A Study to Assess the Effectiveness of BOTOX (Botulinum Toxin Type A) Injections for the Change of Masseter Muscle Prominence in Adult Participants

NCT ID: NCT06068855

Last Updated: 2025-12-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE3
• Total Enrollment: 249 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-10-17
• Study Completion Date: 2025-11-20

Brief Summary

The masseter muscle is one of the muscles in the lower face used for chewing. Prominence of the masseter muscle can appear as a widened and square lower face shape, which is an aesthetic concern for individuals who prefer a narrower and more ovoid lower face shape. Treatments are available for masseter muscle prominice (MMP), but researchers are looking for new non-surgical treatments. This study will assess adverse events and effectiveness of BOTOX in adult participants with MMP.

BOTOX is being investigated for the treatment of MMP. Participants are placed in 1 of 2 groups, called treatment arms. Each group receives a different treatment. There is 1 in 4 chance that participants will be assigned to placebo. Around 248 adult participants with MMP will be enrolled in the study at approximately 30 sites in Europe.

Participants will receive either BOTOX or Placebo administered as 6 intramuscular injections to the masseter on Day 1. Participants who are eligible for retreatment will be given BOTOX on Day 180 and will be followed for up to 6 months.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, checking for side effects and completing questionnaires.

Conditions

Masseter Muscle Prominence

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Double-Blind Period: Botox

Participants will receive 6 intramuscular injections of BOTOX to the masseter on Day 1.

Group Type: EXPERIMENTAL

BOTOX

Intervention Type: DRUG

Intramuscular Injections

Open-Label Period: Botox

Participants who are eligible for retreatment will be given open-label BOTOX on Day 180 and will be followed for up to 6 months

Group Type: EXPERIMENTAL

BOTOX

Intervention Type: DRUG

Intramuscular Injections

Double Blind Period: Placebo

Participants will receive 6 intramuscular injections of Placebo to the masseter on Day 1.

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: DRUG

Intramuscular Injections

Interventions

BOTOX

Intramuscular Injections

Intervention Type: DRUG

Placebo

Intramuscular Injections

Intervention Type: DRUG

Other Intervention Names

Botulinum Toxin Type A

Eligibility Criteria

Inclusion Criteria

• Body mass index < 30 kg/m^2 using the calculation: BMI = weight (kg)/height (m)^2, rounded to the nearest whole number.
• Participants meets the following criteria:

• Bilateral Grade 4 or Grade 5 MMP (identical grades for left and right side of the face), as determined at screening and at the Day 1 visit by the investigator using the MMPS.
• Bilateral Grade 4 or Grade 5 MMP (identical grades for left and right sides of the face), as determined at the Day 1 visit by the participant using the MMPS-P.
• MMP grades, as assessed by investigator and participant, do not need to be identical but have to be a minimum of Grade 4 with bilateral symmetry at Day 1.
• Participants who responded "A lot" or "Extremely" bothered by the appearance of their MMP as measured by the Bother Impact Assessment for Masseter Muscle Prominence (BIA-MMP) and attain a total score of ≥ 15 on the Lower Facial Shape Questionnaire - Impact Assessment (LFSQ-IA), determined at the Day 1 visit.

Exclusion Criteria

• Has current intraoral infection, including infection of the mouth or gums, or facial skin infection requiring medical treatment in the opinion of the investigator.
• Has weakness of the masseter, pterygoid, or temporalis muscles due to trauma, facial nerve injury, or other condition that could interfere with normal chewing and jaw clenching, as determined by the investigator.
• Excess lower facial fat, jowling, loose or lax skin in lower face, or parotid gland prominence that could interfere with MMPS or MMPS-P grading, as determined by the investigator.
• Has 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.
• History of dental or surgical procedure for lower facial shaping or masseter muscle reduction.
• History of any soft tissue fillers in the jawline.
• Has prior exposure to botulinum toxin of any serotype to any part of the body (not including masseter muscle) within the 3 months prior to Day 1.
• History of or current TMJD, or presence of signs/symptoms of possible TMJD in the opinion of the investigator.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

AbbVie

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

ABBVIE INC.

Role: STUDY_DIRECTOR

AbbVie

Locations

Da Vinci Clinic /ID# 246731

Beerse, Antwerpen, Belgium

Evolve Clinic /ID# 246729

Schilde, Antwerpen, Belgium

Universitair Ziekenhuis Brussel /ID# 246311

Jette, Brussels Capital, Belgium

Lightfalls Clinic /ID# 247335

Melle, Oost-Vlaanderen, Belgium

Dermavist - Group Practice for Specialized Medical Care for Skin Disease /ID# 247630

Plovdiv, , Bulgaria

Medical Center Derma Vita EOOD /ID# 247327

Sofia, , Bulgaria

Medical Centre Dermatology Dr. Denkova EOOD /ID# 246591

Sofia, , Bulgaria

Mediti /Id# 246875

Antibes, , France

Cabinet Dermatologie et Esthetique /ID# 246871

Cannes, , France

Cabinet médical /ID# 246873

Paris, , France

Cabinet de Chirurgie Plastique et Esthétique /ID# 246872

Toulouse, , France

Hautok and Hautok-cosmetics /ID# 246600

Munich, Bavaria, Germany

Studienzentrum Theatiner46 /ID# 246601

Munich, Bavaria, Germany

Hautzentrum Koeln /ID# 247502

Cologne, North Rhine-Westphalia, Germany

Privatpraxis Dr. Hilton & Partner /ID# 246602

Düsseldorf, North Rhine-Westphalia, Germany

Universitaet Hamburg /ID# 247503

Hamburg, , Germany

Azienda Unita Sanitaria Locale Latina /ID# 246835

Latina, , Italy

Fondazione Policlinico Universitario Campus Bio-Medico /ID# 246836

Roma, , Italy

CRC - Centro Ricerche Cliniche di Verona S.r.l. /ID# 246834

Verona, , Italy

Gavín Dermatólogos /ID# 252120

Vigo, Pontevedra, Spain

Clinica Alejandria /ID# 247380

Valencia, Valencia, Spain

Grupo Pedro Jaen /ID# 246485

Madrid, , Spain

Clinica Robega /ID# 252239

Madrid, , Spain

Waverley Medical Practice /ID# 246432

Coatbridge, North Lanarkshire, United Kingdom

Dr Nestor's Medical Cosmetic Centre /ID# 246437

Edinburgh, , United Kingdom

Interface Aesthetics Training Limited /ID# 248115

London, , United Kingdom

MediZen /ID# 246431

Sutton Coldfield, , United Kingdom

Countries

Belgium; Bulgaria; France; Germany; Italy; Spain; United Kingdom

Related Links

https://www.abbvieclinicaltrials.com/study/?id=M23-123

Related Info

Other Identifiers

2022-500568-37-00

Identifier Type: OTHER

Identifier Source: secondary_id

M23-123

Identifier Type: -

Identifier Source: org_study_id