Comparison of the efficacy and safety of pregabalin for postherpetic neuralgia in Chinese and international patients

PURPOSE: Pregabalin is indicated for postherpetic neuralgia (PHN) in multiple countries, including China. This analysis compared pregabalin efficacy and safety in Chinese and international patients with PHN. PATIENTS AND METHODS: Data from Chinese and international randomized, double-blind, placebo-controlled trials were compared. Pregabalin was administered at fixed (150, 300, or 600 mg/day) or flexible (150–600 mg/day) doses. The main efficacy measure was mean pain score change at endpoint on an 11-point numeric rating scale ranging from 0 = no pain to 10 = worst possible pain. Secondary efficacy measures included proportions of 30% and 50% pain responders, pain-related sleep interference (PRSI) scores, and proportions of Patient Global Impression of Change (PGIC) responders. The incidences of serious adverse events (SAEs) and adverse events (AEs) were used to assess safety. The effect of baseline pain severity on efficacy was tested. The proportions of patients with severe baseline pain who had moderate or mild pain at endpoint were also assessed. RESULTS: A total of 1166 patients were analyzed: 312 Chinese and 854 international. Overall, results were similar between Chinese and international patients. Pregabalin statistically significantly improved mean pain score versus placebo (least squares mean difference [95% CIs]: Chinese, −0.8 [–1.2, −0.5]; international, −1.3 [–1.6, −1.0]; both p<0.001). Pregabalin was statistically significantly better than placebo in Chinese and international patient groups in the proportions of 30% and 50% pain responders, PRSI scores, and proportions of PGIC responders. Baseline pain severity did not affect efficacy, except for some measures in Chinese patients with moderate baseline pain. Similar proportions of pregabalin-treated patients with severe baseline pain had moderate or mild pain at endpoint in both groups. SAE and AE profiles were comparable in Chinese and international patient groups, except incidences were commonly higher in international patients. CONCLUSION: Chinese and international patients with PHN exhibit comparable pregabalin efficacy and safety, highlighting the utility of pregabalin for diverse PHN patient populations.