Pfizer Inc. said Thursday that it planned to introduce a generic version of its antidepressant Zoloft in the United States as soon as a rival generic hits the market, possibly as early as Saturday.
Pfizer's new version of Zoloft, which generated U.S. sales of almost $2.6 billion in 2005, is known as an authorized generic. Its introduction is part of a growing trend among drug makers of competing head-on with generic drug makers. The generic company that is first to break a branded drug's patent is awarded 180 days of exclusivity in sales. But an authorized generic can compete during this period.
By launching their own generic products, branded companies hope to retain a bigger portion of sales of the drugs they developed and discourage generic companies from making aggressive, early patent challenges. Generic companies, however, say they are not deterred.
"It is still a very attractive market opportunity," said Kevin Mannix, a spokesman for Israel-based Teva Pharmaceutical Industries Ltd., which plans to launch a generic version of the drug in the third quarter.
Pfizer's other authorized generics include discounted versions of its epilepsy drug Neurontin, antifungal Diflucan and antibiotic Zithromax.