Conditions: Neuralgia, Postherpetic
Keywords: Post-herpetic neuralgia(PHN) Neuropathic pain
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 96
Healthy volunteers: no

Brief 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.

Detailed description:
The primary purpose of study PXN110527 was to investigate the efficacy of a high (3600mg/day) dose versus a low (1200mg/day) dose of GEn in subjects with post-herpetic neuralgia (PHN) who have a history of an inadequate response to gabapentin treatment. The study is a cross-over design. Prior to screening subjects are required to have a demonstrated history of an inadequate response (as determined by the investigator) to at least 1800 mg/day of gabapentin. Prior history of treatment with gabapentin includes current treatment at 1800mg/day (2 weeks) or prior treatment with ≥1800mg/day (4 weeks). Subjects could also have been treated with pregabalin monotherapy (150-300mg/day, ≥4 weeks) and had an inadequate response.

Subjects are treated with gabapentin 1800mg/day during the Baseline Period and are randomized if during the Basleline Period they are compliant with gabapentin treatment and have a 24-hour average pain intensity score ≥4.0 based on an 11-point pain intensity numerical rating scale (PI-NRS). Subjects are then randomized to receive gabapentin enacarbil (either 1200mg/day or 3600mg/day in a 1:1 ratio) for Treatment Period 1 (28 days). Followed by a dose of 2400mg/day for 4 days and the alternate fixed dose (either 3600 mg/day or 1200 mg/day) for Treatment Period 2 (28 days).

Arms:
arm 1: gabapentin enacarbil 1200mg/day, 4 weeks treatment in either the first or second treatment period arm 2: gabapentin enacarbil 3600mg/day, 4 weeks treatment in either the first or second treatment period

Interventions: intervention 1: GEn 1200mg/day intervention 2: GEn 3600mg/day
Intervention descriptions: intervention 1: 1200mg/day gabapentin enacarbil intervention 2: 3600mg/day gabapentin enacarbil

Protocol document: