A Double-Blind, Randomized Clinical Trial to Determine Effects of Increasing Doses and Dose-Response Relationship of IncobotulinumtoxinA in the Treatment of Glabellar Rhytids

Comparison of Botulinum Toxin A Formulations for Glabellar Strain Treatment in Women: A Double-Blind Randomized Clinical Trial

Importance

Multiple botulinum toxin A formulations were approved by the US Food and Drug Administration for treating the glabellar rhytids. A comparative quantitative evaluation of their effects on the glabella has not been conducted.

Objective

To provide an objective quantitative assessment of the effect of 4 botulinum toxin A formulations on glabellar strain across using dynamic 3-dimensional photogrammetry.

Design, Setting, and Participants

This single-center, double-blind clinical trial, conducted at the University of Pennsylvania Division of Plastic Surgery clinic, randomized 143 female individuals aged 30 to 65 years into 4 arms receiving different botulinum toxin A formulations on day 0 and with follow-up at days 3, 30, 90, and 180. Dynamic 3-dimensional photogrammetry and surveys were collected from March 2022 to June 2023 and analyzed from July 2023 to April 2024.

Interventions

Participants were randomized 1:1:1:1 into 4 treatment arms: 1 dose of 20 units of onabotulinum toxin A (OBoNT/A); 1 dose of 60 units of abobotulinum toxin A (ABoNT/A); 1 dose of 20 units of prabotulinum toxin A (PBoNT/A); or 1 dose of 20 units of incobotulinum toxin A (IBoNT/A) into the glabellar region (GR).

Main Outcomes and Measures

The primary outcome was change in GR dynamic strain after injection over time. Secondary outcomes included changes in patient-reported satisfaction, the relationship between baseline strain severity and postinjection improvement in strain, and the effect on the strain of the untreated lateral canthal region.

Results

This study recruited 143 female individuals with a mean (SD) age of 43.5 (9.8) years. ABoNT/A and PBoNT/A had the fastest onset at day 3. PBoNT/A and IBoNT/A retained efficacy at day 180 compared with their baseline. Increasing baseline glabellar strain severity resulted in increased improvement with treatment. Lateral canthal region strain increased with decreasing GR strain. PBoNT/A was significantly more effective at day 180 than OBoNT/A. All arms experienced improvement in related FACE-Q module scores up to 90 days.

Conclusions and Relevance

This randomized clinical trial found that ABoNT/A and PBoNT/A displayed the most rapid onset of effect. The peak effect is similar across all toxins. When measuring strain at approximately 6 months, some toxins remain significant relative to their own baseline or compared with other specific toxins.

Trial Registration

ClinicalTrials.gov Identifier: NCT05167864.

IncobotulinumtoxinA for Aesthetic Treatments: Review and Recommendations From Latin America

BACKGROUND

As new aesthetic treatment techniques are developed, the understanding of botulinum toxin type A safety and treatment outcomes continues to evolve.

OBJECTIVE

This article was developed to provide a comprehensive up-to-date reference for clinicians using incobotulinumtoxinA (INCO; Xeomin/Bocouture, Merz Pharmaceuticals GmbH, Frankfurt, Germany) for aesthetic treatments.

PATIENTS AND METHODS/MATERIALS

A Latin American panel of 11 physicians was assembled to discuss and develop recommendations on the use of INCO for aesthetic treatment based on the literature review and their private medical practice.

RESULTS

The panel found that INCO is a highly purified botulinum toxin, without other clostridial proteins (hemagglutinins and nonhemagglutinins). IncobotulinumtoxinA has proven its efficacy and duration over time, maintaining response after multiple treatment cycles.

CONCLUSION

This recommendation provides up-to-date information on the use of INCO for aesthetic treatment, focusing on the differential properties of this product regarding its purity, performance, customization, and patient satisfaction.

Safety and Duration of Effect of 40-Unit PrabotulinumtoxinA-xvfs for the Treatment of Moderate to Severe Glabellar Lines in Adult Patients: A Phase II, Multicenter, Randomized, Double-Blind, Active-Controlled Trial

BACKGROUND

Extending the duration of effect of botulinum toxins-by administering doses beyond those of the approved labels-has been an area of increasing interest in the field of aesthetics.

OBJECTIVES

The aim of this study was to investigate the safety and duration of effect of 40-unit (U) prabotulinumtoxinA-xvfs (twice the approved dose and concentration) for the treatment of moderate-to-severe glabellar lines.

METHODS

A total of 154 adult patients were randomized 1:1:1 to a single treatment of either 40 U prabotulinumtoxinA-xvfs (PRA 40, 5 injections of 8 U/0.05 mL), or 20 U of either prabotulinumtoxinA-xvfs (PRA 20) or onabotulinumtoxinA (ONA 20). Both 20-U controls were administered as 5 injections of 4 U/0.1 mL. Efficacy and safety were assessed on days 2, 7 (by telephone), 30, and every 30 days thereafter up to 365 days or until the patient had returned to baseline. The primary effectiveness endpoint was the duration of effect (estimated by Kaplan-Meier analysis), defined as the number of days from treatment day (baseline) to the day that glabellar line severity at maximum frown by investigator assessment returned to the baseline value.

