NEW YORK (AP) -- Merck & Co. said Monday it is suing to stop Novartis AG's Sandoz division from selling a generic version of its antifungal drug Cancidas.
Filing the patent infringement lawsuit will keep the Food and Drug Administration from approving Sandoz's generic for 30 months, or until the litigation is resolved. Whitehouse Station, N.J.-based Merck said Sandoz is challenging a formulation patent that is set to expire in 2017.
A Novartis spokesperson wasn't immediately available to comment early Monday.
Merck filed suit against another generic drugmaker, Teva Pharmaceutical Industries Ltd., in November over the same drug. Cancidas was approved in January 2001 as a treatment for fungal infections. Merck said U.S. sales totaled $73 million in 2009.
Merck said it hopes to resolve the lawsuits before the mandatory waiting periods are over. The waiting period for Teva ends on April 22, 2012, and on Aug. 25, 2012 for Sandoz.
Merck shares fell 20 cents to $37.51 in morning trading.