Wyeth's Pristiq Wins FDA Approval

Wyeth(WYE Quote) said late Friday it had received Food and Drug Administration approval for its Pristiq antidepressant.

Sales of the drug could help offset the loss of revenue Wyeth will likely encounter when its Effexor XR antidepressant loses patent protection in 2010, The New York Times noted Saturday. Wyeth claims that Effexor XR is the world's most widely prescribed antidepressant.

The FDA said Pristiq could be used to treat adult patients with major depressive disorder.

Like Effexor, Pristiq is a norepinephrine reuptake inhibitor. But Wyeth said the new drug has an advantage because it can be used at a therapeutic dose immediately. With many antidepressants, doctors start patients out at lower doses and then raise the doses over time.

The FDA's approval of Pristiq has some conditions, however. After Wyeth begins marketing the drug, it still must conduct and submit data from a new long-term maintenance study, a sexual dysfunction study, pediatric studies and a study exploring lower doses of Pristiq. The FDA also requested an additional nonclinical toxicity study.

In a session when the major stock indices slumped, Wyeth's shares gained $1.08, or 2.5%, Friday to close at $43.62.