Cubist Pharmaceuticals Inc. said Thursday that Hospira Inc. is challenging the patents supporting its antibiotic Cubicin, which brings in almost all of Cubist's revenue.
Cubist said it will file a lawsuit against Hospira, alleging that the proposed generic would infringe on the patents supporting the drug. The lawsuit will stop the Food and Drug Administration from approving the generic for 30 months or until the patent litigation is resolved.
Cubicin is used to treat severe skin and bloodstream infections. The FDA approved the drug in September 2003, and sales grew 18 percent to $735.5 million in 2011, or 97 percent of its total revenue. Cubist said the patents supporting the drug will expire between 2016 and 2028.
Under terms of a settlement from April 2011, Teva Pharmaceutical Industries Ltd. can start selling a generic version of Cubicin in December 2017 or June 2018. Teva will buy its U.S. supplies of Cubicin from Cubist.
In December, Cubist bought constipation drug maker Adolor Corp. for about $221 million, partly to expand its drug pipeline.
Shares of Cubist fell 84 cents, or 2.1 percent, to $40 in midday trading. Hospira stock lost 69 cents, or 2 percent, to $34.06.