King ends five-year Skelaxin patent suit against CorePharma

BRISTOL, Tenn. & MIDDLESEX, N.J. King Pharmaceuticals has ended is patent lawsuit with CorePharma regarding its muscle relaxant drug Skelaxin and has signed an agreement with CorePharma related to the drug, according to Forbes.

On Jan. 2, the two companies signed an agreement under which, CorePharma will gain certain exclusive rights to Skelaxin 800 mg to market a generic version, called metaxalone and have also gained a non-exclusive license to produce and market a 400 mg version of the drug. This license will come into effect on Jan. 1, 2012.

Back in 2003, CorePharma was one of several biopharmaceutical companies to file with the Food and Drug Administration seeking permission to produce a generic. King countered by suing CorePharma and later Eon Labs and Mutual Pharmaceuticals, who also sought permission to produce a generic.

As of now, CorePharma is the only company that King Pharmaceuticals has an agreement with concerning Skelaxin. The drug is estimated to account for about $400 million in sales in 2008, according to Morgan Stanley.