Long-Term Treatment of Glabellar Rhytides Using OnabotulinumtoxinA

OBJECTIVE To determine whether injection every 4 months with onabotulinumtoxinA provides longer-lasting reduction or elimination of glabellar rhytides. METHODS Toxin-naive women (N = 45) aged 30 to 50 with moderate to severe glabellar lines at maximum contraction completed the study. Five sites were treated with 4U of onabotulinumtoxinA. Participants were assessed at day 30; those with glabellar severity of none to mild remained in the study. Participants received identical treatments at months 4, 8, 12, 16, and 20, and were assessed without treatment at 24, 25, and 26 months. RESULTS Baseline physician-and participant-rated treatment responders at maximum contraction were 84% and 80%, respectively, at month 20; and 56% and 58%, respectively, at month 26. Mean changes from physician-and participant-assessed Facial Wrinkle Scale at maximum contraction from baseline to all postbaseline measurements were significant (pr <= .001). The percentage of participants reporting neutral (0) to couldn't be more satisfied <+4 > with their appearance ranged from 91% to 100% during months 1 to 24. At month 26, 87% of participants reported satisfaction, with appearance scores between 0 and + 14. No adverse events were reported. CONCLUSIONS OnabotulinumtoxinA delivered for 20 months significantly reduces or progressively eliminates glabellar rhytides for up to 6 months after the last treatment.