CC-90003

In biochemical, cellular, and mass spectrometry assays of 347 kinases, CC-90003 was found to strongly inhibit kinase activities of ERK1 and ERK2 with IC50s in the 10 to 20 nmol/L range and had good kinase selectivity. In a 258-kinase biochemical assay panel, significant inhibition of 213 kinases (<50% inhibition), moderate inhibition of 28 kinases (50%–80% inhibition), and >80% inhibition of 17 kinases by CC-90003 were found. In an ActivX cellular kinase screening using A375 BRAF V600E-mutant melanoma cell line, only 5 of 194 kinases (ERK1, ERK2, MKK4, MKK6, and FAK) were inhibited by >80% at 1 mmol/L of CC-90003. At the same concentration, no significant inhibition (<14%) was found in a Cerep panel of 40 nonkinase enzymes and receptors. Through our iterative analyses, only 3 kinases, in addition to ERK1/2, were inhibited in cells at biologically relevant concentrations: KDR, FLT3, and PDGFRa. Tumors with BRAF mutations were particularly sensitive to CC-90003. In many, but not all cases, CC-90003 had cytotoxic effects in KRAS-mutant PDAC, lung cancer, and colorectal cancer cell lines. CC-90003 does not significantly inhibit proliferation of normal lung fibroblasts or bronchial epithelial cells^[1].

The cells were plated at a density of 3,000 cells/well in 90 mL of growth media on 96-well clear bottom black-well plates and incubated with overnight under standard cell culture growth conditions at 37 C with 5% CO2. The followinging day, one plate for each cell line was used for "Day 0" cell growth control readout, whereas others were treated with 9-point3-fold dilutions of one compound or combination of compounds, and a DMSO control. Each concentration was tested in triplicate. Cell viability was measured 72 hours later.

In in vivo studies of an HCT-116 xenograft model, CC-90003 was well tolerated at a range of doses (12.5 mg b.i.d.-100 mg qd), although doses of 50 mpk b.i.d. and 75 mpk b.i.d. group caused mortality by days 6 to 18 of study. Both dosing schedules (qd and b.i.d.) leads to tumor growth inhibition. CC-90003 inhibits tumor growth in vivo of three KRAS-mutant PDX models^[1].