Efficacy and Safety of RelabotulinumtoxinA, a New Ready-to-Use Liquid Formulation Botulinum Toxin: Results From the READY-1 Double-Blind, Randomized, Placebo-Controlled Phase 3 Trial in Glabellar Lines.

[BACKGROUND] RelabotulinumtoxinA (RelaBoNT-A, Galderma, Uppsala, Sweden) is an innovative, ready-to-use liquid botulinum toxin A, produced with PEARL (precipitation-free extraction and activity-preserving refined liquid) manufacturing technology, which yields a potent, complex-free formulation.

[OBJECTIVES] In the READY-1 study, efficacy and safety outcomes following a single RelaBoNT-A treatment for glabellar line correction were examined.

[METHODS] Adults with moderate to severe glabellar lines received RelaBoNT-A (50 U) or placebo in a 3:1 randomized, 6-month, phase 3, multicenter, double-blind study. Primary endpoints (examined at Month 1, maximum frown) comprised the composite ≥2-grade response, defined as ≥2-grades improvement from baseline on concurrent investigator (glabellar line investigator live assessment; GL-ILA) and participant (glabellar line subject live assessment; GL-SLA) severity scales (US endpoint), and the investigator-reported responder rate for participants scored as 0 (none) or 1 (mild) (GL-ILA scale only; EU endpoint). Participant satisfaction and treatment-emergent adverse events (TEAEs) were reported.

[RESULTS] Overall, 297 adults were randomized and treated. Month 1 composite ≥2-grade responder rate was 82.9% (RelaBoNT-A, n = 199) vs 0% (placebo, n = 67; P < .001). Month 1 investigator-reported none or mild responder rate was 96.3% (RelaBoNT-A) vs 4.5% (placebo; P < .001). GL-ILA scores remained higher with RelaBoNT-A (23.6% [none or mild]; 58.1% [≥1-grade improvement]) vs placebo (1.5%; 10.4%, respectively) through Month 6 (P < .001). In the Kaplan-Meier analysis, 75% still showed GL-ILA and GL-SLA improvements from baseline at 169 days (end of study). Participants reported onset of effect from Day 1 (39%) and satisfaction with natural-looking results (96.8%; Month 1). RelaBoNT-A-related TEAEs were low (3.6%) and typically mild.

[CONCLUSIONS] A single RelaBoNT-A treatment was effective and demonstrated a favorable safety profile. RelaBoNT-A provided significant improvements in glabellar line severity, high satisfaction, rapid onset, and enduring effectiveness throughout the 6-month study period.