Clinical comparability of marketed formulations of botulinum toxin

Current Insights into the Formulation and Delivery of Therapeutic and Cosmeceutical Agents for Aging Skin

“Successful aging” counters the traditional idea of aging as a disease and is increasingly equated with minimizing age signs on the skin, face, and body. From this stems the interest in preventative aesthetic dermatology that might help with the healthy aging of skin, help treat or prevent certain cutaneous disorders, such as skin cancer, and help delay skin aging by combining local and systemic methods of therapy, instrumental devices, and invasive procedures. This review will discuss the main mechanisms of skin aging and the potential mechanisms of action for commercial products already on the market, highlighting the issues related to the permeation of the skin from different classes of compounds, the site of action, and the techniques employed to overcome aging. The purpose is to give an overall perspective on the main challenges in formulation development, especially nanoparticle formulations, which aims to defeat or slow down skin aging, and to highlight new market segments, such as matrikines and matrikine-like peptides. In conclusion, by applying enabling technologies such as those delivery systems outlined here, existing agents can be repurposed or fine-tuned, and traditional but unproven treatments can be optimized for efficacious dosing and safety.

AbobotulinumtoxinA Versus OnabotulinumtoxinA in Adults with Upper Limb Spasticity: A Randomized, Double-Blind, Crossover Study Protocol

INTRODUCTION

The safety and efficacy of both abobotulinumtoxinA and onabotulinumtoxinA for upper limb spasticity are well established, but head-to-head comparisons are lacking.

METHODS

DIRECTION is an international, randomized, double-blind, crossover study comparing the safety and efficacy of abobotulinumtoxinA with onabotulinumtoxinA in the management of upper limb spasticity at doses at or near maximum recommended in product labelling. Participants (18-75 years) will be randomized (1:1) to either one cycle of abobotulinumtoxinA (900U) followed by onabotulinumtoxinA (360U) or vice versa. To maintain blinding, a fixed volume (3.6 ml) will be injected into the target upper limb muscles (four wrist and finger flexors and biceps brachii). The second treatment cycle will begin at Week 12 if retreatment criteria are fulfilled, and if not, they will be reassessed every 4 weeks until they meet retreatment parameters.

PLANNED OUTCOMES

The primary hypothesis is that there is comparable safety between products; non-inferiority will be tested based on treatment-emergent adverse event (TEAE) rates from injection to Week 12. A secondary hypothesis is that abobotulinumtoxinA has longer duration of effect than onabotulinumtoxinA. This hypothesis will be tested with secondary efficacy endpoints, including injection cycle duration, Modified Ashworth Scale, Disability Assessment Scale and Physician Global Assessment.

TRIAL REGISTRATION

EudraCT ( http://eudract.ema.europa.eu ): 2021-000161-32 and Clinicaltrials.gov ( http://clinicaltrials.gov ): NCT04936542. Overview of the study protocol by the principal investigator (MP4 185265 KB).

Best Practices in the Clinical Management of Progressive Supranuclear Palsy and Corticobasal Syndrome: A Consensus Statement of the CurePSP Centers of Care

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS; the most common phenotype of corticobasal degeneration) are tauopathies with a relentless course, usually starting in the mid-60s and leading to death after an average of 7 years. There is as yet no specific or disease-modifying treatment. Clinical deficits in PSP are numerous, involve the entire neuraxis, and present as several discrete phenotypes. They center on rigidity, bradykinesia, postural instability, gait freezing, supranuclear ocular motor impairment, dysarthria, dysphagia, incontinence, sleep disorders, frontal cognitive dysfunction, and a variety of behavioral changes. CBS presents with prominent and usually asymmetric dystonia, apraxia, myoclonus, pyramidal signs, and cortical sensory loss. The symptoms and deficits of PSP and CBS are amenable to a variety of treatment strategies but most physicians, including many neurologists, are reluctant to care for patients with these conditions because of unfamiliarity with their multiplicity of interacting symptoms and deficits. CurePSP, the organization devoted to support, research, and education for PSP and CBS, created its CurePSP Centers of Care network in North America in 2017 to improve patient access to clinical expertise and develop collaborations. The directors of the 25 centers have created this consensus document outlining best practices in the management of PSP and CBS. They formed a writing committee for each of 12 sub-topics. A 4-member Steering Committee collated and edited the contributions. The result was returned to the entire cohort of authors for further comments, which were considered for incorporation by the Steering Committee. The authors hope that this publication will serve as a convenient guide for all clinicians caring for patients with PSP and CBS and that it will improve care for patients with these devastating but manageable disorders.

