A Study In Patients With Neuropathic Pain From Diabetic Peripheral Neuropathy (DPN)

Inclusion criteria:

• 18 years or older
• Female subjects are eligible to enter if of non-childbearing potential or not lactating, has a negative pregnancy test and agrees to use a specified highly effective method for avoiding pregnancy
• Documented medical diagnosis of Type 1 or 2 diabetes including:
• Stable glycemic control for 3 months defined as <25% change of routine insulin, <50% change of routine oral anti-diabetic agent dose and HbA1c < 8%. (HbA1c of 8 to 11% eligible if attempts to improve diabetic control failed)
• DPN defined by:
• Bilateral reduced or absent reflexes at the ankles, or
• Bilateral impaired vibration, pinprick, fine touch or temperature perception in the distal lower extremities And
• Persistent distal burning or dull pain in the feet, or
• Persistent proximal aching pain in the legs, or
• Paroxysmal electric, shooting, stabbing pain, or
• Dysasthesias, or
• Evoked pain And
• history of pain for at least six months and no greater than five years attributed to DPN (refers to duration of pain)
• Baseline 24-hour average daily pain intensity score >4.0 as measured on an 11 point pain intensity numerical rating scale
• Provides written informed consent in accordance with all applicable regulatory requirements

Exclusion criteria:

• Other chronic pain conditions not associated with DPN. However, the subject will not be excluded if:
• The pain condition is located at a different region of the body, and
• The pain intensity of this condition is not greater than the pain intensity of the DPN, and
• The subject can assess their DPN independently of other pain condition.
• Other causes of neuropathy or lower extremity pain
• Is unable to discontinue prohibited medications or non-drug therapies or procedures throughout the duration of the study
• Hepatic impairment defined as ALT or AST > 2x upper limit of normal (ULN) or alkaline phosphatase or bilirubin > 1.5x ULN
• Chronic hepatitis B or C
• Impaired renal function defined as either creatinine clearance < 60 mL/min or requiring hemodialysis
• Corrected QT (QTc) interval >450 msec or QTc interval >480 msec for patients with Bundle Branch Block
• Uncontrolled hypertension at screen (sitting systolic >160 mmHg and/or sitting diastolic >90 mmHg
• Current diagnosis of active epilepsy or any active seizure disorder requiring chronic therapy with antiepileptic drug(s)
• Medical condition or disorder that would interfere with the action, absorption, distribution, metabolism, or excretion of GEn or pregabalin, or, in the investigator's judgment:
• Is considered to be clinically significant and could pose a safety concern or,
• Could interfere with the accurate assessment of safety or efficacy, or,
• Could potentially affect a subject's safety or study outcome
• Meets criteria defined by the DSM‑IV‑TR for a major depressive episode or for active significant psychiatric disorders within last year
• Depression in remission, with or without antidepressant treatment, may participate, unless stable antidepressant regimen is a prohibited medication
• Antidepressant medication may not be changed or discontinued to met entry criteria and must be stable for at least 3 months prior to enrollment
• History of clinically significant drug or alcohol abuse (DSM‑IV‑TR). Benzodiazepines or atypical benzodiazepines as hypnotic sleep agents permitted
• Currently participating in another clinical study in which the subject is, or will be exposed to an investigational or non-investigational drug or device
• Has participated in a clinical study and was exposed to investigational or non-investigational drug or device:
• Within preceding month for studies unrelated to DPN, or
• Within six months for studies related to DPN
• Treated previously with GEn
• History of allergic or medically significant adverse reaction to investigational products (including gabapentin or pregabalin) or their excipients, acetaminophen or related compounds