Drug Drop Slams Pfizer

Lipitor is also under pressure from managed care organizations, which are encouraging doctors to prescribe cheaper generic versions of popular cholesterol fighters from Merck and Bristol-Myers Squibb(BMY Quote). Merck's Zocor and Bristol-Myers Squibb's Pravachol lost U.S. patent protection earlier this year.

Even though torcetrapib created controversy because recent test results revealed some elevation in blood pressure, many analysts viewed it as the biggest thing in Pfizer's near-term R&D efforts. Clinical trials showed the combination pill did a good job of fighting bad cholesterol and raising levels of good cholesterol.

Surprising Results

However, Pfizer cancelled work on its combination pill -- as well as a stand-alone torcetrapib pill -- because an independent data safety monitoring board detected "an imbalance of mortality and cardiovascular events" in the 15,000-patient clinical trial, nicknamed "Illuminate."

Clinical trials have independent units that monitor tests periodically, looking for any unusual negative or positive outcomes. Although these monitoring boards will report such events to the test's sponsor, the company itself doesn't get a sneak peak at the study in progress.

"Based on all the evidence we have seen regarding torcetrapib and in light of prior study results, we were very surprised by the information received from [the monitoring board]," Dr. Philip Barter, director of the Heart Research Institute in Australia, said Saturday. He is chairman of the steering committee overseeing the clinical trial. "We believed that the study was coming along as expected, and this new information was totally unexpected and disappointing, given the potential benefits of this drug."

The clinical trial compared patients taking the combination pill with others taking Lipitor. Barter emphasized that the side effect problem affected only torcetrapib. "Nothing in [Saturday's] information has any impact on the safety or efficacy of Lipitor whatsoever."

In Illuminate, about 7,500 patients got the combination pill, for which there were 82 deaths, and 7,500 patients received Lipitor, for which there were 51 deaths.

The Food and Drug Administration, which said it supported Pfizer's decision, said the data safety monitoring board told Pfizer of the death-rate data early Saturday morning and that the company told the FDA at 4 p.m. that afternoon that it planned to cancel work on torcetrapib.