Decision due soon on Lilly, Daiichi blood thinner

NEW YORK (Reuters) - Two large drug makers, Eli Lilly and Co and Daiichi Sankyo Co Ltd, face a critical U.S. decision this week on their shared blood-clot preventer that could dramatically boost their bottom lines.

“It’s by far the biggest event at Lilly for quite some time,” said David Heupel, a portfolio manager with Thrivent Investment Management.

The decision by the U.S. Food and Drug Administration on whether to approve the drug, prasugrel, could also sway the stock prices of Bristol-Myers Squibb Co and Sanofi-Aventis, which co-market a rival clot treatment, Plavix.

The deadline is September 26 for the FDA to rule on the drug, which would be sold under the brand name Effient.

The main study for the drug contained mixed results -- potent effectiveness at preventing heart problems, but with heightened bleeding risks -- leaving Wall Street weighing multiple scenarios for an FDA ruling.

Lilly stock could jump as much as 10 percent on an approval, or fall as much as 10 percent if regulators require additional extensive data, JP Morgan analyst Chris Schott said.

Lilly shares have fallen 14 percent so far this year, compared with a 12 percent decline for the American Stock Exchange Pharmaceutical Index of large U.S. and European drugmakers.

For prasugrel, the FDA has declined to convene a public meeting of its advisers, which it often does for new experimental medicines to get further opinions. The lack of a meeting has made the prasugrel decision difficult to handicap, said Deutsche Bank analyst Barbara Ryan.

“This, along with a number of approval disappointments from a seemingly more risk averse and less transparent FDA has made investors wary of stepping into (Lilly) ahead of the” FDA deadline, Ryan said in a recent research note.

Morningstar analyst Matthew Coffina gives prasugrel a 70 percent chance of approval at some point, and is expecting a U.S. launch of the drug in mid-2009. Coffina sees it achieving annual sales of $2 billion in about 10 years.

In a clinical trial, prasugrel was pitted against Plavix, the current standard of care and one of the world’s biggest-selling medicines. Each treatment stops blood cells called platelets from clumping together.

Results released last November showed that prasugrel was 19 percent more effective than Plavix in preventing cardiovascular death, nonfatal heart attacks and strokes.

But prasugrel was 32 percent more likely to cause serious bleeding, raising questions about its overall attractiveness to doctors and patients and FDA examiners.

The bleeding risk in the study was most common among patients weighing less than 135 pounds (61.2 kgs), over 75 years old or who had suffered a stroke previously. The FDA initially was expected to rule on prasugrel in June, but extended the review by three months to weigh more information.

The FDA could approve prasugrel, but with restrictions that address these patients that are most at risk of bleeding, analysts say.

Regulators could warn doctors against prescribing it for those at-risk patient groups. Patients using the drug might also be required to enroll in a registry to make sure they are safely taking the medicine. Such a registry -- deemed unlikely by analysts -- could dampen potential sales if physicians find the conditions too burdensome.

JP Morgan’s Schott said he would not be surprised if the FDA required an additional short study testing a lower-dose version in the bleeding-prone groups, which would likely delay the drug’s approval by a year.

Another scenario suggested the agency could require data from an ongoing large 10,000 patient study that is testing prasugrel against Plavix among patients with heart problems. Results of that study are not expected until early 2011.

Such a prolonged delay could prevent prasugrel from making deep inroads before cheap generic forms of Plavix reach the market in late 2011.

“Generic Plavix will be a competitive threat no matter when prasugrel is launched,” Morningstar’s Coffina said. “If it were delayed it would just make it that much harder.”

Additional reporting by Ransdell Pierson, editing by Leslie Gevirtz, Gary Hill