The ENHANCE Study: an unusual publication of trial data raises questions beyond ezetimibe

Over the past 2 years two unsuccessful clinical trials of lipid-modifying agents, the ILLUMINATE Study for raising high-density lipoprotein and the ENHANCE Study for lowering low-density lipoprotein, have been reported. These results have surprised the field and led to a reassessment of the scientific and clinical basis for the overall mechanisms.

This paper aimed to consider the impact of the two trials, particularly the ENHANCE Study, on drug discovery and developments in dyslipidaemia and atherosclerosis.

The ILLUMINATE Study, which was a trial of the cholesteryl ester transfer protein inhibitor torcetrapib is briefly reviewed, followed by a more detailed discussion of the press release of the ENHANCE Study with ezetimibe, a cholesterol absorption inhibitor. The reaction of opinion leaders in the field with respect to low-density lipoprotein-lowering strategies and imaging methods is discussed.

Even when accessible surrogate end-points such as plasma lipoprotein levels are available, the development of anti-atherosclerotic drugs acting by new mechanisms may be becoming more challenging. Imaging studies as an intermediate between early clinical studies and major outcome trials may be the way forward.