Bristol-Myers Squibb - 10 Largest U.S. Patent Losses

Drug: Plavix
Company: Bristol-Myers Squibb, in a co-marketing deal with Sanofi
2010 U.S. sales: $6.154 billion, booked by BMS
Impact: 48.79% of U.S. revenue
Exclusivity expires: May 2012

Bristol-Myers Squibb has been staring down the barrel of Plavix's patent expiration for years. Ever since Apotex briefly launched a generic version in 2006--wreaking havoc on sales for months--the company has known firsthand how painful copycat competition can be. But now that BMS has slimmed down to its prescription-drug core, Plavix sales account for a bigger chunk of its revenue: almost half in the U.S., about three-tenths worldwide.

That's not dampening CEO Lamberto Andreotti's (photo) enthusiasm, however. Andreotti simply wants people to look beyond the next few years, when the Plavix suffering will be its most intense. Rather than focusing on numbers, check out the company's new melanoma drug, Yervoy, which is performing well in the U.S. Or watch the promising data stack up for its blood thinner, Eliquis, which it's developing in partnership with Pfizer and hopes to get onto the U.S. market soon. BMS's growth after 2015 will be "better than anybody else can deliver," Andreotti promised at a recent conference.

Bristol-Myers Squibb - 10 Largest U.S. Patent Losses