OnabotulinumtoxinA for Platysma Prominence: Safety and Efficacy Results from a Phase 3 Open-Label Repeat Treatment Study.

BACKGROUND:OnabotulinumtoxinA (onabotA) treatment of prominent platysma muscles demonstrates a safety profile consistent with other onabotA aesthetic indications and effectively improves the appearance of vertical neck bands and jawline definition. The authors evaluated the safety and efficacy of repeat onabotA treatment for improving the appearance of moderate to severe platysma prominence. METHODS:Participants received up to 4 onabotA treatments administered a minimum of 3 months apart, including treatment with onabotA or placebo in the double-blind lead-in study. RESULTS:All treatment-emergent adverse events related to study treatment were mild in severity with no observed trends across treatment cycles. Four participants reported 6 adverse events of special interest, including dysphagia (4 events) and facial paresis (2 events). All were mild in severity with no evidence of distant spread of toxin; almost all resolved by study end and none resulted in discontinuation. The percentages of participants achieving a one-grade or better improvement at maximum contraction on day 14 for each treatment cycle were 83.6%, 92.0%, 90.0%, and 98.0% as assessed by clinicians, and 82.5%, 90.4%, 87.0%, and 94.0% as assessed by participants. CONCLUSION:Repeated onabotA treatment is well tolerated and improves platysma prominence over the course of multiple treatment cycles.