Methods/Technique: Subjects aged >19 years with moderate-to-severe FHL at maximum contraction were randomized in a 1:1:1 ratio (N=50 per group) at 7 Canadian study sites to receive a single onabotulinumtoxinA treatment or placebo: onabotulinumtoxinA 30 U (forehead, 10 U; glabella, 20 U); onabotulinumtoxinA 40 U (forehead, 20 U; glabella, 20 U); and placebo (forehead, glabella, 0 U each). Response was assessed at weeks 1, 2, day 30, and at 30-day intervals thereafter throughout study duration of 180 days. Co-primary efficacy measures were achievement with a score of “none” or “mild” for investigator- and subject-assessed FHL using the Facial Wrinkle Scale with Photonumeric Guide (FWS; 0=none, 1=mild, 2=moderate, or 3=severe) at maximum eyebrow elevation on day 30. Additional assessments included Facial Lines Outcomes (FLO) responses from subjects as well as FWS-based time to return to nonresponder status at rest and maximum eyebrow elevation by both physician- and subject-assessed contraction.
Results/Complications: The percentage of subjects achieving the co-primary efficacy endpoints were 87% and 92% among the 30 U group for investigator- and subject-assessments, respectively; and 91% among the 40 U group for both investigator- and subject-based FWS assessment. In comparison, the percentage of responders for placebo-treated patients was 3% and 7% for investigator- and subject-assessment, respectively. Subjects in active treatment groups demonstrated a statistically significantly greater treatment response compared with placebo, which was sustained through the end of study.
Responder rates of FWS in FHL achieving none or mild at maximum eyebrow elevation remained statistically significant between onabotulinumtoxinA and placebo groups through day 180 for both onabotulinumtoxinA groups (investigator-assessed FWS: 30 U, 23%; 40 U, 32%; subject-assessed FWS: 30 U, 22%; 40 U, 32%). FLO-11 items 2, 5, and 8 for FHL were significantly better (P<.05) in both onabotulinumtoxinA-treated groups by week 1 and remained so throughout the study. Adverse events reported were mainly mild-to-moderate in severity and were similar among treatment groups (30 U, 33%; 40 U, 33%; placebo, 28%). No subject withdrawals occurred due to adverse events.
Conclusion: Combination treatment with onabotulinumtoxinA in total doses of 30 U and 40 U for the correction of forehead and glabellar lines was safe, effective, and durable. Both active-treatment doses were associated with high subject satisfaction.