Advances in Topical Botulinum Therapy

BACKGROUND A successfully developed topical botulinum toxin product would overcome the disadvantages of injectable administration commonly seen with all available botulinum products, including the potential pain, bleeding, and bruising associated with injection. OBJECTIVE Identify the disadvantages of injectable administration of botulinum products and advantages of topical administration. Identify previous attempts to develop topical products and review the only topical product candidate (ET-01, abbreviated EMX) under clinical development. MATERIALS AND METHODS A literature review regarding injectable botulinum products and topical botulinum product candidates and an analysis of data regarding EMX development were performed. RESULTS Multiple disadvantages of injectable administration and advantages of topical administration of botulinum toxin were identified. If available, topical botulinum products are expected to expand the clinical use of botulinum toxin. Several previous attempts to develop topical products were identified. EMX has been studied for lateral canthal line treatment in multiple controlled phase 2 clinical trials including over 700 subjects. EMX has demonstrated statistically significant positive results. CONCLUSION The development of a topical botulinum toxin is appealing because it overcomes multiple disadvantages observed with injectable administration and would likely result in increased clinical use of botulinum toxin. The development of EMX shows promise and merits further study.