Even though there were no safety signals associated with dalcetrapib, the independent Data and Safety Monitoring Board recommended stopping the phase III dal-OUTCOMES trial, according to drugmaker Roche.
The board said that the second interim analysis of the trial showed the results lacked a "clinically meaningful efficacy," according to a company statement.
Dalcetrapib, a cholesteryl ester transfer protein (CETP) inhibitor, had two positive safety trials.
The phase IIb study dal-PLAQUE showed the drug did not adversely affect vascular structure or increase arterial inflammation. Researchers used MRI and PET/CT imaging, respectively, to assess the potential effects of dalcetrapib on atherosclerosis.
Another phase IIb study -- dal-VESSEL -- showed no adverse results to endothelial function, determined by measuring flow-mediated dilation of the brachial artery. At the time, researchers said they were disappointed that dalcetrapib did not improve endothelial function.
The dal-VESSEL results gave the green light to proceed with dal-OUTCOMES.
Many in the cardiology field were cautiously encouraged by the safety results of dalcetrapib, particularly because of the failure of torcetrapib, the first CETP inhibitor developed.
Although torcetrapib raised HDL and lowered LDL cholesterol, it was at the expense of an increase in cardiovascular events and mortality. Its phase III trial, ILLUMINATE, was also stopped prematurely.
The dal-OUTCOMES trial evaluated the safety and efficacy of dalcetrapib in patients with stable coronary heart disease following an acute coronary syndrome.
Other trials in the "dal-HEART" program will be terminated as well. They are dal-OUTCOMES 2, dal-PLAQUE 2, and dal-ACUTE.