The efficacy of botulinum toxin A treatment for tension-type or cervicogenic headache: a systematic review and meta-analysis of randomized, placebo-controlled trials

OBJECTIVES

The pathogeneses of chronic tension-type headache (CTTH) and cervicogenic headache (CEH) are not well established. Peripheral activation or sensitization of myofascial nociceptors is suggested as a potential mechanism and injections of botulinum toxin (BONTA) have thus been used in the treatment for both headache conditions. BONTA inhibits the release of acetylcholine at the neuromuscular junction and inhibits contraction of skeletal muscles. If the pain is precipitated by increased tone in cervical muscles, local injections of BONTA could represent a prophylactic measure. However, the treatment is still controversial, and a thorough assessment of the current evidence is required. This review aims to assess the evidence of BONTA injection as a prophylactic treatment for CTTH and CEH by reviewing and examining the quality of placebo-controlled, randomized trials.

METHODS

Data sources: we searched in the following databases: PubMed (including Medline), Embase, Cochrane Central register of Controlled Trials, Cinahl, Amed, SCOPUS and Google Scholar including other repository sources. Both MeSH and free keywords were used in conducting the systematic search in the databases. The search covered publications from the root of the databases to November 2020.

STUDY ELIGIBILITY CRITERIA

The review included RCTs, comparing single treatment of BONTA with placebo on patients with CTTH or CEH above 18 years of age, by measuring pain severity/relief or headache frequency.

DATA EXTRACTION

The following data were extracted: year of publication, country, setting, trial design, number of participants, injection procedure, BONTA dosages, and clinical outcome measures.

STUDY APPRAISAL

To assess validity and quality, and risk of bias, the Oxford Pain Validity Scale, Modified Jadad Scale, last version of Cochrane Collaboration's tool for assessing risk of bias (RoB 2), and the CONSORT 2010 Checklist were used. The trials were assessed, and quality scored independently by two of the reviewers. A quantitative synthesis and meta-analyses of headache frequency and intensity were performed.

RESULTS

We extracted 16 trials, 12 on prophylactic BONTA treatment for CTTH and four on CEH. Of these 12 trials (8 on CTTH and 4 on CEH) were included in the quantitative synthesis. A majority of the trials found no significant difference on the primary outcome measure when BONTA treatment was compared with placebo. Three "positive" trials, reporting significant difference in favor of BONTA treatment, but two of these were hampered by low validity and quality scores and high risk of bias.

CONCLUSIONS

There is no clear clinical evidence supporting prophylactic treatment with BONTA for CTTH or CEH.

Botulinum toxin type A for the treatment of dyssynergic defaecation in adults: a systematic review

AIM

Dyssynergic defaecation (DD) is characterized by inappropriate coordination of the pelvic floor muscles during defaecation, resulting in impaired stool expulsion. The mainstay of treatment is biofeedback and alternative therapies are limited in those who do not respond. This systematic review evaluated botulinum toxin type A injection (BTXA) as a treatment option for dyssynergia.

METHODS

PubMed, Embase and Cochrane Central Register of Controlled Trials were searched for studies evaluating adult patients with DD treated with BTXA injection into the puborectalis and/or external anal sphincter. All study designs, except case reports, were included in the review with no language restriction. Studies limited to patients with specific neurological diagnoses or with a follow-up period under 1 month were excluded. Study selection, assessment and data extraction were performed by two reviewers and results were synthesized narratively.

