Dalcetrapib is a cholesteryl ester transfer protein (CETP) inhibitor developed to improve cardiovascular outcomes by increasing high-density lipoprotein (HDL) cholesterol levels. It was investigated for use in patients with existing cardiovascular disease to reduce the risk of atherosclerosis progression and related events such as heart attack or stroke. The compound aimed to shift the balance of lipid metabolism by blocking the transfer of cholesterol esters from HDL to low-density lipoproteins (LDL), thereby promoting reverse cholesterol transport.

Clinical trials focused on its potential to stabilize or regress atherosclerotic plaques and lower cardiovascular risk when added to standard therapies like statins. However, development was discontinued after phase III trials failed to demonstrate a significant reduction in cardiovascular events compared to placebo, despite favorable changes in HDL levels. As a result, dalcetrapib is not used clinically and remains an example of a targeted lipid-modifying agent that showed promise in early studies but did not translate into measurable patient outcomes in large-scale trials.