Pregabalin (Pfizer).

Pfizer is developing pregabalin, a follow-up compound to its GABA agonist gabapentin, for the potential treatment of several central nervous system (CNS) disorders including epilepsy, neuropathic pain, anxiety and social phobia [286425]. By December 2000, Pfizer anticipated filing an NDA for pregabalin for seven major indications (beginning with neuropathic pain and add-on epilepsy), with the FDA by the end of 2001. Filings for generalized anxiety disorder (GAD), social anxiety disorder and fibromyalgia are expected to take place in 2002, and filings for epilepsy monotherapy and panic disorders are expected to take place in early- and late-2003, respectively [336918], [393182], [399956]. By January 2001, pregabalin was in phase II development in Japan for the potential treatment of neuropathic pain, with an anticipated approval date of 2005 [394827]. However, following analysis by the FDA of a mouse study that showed incidence of a specific tumor type, Pfizer announced in February 2001, that it is restricting the use of pregablin in some clinical patients [398726] and it has frozen trials for neuropathic pain [398785]. In April 2001, Morgan Stanley Dean Witter predicted potential sales of $350 million in 2002, rising to $1750 million in 2006, with peak sales in excess of $2000 million [406923].