RESULTS

Eleven studies (three randomized control trials) involving 248 participants were included. All studies used the transanal approach to deliver the injection, most commonly at the 3 and 9 o'clock positions using digital palpation for guidance. The most commonly used patient position was left lateral, and most studies did not use any anaesthesia. The dose of BTXA varied (Botox 12-100 units, Dysport 100-500 units), and outcomes measured were heterogeneous (global rating ± up to five investigations). Symptomatic improvement varied between 29.2% and 100% and adverse effects occurred in 0% to 70%.

CONCLUSION

The evidence to support using BTXA for DD is poor and only covers a transanal approach. Future studies should redress these limitations: heterogeneity of design, dose and outcome measures.

A review on iatrogenic botulism

Background:

With the flourishing application of botulinum toxin cosmetically and therapeutically is the emergence of iatrogenic botulism, a new type of botulism in addition to the traditional ones.

Objectives:

We aim at a comprehensive review of the clinical characteristics of iatrogenic botulism. Methods: The available publications are retrieved and studied.

Results:

Botulinum toxin blocks cholinergic transmission in the neuromuscular junctions and autonomic ganglia. The blockade can spread from the site of tissue injection to adjacent or sometimes far off structures, resulting in inadvertent disabling or even lethal effects. On literature review, weakness and dysphagia are the commonest complications of iatrogenic botulism, whereas ophthalmological and oropharyngeal symptoms are more prevalent in the cosmetic group and dyspnea in the therapeutic group. Antitoxin therapy is required in about 20% of the patients. Diagnosis of iatrogenic botulism is primarily clinical and should not be confused with the neurological diagnoses possessing similar clinical manifestations. Vigilance to the drug formulation, dosage, and administration during botulinum toxin injection are part of the preventive measures in minimizing the occurrence of iatrogenic botulism.

Conclusion:

While overlapping with the traditional types of botulism, iatrogenic botulism carries its unique clinical characteristics.

A retrospective study on comparing the surgery and microneedles radiofrequency and microwaves treatment in axillary osmidrosis

Objective: To compare the traditional treatment of minimally invasion surgery with the evolving treatments of microneedles radiofrequency and microwaves, this study mainly focused on the clinical efficacy and the incidence rate (IR) of complications among three treatments.Methods: From August 2017 to August 2018, a total of 76 patients with bilateral axillary osmidrosis were enrolled respectively underwent minimally invasion surgery, microneedles radiofrequency and microwaves treatment. All these subjects were evaluated the clinical outcomes and collected the complications by themselves or physicians. The difference of objective recovery or effective rate, subjective effective rate, the intense of sweat secretion or armpits hair, IR of complications among these three groups were studied.Results: The baseline characteristics of 33 patients in surgery group, 24 patients in microneedles group and 19 patients in microwaves group were similar. Firstly, the objective clinical efficacy was similar, but the subjective effective rate in surgery group was the soundest. In addition, the reduction of sweat secretion was homologous in three group, but the intense of armpits hair reduction in microneedles group was the minimum in three groups. Moreover, surgery treatment caused the highest IR of complications and the broadest types of complications, especially for the IR of 87.9% in postoperative scar formation. Meanwhile, the microwaves treatment had the best safety profile. At last, the recurrence rate on 6 months postoperatively was also identical with no significant difference.Conclusions: For the advantages and disadvantages of these three treatments, axillary osmidrosis patients should choose the proper therapy with comprehensive considerations.

Progress in Applying the Three Rs to the Potency Testing of Botulinum Toxin Type A

