MK-5108 (VX-689)

MK-5108, also known as VX-689, is a novel, potent and selective inhibitor of Aurora A kinase (AAK) that competitively binds to the ATP binding site of AAK and hence potently inhibits the activity of AAK with 50% inhibition concentration IC₅₀ value of 0.064 nM. MK-5108 also inhibits other members of Aurora kinase family, including Aurora B kinase (IC₅₀ = 14 nM) and Aurora C kinase (IC₅₀ = 12 nM), with a lesser potency. MK-5108 has been extensively studies and found to exhibit antitumor activity in a wide range of cancer types, including breast, cervix, colorectal, ovary and pancreas neoplasms.

Reference

Myke R. Green, BS, Pharm.D., BCOP, Joseph E. Woolery, BS, Pharm.D, and Daruka Mahadevan, MD, PhD. Update on Aurora Kinase Targeted Therapeutics in Oncology. Recent Pat Anticancer Drug Discov. 2008 November ; 3(3): 162–177.

Aurora kinase inhibitor patents and agents in clinical testing: an update (2011 - 2013).[Pubmed:24965505]

Expert Opin Ther Pat. 2014 Sep;24(9):1021-38.

INTRODUCTION: Aurora kinase A, B and C, members of serine/threonine kinase family, are key regulators of mitosis. As Aurora kinases are overexpressed in many of the human cancers, small-molecule inhibitors of Aurora kinase have emerged as a possible treatment option for cancer. AREAS COVERED: In 2009 and 2011, the literature pertaining to Aurora kinase inhibitors and their patents was reviewed. Here, the aim is to update the information for Aurora kinase inhibitors in clinical trials and the patents filed between the years 2011 and 2013. Pubmed, Scopus(R), Scifinder(R), USPTO, EPO and www.clinicaltrials.gov databases were used for searching the literature and patents for Aurora kinase inhibitors. EXPERT OPINION: Even though both Aurora sub-type selective as well as pan-selective inhibitors show preclinical and clinical efficacy, so far no Aurora kinase inhibitor has been approved for clinical use. Particularly, dose-limiting toxicity (neutropenia) is a key issue that needs to be addressed. Preliminary evidence suggests that the use of selective Aurora A inhibitors could avoid Aurora B-mediated neutropenia in clinical settings. Also, use of adjunctive agents such as granulocyte stimulating factor to overcome neutropenia associated with Aurora B inhibition could be an answer to overcome the toxicity and bring Aurora inhibitors to market in the future.

Long residence times revealed by Aurora A kinase-targeting fluorescent probes derived from inhibitors MLN8237 and VX-689.[Pubmed:24403173]

Chembiochem. 2014 Feb 10;15(3):443-50.

We report the development of three fluorescent probes for protein kinase Aurora A that are derived from the well-known inhibitors MLN8237 and VX-689 (MK-5108). Two of these probes target the ATP site of Aurora A, and one targets simultaneously the ATP and substrate sites of the kinase. The probes were tested in an assay with fluorescence polarisation/anisotropy readout, and we demonstrated slow association kinetics and long residence time of the probes (kon 10(5)-10(7) M(-1) s(-1), koff 10(-3)-10(-4) s(-1); residence time 500-3000 s). The presence of the Aurora A activator TPX2 caused a significant reduction in the on-rate and increase in the off-rate of fluorescent probes targeting ATP site. These observations were supported by Aurora A inhibition assays with MLN8237 and VX-689. Overall, our results emphasise the importance of rational design of experiments with these compounds and correct interpretation of the obtained data.