(CN) - The makers of the heart-attack prevention drug Plavix have a valid patent on the drug, the Federal Circuit ruled, rejecting a challenge by competitor Apotex Inc.
Plavix is used to prevent the accumulation of blood platelets in order to prevent heart attacks and strokes.
Apotex challenged the validity of Sanofi-Synthelabo's patent on Plavix. Apotex wanted to market a product that it concedes infringed on the patent, and the district court granted Sanofi an injunction blocking the sale of the Apotex drug during the trial.
The district court trial affirmed the validity of the patent.
The federal appeals court in Washington, D.C., affirmed the decision, citing the specialized knowledge in the patent.
"The knowledge that enantiomers may be separated is not "anticipation" of a specific enantiomer that has not been separated, identified and characterized," Judge Newman wrote.
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