Pfizer loses appeal to revive patent

Pfizer Inc. lost an appeals court bid to revive its patent on the hypertension drug Norvasc, a ruling that opened the door to generic competition.

The U.S. Court of Appeals for the Federal Circuit in Washington denied Pfizer’s request to reconsider a March 22 ruling that the patent was invalid.

The March ruling allowed Mylan Laboratories Inc. to make a generic version of Norvasc. Apotex Inc., the Canadian drug maker that won the lawsuit over the patent’s validity, also may enter the market as early as today.