The Efficacy and Duration of Onabotulinum Toxin A in Improving Upper Facial Expression Lines With 64-Unit Dose Optimization: A Systematic Review and Meta-Analysis With Trial Sequential Analysis of the Randomized Controlled Trials

Abstract

Background: Onabotulinumtoxin A (Onabot A) was the first treatment to be approved for aesthetic indications, namely glabellar lines (GLs), crow's feet lines (CFLs), and forehead lines (FHLs), with a cumulative dose of 64 U.

Objectives: The aim of this study was to conduct a meta-analysis to combine the available data for approved doses for GLs, CFLs, and FHLs to explore the effect and duration of simultaneous treatment with Onabot A.

Methods: PubMed/MEDLINE, Embase, and other national clinical trial registries were searched for randomized controlled trials from January 2010 to July 2022. The meta-analysis, trial sequential analysis, and investigator-assessed time to return to nonresponder status in GLs, CFLs, and FHLs following Onabot A were plotted to elicit a cumulative dose-adjusted response curve based on Kaplan-Meier analysis with a log-rank test.

Results: Fourteen randomized controlled trials were eligible for quantitative analysis. A total of 8369 subjects were recruited across the trials. The meta-analysis results show that Onabot A is very effective in reducing moderate to severe GLs, CFLs, and FHLs. The cumulative Z-curve for GLs, CFLs, and FHLs also exceeds the required information size (RIS). Kaplan-Meier analysis with a log-rank test demonstrated that simultaneous treatment of GLs, CFLs, and FHLs requires 182 days (95% CI = 179, 215 days) (P < 0.00002) to return to nonresponder status.

Conclusions: Treatment of the upper facial expression lines with Onabot A is effective, and the approved cumulative dose of 64 U gives longer-lasting effects.