Teva Pharmaceutical Industries says it is filing legal action against the US Food and Drug Administration over a decision that effectively eliminates the generics firm's marketing exclusivity for a copycat version of Bristol-Myers Squibb’s lipid-lowerer, Pravachol (pravastatin).

Under the Hatch-Waxman Act in the US, the first company to file a generic version of a drug with the US regulatory agency is typically entitled to 180 days of market exclusivity before other copycat versions of the drug can be sold.

However, Teva said it had received a letter from the FDA stating that the exclusivity period for Pravachol began on August 22 last year, the same date that a lawsuit filed against B-MS by another generics manufacturer, Apotex, was dismissed. Apotex had challenged three patents covering Pravachol. Teva argues that it is entitled to the 180-day exclusivity, having been the first company to seek the green light for a generic version of Pravachol in 10mg, 20mg and 40mg dosage strengths, and is seeking to have the FDA's decision overturned.

Israel Makov, Teva’s president and chief executive, said: “Although we are disappointed by this ruling which we intend to strongly oppose, we are confident that Teva’s portfolio of new generic products will contribute to significant growth during 2006 and 2007, a period during which we expect to launch approximately 80 generic products in the US.”