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

Background: Recent data provides evidence that increasing the dose of botulinum toxin type A increases the duration of efficacy (Polacco, et al, 2020). A 2-stage Phase 2, randomized, double-blind study investigated the duration of effect and safety of incobotulinumtoxinA (INCO, Merz Pharmaceuticals GmbH) at doses higher than the approved 20 units (U) for glabellar frown lines (GFL). Primary endpoints of Stage 1 are reported here. Methods: One hundred fifty-one subjects with moderate-to-severe GFL were randomized 1:2:2 to receive a single treatment with 20 U, 50 U, or 75 U 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 50 U dose group (95% CI: [182, 205]) and 210 days for the 75 U dose group (95% CI: [182, 217]). Duration of effect was significantly longer for 75 U vs 50 U (P=0.0400) and 20 U (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 50 U vs 20 U; however, statistical significance was not reached (P=0.4349). The incidence of treatment-related adverse events was low across all doses (20 U:2[6.7%], 50 U:6[10.0%], and 75 U: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 20 U INCO for GFL. Funding: Merz Pharmaceuticals GmbH, Frankfurt am Main, Germany Keywords: Duration; Glabellar frown lines; IncobotulinumtoxinA Reference Polacco MA, Singleton AE, Barnes CH, Maas C, Maas CS. A double-blind, randomized c linical trial to determine effects of increasing doses and dose-response relationship of incobotulinumtoxinA in the treatment of glabellar rhytids. Aesthet Surg J. 2020; Jul 28; sjaa220. Online ahead of print.