Botulinum toxin type A (BTA) is being increasingly used for a range of therapeutic purposes and also for cosmetic reasons. For many years, the potency of BTA has been measured by using an LD50 assay in mice. This assay is a cause for concern due to its unpleasant nature and extreme severity, and the requirement for high numbers of mice to be used. Alternatives to this potency assay are presently reviewed with particular reference to the work at the National Institute for Biological Standards and Control (NIBSC), and to recent work by the UK manufacturer of the substance. An in vivo local paralysis assay with considerably less severity has been developed and is in use at the NIBSC. Alternative, ex vivo functional assays in use include the measurement of BTA-induced paralysis of neurally-stimulated rodent diaphragm or rat intercostal muscle. The latter method has the advantage of allowing more preparations to be derived from one animal. However, these ex vivo methods have not yet been fully validated and accepted by regulatory agencies as potency assays. Endopeptidase assays, although not measuring muscle paralysis directly, may provide a very useful consistency test for batch release and may replace the routine use of the LD50 test for that purpose. These assays measure the cleavage of the SNAP-25 protein (the final stage of BTA action), and have been validated for batch release by the National Control Laboratory (NIBSC), and are in regular use there. ELISA assays, used alongside the endopeptidase assay, also provide useful confirmatory information on the amounts of functional (and non-functional) BTA present. The UK manufacturer is further validating its endopeptidase assay, an ex vivo muscle assay and an ELISA. It is anticipated that their work will lead to a change in the product license, hopefully within the next two years, and will form a critical milestone towards the end of the LD50 potency test.

Botulinum Toxin Treatment for Mild to Moderate Platysma Bands: A Systematic Review of Efficacy, Safety, and Injection Technique

Background

Platysma bands are characteristic of an aging neck. Resection and plication of the platysma muscle is the basis of treatment. However, unfavorable surgical outcomes and improved understanding of platysma band etiology have shifted treatment towards nonsurgical rejuvenation.

Objectives

The aim of this paper was to assess the efficacy, injection techniques, and complications associated with botulinum toxin injection for the treatment of platysma bands.

Methods

A systematic literature search was performed to identify articles reporting botulinum toxin injections for platysma bands in neck rejuvenation. The search included published articles in three electronic databases-Ovid MEDLINE, EMBASE, and the Cochrane Library-between January 1985 and December 2017.

Results

Three studies met the inclusion criteria, with a total of 78 patients undergoing botulinum toxin injection for platysma bands. Incobotulinumtoxin A was used in 62.3% (n = 45/78) of patients, with 38.4% (n = 30/78) receiving abobotulinumtoxin A. Efficacy was assessed using the Merz platysma score scale. A mean score improvement of 2.0 points, with a response rate of 93.7%, was observed after 14 ± 2 days. At 3 months, the mean score improvement was 1.2 points with a response rate of 86%. Patient-reported metrics demonstrated an improvement in 91% (n = 71/78) of subjects. The three studies used a standard injection technique, with a maximum 20 IU of incobotulinumtoxin A and 5 U abobotulinumtoxin A administered per band. Complications were reported in 15.4% (n = 12/78) of patients, with none requiring further intervention.

Conclusions

Botulinum toxin is a highly effective treatment for isolated platysma bands. A safe injection technique is described and recommended for clinical practice.

Level of Evidence 4

Pharmacological differences and clinical implications of various botulinum toxin preparations: a critical appraisal

Three different type A botulinum neurotoxins (BoNTAs) - onabotulinumtoxinA, abobotulinumtoxinA and incobotulinumtoxinA) - are currently marketed in Europe to treat several conditions. Differences between BoNTA preparations, which depend on their specific biotypes and manufacturing processes, lead to clinically relevant pharmacotherapeutic dissimilarities. All three available products are separately recognized and reviewed in American Academy of Neurology guidelines. The neurotoxin load/100U is likewise different among the different BoNTAs, with the result that the specific potency of the 150kD BoNTA neurotoxin is calculated as 137 units/ng for onabotulinumtoxinA, 154 units/ng for abobotulinumtoxinA, and 227 units/ng for incobotulinumtoxinA. It is important for clinicians to have all three BoNTAs available in order to choose the most suitable preparation for the specific indication in the single patient. Commercially available BoNTAs must be recognized as different from one another, and therefore as non-interchangeable. The essential experience of the clinician is of the utmost importance in choosing the most appropriate treatment.

