Mirogabalin for the management of postherpetic neuralgia: a randomized, double-blind, placebo-controlled phase 3 study in Asian patients

This study investigated the safety and efficacy of mirogabalin, a novel, potent, selective ligand of the α(2)δ subunit of voltage-dependent Ca(2+) channels, for the treatment of postherpetic neuralgia (PHN). In this multicenter, double-blind, placebo-controlled phase 3 study, Asian patients ≥20 years with PHN were randomized 2:1:1:1 to placebo or mirogabalin 15, 20, or 30 mg/day for up to 14 weeks (NCT02318719). The primary efficacy endpoint was the change from baseline in average daily pain score at week 14, defined as a weekly average of daily pain (0 = “no pain” to 10 = “worst possible pain,” for the last 24 hours). Of 765 patients randomized, 763 received ≥ 1 dose of the study drug and were included in the analysis; 303, 152, 153, and 155 received placebo, mirogabalin 15, 20, or 30 mg/day, respectively. A total of 671 (87.7%) patients completed the study. At week 14, the difference in average daily pain score least squares mean vs placebo was −0.41, −0.47, and −0.77, respectively; all mirogabalin groups showed statistical significance. The most common treatment-emergent adverse events were somnolence, nasopharyngitis, dizziness, weight increase, and edema, and all of them were mild or moderate in severity. Mirogabalin was superior to placebo in all groups for relieving PHN and appeared well tolerated.