Pristiq Mystique: Will FDA Approve Wyeth Drug?

Later this week, the agency is expected to decide whether the Wyeth medication should be used to treat depression. Given repeated setbacks the drugmaker has experienced with this drug, however, it remains unclear what the agency will do. One Wall Street analyst, for instance, believes the odds are slightly in Wyeth's favor, but also issues a whole bunch of caveats.

Wyeth, you may recall, has submitted Pristiq for two indications - treating menopausal hot flashes and major depressive disorder. The drug is, essentially, a version of Effexor XR, and Wyeth is hoping Pristiq can makes it way to medicine cabinets because the Effexor patent expires in a couple of years, although one generic drugmaker is already seeking to sell a tablet form.

But the agency set aside its application several times and, so far, has issued only an approvable letter for menopausal symptoms. The ongoing delays have frustrated Wyeth execs enormously; chairman Bob Essner recently chastised the FDA for its newly found conservative stance and for "creating monopolies." The setbacks are being cited for a 10 percent cut in the drugmaker's global workforce.

In a research note this morning, Credit Suisse analyst Catherine Arnold acknowledges there are other meds on the market, lessening the need if the FDA wants more data to weigh benefits; the FDA may not have disclosed any concerns with clinical trial data and, most of all, the FDA is "increasingly conservative." And so, "given some of the challenges Wyeth and its peers have faced in obtaining approval for new molecular entities, Wall Street is greeting every pending action date with some degree of skepticism."

On the other hand, she says a few things work in Wyeth's favor: Pristiq is an active metabolite of Effexor, which has been on the market for 15 years; the benefit-risk ratio for Pristiq in major depressive disorder is more favorable than for treating hot flashes and an approvable letter for that indication was already issued, and in her view, there's a need for a new med to treat depression. Her odds - 60-40 in Wyeth's favor.