Israeli pharamceutical giant Teva said on Monday that it plans to appeal a decision by the U.S. District Court for the District of Delaware invalidating patents covering Teva's multiple sclerosis treatment Copaxone.
The generic-drug leader's stocks dropped about 15 percent following news of the ruling but rallied to close with a loss of about nine percent in New York. Off-hours trading saw the loss expand to 10 percent.