To switch from Botox to Dysport in children with CP, a real world, dose conversion, cost-effectiveness study

BACKGROUND AND OBJECTIVES

Children with cerebral palsy (CP) are routinely treated with botulinum toxin A (BoNT-A). Two non dose-equivalent and differently priced products, Botox and Dysport are used. Depending on the conversion one of the products is considerably cheaper. However, the dose conversion factors studied to date have varied widely and relevant studies have not included children. Our objective here was to compare the efficacy and health economics of the switch from Botox to Dysport in children with CP when conversion was set to 1:2. Specifically were these treatments perceived as equivalent in terms of efficacy, duration and side-effects and were the drug cost lowered by using Dysport.

METHODS

This prospective, real-world, cost-effectiveness population-based observational study included all children with CP, (n = 159) mean age 9.4 years (SD, 4.3), in the larger Stockholm area who received BoNT-A between September 1, 2014, and December 31, 2015. Parents reported the efficacy, duration and side-effects of previous treatment while physicians reported doses and goals set by children and parents for the present treatment. Drug acquisition costs were provided by county administrators.

RESULTS

In connection with 341 visits caregivers reported comparable effects of similar duration with these products, with few, similar and transient side-effects. The drug-cost per treatment was 4029 SEK for Botox and 2380 SEK in the case of Dysport.

CONCLUSION

When Botox was replaced by a two-fold higher Unit dose of Dysport (conversion 1:2) parents perceived the treatment of their children with CP to be equally effective while the cost was 41% lower according to procured prices.

Changes in Management of Poorly Compliant Bladder in Botulinum Toxin A Era

Bladder compliance is a measure of distensibility. Maladies such as myelodysplasia, myelomeningocele, spinal cord injury, multiple sclerosis and obstructive uropathy are known to decrease bladder compliance. Decrease in bladder compliance is a characteristic of neurogenic bladders. The pathophysiology of bladder compliance is complex but ultimately leads to high pressure during filling and storage phases. These high pressures lead to renal impairment, incontinence, and recurrent urinary tract infections. This review presents management of poorly compliant bladders with onabotulinumtoxinA.

[Conversion ratio between different botulinum neuroprotein product in neurological practice]

Despite nearly 30 years of experience in the application of botulinum toxin type A (BTA) in clinical practice, many fundamental questions of therapy remain valid. There are 5 botulinum toxin type A used for neurological indications in the Russian Federation in 2017. They contain different number of active neuroprotein (150 kDa) in a therapeutic dose of the drug that may have a potential impact on the efficacy and duration of action. The current SmPC of each BTA stated that the unit of activity is unique and can not be compared with any other BTA. In scientific publications one can find many details concerning the equivalence doses of onabotulinumtoxin A (botox) and abobotulinumtoxin A (dysport) and the ratio of units varies from 1:1 to 1:11. However, according to clinical guidelines, systematic reviews and high quality research evidence of recent years, the ratio of units of abobotulinumtoxin A (dysport) and onabotulinumtoxin A (botox) is 3(2,5):1. Use of a fixed ratio of units is possible only when switching from one drug to another or in case of limiting access to specific drug. Botulinum toxin type A is the first line of therapy in the treatment of several neurological diseases. The most commonly used drugs of botulinum toxin type A (botox, dysport, xeomin) have a significant evidence base that confirms their efficacy and optimal safety profile. The main difference between botulinum toxin type A is their potential activity of action, i.e., activity units and total therapeutic dose.

Switch to Abobotulinum toxin A may be useful in the treatment of neurogenic detrusor overactivity when intradetrusor injections of Onabotulinum toxin A failed

AIMS

To assess the outcomes of switching to a different brand of botulinum toxin A (BTA, from Botox® to Dysport®) in case of failure of intradetrusor injections (IDI) of Botox® in the treatment of neurogenic detrusor overactivity (NDO).

METHODS

The charts of all patients who underwent a switch to IDI of Dysport® after failure of an IDI of Botox® at six departments of neurourology were retrospectively reviewed. The main outcomes of interest were the bladder diary data and four urodynamic parameters: maximum cystometric capacity (MCC), maximum detrusor pressure (PDET max), and volume at first uninhibited detrusor contraction (UDC).

