To evaluate the efficacy and safety of two doses of DaxibotulinumtoxinA for Injection (DAXI) compared with placebo for treatment of cervical dystonia (CD).

DAXI is a novel botulinum toxin type A product formulated with a proprietary peptide excipient. A Phase 2 study demonstrated promising efficacy and duration of effect in CD. Here we report results of a large, multicenter, Phase 3 double-blind placebo-controlled trial.

301 subjects were randomized to placebo (n=46), DAXI 125U (n=125), or DAXI 250U (n=130). Demographics were similar across cohorts. Mean baseline TWSTRS total score was 43.3. Mean improvement from baseline in TWSTRS total score at the primary timepoint was 4.3±1.82 for placebo, 12.7±1.30 for DAXI 125U (p<0.0001 vs placebo), and 10.9±1.25 for DAXI 250U (p=0.0006 vs placebo). There was no statistical difference in TWSTRS total score reduction between DAXI dose groups. Median duration of effect was 24.0 and 20.3 weeks for DAXI 125U and DAXI 250U, respectively, as determined by time to loss of 80% peak treatment benefit.

The most commonly reported treatment-related adverse events were injection site pain, headache, injection site erythema, muscular weakness, and musculoskeletal pain. Dysphagia was reported in 1.6% and 3.9% of subjects treated with DAXI 125U and DAXI 250U, respectively.