For years, excitement has built over the drug torcetrapib. Part of a new class of drugs (cholesterol ester transfer protein inhibitors, or CETPs), it was developed to increase HDL cholesterol levels (i.e., the "good" cholesterol.)
Early studies reported that HDL cholesterol levels rose rapidly in all patients taking this drug, whether or not they were also taking statins. They also reported few side effects. Since raising HDL levels had become the "Holy Grail" of heart disease prevention, expectations for torcetrapib, and other CETP inhibitors, was high.
Unfortunately, it was discovered in late 2006 that patients whose HDL cholesterol levels increased with torcetrapib did not reduce their risk of heart disease--they actually experienced an increased risk. In the ILLUMINATE study, patients who received torcetrapib and atorvastatin had an increased risk of death and cardiac events compared to patients who only took atorvastatin.
This result has greatly complicated the picture. Were results worse with torcetrapib because of some feature of the drug itself, because of some feature of CETP inhibitors in general, or because we just don't understand enough about HDL cholesterol and how it works?
Whatever the answer turns out to be, torcetrapib, is far from being the next blockbuster drug.
Sources:
Pfizer announces its withdrawal of torcetrapib from development. http://www.pfizer.com/pfizer/download/investors/financial/8k_1202_06.pdf
