Characterization of compound mechanisms and secondary activities by BioMAP analysis.

INTRODUCTION: Unexpected drug activities account for many of the failures of new chemical entities in clinical trials. These activities can be target-dependent, resulting from feedback mechanisms downstream of the primary target, or they can occur as a result of unanticipated secondary target(s). Methods that would provide rapid and efficient characterization of compounds with respect to a broad range of biological pathways and mechanisms relevant to human disease have the potential to improve preclinical and clinical success rates.
METHODS: BioMAP assays containing primary human cells (endothelial cells and co-cultures with peripheral blood leukocytes) were stimulated in complex formats (specific combinations of inflammatory mediators) for 24 h in the presence or absence of test agents (drugs, experimental compounds, etc.). The levels of selected protein readouts (adhesion receptors, cytokines, enzymes, etc.) were measured and activity profiles (normalized data sets comprising BioMAP profiles) were generated for each test agent. The resulting profiles were compared by statistical methods to identify similarities and mechanistic insights.
RESULTS: Compounds with known mechanisms including inhibitors of histamine H1 receptor, angiotensin converting enzyme, IkappaB kinase-2, beta2 adrenergic receptor and others were shown to generate reproducible and distinguishable BioMAP activity profiles. Similarities were observed between compounds targeting components within the same signal transduction pathway (e.g. NFkappaB), and also between compounds that share secondary targets (e.g. ibuprofen and FMOC-L-leucine, a PPARgamma agonist). DISCUSSION: Complex primary cell-based assays can be applied for detecting and distinguishing unexpected activities that may be of relevance to drug action in vivo. The ability to rapidly test compounds prior to animal or clinical studies may reduce the number of compounds that unexpectedly fail in preclinical or clinical studies.