Duramed sues Watson, Sandoz over Seasonale patent

CINCINNATI Duramed Pharmaceuticals is suing Watson Pharmaceuticals and Sandoz, claiming that the companies violate a Duramed patent by marketing or planning to market the generic version of its extended cycle birth control Seasonale, according to published reports.

Seasonale (levonorgestrel/ethinyl estradiol tablets) is a birth control tablet that reduces a women’s menstrual cycle to four periods per year. Duramed said that its patent for the drug was reissued in September 2007. Watson launched its generic version, Quasense, in 2006, and Sandoz has filed an application with the Food and Drug Administration to produce its version.

Seasonale had sales in the U.S. of about $110 million for 2006.