RESULTS

Patients had a mean age of 47 years (20-72 years); 69.5% had severe glabellar lines at baseline. Of the 36 adverse events, 32 (88.9%) were mild and 4 (11.1%) were moderate in severity; none were serious. The median durations of effect were estimated to be 183, 149, and 148 days for PRA 40-, PRA 20-, and ONA 20-treated patients, respectively.

CONCLUSIONS

In this phase 2 pilot study, 40 U prabotulinumtoxinA-xvfs was observed to be safe and had a duration of 6 months.

LEVEL OF EVIDENCE: 1

Assessment of the Efficacy and Durability of IncobotulinumtoxinA in the Treatment of the Upper Face in Adult Women

INTRODUCTION

IncobotulinumtoxinA (Xeomin®) is used in the treatment of dynamic wrinkles and the aesthetic repositioning of facial structures. The duration of its muscular effect typically extends for around 4 months. However, the residual aesthetic benefit can be observed for a longer period. To date, the long-term aesthetic benefit of incobotulinumtoxinA in facial aesthetics has not been systematically evaluated. This study aimed to evaluate longitudinally the duration and aesthetic benefits of incobotulinumtoxinA in the treatment of the upper face in adult women.

METHODS

A quasi-experimental, evaluator-blind, clinical trial involving 28 adult women (30-60 years old) with facial movement lines, undergoing treatment of the upper face with incobotulinumtoxinA by two injectors, following an individualized protocol (ONE21 and glabellar contraction patterns) was performed. Participants were evaluated on the day of the intervention (day 0) and days 30, 120, 180, and 240, and subjected to standardized photographs. The following outcomes were evaluated blindly at each visit: Merz Aesthetics Facial Contraction Scale (MAS), GAIS (Global Aesthetic Improvement Scale), and patient satisfaction. Adverse effects were evaluated at each visit.

RESULTS

Participants ranged in age from 30 to 60 years, 93% were self-declared white, and most of their baseline MAS scores for dynamic lines were moderate and severe. All the parameters presented significative reduction from baseline until day 180. At day 240, the dynamic MAS scores were lower than baseline for forehead lines in 15.4% (95% confidence interval (CI) 0.8-30.0%) of the participants, for glabellar lines in 38.5% (95% CI 18.8-58.1%), and for crow's feet lines in 26.9% (95% CI 9.0-44.8%). Aesthetic improvement compared to baseline was identified in 35% (CI 95% 23‒50%) of the participants at day 240, and 62% (CI 95% 42‒81%) of the sample kept reporting some satisfaction with the procedure.

CONCLUSION

The aesthetic treatment of the upper face with incobotulinumtoxinA demonstrates enduring clinical benefits, and patient satisfaction lasting up to 180 days in most participants. The length of efficacy, which exceeded those reported in the literature, may be attributed to the use of techniques based on individualized assessment such as ONE21 and glabellar patterns of contraction.

Update on Non-Interchangeability of Botulinum Neurotoxin Products

The growing use of botulinum neurotoxins (BoNTs) for medical and aesthetic purposes has led to the development and marketing of an increasing number of BoNT products. Given that BoNTs are biological medications, their characteristics are heavily influenced by their manufacturing methods, leading to unique products with distinct clinical characteristics. The manufacturing and formulation processes for each BoNT are proprietary, including the potency determination of reference standards and other features of the assays used to measure unit potency. As a result of these differences, units of BoNT products are not interchangeable or convertible using dose ratios. The intrinsic, product-level differences among BoNTs are compounded by differences in the injected tissues, which are innervated by different nerve fiber types (e.g., motor, sensory, and/or autonomic nerves) and require unique dosing and injection sites that are particularly evident when treating complex therapeutic and aesthetic conditions. It is also difficult to compare across studies due to inherent differences in patient populations and trial methods, necessitating attention to study details underlying each outcome reported. Ultimately, each BoNT possesses a unique clinical profile for which unit doses and injection paradigms must be determined individually for each indication. This practice will help minimize unexpected adverse events and maximize efficacy, duration, and patient satisfaction. With this approach, BoNT is poised to continue as a unique tool for achieving individual goals for an increasing number of medical and aesthetic indications.

Neuromodulators for Skin

Neurotoxins are the most popular nonsurgical aesthetic procedure for men and women of all ages. Five botulinum toxin A (BoNTA) products represent the current palette of available BoNTA for cosmetic use. Off-label uses of BoNTA continue to expand and are now used for skin rejuvenation, to treat various skin disorders, and in facial nerve paralysis. Dermal and subdermal injections of dilute BoNTA has grown in popularity and been shown to improve skin texture and quality. Common targets for chemodenervation in facial nerve synkinesis are ipsilateral orbicularis oculi, mentalis, depressor anguli oris, buccinator, corrugator muscles, and the ipsilateral and/or contralateral frontalis.

