ARTICLE | Company News

Pfizer withdraws PAH drug

December 11, 2010 12:18 AM UTC

Pfizer Inc. (NYSE:PFE) will withdraw pulmonary arterial hypertension (PAH) drug Thelin sitaxentan in Europe, Canada and Australia after two cases of fatal liver injury were reported in a clinical trial. Pfizer said the drug's benefit no longer outweighs its risks given the availability of alternate treatments. The pharma noted that while liver toxicity is a known complication of the endothelin A receptor antagonist class, a new idiosyncratic risk of liver injury was observed with Thelin. Pfizer also will discontinue clinical trials of Thelin, including the Phase III SR-PAAS program for PAH. In 2007, FDA issued a third approvable letter for sitaxentan that requested an additional study. Pfizer, which gained the drug through its 2008 acquisition of Encysive Pharmaceuticals Inc., reported $44.4 million in Thelin sales for the nine months ended Sept. 30. ...