A Phase 2a, Randomized, Crossover Trial of Gabapentin Enacarbil for the Treatment of Postherpetic Neuralgia in Gabapentin Inadequate Responders. Issue 12 (18th September 2013)

• Record Type: Journal Article
• Authors: Harden, R. Norman; Freeman, Roy; Rainka, Michelle; Zhang, Lixin; Bell, Chris; Berges, Alienor; Chen, Chao; Graff, Ole; Harding, Kathleen; Hunter, Setrina; Kavanagh, Sarah; Schwartzbach, Caryl; Warren, Samantha; McClung, Carrie
• Is Part Of: Pain medicine. Volume 14:Issue 12(2013)
• Page Start: 1918
• Page End: 1932
• Publication Date: 2013-09-18
• Subjects: Pain -- Periodicals; Pain -- Treatment -- Periodicals; Analgesics -- Periodicals; Pain -- Periodicals; Pain Management -- Periodicals; Douleur -- Périodiques; Douleur -- Traitement -- Périodiques; Analgésiques -- Périodiques; Analgésique; Soulagement de la douleur; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.047205
• DOI: 10.1111/pme.12227
• Languages: English
• ISSNs: 1526-2375

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="pme12227-sec-0001" sec-type="section"> <title>Objective</title> <p>To compare the efficacy of high‐dose (3, 600 mg/day) vs low‐dose (1, 200 mg/day) oral gabapentin enacarbil (GEn) on pain intensity in adults with postherpetic neuralgia (PHN) and a history of inadequate response to ≥1, 800 mg/day gabapentin.</p> </sec> <sec id="pme12227-sec-0002" sec-type="section"> <title>Design</title> <p>Multicenter, randomized, double‐blind, crossover study (NCT00617461).</p> </sec> <sec id="pme12227-sec-0003" sec-type="section"> <title>Setting</title> <p>Thirty‐five outpatient centers in Germany and the United States.</p> </sec> <sec id="pme12227-sec-0004" sec-type="section"> <title>Subjects</title> <p>Subjects aged ≥18 years with a diagnosis of PHN.</p> </sec> <sec id="pme12227-sec-0005" sec-type="section"> <title>Methods</title> <p>During a 2‐week baseline period, subjects received open‐label treatment with 1, 800 mg/day gabapentin. Subjects who had a mean 24‐hour average pain intensity score ≥4 during the last 7 days of the baseline period were randomized to receive GEn (1, 200 or 3, 600 mg/day) for treatment period 1 (28 days), followed by GEn 2, 400 mg/day (4 days), and the alternate GEn dose for treatment period 2 (28 days).</p> </sec> <sec id="pme12227-sec-0006" sec-type="section"> <title>Results</title> <p>There was a modest but significant improvement in pain intensity scores with GEn 3, 600 mg vs 1, 200 mg (adjusted mean [90% confidence interval] treatment difference, −0.29 [−0.48 to −0.10]; <italic>P</italic> = 0.013). The difference in efficacy between doses was observed primarily in subjects who received the higher dose during treatment period 2; certain aspects of the study design may have contributed to this outcome. Plasma steady‐state gabapentin exposure during GEn treatment was as expected and consistent between treatment periods. No new safety signals or adverse event trends relating to GEn exposure were identified.</p> </sec> <sec id="pme12227-sec-0007" sec-type="section"> <title>Conclusions</title> <p>While the overall results demonstrated efficacy in a PHN population, the differences between treatment periods confound the interpretation. These findings could provide insight into future trial designs.</p> </sec> </abstract>