Therapeutic Efficacy and Safety of Recombinant Botulinum Toxin Type A for Moderate to Severe Glabellar Lines: A Randomized, Controlled, Double-blind, Phase III Trial in Chinese Adults

Clinical Snapshot

Key Findings

• P Value: P < .0001 for YY001 vs both comparators

• Effect Size: 20 percentage point superiority of YY001 over Botox®

• Primary Outcome: Composite response rate at Week 4: YY001 86.7% vs Botox® 66.7% vs vehicle 1.3%

• Nnt Or Sensitivity: NNT approximately 5 for YY001 vs Botox® based on response rate difference

• Confidence Interval: Not reported in abstract

Clinical Application

Requires specialized training in botulinum toxin injection techniques and appropriate clinical facilities Would require TGA approval for therapeutic use; currently Botox® is PBS-listed for specific medical indications but not cosmetic use. RACGP guidelines emphasize informed consent and appropriate training for cosmetic procedures Adults with moderate to severe glabellar lines seeking cosmetic improvement

Abstract

BACKGROUND: Conventional botulinum toxin type A (BoNT/A) products include non-therapeutic accessory proteins vary in composition and manufacturing processes, which may contribute to differences in purity and biochemical characteristics. YY001 (Retoxin®) is a novel recombinant BoNT/A manufactured via E. coli expression to reduce impurities, improve purity, and minimize immunogenic risk. OBJECTIVES: To evaluate the efficacy, safety, and immunogenicity of YY001, a recombinant botulinum toxin type A (Chongqing Claruvis Pharmaceutical Co., Ltd., Chongqing, China), in the treatment of moderate-to-severe glabellar lines. METHODS: In this multicenter, randomized, double-blind, vehicle- and active-controlled Phase III trial, 529 adults aged 18-65 with moderate to severe glabellar lines were randomized 4:2:1 to receive a single 20 U injection of YY001, Botox®(Allergan Pharmaceuticals Ireland, Westport, Ireland), or vehicle. The primary endpoint was composite response rate (CRR) at Week 4, defined as a ≥2-grade improvement of glabellar line severity assessed by both investigator and participant. Secondary endpoints included onset time, duration, satisfaction, and safety. RESULTS: YY001 achieved a CRR of 86.7% at Week 4, significantly outperforming Botox® (66.7%, P < .0001) and vehicle (1.3%, P < .0001). It showed faster onset, longer median duration (97 days), and high participant satisfaction. Adverse events were mild and comparable across groups. Only one case of anti-drug antibody was observed; no neutralizing antibodies were detected. A 12-week follow-up and ethnically homogenous population may limit generalizability. CONCLUSIONS: YY001 demonstrated strong efficacy and a favorable safety profile than Botox®. Longer-term and multicenter studies are needed to assess durability, immunogenicity, and applicability across broader populations. LEVEL OF EVIDENCE: 1 (THERAPEUTIC): For image description, please refer to the figure legend and surrounding text.

References

1. 1.Wu, Y., Long, X., Yu, N., Chen, J., Lu, J., Tan, L., Lai, W., Li, L., Wu, S., Wu, L., Sun, J., Bi, H., Geng, S., Wang, H., Luo, S., Hu, Z., Yang, J., Wang, B., Yang, W., Sun, X., & Sun, X. (2026). Therapeutic efficacy and safety of recombinant botulinum toxin type A for moderate to severe glabellar lines: A randomized, controlled, double-blind, phase III trial in Chinese adults. Aesthetic Surgery Journal. https://doi.org/10.1093/asj/sjag042