Dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) are effective and safe oral incretin-based antihyperglycemic drugs. In preclinical studies, DPP-4 inhibitors have demonstrated cardiovascular benefits, independent of glycemic control, in patients with type-2 diabetes mellitus. Since 2005, various DPP-4 inhibitors (sitagliptin, linagliptin and saxagliptin) have been clinically available in the United States. Since 2013, alogliptin is the 4(th) approved DPP-4 inhibitor available on the market. Studies have shown that alogliptinis non-inferior to comparator drugs among newly diagnosed type 2 diabetes mellitus patients. Alogliptin can effectively be used as a single agent or as an add-on drug in combination with other glucose lowering drugs with favorable outcomes on glycemic control and HbA1C levels.

PCSK9 proprotein convertase subtilisin/kexin type (PCSK9) protein plays an important role in LDL cholesterol (LDL-C) metabolism, due to its role in the degradation of the LDL receptor. Preliminary clinical data of PCSK9 inhibition are quite promising and indicate that PCSK9 inhibition may be a novel strategy for the treatment of dyslipidemia particularly for those with refractory hypercholesterolemia, statin intolerance, or an elevated lipoprotein (a) level and associated cardiovascular diseases. Furthermore, development of PCSK9 inhibitor is an excellent example of "bench to bedside" concept where discovery of a genetic mutation was translated into a novel therapy to address unmet clinical needs. Although several approaches have been attempted to inhibit PCSK9 activity including small molecules, gene silencing and inhibitory antibodies, the most promising approach appears to be the use of monoclonal antibodies with a 50 -70% LDL cholesterol reduction on top of maximal doses of statins. In this article, we review the pharmacology of PCSK9 and summarize findings from key clinical studies using PCSK9 inhibitors.