Israel-headquartered Teva could lose its market exclusivity in the USA for a generic version of Bristol-Myers Squibb’s cholesterol-lowering drug Pravachol, after an appeals court asked the Food and Drug Administration to look into the matter.

Last October, Teva won a lawsuit brought against the FDA after the agency refused to grant it six months’ exclusivity for its generic Pravachol (pravastatin) 10mg, 20mg and 40mg doses from April 2006, when B-MS' patent expires.

But the appeals court vacated that ruling, and referred the case back to the FDA for further proceedings.

Earlier, the Israeli firm had convinced the lower court that it was entitled to exclusivity under the Hatch-Waxman legislation, which rewards generics companies who file first for approval of a generic. This would give Teva a great opportunity to win a slice of Pravachol’s $1.6 billion annual US sales before the inevitable price declines that would follow the introduction of other pravastatin generics.

In a statement, Teva said it expected the FDA to determine that it would retain exclusivity for the six-month period. The agency had originally argued that an earlier lawsuit between B-MS and Apotex, which was dismissed in August 2004, kicked off Hatch-Waxman from that date.