Shares of Teva Pharmaceuticals fell as much as 6 percent on Wednesday after the U.S. Patent Office invalidated two of the company's patents.
Mylan had filed a total of four claims related to Copaxone 40 mg. The two patents invalidated on Wednesday are owned by Yeda Research & Development and licensed to Teva. The involved parties are still waiting on a ruling for a third patent, which is expected by Sept. 1.
Earlier this month, the Patent Office had ruled that a fourth patent was not eligible for review due to procedural reasons. On Wednesday, Mylan said that it believes the favorable rulingundermines that earlier judgement. The company said it will be "pursuing all avenues to challenge" the earlier patent.
Teva CEO Erez Vigodman said in a statement, "We remain confident in the strength of our intellectual property surrounding COPAXONE 40mg." He also said that the company is "prepared to defend the full suite of our intellectual property... regardless of the time required."
Teva also said it plans to appeal the decision in the U.S. Court of Appeals for the Federal Circuit.
The stock recovered some losses and closed about 3 percent lower.