RESULTS

Fifty-seven patients were included. After the first injection of Dysport®, no adverse events were reported. A significant decrease in number of urinary incontinence episodes per day was observed in 52.63% of patients (P < 0.001) and all patients experienced a reduction in PDET Max (-8.1 cmH20 on average; P = 0.003). MCC significantly increased by a mean of 41.2 (P = 0.02). The proportion of patients with no UDC increased significantly at week 6 after ATA injections (from 15.79% to 43.9%; P = 0.0002). Hence, 32 patients draw clinical and/or urodynamic benefits from the botulinum toxin switch from (56.14%). After a median follow up of 21 months, 87% of responders to BTA switch were still treated successfully with BTA.

CONCLUSION

Most patients refractory to Botox® (56.14%) draw benefits from the switch to Dysport®.

Use of botulinum toxin for voiding dysfunction

The use of botulinum toxin A (BoNT-A) has expanded across a range of lower urinary tract conditions. This review provides an overview of the current indications for BoNT-A in the lower urinary tract and critically evaluates the published evidence within each area. The classic application of BoNT-A has been in the management of refractory neurogenic detrusor overactivity (NDO) and overactive bladder (OAB). There is a large volume of high-quality evidence, including numerous randomized placebo-controlled trials, which demonstrate the efficacy of BoNT-A over a long follow-up period. The culmination of this robust evidence-base has led to onabotulinumtoxin A (onaBoNT-A) receiving regulatory approval as a second-line treatment for NDO at a dose of 200 U and OAB at dose of 100 U. Other applications for BoNT-A are used on an off-license basis and include interstitial cystitis/bladder pain syndrome (IC/BPS), benign prostatic hyperplasia (BPH), and detrusor sphincter dyssynergia (DSD). These applications are associated with a less mature evidence-base although the literature is rapidly evolving. At present, the results for painful bladder syndrome (PBS) are promising and BoNT-A injections are recommended as a fourth line option in recent international guidelines, although larger randomized study with longer follow-up are required to confirm the initial findings. As a treatment for DSD, BoNT-A injections have shown potential but only in a small number of trials of limited quality. No definite recommendation can be made based on the current evidence. Finally, the results for the treatment of BPH have been variable and recent high quality randomized controlled trials (RCTs) have suggested no benefit over placebo so at present it cannot be recommended for routine clinical practice. Future advances of BoNT-A include liposome encapsulated formulations which are being developed as an alternative to intravesical injections.

Medium- to long-term outcomes of botulinum toxin A for idiopathic overactive bladder

Botulinum toxin A (BoNT-A) has become an important therapeutic tool in the management of refractory overactive bladder (OAB). Over the last decade, there have been growing numbers of patients receiving repeat injections and these outcomes have begun to be reported in large, high-quality cohorts. This article reviews the current evidence for the medium- to long-term use of BoNT-A in adults with idiopathic detrusor overactivity (IDO) receiving repeat injections. We find that medium-term outcomes are encouraging but long-term outcomes are not as extensively reported. There is high-quality evidence that efficacy following the first injection persists across multiple treatment cycles. There are no additional safety concerns from repeat injections up to six treatment cycles. However, there is a need for further data to confirm the efficacy and safety of BoNT-A beyond the follow-up period in the current literature.

Treatment of Primary Axillary Hyperhidrosis by Fractional Microneedle Radiofrequency: Is it Still Effective after Long-term Follow-up?

Background:

Primary axillary hyperhidrosis (PAH) is a chronic idiopathic disorder causing major stress in patients. Among the common therapies for PAH, only surgical interventions have proven feasible as a permanent solution.

Objective and Aim:

The aim of this study was to evaluate the efficacy and safety of fractional microneedle radiofrequency (FMR) as an alternative permanent treatment for PAH with long-term follow-up.

Materials and Methods:

This was a single-blind, sham-controlled comparative study. Twenty-five patients with severe PAH were provided three treatments of FMR at 3-week intervals (the treatment group), and a control group was provided the sham treatment. Clinical efficacy was evaluated using the hyperhidrosis disease severity scale (HDSS) at baseline and the end of the study, as well as during the 1 year follow-up phase.

