In clinical trials against lymphoma MK-8776 was administered as an intravenous infusion over at least 30 minutes.

An in vitro assay utilizing recombinant His-CHK1 expressed in the baculovirus expression system as an enzyme source and biotinylated peptide based upon CDC25C as substrate. His-CHK1 was diluted to 32 nM in kinase buffer containing 50 mM Tris pH 8.0, 10 mM MgCl2, and 1 mM DTT. CDC25C (CDC25 Ser216 C-term biotinylated peptide, Research Genetics) peptide was diluted to 1.93 lM in kinase buffer. For each kinase reaction, 20 lL of 32 nM CHK1 enzyme solution and 20 lL of 1.926 lM substrate solution were mixed and combined with 10 lL of compound diluted in 10% DMSO, making final reaction concentrations of 6.2 nM CHK1, 385 nM CDC25C and 1% DMSO after addition of start solution. The reaction was started by addition of 50 lL of start solution consisting of 2 lM ATP and 0.2 lCi of 33PATP, making a final reaction concentration of 1 lM ATP, with 0.2 lCi of 33P-ATP per reaction. Kinase reactions ran for 2 h at room temperature and were stopped by the addition of 100 lL of stop solution consisting of 2 M NaCl, 1% H3PO4, and 5 mg/mL Streptavidin-coated SPA beads. SPA beads were captured using a 96-well GF/B filter plate and a Filtermate universal harvester. Beads were washed twice with 2 M NaCl and twice with 2 M NaCl with 1% phosphoric acid. Signal was then assayed using a TopCount 96-well liquid scintillation counter. Dose–response curves were generated from duplicate 8 point serial dilutions of inhibitory compounds.