The justices ruled 7-2 that a federal appeals court wrongly overturned five of Teva's patents for the drug Copaxone. The high court's decision gives the Israel-based company another chance to keep its exclusive rights to the drug until September 2015.
Copaxone generates about USD 4 billion in annual sales for Teva.
Teva had argued that the US Court of Appeals for the Federal Circuit should not have second-guessed factual findings made by a federal district court that had earlier ruled in Teva's favor.
The high court's ruling is a loss for generic companies Mylan Inc, Momenta Pharmaceuticals Inc, Natco Pharma Ltd and Sandoz, Inc. Those companies had failed to convince a federal judge in New York that Teva's patent claim based on the drug's molecular weight was too ambiguous.
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The Supreme Court's ruling sends the case back to lower courts for further proceedings.
In dissent, Justices Clarence Thomas said that reviewing patents is not simply a factual question, but falls more on the side of a legal determination. He said a judge's resolution of a patent claim is similar to interpreting a law, and should therefore merit a fresh review by the appeals court.
Thomas was joined in dissent by Justice Samuel Alito.