IncobotulinumtoxinA demonstrates safety and prolonged duration of effect in a dose-ranging study for glabellar lines

BACKGROUND Recently reported clinical data provides evidence that increasing the dose of botulinum toxin A increases the duration of efficacy. A 2-stage Phase 2, randomized, double-blind study investigated the duration of effect and safety of IncobotulinumtoxinA (INCO; Xeomin®, Bocouture®; Merz Pharmaceuticals GmbH, Frankfurt am Main, Germany) at doses higher than the approved 20 units (U) for glabellar frown lines (GFL). Primary safety and efficacy endpoints of Stage 1 are reported here. METHODS 151 subjects with moderate-to-severe GFL were randomized 1:2:2 to receive a single treatment with 20U, 50U, or 75U INCO. The primary efficacy endpoint was median duration of at least 1-point improvement from baseline as assessed by investigator at maximum frown on the Facial Wrinkle Scale. RESULTS The median duration of effect was 185 days for the 50U dose group (95% CI:[182, 205]) and 210 days for the 75U dose group (95% CI:[182, 217]). Duration of effect was significantly longer for 75U vs 50U (P=0.0400) and 20U (P=0.0166) despite the study not being powered for confirmatory statistical significance testing between the dose groups. Duration of effect was also longer for 50U vs 20U, however; statistical significance was not reached (P=0.4349). The incidence of treatment-related adverse events was low across all doses (20U:2[6.7%], 50U:6[10.0%] and 75U:8[13.1%]). CONCLUSIONS These results demonstrate a dose effect of at least 6 months duration with higher doses in the majority of GFL subjects. All doses were well tolerated and safety was consistent with the known safety profile of 20U INCO for GFL. J Drugs Dermatol. 2020;19(10):985-991. doi:10.36849/JDD.2020.5454.