NEW YORK (AP) – Pfizer Inc. said Saturday it has cut off all clinical trials and development for a cholesterol drug that was supposed to be the star of its pipeline because of an unexpected number of deaths and cardiovascular problems in patients who used it.

The world’s largest drugmaker said it was told Saturday that an independent board monitoring a study for torcetrapib, a drug that raises levels of HDL, or what’s commonly known as good cholesterol, recommended that the work end because of “an imbalance of mortality and cardiovascular events.”

Pfizer said it is asking all clinical investigators conducting trials to warn patients to stop taking the drug immediately.

The news is devastating to Pfizer, which had been counting on the drug to revitalize stagnant sales that have been hurt by numerous patent expirations on key products.

Just two days ago, Pfizer had said it hoped to file an application with the Food and Drug Administration for approval of torcetrapib by the second half of next year. But on Saturday, the company said the loss of the drug will not affect its financial guidance for 2006.

New York-based Pfizer had expected to sell Torcetrapib in combination with Lipitor, which lowers bad cholesterol and is the company’s – and the world’s – best-selling drug.

According to Pfizer spokesman Paul Fitzhenry, 82 patients taking the combination of torcetrapib died, compared to 51 deaths in the arm of the study where patients were taking Lipitor alone. Each arm of the study had 7,500 patients. Pfizer said that the study didn’t raise any questions about Lipitor’s safety.

There already had been concerns about Torcetrapib because a study showed it caused an increase in blood pressure. In raising its earnings guidance for the year Thursday the company emphasized that it has 242 research programs and other promising drugs in the pipeline, but analysts remained focused on Torcetrapib and said Pfizer would struggle without it.

Patent expirations will cost the company $14 billion in annual sales between 2005 and 2007, the company said. Lipitor, which had $12.2 billion in sales last year, may lose patent protection by 2010.

Dr. Philip Barter, chairman of the steering committee overseeing the study, said in Pfizer’s release that the findings of the data safety monitoring board Torcetrapib were a surprise “in light of prior study results.”

“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,” said Barter, Director of the Heart Research Institute in Australia.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.