Diabetic Peripheral Neuropathy

Inclusion Criteria

• Patient has given written informed consent to participate in the study in accordance with local regulations
• Adult male and female patients ≥18 years of age at the Screening Visit:
• a. Females of childbearing potential must have a negative serum or urine pregnancy test prior to the start of study drug. In the case of positive urine pregnancy testing, a negative serum sample for pregnancy testing, to confirm that the patient is not pregnant, must be obtained prior to start of study. They must also agree to use adequate methods of contraception which include the following: condom with spermicidal gel, diaphragm with spermicidal gel, coil (intrauterine device), surgical sterilization, vasectomy, oral contraceptive pill, depo-progesterone injections, progesterone implant (ie, Implanon®), NuvaRing®, Ortho Evra®.
• b. Nonsterile male patients with sexual partners of childbearing potential must agree to use adequate methods of contraception from Baseline through the Week 56 Visit
• Diagnosis of T1DM or T2DM with chronic DPNP, (defined as distal symmetric polyneuropathy characterized by burning pain, paresthesia, and/or numbness with reduced or absent deep tendon reflex at both ankles) at Screening

Exclusion Criteria

Patients who meet any of the following criteria will be excluded from participating in the study:

• Presence of other painful conditions that may confound assessment or self-evaluation of DPNP:
• a. Patients should not have any other neurological disorder or conditions that can cause symptoms that may mimic peripheral neuropathy or that might confound assessment of distal symmetrical sensory polyneuropathy, and especially should not have any neuropathy due to nondiabetic causes. Patients with any condition that mimics peripheral neuropathy including but not limited to: stroke with distal neurological deficit; amyotrophy; polyradiculopathy; history of transient ischemic attacks; multiple sclerosis; mononeuropathy multiplex; chemotherapy, alcohol, or heavy metal-induced neuropathies should be excluded.
• b. Other causes of diffuse painful peripheral neuropathy including but not limited to: paraproteinemia, untreated hypothyroidism (previously treated hypothyroidism not excluded if treated and euthyroid for at least 6 months), vitamin B12 deficiency, neurologically-evident vasculitis, malignancy, amyloidosis, renal insufficiency, connective tissue disease (eg, Sjogren's, systemic lupus erythematosus), porphyria, hereditary motor sensory neuropathy, postherpetic neuralgia, complex regional pain syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, alcoholism, human immunodeficiency virus (HIV) infection, hepatitis, uremia, syphilis, myeloma, or other systemic disease associated with a secondary painful neuropathy should be excluded.
• c. Patients should not have had any exposure to drugs/toxic environmental agents known to cause neuropathy
• History of neurolytic or neurosurgical therapy for DPNP
• Use of opioid medications for management of DPNP within the 2 months prior to the Screening Visit. Note: Brief use (<1 week) of opioid medication for management of non-DPN acute pain (eg, tooth extraction/acute injury) greater than 30 days prior to Screening Visit is permitted.
• Use of prescription topical analgesics (eg, capsaicin) indicated for neuropathic pain within 3 months prior to Screening.
• Use of NSAIDs less than 2 weeks prior to Screening