Safety and efficacy of RT002, an injectable botulinum toxin type A, for treating glabellar lines: results of a phase 1/2, open-label, sequential dose-escalation study.

BACKGROUND: RT002 is a new injectable BoNTA product. This formulation limits the spread of BoNTA, potentially permitting safe administration of larger doses and possibly extending its duration of action. OBJECTIVE: This phase 1/2 clinical study was designed to establish the safety of RT002 for the treatment of moderate-to-severe glabellar lines. MATERIALS AND METHODS: Subjects were randomized into four groups (N=12/group). Cohorts 1-3 received escalating doses of RT002 ranging from half the equivalent dose of approved toxins up to twice the current dose levels. The safety of each dose was confirmed prior to administering the next dose. Subjects in Cohort 4 were treated with the highest dose and observed for 36 weeks or until GLSS returned to baseline. RESULTS: All doses of RT002 were well-tolerated. Common AEs were headache and mild injection site reactions. At Week 4, all doses of RT002 were highly effective at maximum frown. Cohort 4 achieved 7 month median duration. At 6 months, 80% of subjects maintained a ≥1-point improvement in Investigator GLSS and 60% maintained WSS of None or Mild. Study limitations include an open-label design and modest number of subjects. CONCLUSION: RT002 is a safe and effective BoNTA product with an extended duration of action.