Efficacy and safety of pregabalin for painful diabetic peripheral neuropathy in a population of Chinese patients: A randomized placebo-controlled trial

Background Limited information exists on the efficacy of pregabalin in Chinese patients with diabetic peripheral neuropathy (pDPN). Methods An 11-week, double-blind, placebo-controlled trial in Chinese pDPN patients randomized (1:1) to pregabalin 300 mg/day or placebo. Primary efficacy endpoint was change from baseline in mean daily pain score (0 = no pain;10 = worst possible pain). Secondary efficacy endpoints included overall weekly mean pain score, responder status, impression of change, pain intensity, and sleep. Subgroup analysis assessed change in pain in patients with severe (≥7) baseline pain. Adverse events (AEs) were reported. ClinicalTrials.gov Identifier:NCT01332149. Results In total, 620 patients were randomized and treated (313, pregabalin; 307, placebo). Improvement in mean pain score with pregabalin versus placebo was not significant (mean treatment difference –0.28;P=0.0559). Post-hoc sensitivity analyses, excluding one patient due to GCP non-compliance, showed pregabalin significantly improved mean pain score when excluding the patient (–0.30;P=0.0448) or the associated site (–0.38;P=0.0142). Pregabalin significantly improved overall weekly mean pain score (P=0.0164) and ≥50% responders at endpoint (P=0.0384). Improvement in ≥30% responders, impression of change, pain intensity, and sleep were not significant. In the severe subpopulation, pregabalin significantly improved mean pain score versus placebo (–0.79;P=0.0040). The most commonly reported AE was dizziness (9.6% vs 3.9% with placebo). Conclusions Pregabalin did not significantly improve the primary measure of pain. Significant reductions in mean pain score were observed when excluding the GCP–non-compliant patient or site and in the severe subpopulation. Pregabalin was well tolerated in Chinese pDPN patients.