Methods/Technique: Patients were eligible for enrollment in this extension study based on their participation in 4 phase 3 studies; they were aged ≥18 years and had moderate or severe dynamic glabellar lines at maximum frown. Patients received up to 8 treatments over 24 months. Total doses were fixed (50 U) or based on muscle mass (women: 50, 60, or 70 U; men: 60, 70, or 80 U). Adverse events (AEs) were assessed following each session at days 7, 14, 30, and monthly thereafter; monitoring after the final clinic visit continued every 3 months for ≤1 year (total safety monitoring duration, ≤36 mo).
Results/Complications: Of 1415 treated patients (44 US centers), 1120 (79%) completed 2 years of treatment. The mean (SD) age was 49.5 (9.7) years; most patients were women (n=1289, 91%) and white (1151, 81%). Treatment-emergent AEs (TEAEs) occurred in more than two thirds of patients, but most were mild or moderate; severe TEAEs were uncommon. The most common TEAEs were nasopharyngitis, upper respiratory tract infection, sinusitis, and headache. Eyelid ptosis was rare, resolved spontaneously, and resulted in no withdrawals. The incidence of TEAEs was similar over time and with fixed vs variable dosing.
Conclusion: Long-term abobotulinumtoxinA treatment of glabellar lines was well tolerated. No concerns related to cumulative exposure or fixed vs variable dosing were indentified.
Funding Source: This research was supported by Medicis Aesthetics Inc., Scottsdale, AZ.