Torcetrapib

Torcetrapib was a failed statin drug, and one of the most spectacular failures in recent pharmaceutical development.

Pfizer spent hundred of millions on it and got it all the way to Phase III clinical trials (the final phase).

Even in late 2006 Pfizer's chief was quoted as saying "This will be one of the most important compounds of our generation." A few days later, the company ended the trial because of disturbing data that was coming back.

The scientists found an increase in mortality among patients taking the medicine, and they recommended everyone in the trail stop taking the drug immediately. There were 15,000 patients in the trial.

It was a major blow to Pfizer's fortunes. Lipitor (atorvastatin) is the Pfizer's biggest-selling drug, and indeed has been the biggest selling prescription drug in the world for several years. Statins in general are big money-makers for the pharmaceutical industry. More importantly, it was a loss for the patient and medical communities who might have had another weapon in their cholesterol arsenal.

Torcetrapib wasn't a cholesterol-lowering agent; it was a cholesterol-raising agent. But it promised to raise HDL, the good cholesterol.

Pfizer has at one time planned to sell it as part of the same pill as atorvastatin (in a marketing tactic called “bundling”) although they later changed that plan after protests from the medical establishment who wanted more flexibility.

The drug companies have other chemicals in their pipelines that might turn into HDL-raising drugs (torcetrapib was part of a class of drugs called CETP inhibitors), but they all appear to be a long way being proven in the clinical trials process.

An article in Nature Reviews Drug Discovery questions whether attempting to raise HDL is a viable strategy at all, especially given the "intricacy of HDL metabolism".