This study is designed to evaluate the safety and efficacy of RGH-896 in patients with diabetic peripheral neuropathic pain.

Inclusion Criteria:

• Male or female outpatients 18 to 75 years of age
• A diagnosis of painful diabetic neuropathy
• Controlled blood glucose
• Willingness to wash out all analgesic medications used for DPNP
• Female patients either postmenopausal, surgically sterile, or practicing a medically acceptable method of contraception
• Female patients who are not pregnant

Exclusion Criteria:

• Acute infections or cardiac problems
• Past use of pregabalin
• History of severe psychiatric disorder
• History of any amputation due to diabetes
• History of seizure disorder
• Active diabetic foot ulcers