Pfizer halts heart failure trial early for benefit

NEW YORK (Reuters) - Pfizer Inc said on Thursday it is halting recruitment of patients into a heart failure clinical study involving its drug Inspra because the study reached its main efficacy goal early.

An independent committee monitoring the study found in a second interim analysis that patients taking Inspra plus the current standard of care had a significant reduction in risk of cardiovascular death or heart failure hospitalization compared with those on the placebo plus standard of care.

The EMPHASIS-HF trial, which was to enroll about 3,100 participants, involved patients with mild chronic systolic heart failure. Hearts of such patients have enlarged lower chambers -- called ventricles -- which fill with blood but are too weak to pump enough blood to satisfy the body's needs.

The drug is now approved for a fairly narrow population of patients typically with more serious heart failure.

A Pfizer spokesman declined to comment when asked if the company aims to ask regulators for permission to market the medicine to a broader group of patients, in view of favorable data from the study.

"The EMPHASIS-HF trial had an estimated end-date around October 2011, so to have met the pre-defined efficacy endpoints early is certainly a positive outcome," Faiez Zannad, a cardiologist at the University of Nancy in France and co-chair of the trial's steering committee, said in a press release from Pfizer.

Inspra, also known as eplerenone, is a relatively small seller for Pfizer, the world's largest drugmaker. It is a member of the family of treatments called aldosterone blockers and was introduced in 2002. It is also approved in the United States and many overseas markets for treating high blood pressure.

Pfizer shares were up 1 percent at $15.26, amid strong gains for the broad stock market.

(Reporting by Lewis Krauskopf and Ransdell Pierson, editing by Gerald E. McCormick and Gunna Dickson)