Empesertib (BAY1161909)

Empesertib (BAY1161909) is a very effective Mps-1 inhibitor with an IC50 lower than or equal to 1 nM (more potent than 1 nM) in an Mps-1 kinase assay with a concentration of 1 μM/2 mM ATP, and an IC50 lower than 400 nM in a HeLa cell proliferation assay.^[1]

Cultivated tumor cells are plated at a density of 5000 cells/well (MCF7, DU145, HeLa-MaTu-ADR), 3000 cells/well (NCI-H460, HeLa-MaTu, HeLa), or 1000 cells/well (B16F10) in a 96-well multititer plate in 200 μl of their 5 respective growth medium supplemented 10% fetal calf serum. After 24 hours, the cells of one plate (zero-point plate) are stained with crystal violet, while the medium of the other plates was replaced by fresh culture medium (200 μl), to which the test substances are added in various concentrations (0 μM, as well as in the range of 0.01-30 μM; The cells are incubated for 4 days in the presence of test substances. Cell proliferation is determined by staining the cells with crystal violet: the cells are fixed by adding 20 μl/measuring point of an 11 % glutaric aldehyde solution for 15 minutes at room temperature. After three washing cycles of the fixed cells 15 with water, the plates are dried at room temperature. The cells are stained by adding 100 μl/measuring point of a 0.1 % crystal violet solution (pH 3.0). After three washing cycles of the stained cells with water, the plates are dried at room temperature. The dye is dissolved by adding 100 μl/measuring point of a 10% acetic acid solution.

Empesertib (BAY1161909) is a very effective Mps-1 inhibitor with a maximum oral bioavailability (Fmax) in rat that is higher than 70%, determined by means of rat liver microsomes, and a maximum oral bioavailability (Fmax) in dog that is higher than 50%, determined by means of dog liver microsomes, and a maximum oral bioavailability (Fmax) in human that is higher than 60%, determined by means of human liver microsomes.^[1]