Shares in Wyeth climbed 2.6% to close at $47.52 yesterday, as investors were encouraged by news that US regulators have decided that its application to market DVS-233, a modified form of its popular depression drug Effexor, does not require input from an advisory committee after all.

The US Food and Drug Administration said that it has cancelled a meeting to assess the drug's safety and efficacy profile that was scheduled to take place on September 7.

“After further review of the data, the FDA [Food and Drug Administration] decided it was no longer necessary to hold the advisory committee meeting,” Wyeth said in a statement, and added that it believes the drug’s comprehensive clinical trails program will support its approval. A decision is expected in October.

Last month the drug was hit with a setback when the company revealed that it needed to conduct extra clinical trials to see if it can find a level that retains efficacy but improves its tolerability, particularly reducing the tendency of the drug to cause nausea, thereby pushing back its expected launch to 2007.

But hopes for DVS-233 (desvenlafaxine succinate) remain high. The drug has been designed to maintain the company's antidepressant franchise now that Effexor (venlafaxine) is facing generic competition. And, aside from depression, the company is also assessing its utility in the treatment of menopausal symptoms, fibromyalgia and chronic pain from damaged nerve fibers. If its path to market is successful, the drug could well be a key driving force behind pushing Wyeth away from its troubled times of late.

After a 24-hour delay, jury selection began yesterday morning for a case centred on allegations that long-term use of its combined hormone product, Prempro, caused a patient to develop breast cancer. This has certainly come as a blow to the firm, which has only recently turned the corner on a multi-billion-dollar lawsuit for the diet drugs fenfluramine and dexfenfluramine.

Starts constipation trial

In other news for the firm, Wyeth and Progenics have started a mid-stage trial designed to find the optimal dose/doses of oral methylnaltrexone for testing in a Phase III trial for opioid painkiller-related constipation.

More than 100 clinical sites in 21 countries are expected to participate in this randomized, double blind, placebo-controlled, parallel-group Phase II trial, with around 200 to 400 patients taking part.

Late-stage studies are due to kick off next year, in time for a marketing application towards the end of 2008 or early 2009, the groups said.