Patent lapsing, Pfizer unit to sell generic version of Zoloft

NEW YORK -- Drug maker Pfizer Inc. confirmed yesterday its subsidiary Greenstone Ltd. is prepared to release a generic version of the antidepressant Zoloft to compete with generic drug makers, who can release their own versions after the drug's patent expires in two days.

The news, first reported in The Wall Street Journal, sent US shares of Israeli drug maker Teva Pharmaceutical Industries Ltd. lower by more than 3 percent. For its part Teva, which plans to begin selling a generic version of Zoloft during the third quarter, downplayed the news.

Pfizer spokesman Paul Fitzhenry confirmed that Greenstone is ready to launch a generic version of Zoloft, also known by its active ingredient sertraline, ``if and when others release" their generic versions of the drug.

As more blockbuster drugs lose patent protection, greater attention has become focused on the practice of branded drug makers allowing ``authorized generics," or unbranded versions of branded drugs they control, to compete with dedicated generic drug makers. Over the next five years, brand-name prescription drugs representing about $50 billion in annual sales are scheduled to lose patent protection. After today, Zoloft will no longer be protected by its main patent.

Pfizer sold about $3.3 billion in Zoloft worldwide in 2005.

American depositary shares of Teva fell $1.05 to $31.29 on the Nasdaq at above-average volume.

The company, however, downplayed the news.

``The use of authorized generics by branded drug makers has been a common practice for years," Teva spokesman Kevin Mannix said in an interview. ``The fact that Pfizer is going to introduce an authorized generic version of Zoloft is not a new development. Teva always expects to compete against an authorized generic whenever it launches a product with 180 days of exclusivity."

Teva inherited the rights to generic Zoloft through its acquisition of Ivax Corp. earlier this year. Ivax received Food and Drug Administration approval in December 2004 to sell a generic version of Zoloft after the patent expires, and 180 days of marketing exclusivity upon launch. However, the exclusivity period does not apply to authorized generics.

Mannix said that Teva plans to release its generic version ``sometime during the third quarter," which begins tomorrow.

The Zoloft news follows a recent effort by Merck & Co. to sell its cholesterol medicine Zocor at a discount to a generic version made by Teva, after the drug lost patent protection last Friday. Investors may have sold Teva shares after interpreting Pfizer's decision on an authorized generic of Zoloft as similar to Merck's action on Zocor.