A Safety and Efficacy Study in Subjects With Diabetic Neuropathic Pain

Inclusion Criteria: * Males and females, age 18 to 75 * If female, must be of non-childbearing potential or practicing birth control * Has diabetes mellitus (Type 1 or 2) and a diagnosis of painful distal symmetric diabetic polyneuropathy * Has had pain from distal symmetric diabetic polyneuropathy for a minimum of 6 months * Must be willing to washout of all analgesic medications prior to entry into the study Exclusion Criteria: * Has other conditions that may cause pain * Currently receiving analgesic medications for conditions other than diabetic neuropathic pain * Has a history of certain psychiatric diseases * Has a history of certain heart or cardiovascular conditions * Has any clinically significant recent infection, injury, or illness * Current participation in another clinical study or participation within the past 30 days * Is incapacitated, bedridden or confined to a wheelchair * Is pregnant and/or breastfeeding * Previous participation in this study or any other study with this investigational product.