Treatment of Neuropathic Pain Associated With Diabetic Peripheral Neuropathy

Inclusion Criteria

• Age > 18 years of age
• Able to give informed consent and willing to comply with scheduled visits, treatment plan, laboratory tests, and other trial procedures
• Type 1 or type 2 diabetes with a hemoglobin A1c (HbA1c) ≤ 10% at Screening and on a stable antidiabetic medication regimen for at least 30 days prior to Screening (insulin therapy is acceptable)
• Painful distal symmetrical sensorimotor polyneuropathy (as per American Society of Pain Educators guidelines ) diagnosed for at least 6 months, based on neurological history and/or examination; diagnosis includes absent or reduced deep tendon reflexes at both ankles
• At Screening, a pain score of ≥ 40 mm on the SF-MPQ VAS
• At Randomization, a pain score of ≥ 40 mm on the SF-MPQ VAS and an ADPS of ≥ 4 on the 11-point NRS, the latter calculated from a minimum of 4 pain ratings in daily diaries obtained during the 1-week Baseline Period (prior to randomization)
• Creatinine clearance > 60 mL/min (estimated using the Cockcroft-Gault equation)
• Antidiabetic and other medications anticipated to remain stable and constant during the study period
• Women of child bearing potential (WOCBP) must be using an adequate method of contraception as detailed in the protocol to avoid pregnancy during the study and for 4 weeks after study completion

Exclusion Criteria

• Diagnosis of mononeuropathy
• Use of concomitant medications that may confound assessments of efficacy and/or safety (see Section 5.2)
• Major psychiatric disorders
• Have had a malignancy other than basal cell carcinoma within the past 2 years
• At Visit 1, have a white blood cell count < 2500/mm3, neutrophil count < 1500/mm3, or platelet count < 100 x 103/mm3
• Clinically significant unstable diabetes mellitus, unstable hepatic, respiratory, or hematologic illness, unstable cardiovascular disease (including myocardial infarction in the 3 months prior to Visit 1), or symptomatic peripheral vascular disease
• Clinically significant findings on the Screening ECG
• History of pernicious anemia, untreated hypothyroidism, chronic hepatitis B, hepatitis B within the past 3 months, or human immunodeficiency virus infection
• Amputations of body parts other than toes
• Prior therapeutic failure of pregabalin or gabapentin (considered unresponsive or intolerant to treatment); therapeutic failure implies lack of efficacy following full titration to effective doses (eg, 300 mg/day for pregabalin)
• Known hypersensitivity to pregabalin or gabapentin
• Requirement for concomitant anticonvulsant and antidepressant therapy, with the exception of stable doses of SSRIs
• Neurologic disorders unrelated to DPN that may confound the assessment of pain associated with DPN
• Skin conditions that could alter sensation
• Other sources of pain that may confound assessment or self-evaluation of the pain due to DPN
• Abuse of prescription medications, street drugs or alcohol (including alcohol dependence) within the last 1 year
• Current enrollment in another investigational study, participation in another investigational study with the past 30 days, or other current or recent use of any investigational drug
• Pregnancy (as based on lab test results) or breast feeding
• Laboratory values exceeding limits listed in Table 4.1 of the protocol