Pristiq

ANALYST OUTLOOK

Pristiq (desvenlafaxine; Pfizer) is purely a follow-on product to the former leading serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressant Effexor (venlafaxine; Pfizer). The drug has few clinical advantages, except for a simplified dosing schedule requiring no titration. Nevertheless, Pfizer has been able to grow Pristiq into a lucrative brand in the US market, before the entrance of multiple generic competitors in March 2017. Consequently, Pristiq’s sales will erode considerably, preventing Pfizer from following the success of its Effexor franchise. This loss of exclusivity for Pristiq will likely herald an end to Pfizer’s involvement in the depression market, as the company has no other major commercial brands and no visible involvement in the clinical development of novel antidepressants.

DRUG OVERVIEW

Pfizer (formerly Wyeth) developed and launched Pristiq, an SNRI antidepressant in a sustained-release tablet formulation, as a followon product to its blockbuster antidepressant Effexor. Pristiq contains the active metabolite of venlafaxine; desvenlafaxine. Following approval by the US Food and Drug Administration in February 2008 for major depressive disorder in adults, Wyeth launched Pristiq in the US in May 2008. In October 2008, Wyeth withdrew Pristiq’s (branded Ellefore in the EU) application for centralized approval with the European Medicines Agency, and the drug remains unavailable in this region. Pfizer also completed Phase III trials of Pristiq in Japan in 2010 and 2011, although there is no indication that the drug will be filed for approval.