BOTOX® Treatment for Adults With a Wide Lower Face Due to Masseter Muscle Prominence

Study Overview
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Brief Summary
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This study is designed to evaluate the safety and effectiveness of administering BOTOX for the treatment of Masseter Muscle Prominence (MMP) in adults.

Official Title
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BOTOX® (onabotulinumtoxinA) Treatment of Masseter Muscle Prominence: A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study

Conditions
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Masseter Muscle Prominence

Intervention / Treatment
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* Biological: Botulinum Toxin Type A
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Inclusion Criteria: Masseter prominence at the Day 1 visit BMI ≤ 30 kg/m2 using the calculation: BMI = weight (kg)/[height (m)]2 A female participant must be willing to minimize the risk of inducing pregnancy for the duration of the clinical study and follow-up periods Exclusion Criteria: Any medical condition that may put the participant at increased medical risk with exposure to BOTOX, including diagnosed myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, or any other condition that might interfere with neuromuscular function An anticipated need for surgery or overnight hospitalization during the study An anticipated need for treatment with botulinum toxin of any serotype for any indication during the study (other than study intervention) History of dental or surgical procedure for lower facial shaping or masseter muscle reduction Prior mid-facial and/or lower facial treatment with nonpermanent soft tissue fillers, synthetic implantations, autologous fat transplantation, fat-reducing injectables, and/or skin-tightening laser treatments within 6 months prior to Day 1 Prior exposure to botulinum toxin of any serotype to the masseter muscle or lower face at any time, or to any other part of the body within the 6 months prior to Day 1 History of temporomandibular joint disorder (TMJD) Masseter prominence due to other etiologies (eg, parotid gland infection, parotiditis, malignancy) Known allergy or sensitivity to any of the components of the study treatments or any materials used in the study procedures History of alcohol or drug abuse within 12 months of Day 1

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Botulinum Toxin Type A (BOTOX®)<br>Botulinum Toxin Type A (BOTOX ®) will be administered on Day 1 as bilateral intramuscular injections into the masseter with the possibility of 2 additional treatments | Biological: Botulinum Toxin Type A<br>* Day 1 Administration of bilateral intramuscular injections into the masseter<br>* Other names: BOTOX®;|
| Placebo Comparator: Placebo<br>Placebo (normal saline) will be administered on Day 1 as bilateral intramuscular injections into the masseter | Other: Placebo<br>* Day 1 Administration of bilateral intramuscular injections of placebo (normal saline) into the masseter<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of responders that show change in masseter muscle prominence (MMP) | Investigator assessment of severity of MMP using the Masseter Muscle Prominence Scale (MMPS). Score ranges from 1 = minimal to 5 = very marked | Baseline, Day 90 | 
| Incidence of Adverse Events (AEs) | The number of patients who experienced one or more AEs during the study | Up to 18 Months | 
| Change from baseline in vital sign values (blood pressure, respiratory rate, and pulse rate) | Summary statistics of change from baseline vital sign values | Up to 18 Months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of responders who achieve a clinical target on a MMP scale | Investigator assessment of MMP using a scale ranging from minimal to very marked | Baseline, Day 90 | 
| Proportion of responders who achieve improvement using a self-assessment scale | Improvement of MMP is self-assessed by the participant using a scale ranging from not at all pronounced to very pronounced. | Baseline, Day 90 | 
| Proportion of responders that show improvement in MMP | Improvement of MMP is self-assessed by the participant using a scale for change in MMP ranging from much improved to much worse | Baseline, Day 90 | 
| Change from baseline in lower facial width | Calculated from standardized images, measured in millimeters (mm) | Baseline, Day 90 | 
| Duration of treatment effect | Improvement from baseline of MMP | Baseline, Day 90 |