Patent Trouble Pending: Wyeth And Effexor XR

Bernard Poussot has many challenges as he gets ready to

succeed Bob Essner as Wyeth ceo. High on that list is Effexor XR, the big-selling antidepressant. The pill's exclusivity is being threatened by Sun Pharmaceutical, an Indian generics maker, which is seeking FDA approval to sell a version with the same active ingredient, but with an important difference - in tablet, not capsule form, the Associated Press writes.

FDA approval could come as early as June, when patent protection for Effexor's active ingredient, venlafaxine, runs out, while the patent on the capsule formation doesn't expire until later. So as the AP points out, Sun's different formulation should allow it to sidestep Wyeth's patent rights, and grab up to 15 percent of Effexor XR's market share, or more than $500 million in lost sales, according to a Bank of America estimate.

This is just one of many challenges facing Wyeth, which isn't suing for patent infringement. The FDA has repeatedly delayed approval for a new version of Effexor that Wyeth wants to market as antidepressant and to treat hot flashes caused by menopause. And its Protonix heartburn pill also faces looming generic threats. The move by Sun isn't "helpful," Deutsche Bank analyst Barbara Ryan tells the AP. "The issue is Wyeth has tremendous exposure to generic competition between now and 2010, and a lot of arrows are pointed at their two major drugs, Protonix and Effexor." Indeed, Wyeth shares have fallen 25 percent since hitting a five-year high in June of $62.20, the AP writes.

Wyeth has played down the potential impact, the AP writes. For one thing, the Sun pills are unlikely to be certified by the FDA as the exact equivalent of Effexor XR because of the different formulation. As a result, Sun's pill won't benefit from state laws that require pharmacies to automatically substitute generics for branded drugs. The laws require generics to be exact copies, including the same formulation. In other words, docs would have to write new prescriptions specifically for Sun's pill, not Effexor XR, the AP explains.

"It's more than a difference of being a capsule versus a tablet," Joe Mahady, Wyeth's senior vp, told investors at a conference last month. "It is likely to be a very different technology. It may indeed be a very different delivery profile of the product."

Sun's tactic is somewhat unusual. Typically, generic makers want to sell exact copies, and either wait for patent protection to run out, or claim patents are invalid in the hopes of selling a copycat before patents expire. "The challenge is clear" because of the alternative formulation, Uday Baldota, Sun's vp of investor relations, tells the AP. "The effort on promotion and marketing will be different from what you will do on a fully substitutable generic product."