The purpose of this study is to evaluate the safety and efficacy of a 6 mg twice a day dose of an investigational product in subjects with diabetic neuropathy

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.