Washington, DC - A ruling by the US District Court for the District of Columbia will likely limit the number of available generic versions of simvastatin (Zocor, Merck & Co) when the cholesterol-lowering drug comes off patent protection this June.

The court ruled that the Food and Drug Administration unlawfully denied Teva Pharmaceutical Industries Ltd, the world's largest generic drug maker, and Ranbaxy Laboratories Ltd, another large pharmaceutical company, based in India, exclusive rights to manufacture and market simvastatin when the drug comes off patent. The companies had sought exclusive rights to sell simvastatin in 10-, 20-, and 40-mg doses for 180 days after the patent on simvastatin expired, but the FDA denied their requests.

This, the court said, was unlawful, and the matter has been handed back to the FDA. Unless the decision is overturned on appeal, only three generic versions of simvastatin will be on the market in 2006. Last February, a third company, Dr Reddy's Laboratories, also based in India, made a deal with Merck to sell generic versions of simvastatin if another company gained exclusivity after the patent expired. This will allow Merck to share in the profits of Dr Reddy's generic simvastatin sales.

Importantly, fewer generic drugs on the market mean higher prices for patients, employers, and insurance companies. There was speculation that as many as 10 versions of simvastatin could have been available this year. The FDA can appeal the court ruling to the US Court of Appeals for the District of Columbia Circuit but has not publicly stated whether it will do so.