Acorda plummets after court invalidates Ampyra patents

Acorda Therapeutics Inc. (NASDAQ:ACOR) sank $5.75 (21%) to $21 on Friday after a federal court invalidated four of the five Orange Book-listed patents protecting multiple sclerosis drug Ampyra dalfampridine. Acorda said it plans to appeal the decision.

The U.S. District Court for the District of Delaware upheld one Ampyra patent, U.S. Patent No. 5,540,938, which expires in July 2018. It covers use of a sustained-release formulation of 4-aminopyridine (4-AP). The four invalidated patents -- U.S. Patent Nos. 8,007,826; 8,663,685; 8,354,437; and 8,440,703 -- covered use of a 10 mg dose of the formulation to treat walking impairments in MS patients. ...