Long-term safety and efficacy of a new botulinum toxin type A in treating glabellar lines.

OBJECTIVE: To evaluate the long-term safety of repeated administrations of a new botulinum toxin type A (Reloxin; Medicis Pharmaceutical Corp, Scottsdale, Arizona) in the treatment of moderate to severe glabellar lines.

METHODS: Open-label assessment of 1200 patients receiving as many as 5 treatments of Reloxin over a 13-month period. The product was diluted in 2.5-mL sterile physiologic saline solution, 0.9%, without preservative to a concentration of 50 U of Reloxin per 0.25 mL of solution. Investigators injected 0.05 mL of the solution (10 U each) into each of 5 injection sites in the glabellar area on day 0 of each treatment cycle. There was a minimum 85-day gap between treatments. Postinjection clinical evaluation was performed on days 14 and 30 and monthly thereafter until retreatment, study completion, or early termination. The patients were telephoned on day 7 to check for adverse events (AEs) and concomitant medications, and patient diaries were used to document the onset of treatment effect.

RESULTS: The majority (72%) of treatment-emergent AEs were considered unlikely or not related to study treatment. Probably or possibly related treatment-emergent AEs occurred in 36% of patients. The most frequently occurring related AEs were injection site disorders (18%), nervous system disorders (14% and 12% headache), and eye disorders (9%). Related AEs around the injection site or eyes were usually reported by day 7 and then resolved. Reported ptosis does not differentiate between brow ptosis and eyelid ptosis. A total of 45 patients had a total of 55 instances of ptosis across all cycles, with most episodes lasting less than 3 weeks. The rates of ptosis decreased during successive cycles from 2.4% in cycle 1 to 0.6% in cycle 5. The proportion of patients reporting an onset of response by day 7 ranged from 93% to 95%. By investigator assessment, the response rate (patients reporting none or mild glabellar line severity scale scores on day 30) ranged from 80% to 91% during cycles 1 to 5.

CONCLUSIONS: There was no evidence of cumulative AEs or tachyphylaxis with multiple Reloxin treatments over a period of 13 months. The treatments were well tolerated. The rates of ptosis decreased over successive cycles, and the proportion of responders by day 7 ranged from 93% to 95%.