Teva Pharmaceutical Industries has become the first drugmaker to win US approval for a generic version of Bristol-Myers Squibb’s cholesterol-lowerer Pravachol (pravastatin), and says it will start shipping its product immediately.

The US Food and Drug Administration has cleared Teva’s 10mg, 20mg and 40mg strengths of pravastatin, which together accounted for sales of $1.5 billion in 2005. Teva has the exclusive right to sell generic pravastatin in the USA for 180 days, under the country’s first-to-file generics legislation.

Pravachol drug has already lost patent protection in Europe, and this was behind an 18% drop in global fourth-quarter 2005 sales of the product to $584 million.

The Israeli company got an earlier –than-expected entrance into the market for generic pravastatin after a US Court of Appeals denied an injunction sought by rival generics house Apotex.

B-MS’ patents on Pravachol expired earlier this month, but Teva was forced to wait for the resolution of the legal challenge by Apotex, which challenged Teva’s rights to exclusivity in the US marketplace.

Last year, Teva won a lawsuit against the FDA brought after the agency refused to grant it six months of sole rights to generic pravastatin, although an appeals court later vacated that ruling and referred the case back to the FDA for further action.

The agency had originally argued that an earlier lawsuit between B-MS and Apotex, which was dismissed in August 2004, kicked off the exclusivity period from that date, but reversed its decision on April 11.

The approval of generic pravastatin marks a significant change in the US cholesterol-lowering market, with more potent drugs such as Pfizer’s Lipitor (atorvastatin) expected to see their growth pegged back by low-cost generic rivals. Teva has also won tentative approval for a generic version of Merck & Co’s Zocor (simvastatin), another big seller that is due to lose patent protection in June.