MK-0533 is a novel selective peroxisome proliferator-activated receptor gamma modulator for the treatment of type 2 diabetes mellitus. In comparison with PPARγ full agonists, MK-0533 displayed diminished maximal activity (partial agonism) in cell-based transcription activation assays and attenuated gene signatures in adipose tissue. MK-0533 exhibited comparable efficacy to rosiglitazone and pioglitazone in vivo. However, with regard to the induction of untoward events, MK-0533 displayed no cardiac hypertrophy, attenuated increases in brown adipose tissue, minimal increases in plasma volume, and no increases in extracellular fluid volume in vivo. MK-0533 was teste in phase II clinical trials but future development was discontinued.