Teva Pharmaceutical Industries said on Thursday it was granted tentative U.S. Food and Drug Administration approval for Rabeprazole Sodium delayed-release tablets.
The drug is a generic version of Japanese company Eisai Co.'s acid pump inhibitor Aciphex tablets.
Annual sales of the branded product are about $1.2 billion, Teva said in a statement.
Teva, the world's largest generic drugmaker, said it was currently in patent litigation regarding the product in the U.S. District Court for the Southern Disctrict of New York.
A suit was brought against Teva in November of 2003 involving the product's patent. A trial date has not been set.
Final approval is expected upon a favourable decision in the case or the expiry of the mandatory stay of approval in February 2007, whichever is earlier.
Teva stock from 2004