Move Over Botox -- There’s a New Kid in Town Evaluation of Variable-Dose Treatment With a New U.S. Botulinum Toxin Type A (Dysport) for Correction of Moderate to Severe Glabellar Lines: Results From a Phase III, Randomized, Double-Blind, Placebo-Controlled Study

Background: Botulinum toxin type A has been shown to reduce the activity of glabellar muscles, decreasing the occurrence of expression-related facial lines. In April 2009, the U.S. Food and Drug Administration (FDA) approved a new formulation called Dysport. Objective: To evaluate the safety, efficacy, and duration of response of variable-dosed Dysport in the treatment of moderate to severe glabellar lines. Design: Randomized, double-blind placebo-controlled study. Participants: 816 patients from among 27 centers. Methods: Patients were randomized in a 2:1 ratio to 1 treatment of Dysport (n=544) or placebo (n=272). Patients were excluded if they had received previous treatment within the last 150 days. African-American patients were randomized separately. A subset of patients was evaluated for treatment-related effects on QT prolongation. Each patient received 5 injections: procerus, right and left corrugators, right and left lateral corrugators/orbicularis. Efficacy and duration of effect were measured at 14, 30, 60, 90, 120, and 150 days. Patients treated with variable-dosed Dysport displayed longer duration of treatment compared to those who received placebo. Results: Median duration of effect was approximately 108 days. African American patients had a longer median duration of action. At 90 days, 61% of patients continued to show a response, and at 150 days, 17% showed a response. A visible reduction in glabellar lines was seen as early as 24 hours, with a median onset of 4 days. Subgroup analysis revealed the following: lower response rates in patients aged >65 years and higher response rates in women versus men as well as in patients with less severe glabellar lines. With regard to side effects of treatment, 168 patients (31%) experienced adverse events, only 33 (6%) of which were believed to be "probably" related to treatment. Of all events, the majority were eye-related disorders, with 12 reported cases of eyelid ptosis (only 1 was "probably" related to treatment), and 18 patients reported injection site-related effects (bruising, irritation, pain, etc). No prolongation of the QT interval was related to treatment. Conclusions: Dysport is well tolerated and provides a longer-lasting reduction in glabellar lines compared to placebo. Reviewer's Comments: Botulinum toxin type A injections have become increasingly common for treatment of glabellar lines as well as several off-label injection sites. The FDA has now approved an alternative to the commonly prescribed treatment known as Botox. This study confirms that Dysport is a safe and effective option for treatment of glabellar lines. An even more beneficial study will now be to compare Dysport to the commonly prescribed Botox. A comparison study may encourage practitioners to modify their treatment algorithms to include Dysport since a study comparing this new product to placebo is less than likely to do so. (Reviewer-Robert T. Grant, MD).