Intermune shares surge as FDA reviews lung drug

By MATTHEW PERRONE AP Business Writer

WASHINGTON (AP) - Shares of drug developer InterMune Inc. surged Friday after federal health officials posted their review of the experimental drug pirfenidone, which is designed to treat a rare lung disease.

The stock advanced $9.39, or 64.3 percent, to $24 in morning trading. The stock earlier traded at $25.37, its highest price since 2007.

InterMune has asked the Food and Drug Administration to approve its drug for idiopathic pulmonary fibrosis, an often fatal disease for which there are no approved drugs.

The FDA already has reviewed the drug, but in documents posted Friday the agency said it would ask its panel of lung experts to vote on the drug's safety and effectiveness next Tuesday. The agency is not required to follow the panel's advice, though it often does.

FDA drug reviewers voiced "uncertainty" about whether InterMune's drug provides a meaningful benefit, because there are no currently approved treatments for the FDA to measure pirfenidone against.

InterMune measured patients' so-called forced vital capacity, a measure of lung strength based on the volume of air exhaled. One of the company's studies showed a 4.4 percent increase in lung strength, which was significant. However, the drug did not achieve significant results in another study. While slightly more patients taking pirfenidone survived compared with patients taking placebo, there wasn't an overall survival benefit in the studies, according to the FDA.

The FDA will ask its panel of lung specialists to weigh the drug's potential benefits against its safety risks, which included nausea, rash and fatigue. Those were reported in 30 percent of patients.

More serious adverse effects included abnormalities in liver function.

In its own briefing documents, Brisbane, Calif.-based InterMune stressed the need for a drug to treat the severe lung disease.

"There remains no effective therapy, nor has the prognosis been substantially altered over the last two decades."

About 200,000 people in the U.S. and Europe have idiopathic pulmonary fibrosis. The disease causes scarring and stiffening of the lungs, which makes it increasingly difficult to breathe over time. The cause of the disease is unknown.

FDA is scheduled to make a decision on the drug by May 4. If approved, InterMune plans to market the drug in the U.S. under the name Esbriet. The drug was approved in Japan in October 2008, where it is sold under the name Pirespa by Shionogi and Co.

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AP Business Writer Marley Seaman contributed to this report from New York.