FDA OKs Lilly's Blood Thinner: Effient Had Faced Years of Delays

Eli Lilly and Co. and its Japanese partner finally won approval Friday to put their anti-clotting drug on the U.S. market, where it will compete head-on with the popular blood thinner Plavix in treating heart patients.

The long-awaited approval for the new drug, called Effient, comes with a key qualifier: It must carry a black-box warning of potentially fatal bleeding in some patients.

A black-box warning is the strictest Food and Drug Administration warning that can go on a drug's label, and it can be a sales-depressing factor by making some doctors and patients wary of using a drug.

Troy J. Turner, who will head U.S. marketing of the drug for Lilly, said the warning isn't a surprise. "I don't see it as a significant obstacle to . . . being able to promote the product," he added.

Effient has the potential to become a blockbuster drug for Lilly and partner Daiichi Sankyo.

It becomes the only FDA-approved option to Plavix, which is made by Bristol-Myers Squibb of New York. Plavix is the world's second-best-selling drug, with 2008 sales of $8 billion.

Effient could capture 17 percent of the U.S. market for blood thinners by 2015, which would bring in sales of $2 billion, estimated Credit Suisse drug analyst Catherine Arnold.

The Indianapolis drug maker is counting on Effient to generate new revenue that would replace lost sales from six of its top-selling drugs whose patents will begin to expire in 2011. Without patent protection, a brand-name drug usually sees a drastic falloff in sales.