Genzyme sues Impax in patent fight

WASHINGTON - Genzyme Corp., the world's largest maker of drugs for rare genetic disorders, sued Impax Laboratories Inc. for allegedly infringing a patent used for its Renagel kidney medicine.

Impax has petitioned the Food and Drug Administration to approve a generic version of Renagel, violating Genzyme's patent, the company claimed in the lawsuit filed Friday in federal court in Baltimore.

Impax, based in Hayward, Calif., filed its petition to the FDA in November challenging Genzyme's patent.

Genzyme, based in Cambridge, Mass., filed a similar suit this month against Indian drug maker Lupin Ltd., which has planned to market its own version of Renagel. Genzyme rose $2.55 to $58.39.