Dec. 12 (Bloomberg) -- Bristol-Myers Squibb Co. and Sanofi- Aventis SA won an appeals court ruling that will help them block generic competition to the blood-thinner Plavix, the world’s second-biggest drug, in the U.S. until 2011.

Bristol-Myers and Sanofi said that, as a result of today’s ruling, they will seek reimbursement from Canadian drugmaker Apotex Inc. for its decision to enter the market in 2006, although there may be limits on how much they can collect. Bristol-Myers has said it lost as much as $1.75 billion in sales after Apotex flooded the market during a three-week period.

The case was in court after a failed attempt by New York- based Bristol-Myers to settle the dispute to ensure there would be no competition until just months before the patent expired. That effort failed, leading Bristol-Myers to fire its chief executive and plead guilty to making false statements to federal regulators about the botched accord.

Plavix, whose chemical name is clopidogrel bisulfate, is the biggest seller for Bristol-Myers and second-biggest for Paris- based Sanofi, behind the Lovenox anti-clot treatment. Apotex failed in its argument that the patent doesn’t contain a new invention and that Sanofi scientists used known research methods on known compounds to come up with Plavix’s key ingredient, the appeal court said.

‘Hindsight Inappropriate’

“The application of hindsight is inappropriate,” a three- judge panel of the U.S. Court of Appeals for the Federal Circuit in Washington said in upholding the patent. “The district court thoroughly discussed the many issues and arguments raised by Apotex. We discern no error in the district court’s findings.”

Apotex said in an e-mailed statement it would ask the appeals court to reconsider the case.

“We believe the appeals court made the wrong decision and will continue fighting to bring this product back into the market place,” Apotex Chief Executive Officer Barry Sherman said in the statement. “We will pursue all options available to us in our effort to once again provide the public with a quality, affordable generic Plavix.”

Plavix, sold by Bristol-Myers in the U.S. under an agreement with Sanofi, last year regained its title as the world’s second- best-selling drug, behind Pfizer Inc.’s Lipitor, with $8.1 billion in global sales. The drug first gained regulatory approval in 1997.

The Apotex copies cost from $1.45 billion to $1.75 billion in lost sales, Bristol-Myers said Feb. 22 in a regulatory filing. Under the failed agreement, Bristol-Myers and Sanofi can’t ask for compensation of more than 70 percent of net lost sales and waived their right to ask the judge to triple the damages because of willful infringement, Sanofi said in an Aug. 8, 2006, statement.

Six Months’ Supply

When the agreement was rejected by U.S. regulators and state attorneys general, Apotex began selling a generic version until it was ordered to stop by U.S. District Judge Sidney Stein in New York. During a three-week period, the company shipped about six months’ worth of the medicine.

In an August 2006 interview, Apotex’s Sherman said he expected the agreement to be rejected by regulators, and signed the agreement in order to wring concessions, including the limit on damages.

Bristol-Myers rose $1.06, or 4.9 percent, to $22.51 at 4:15 p.m. in New York Stock Exchange composite trading. Sanofi American depositary receipts, two of which represent one ordinary share, rose 87 cents to $29.78.

The case is Sanofi-Synthelabo v. Apotex Inc., 2007-1438, U.S. Court of Appeals for the Federal Circuit (Washington). The lower case is Sanofi-Synthelabo v. Apotex Inc., 02cv2255, U.S. District Court, Southern District of New York (Manhattan).

To contact the reporters on this story: Susan Decker in Washington at sdecker1@bloomberg.net; William McQuillen in Washington at bmcquillen@bloomberg.net.

Last Updated: December 12, 2008 16:39 EST