King Pharma loses patents for top-selling Skelaxin

In a blow to King Pharmaceuticals, a judge at the U.S. District Court in New York invalidated two of three patents for the drugmakers' top selling drug, muscle relaxant Skelaxin. The patent challenge was brought by Eon Labs, one of several generics makers with their eyes set on Skelaxin.

The ruling rattled investors, as King's stock fell 8.6 percent Wednesday, according to the Wall Street Journal. It comes at a time when the company has been facing declining sales, and its bid for a bigger presence in the pain market has been derailed by the FDA's request for more data on its "tamper-proof" version of oxycodone. But Cowen & Co. analyst Ian Sanderson told the Associated Press that he had expected a generic version of Skelaxin to reach the market later this year--even before the judgement was issued--and that he's sticking to his target price for the stock. 

The Tennessee-based company plans to appeal after a formal ruling is issued in a few weeks, but already has its hands in the pot. Last January, King dropped a patent infringement suit against CorePharma and instead inked a deal with that company for an authorized generic Skelaxin. 

- read the AP article in Forbes for more
- check out the WSJ article