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)
Goseki et al. (2026) studied this question.