Diabetic peripheral neuropathy (DPN) represents a diffuse symmetric and length-dependent injury to peripheral nerves that has major implications on quality of life (QOL), morbidity, and costs from a public health perspective. Painful diabetic neuropathy affects approximately 16% of patients with diabetes. Pharmacological agents used in the management of painful DPN mainly include tricyclic antidepressants, selective serotonin and norepinephrine reuptake inhibitors, opioid, and anti epileptic drugs. The available treatment options do not give total relief, are not effective in all patients, and only about one-third of patients may achieve more than 50% pain relief. Hence newer therapies are required for the treatment of DPN. The primary outcome measures will be the change from baseline to end of treatment in the mean 24-hour average pain intensity.

Inclusion Criteria:

1. Patients willing to provide voluntary written informed consent
2. Male and female patients ≥18 yrs and ≤75 yrs
3. Patients with diabetes mellitus with painful peripheral neuropathy for at least 6 months
4. A baseline 24-hour average daily pain intensity score ≥5
5. Women must be of non child-bearing potential, defined as post menopausal or surgically sterile

Exclusion Criteria:

1. Other chronic pain conditions not associated with DPN, that may confound the assessment of neuropathic pain
2. Other causes of neuropathy or lower extremity pain
3. Complex regional pain syndrome or trigeminal neuralgia
4. Lower extremity amputations other than toes
5. Participation in another study with an investigational compound within the previous 90 days prior to study medication administration, or concurrent participation in another clinical study
6. Major depression.
7. Presence or history of cancer within the past 5 years with the exception of adequately treated localized basal cell skin cancer or in situ uterine cervical cancer.
8. Patients with clinically significant or uncontrolled hepatic, gastrointestinal, cardiovascular, respiratory, neurological (other than neuropathy), psychiatric, hematological, renal, or dermatological disease, or any other medical condition that according to Investigator's medical judgment: Could interfere with the accurate assessment of safety or efficacy, or, Could potentially affect a patient's safety or study outcome