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

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.

Self-perception of natural outcome, appearance, and emotional well-being after OnabotulinumtoxinA treatment for upper facial lines: Post hoc analysis across age and gender

BACKGROUND

OnabotulinumtoxinA (onabotA) is indicated for upper facial lines (UFL). Fear of unnatural-looking outcomes is a frequently reported treatment barrier.

AIMS

Examine patient-reported outcomes (PROs) after onabotA treatment for UFL.

METHODS

A post hoc analysis was conducted on two 12-month pivotal studies of onabotA for forehead and glabellar lines (20 U each), with/without treatment of crow's feet lines (±24 U). This analysis used PROs from the Facial Line Satisfaction Questionnaire: Items 4 (natural look), 5 (treatment effect), 11 (met expectations), and Impact Domain (appearance and psychological impact). The analysis included 458 neurotoxin-naive adults achieving a ≥2-grade improvement in forehead line (FHL) severity on the Facial Wrinkle Scale at Day 30 (primary endpoint). [Corrections made on 28 December 2023, after first online publication: 'UFL' in the previous sentence has been corrected to 'forehead line (FHL)' in this version.] Data were further stratified into millennials and men.

RESULTS

At Day 30, 90.5% of all participants, 94.6% of millennials, and 85.7% of men were satisfied with receiving a natural look. Millennials had higher odds of being satisfied with natural outcomes at Day 30. This measure remained > 80% for all groups throughout the 12 months. Additionally, ≥80% were satisfied with the treatment effect, and >90% reported results met expectations. At Day 30, ≥50% reported positive impacts on self-perceived appearance and psychological well-being, but millennials had higher, and men had lower odds of reporting these improvements.

CONCLUSIONS

Participants achieving a ≥2-grade improvement in FHL severity after onabotA reported high satisfaction with natural outcomes and the treatment effect, with improved self-perceived appearance and psychological well-being. [Corrections made on 28 December 2023, after first online publication: 'UFL' in the previous sentence has been corrected to 'FHL' in this version.] These results may help aesthetic providers and patients address fears regarding unnatural results with onabotA.

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.

Bridging the Gap: Sustained Treatment Effect of Glabellar Lines With Twice-A-Year Treatment With DaxibotulinumtoxinA

BACKGROUND

To achieve natural-looking outcomes when treating dynamic lines with botulinum toxin (BoNT), retreatment must be timed such that the patient maintains a relatively constant aesthetic outcome. Although first-generation BoNT products require retreatment with 3- to 4-month frequency to avoid discontinuous correction, the average patient returns for treatment every 6 months, when these toxins have generally fully worn off.

OBJECTIVE

To discuss the number of days a typical patient treated with daxibotulinumtoxinA for injection (DAXI) or legacy BoNT products will spend undertreated or uncorrected in a given calendar year.

MATERIALS AND METHODS

Median time for maintaining glabellar lines in the "none" or "mild" severity range was compared for approved doses of onabotulinumtoxinA (ONA; 120 days) and DAXI (168 days).

RESULTS

The average patient treated with 40U of DAXI every 6 months can expect to be uncorrected (with "moderate" or "severe" glabellar lines) for 14.5 days between visits compared with 61.5 days for 20U of ONA.

CONCLUSION

An extended duration BoNT product can be expected to create greater consistency in aesthetic outcome and minimize the discontinuous correction commonly seen with first-generation BoNT products for patients treated twice a year, without requiring a change in patient behavior regarding visit frequency.

A technology evaluation of the atypical use of a CPP-containing peptide in the formulation and performance of a clinical botulinum toxin product

INTRODUCTION

Cell-penetrating peptides (CPPs), are small peptides that facilitate cytosolic access and, thus, transport of therapeutic macromolecules to intracellular sites when conjugated to cargo proteins. As with all new delivery platforms, clinical development of CPP-containing therapeutics has faced considerable challenges.

AREAS COVERED

RTP004 is a novel, 35-amino acid, bi-CPP-containing excipient that binds noncovalently with its cargo (botulinum toxin type A) rather than conjugated as a fusion protein. An RTP004-containing neurotoxin formulation, daxibotulinumtoxinA-lanm for injection (DAXI), has recently been approved by the FDA. The formulation and pharmacological characteristics of RTP004 and the efficacy and safety of the RTP004-neurotoxin formulation are discussed.

EXPERT OPINION

RTP004 is a highly positively charged lysine- and arginine-rich structure that provides formulation stability, preventing self-aggregation of the cargo protein and adsorption to container surfaces. The presence of RTP004 in the formulation also appears to increase presynaptic binding of the neurotoxin, reduces post-injection diffusion, and thus facilitates an increase in the cleavage of the intracellular substrate for the botulinum toxin, likely through enhanced cellular uptake. The RTP004-neurotoxin formulation is the first CPP-containing product approved for clinical use. The potential for RTP004 to facilitate other therapeutic cargo molecules requires further research.

Modulation of amygdala activity for emotional faces due to botulinum toxin type A injections that prevent frowning

According to the facial feedback hypothesis, when we see an angry or happy face, we contract or flex the relevant muscles to recreate the expression to assist in identifying and experiencing the emotion reflected. We investigated the facial feedback hypothesis by using botulinum toxin type A (onabotulinumtoxinA; onabotA) injections to induce temporary paralysis in the glabellar muscles (responsible for frowning) and measured functional brain activity during the processing of emotional faces. Ten females viewed pictures of happy and angry faces during two functional magnetic resonance imaging (fMRI) scan sessions: one prior (Pre) to onabotA and one following (Active) onabotA injections. We found Pre vs. Active onabotA modulation of activity in the amygdala for both happy and angry faces, as well as modulation of activity in the fusiform gyrus for happy faces. Consistent with our predictions, preventing frowning through inhibition of glabellar muscle contraction altered amygdala processing for emotional faces. The modulation of amygdala and fusiform gyrus activity following onabotA may reflect compensatory processes in a neuroanatomical circuit involved in emotional processing that is engaged when facial feedback is impaired. These data contribute to a growing literature suggesting that inhibition of glabellar muscle contraction alters neural activity for emotional processing.Clinical Trials.gov registration number: NCT03373162.