Par Pharmaceutical Companies Incs’ marketing partner, Three Rivers Pharmaceuticals, has been granted tentative approval by the US Food and Drug Administration for its abbreviated new drug application for ribavirin 200 mg, 400 mg and 600 mg tablets.

Ribavirin, a synthetic nucleoside analogue with antiviral activity, is used in combination with peginterferon alfa-2a for the treatment of Hepatitis C. Ribavirin tablets are currently marketed by Roche Pharmaceuticals under the brand name Copegus. Annual US sales of the product are approximately $200 million.

Par expects final approval of ribavirin tablets following the expiration of Copegus' exclusivity on December 3, 2005. Under the terms of its agreement with Three Rivers, Par will co-market Three Rivers' ribavirin tablets and the companies will split profits from the sales of the product, informs a company release.

Par Pharmaceutical Companies Inc. develops, manufactures and markets generic pharmaceuticals through its principal subsidiary, Par Pharmaceutical Inc. The company is also developing an additional line of branded pharmaceutical products, the first of which is Megace ES, for specialty markets.