The objective of this study is to investigate the safety and efficacy of an investigational drug, V3381, for the treatment of diabetic peripheral neuropathic (DPN) pain (pain in one's feet and legs, or even in one's hands and arms, sometimes experienced by people with diabetes). An investigational drug is one that is not approved by the United States Food and Drug Administration (FDA) and/or Health Canada.

Diabetic Peripheral Neuropathic Pain (DPNP) is pain in your feet and legs, or even in your hands and arms, sometimes experienced by people with diabetes. Neuropathic pain syndromes are much more common than is perhaps generally recognized. Approximately 1% of the population in western countries suffers from neuropathic pain. Some clinical conditions are associated with a relatively high incidence of neuropathic pain. Approximately 15% of patients with diabetic neuropathy have persistent neuropathic pain in the feet, legs and hands.

Inclusion Criteria:

• Males or females 18-75 years of age
• Diabetes mellitus (type I or type II)
• No change in medications for reducing blood sugar within 4 weeks before screening
• Experiencing daily pain due to diabetic neuropathy for at least 6 months but not more than 5 years
• Neuropathic pain must begin in the feet, with relatively symmetrical onset.
• Willing to perform self-monitoring of blood glucose
• Able to communicate intelligibly with the investigator and study coordinator
• Keeping all appointments for clinic visits, tests, and procedures

Exclusion Criteria:

• Any clinically significant neurologic disorders (with the exception of diabetic peripheral neuropathic pain)
• Any clinically significant or unstable medical or psychiatric condition that would interfere with the patient's ability to participate in the study
• Prior renal transplant or current renal dialysis
• Pernicious anemia
• Untreated hypothyroidism
• Amputations due to diabetes mellitus (with the exception of toes)
• Any clinically significant abnormal electrocardiogram (ECG)
• Any history of cardiac arrhythmia
• History of myocardial infarction
• Active angina
• Uncontrolled hypertension (i.e., > 140/90 mm Hg)
• Known or at high risk of hepatitis B or C infection
• Known or at high risk of human immunodeficiency virus (HIV) infection
• Any anticipated need for surgery during the study
• Glycosylated hemoglobin (HbA1c) > 9%
• Known seizure disorder
• Any malignancy in the past 2 years (with the exception of basal cell carcinoma)
• Pain that cannot be clearly differentiated from, or conditions that interfere with the assessment of diabetic neuropathic pain.
• Use of anticonvulsants, antidepressants, or prescription membrane-stabilizing agents
• History of substance abuse or dependence within the past year, excluding nicotine and caffeine
• Frequent and/or severe allergic reactions with multiple medications
• Participation in any clinical trial within 30 days before screening