Across both studies, 382 subjects received 1240 DAXI treatments. Mean change from baseline (CFB) in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total score, averaged over Weeks 4 and 6 post injection, increased over the 5 treatment cycles (-12.3 in ASPEN-1; -15.4, -17.7, -17.9, and -19.9 for Cycles 1-4 of ASPEN-OLS, respectively). Similar trends for increasing CFB over successive cycles were seen for TWSTRS subscales of pain (-3.0 to -5.8), disability (-3.5 to -6.0), and severity (-5.7 to -8.3). Clinical and Patient Global Impression of Change responder rates (≥2-point improvement) at Weeks 4 or 6 also increased from ASPEN-1 (58.8% and 52.2%) to Cycle 4 of ASPEN-OLS (83.1% and 69.2%).

Treatment-related dysphagia was reported in 2.7% of DAXI-treated subjects in ASPEN-1 and in 3.9%, 4.3%, 4.7%, and 3.1% of subjects in ASPEN-OLS Cycles 1-4, respectively (4.2% of 985 treatments in ASPEN-OLS). The incidence of treatment-induced anti-drug antibodies was low, with no observed trend in incidence over successive doses.