Liver damage prompts Pfizer to pull back new blood pressure drug

Liver damage prompts Pfizer to pull back new blood pressure drug

Liver damage has been noted during the clinical trial of the new Pfizer blood pressure drug Thelin, prompting the pharmaceutical firm to withdraw it from the market. Thelin or sitaxsentan, was available in Australia, Canada and Europe and was medically indicated to lower blood pressure in the pulmonary artery. Pfizer, based in New York City, disclosed that their clinical data revealed a previously undetected direct toxicity to the liver. At least two patients who were enrolled in the trials have died, Pfizer said.

The company said they have previously identified liver damage as a possible adverse effect of taking Thelin, but it said other risk factors were considered. The newly discovered link to liver damage has ruled out other factors and may be directly linked to the drug itself. Liver damage was irreversible in some patients even after the drug was discontinued according to Pfizer. The company concluded that the risks posed by Thelin were greater than its benefits and that it was their voluntary decision to withdraw the drug. Pfizer also said it was not pushing for an approval to market Thelin in the United States.

All clinical studies of Thelin are suspended by Pfizer. Thelin has previously been denied FDA approval in 2005 because the agency was not convinced of its effectiveness. It was then developed by Encysive Pharmaceuticals, Inc., which Pfizer acquired later. Other health authorities have only given their approval of the drug for cases of severe high blood pressure where patients daily functioning is markedly affected. Thelin sold $44.4 million from January until September this year.

Posted by George Daniels on Saturday December 11 2010, 3:14 AM EST. Ref: AP. All trademarks acknowledged. Filed under Featured News, Health. Comments and Trackbacks closed. Follow responses: RSS 2.0