PrabotulinumtoxinA for the Treatment of Moderate-to-Severe Glabellar Lines in Adult Patients With Skin of Color: Post Hoc Analyses of the US Phase III Clinical Study Data

Abstract

Background: Limited US clinical data are available on the use of aesthetic products in patients with skin of color (SOC).

Objective: To compare the efficacy and safety of prabotulinumtoxinA for the treatment of glabellar lines in patients with and without SOC.

Methods and materials: Post hoc analyses were performed on the pooled population of all 492 patients treated with 20U prabotulinumtoxinA in the 2 US single-dose Phase III glabellar line clinical studies. Patients were grouped by Fitzpatrick skin Type: IV + V + VI (with SOC) versus I + II + III (without SOC). The primary efficacy end point was the proportion of responders with a ≥1-point improvement from baseline at maximum frown on the 4-point Glabellar Line Scale. Adverse events (AEs) were also summarized.

Results: Responder rates among patients with SOC (n = 140) were lower than those without SOC (n = 352), by 5.9% on average across all visits; at no time point were differences statistically significant. At Day 30, responder rates were 94.0% and 96.0%, respectively (p = .401). Headache was the most common treatment-related AE, occurring in 12.1% and 8.2% of patients with and without SOC, respectively.

Conclusion: A single dose of 20U prabotulinumtoxinA was well tolerated and similar in effectiveness in patients with and without SOC for the treatment of glabellar lines.

Conflict of interest statement

S.C. Taylor and J.H. Joseph served as principal investigators for the EV-002 clinical study; P.E. Grimes served as a principal investigator for the EV-001 clinical study. J.H. Joseph holds stock in Evolus, Inc., provided funding, study materials, equipment, and medications to all investigational sites. Evolus also provided funding to contract organizations involved in data collection, analysis, and reporting of the results, including these post hoc analyses. Anneke Jonker of Medical Writing Associates, West Vancouver, BC, Canada, provided technical assistance with manuscript preparation and submission; she holds stock in Evolus, Inc. R.L. Avelar is the Head of R&D and Chief Medical Officer for Evolus, Inc. and receives compensation in salary, stock, and stock options.

Copyright © 2020 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.

Figures

Figure 1.

(A–G) Photographs of glabellar lines at maximum frown at baseline (A) and at each of Day 2 (B), Day 7 (C), Day 30 (D), Day 90 (E), Day 120 (F), and Day 150 (G) after treatment with 20U PrabotulinumtoxinA in a 36-year-old female patient with skin of color. This representative patient with skin of color was assessed as having Fitzpatrick skin Type VI and moderate glabellar lines at maximum frown at baseline by investigator assessment.

Figure 2.

Percentage of responders based on a ≥1-Point improvement on the GLS at maximum frown from Day 0, by Fitzpatrick skin type and race as well as by visit (N = 492). GLS = Glabellar line scale (0 = no lines, 1 = mild, 2 = moderate, and 3 = severe); SOC = skin of color; with SOC = Fitzpatrick skin Types IV + V + VI; without SOC = Fitzpatrick skin Types I + II + III.

Figure 3.

Percentage of positive responders (improved + much improved) on the GAIS, by Fitzpatrick skin type and race as well as by visit (N = 492). GAIS = Global Aesthetic Improvement Scale (2 = much improved, 1 = improved, 0 = no change, −1 = worse, and −2 = much worse); SOC = skin of color; with SOC = Fitzpatrick skin Types IV + V + VI; without SOC = Fitzpatrick skin Types I + II + III.

Figure 4.

Percentage of positive responders (satisfied + very satisfied) on the SSS, by Fitzpatrick skin type and race as well as by visit (N = 492). SSS = Subject Satisfaction Scale (2 = very satisfied, 1 = satisfied, 0 = indifferent, −1 = unsatisfied, and −2 = very unsatisfied); SOC = skin of color; with SOC = Fitzpatrick skin Types IV + V + VI; without SOC = Fitzpatrick skin Types I + II + III.