A Clinical Study in Subjects With Neuropathic Pain From PHN Who Have Had an Inadequate Response to Gabapentin Treatment

• Status: Completed
• Trial end date: 2009-07-01
• Target enrollment: 0
• Participant gender: All

Summary

The purpose of this study is evaluate the difference between two doses of gabapentin enacarbil (XP13512/GSK1838262), hereafter referred to as GEn, on pain associated with post-herpetic neuralgia.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: XenoPort, Inc.
• Treatments: Gabapentin; gamma-Aminobutyric Acid

Criteria

Inclusion Criteria:

• 18 years or older

• Documented medical diagnosis of PHN with pain present for at least 3 months from the healing of a herpes zoster rash

• Female subjects are eligible if of non-childbearing potential or not lactating, has a negative pregnancy, and agrees to use one a specified highly effective method for avoiding pregnancy.

• Currently on a stable dose of 1800 mg/day of gabapentin for ≥2 weeks with inadequate response OR

• Not currently treated with gabapentin, but previously treated with ≥1800 mg/day of gabapentin for 4 weeks or more with inadequate response.

• Baseline 24-hour average pain intensity score ≥ 4.0 based on an 11-point PI-NRS

• Provides written informed consent in accordance with all applicable regulatory requirements

Exclusion Criteria:

• Other chronic pain conditions not associated with PHN. However, the subject will not be excluded if:

• The pain is located at a different region of the body; and

• The pain intensity is not greater than the pain intensity of the PHN; and

• The subject can assess PHN pain independently of other 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 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 drugs

• Medical condition or disorder that would interfere with the action, absorption, distribution, metabolism, or excretion of GEn, or, in the investigator's judgment

• Is considered to be clinically significant and may 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

• Current or chronic history of liver disease (including acute viral hepatitis), or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones).

• 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 meet entry criteria and must be stable for at least three months prior to enrollment

• History of clinically significant drug or alcohol abuse (DSM-IV-TR) or is unable to refrain from substance abuse throughout the study. 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 PHN, or

• Within preceding six months for studies related to PHN

• Treated previously with GEn

• History of allergic or medically significant adverse reaction to investigational products (including gabapentin) or their excipients, acetaminophen or related compounds