :In the NCI-H2122 KRASG12C mutant non-small cell lung carcinoma (NSCLC) xenograft model, treatment with up to 5 mg/kg Cobimetinib (GDC-0973) lead to moderate TGI and at 10 mg/kg approaches tumor stasis. GDC-0973 and GDC-0941 are administered to A2058 tumor-bearing mice daily (QD) or every third day (Q3D) either as single agents or in combination. The population rate constants associated with tumor growth inhibition for GDC-0973 and GDC-0941 are 0.00102 and 0000651 μM-1 h-1, respectively. Following single doses of GDC-0973 (1, 3, or 10 mg/kg, p.o.) estimated in vivo IC50 values of %pERK decrease based on tumor concentrations in xenograft mice are 0.78 (WM-266-4) and 0.52 μM (A375) .