In vitro: CCT245737 shows <50% inhibition at 10 μM for 85/121 kinases, representing a selectivity for CHK1 inhibition of >5000-fold over these enzymes. [1] CCT245737 enhanced gemcitabine antitumor activity to a greater degree than for higher doses of either agent alone, without increasing toxicity. In vivo: CCT2457374 shows an increase in plasma and tumoconcentrations between 3?100 mg/kg po.