Efficacy and Safety of IncobotulinumtoxinA for the Treatment of Blepharospasm: A Multicenter, Phase 3 Study in Japan

This open-label, uncontrolled, single-arm, multicenter, phase 3 study evaluated the efficacy and safety of incobotulinumtoxinA in Japanese patients with blepharospasm. Eligible patients received incobotulinumtoxinA injections at fixed doses (50, 75, or 100 units [U] for those who had previously received botulinum toxin treatment; 50 U for treatment-naïve patients), followed by flexible doses up to 100 U for 48 weeks, with at least 6-week intervals. In total, 29 Japanese patients were enrolled (26 [89.7%] women, mean age 64.6 years, mean baseline Jankovic Rating Scale [JRS] severity score 3.24). The primary endpoint, the least squares mean of change in JRS severity scores from baseline to 6 weeks after the first injection, was -2.08 (95% confidence interval: -2.49, -1.66), meeting the prespecified efficacy criteria. The secondary endpoint results (JRS severity, frequency, and total scores for 48 weeks; Blepharospasm Disability Index; Patient Evaluation of Global Response; and fast blinking test) supported the efficacy of repeated incobotulinumtoxinA injections. Adverse events (AEs) occurred in 19 (65.5%) patients, with eyelid ptosis being the most common treatment-related AE (4 [13.8%] patients). No severe or serious AEs were reported. IncobotulinumtoxinA demonstrated sustained efficacy in Japanese patients with blepharospasm, without new safety concerns. (Japan Registry of Clinical Trials identifier, jRCT2031230711).