Pristiq posing as pristine

The Trouble With Spikol has linked to an article in the San Diego Union-Tribune (via Reuters) that covers Wyeth's new Effexor XR knock-off, Pristiq (desvenlafaxine succinate). Why are they launching Pristiq? Their patent on Effexor will expire in July 2010 when making generic versions of the drug will be up for grabs.

"Wyeth said in July, however, that it will not introduce Pristiq until it completes tests of a low 50-milligram dose of the drug, following trials of higher dosages in which about half the patients experienced nausea."

Too bad clinical trials don't test for withdrawal symptoms. Will Pristiq avoid the withdrawal hell issues that Effexor XR has?

“'We will wait for the results of the low-dose trials, which we've said we expect in early 2007, before making a decision' on when to launch Pristiq, company spokeswoman Gwen Fisher told Reuters on Friday.

She said nausea seen in the earlier trials was mild to moderate and generally went away within a week after treatment began.”

How long were these clinical trials and if the nausea was seen in the "earlier trials," what about the most recent trials?

Pending FDA approval, Wyeth would also like to use Pristiq for vasomotor symptoms in menopausal women.  Wyeth's unannounced strategy will be to introduce Pristiq long before Effexor's patent expires so they don't lose any of their $1 billion market share to an Effexor generic.

A Wyeth PR that went under my radar:

“Pristiq, a serotonin/norepinephrine reuptake inhibitor (SNRI) now is being studied with a specific focus on women. It initially was developed for two indications that currently are pending approval from the U.S. Food and Drug Administration (FDA) – the treatment of major depressive disorder (MDD) and vasomotor symptoms (VMS) associated with menopause. 

In the area of depression, Pristiq is expected to improve the balance of serotonin and norepinephrine as compared with serotonin reuptake inhibitors (SSRI) because of its pharmacologic profile as a dual reuptake inhibitor.”

Isn’t that what SNRIs are supposed to do?

“Clinical studies confirm that Pristiq is effective in both men and women. However, women over age 40 represent about 50 percent of the depression market and could benefit from an antidepressant that addresses their symptoms and physiology.”

No kidding – 50 percent of the depression market and the implication of all women over 40 years old? Sure, I believe that. Looks like Wall Street doesn't have much hope for the new drug either.

“Pristiq also may be a treatment option for patients who are on multiple medications. The compound has a low risk of drug-drug interactions. This is important when considering that depression often is a co-morbid condition in medically ill patients and that these patients frequently are taking multiple medications. The Company expects FDA action for the MDD indication in January 2007.”

The multiple medications thing. Um, I’m not a fan of that unless it’s absolutely necessary. It isn’t necessary in a lot of cases.

“FDA action for the second application for Pristiq for vasomotor symptoms associated with menopause is anticipated in April 2007. Pristiq is expected to provide significant relief of hot flushes (decrease in number and severity) associated with menopause.

If approved, Pristiq will be the first non-hormonal treatment indicated for relief of VMS.

The Company also plans to pursue indications for Pristiq that would include fibromyalgia syndrome and diabetic neuropathic pain.”

Wyeth certainly is attempting to milk this new drug for all it’s worth. I hope Furious Seasons or CLPsych take up on investigating this one since I simply don’t have the time, resources, or ability.