Inhibitors of phospholipase A and their therapeutic potential: an update on patents (2012-2016).

The regulation of the catalytic activity of the various phospholipase A enzymes is of high importance because these enzymes are involved in various pathological conditions such as arthritis, cardiovascular diseases, neurological diseases, and cancer. Thus, a great effort has been devoted in developing synthetic inhibitors as new agents to treat inflammatory diseases. Some of them have reached clinical trials. Areas covered: This review article discusses the phospholipase A inhibitors presented in patent literature from October 2012 to June 2016, their activities in vitro and in vivo as well as the results of clinical trials using synthetic PLA inhibitors. Expert opinion: None of the inhibitors studied in clinical trials have reached the market yet. The failure of lipoprotein-associated PLA inhibitor darapladib to reduce the risk of major coronary events suggests that this enzyme may be a biomarker of vascular inflammation rather than a causal pathway of cardiovascular diseases. These findings, together with the failure of secreted PLA inhibitor varespladib for the treatment of cardiovascular disease, indicate that deeper knowledge on these enzymes is needed. Inhibitors of cytosolic PLA are in clinical trials against psoriasis and atopic dermatitis.