Efficacy and Safety of Botulinum Toxin Type A for Treatment of Glabellar Lines: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Botulinum toxin type A (BoNT/A) has been used in aesthetic applications worldwide, including glabellar lines. Currently, four BoNT/A preparations were approved for the improvement of moderate-to-severe glabellar lines: onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and prabotulinumtoxinA. DaxibotulinumtoxinA is a new form of BoNT/A drug that is developed in clinical application. We performed this network meta-analysis (NMA) to assess the efficacy and safety of all these different BoNT/A formulations for treating glabellar lines.

METHODS

The investigators searched randomized controlled trials (RCTs) using the Medical Subject Headings (MeSH) terms "botulinum toxin" and "glabellar lines." We searched the relevant studies in electronic databases as following: PubMed, Elsevier, EMBASE and the Cochrane Library. The end points included the percentage of subjects with a glabellar line severity (GLS) score of none (0) or mild (1), and the percentage of subjects achieving ≥ 1-point and 2-point improvement in glabellar line severity at maximum frown at approximately month 1 by the investigators' assessment.

RESULTS

All formulations of BoNT/A were far superior to placebo in efficacy. DaxibotulinumtoxinA was the only treatment that significantly increased the proportion of subjects achieving ≥ 1 point improvement in GLS score compared with other BoNT/A formulations. Moreover, daxibotulinumtoxinA was ranked the highest for the proportion of subjects achieving ≥ 2-point improvement in GLS score. No significant differences were revealed for the incidence of any adverse events (AEs) that related to treatment or drug among all BoNT/A preparations.

CONCLUSION

The overall results of this NMA suggested that daxibotulinumtoxinA is a new BoNT/A preparation that may be not only more effective but also well-tolerated for the treatment of glabellar lines.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Safety, Pharmacodynamic Response, and Treatment Satisfaction With OnabotulinumtoxinA 40 U, 60 U, and 80 U in Subjects With Moderate to Severe Dynamic Glabellar Lines

BACKGROUND

OnabotulinumtoxinA 20 U reduces glabellar line (GL) severity at maximum frown for approximately 3 to 4 months. Small studies have suggested that >20-U doses may increase the efficacy and duration of response for GLs.

OBJECTIVES

The aim of this study was to evaluate safety, pharmacodynamic response, and treatment satisfaction with onabotulinumtoxinA doses ≥20 U for GLs.

METHODS

This 48-week, double-blind study compared 40, 60, and 80 U onabotulinumtoxinA vs 20 U and placebo in women with moderate or severe dynamic GLs on the Allergan Facial Wrinkle Scale. The following parameters were evaluated: the percentage of subjects with investigator-assessed ≥1-grade Facial Wrinkle Scale improvement from baseline at maximum frown (responders) at Week 24; the estimated median duration of response; the proportion of mostly/very satisfied responders on the Facial Line Satisfaction Questionnaire follow-up Items 1 to 5; and treatment-emergent adverse events.

RESULTS

The modified intent-to-treat population (N = 226) had a mean age of 48.0 years, with similar baseline GL severity between treatment groups. Week 24 responder rates were 0% for placebo and 16.0%, 32.0%, 30.6%, and 38.5% for onabotulinumtoxinA 20, 40, 60, and 80 U, with significant (P < 0.05) differences for 40 and 80 U vs 20 U. Median duration of response was longer with all higher doses vs 20 U (≥24.0 vs 19.7 weeks; P < 0.05 vs 20 U at Week 24). Facial Line Satisfaction Questionnaire results indicated high subject satisfaction. The incidence and severity of treatment-emergent adverse events did not exhibit a dose-response effect.

CONCLUSIONS

GL treatment with onabotulinumtoxinA doses >20 U demonstrated longer duration of response and higher patient-reported satisfaction vs the on-label 20-U dose with no apparent impact on safety variables.

LEVEL OF EVIDENCE: 2

Botulinum Toxin Type A for Glabellar Frown Lines: What Impact of Higher Doses on Outcomes?

Botulinum toxin serotype-A (BoNT-A) preparations are widely used to improve the appearance of wrinkles. While effective and well tolerated, patients require retreatment over time to re-establish the effects. There is growing interest from patients as to whether higher doses can prolong response without significantly increasing side effects. We reviewed the efficacy and safety evidence for high-dose BoNT-A treatment of glabellar lines, by evaluating high-dose studies published since 2015. Toxins approved for glabellar line treatment in the US or Europe were considered. "High-dose" indicated doses above the licensed dose for each BoNT-A preparation. Five studies met the inclusion criteria and most were randomized, double-blind trials; designs and population sizes varied. Findings suggested that higher-dose BoNT-A treatment is feasible and may improve response duration without increased safety issues. Around 9 months' median duration was achieved with a 2-2.5-fold increase of the abobotulinumtoxinA on-label dose, or with a 5-fold increase in incobotulinumtoxinA dose. A 2-4-fold increase of the onabotulinumtoxinA on-label dose yielded a median duration of around 6 months. Importantly, patient satisfaction and natural look remained with increasing abobotulinumtoxinA doses. While more data are needed, these findings may lead to more effective, individually tailored treatment plans to meet patient expectations.