Notes: JNJ-38877605 is an ATP-competitive inhibitor of Met kinase (IC50 = 4 nM).{46502} It is at least 600-fold selective for Met in a panel of approximately 250 tyrosine and serine-threonine kinases. JNJ-38877605 inhibits the growth of cancer cell lines with MET gene amplification (IC50s = 11-50 nM) but has no effect on the growth of control cells with normal MET gene copy number or no MET expression.{46503} The efficacy of JNJ-38877605 against MET-amplified cells decreases in the presence of increasing concentrations of recombinant human hepatocyte growth factor (HGF). JNJ-38877605 (50 mg/kg) sensitizes tumors to radiotherapy in U251 glioma and MDA-MB-231 breast cancer mouse xenograft models and increases apoptosis in irradiated tumors in the MDA-MB-231 mouse xenograft model.{46504} It reduces tumor size by 6-fold and the number of blood vessels in tumors by 80% in an RU-P melanoma mouse xenograft model when administered at a dose of 20 mg/kg.{46505}