Results:

HDSS demonstrated significant improvement after treatment in the treatment group compared to the sham control. The mean (±standard deviation) of HDSS in the group being treated with radiofrequency was 2.50 (±0.88) after 1 year follow-up, and that of the control group was 3.38 (±0.49; P < 0.001). Follow-up results show that there were 10 patients (41.6%) with no relapse and 11 patients (45.9%) with relapse after 1 year. There was a significant correlation between HDSS changes in relapse and body mass index (BMI) (P = 0.03).

Conclusion:

Treatment of PAH with FMR is a safe and noninvasive procedure with a positive therapeutic effect on HDSS. It is recommended, however, that sessions of FMR be repeated after 1 year, particularly in overweight patients with high BMIs.

Clinical Trial Registration:

IRCT2013111915455N1.

Level of Evidences:

Level II-1.

Conversion Ratio between Botox®, Dysport®, and Xeomin® in Clinical Practice

Botulinum neurotoxin has revolutionized the treatment of spasticity and is now administered worldwide. There are currently three leading botulinum neurotoxin type A products available in the Western Hemisphere: onabotulinum toxin-A (ONA) Botox(®), abobotulinum toxin-A (ABO), Dysport(®), and incobotulinum toxin A (INCO, Xeomin(®)). Although the efficacies are similar, there is an intense debate regarding the comparability of various preparations. Here we will address the clinical issues of potency and conversion ratios, as well as safety issues such as toxin spread and immunogenicity, to provide guidance for BoNT-A use in clinical practice. INCO was shown to be as effective as ONA with a comparable adverse event profile when a clinical conversion ratio of 1:1 was used. The available clinical and preclinical data suggest that a conversion ratio ABO:ONA of 3:1-or even lower-could be appropriate for treating spasticity, cervical dystonia, and blepharospasm or hemifacial spasm. A higher conversion ratio may lead to an overdosing of ABO. While uncommon, distant spread may occur; however, several factors other than the pharmaceutical preparation are thought to affect spread. Finally, whereas the three products have similar efficacy when properly dosed, ABO has a better cost-efficacy profile.

Systematic Literature Review of AbobotulinumtoxinA in Clinical Trials for Blepharospasm and Hemifacial Spasm

Background

The aim was to elucidate clinical trial efficacy, safety, and dosing practices of abobotulinumtoxinA (ABO) treatment in adult patients with blepharospasm and hemifacial spasm. To date, most literature reviews for blepharospasm and hemifacial spasm have examined the effectiveness of all botulinum neurotoxin type A products as a class. However, differences in dosing units and recommended schemes provide a clear rationale for reviewing each product separately.

Methods

A systematic literature review was performed to identify randomized controlled trials and other comparative clinical studies of ABO in the treatment of blepharospasm and hemifacial spasm published in English between January 1991 and March 2015. Medical literature databases (PubMed, Cochrane library, EMBASE) were searched. A total of five primary publications that evaluated ABO for the management of blepharospasm and hemifacial spasm were identified and summarized.

Results

Data included 374 subjects with blepharospasm and 172 subjects with hemifacial spasm treated with ABO. Total ABO doses ranged between 80 and 340 U for blepharospasm and 25 and 85 U for hemifacial spasm, depending on the severity of the clinical condition. All studies showed statistically significant benefits for the treatment of blepharospasm and hemifacial spasm. ABO was generally well tolerated across the individual studies. Adverse events considered to be associated with ABO treatment included: ptosis, tearing, blurred vision, double vision, dry eyes, and facial weakness.

Discussion

These data from 5 randomized clinical studies represents the available evidence base of ABO in blepharospasm and hemifacial spasm. Future studies in this area will add to this evidence base.

Botulinum toxin in the management of blepharospasm: current evidence and recent developments

Blepharospasm is a focal (although usually bilateral) dystonia of the orbicularis oculi muscles, producing excessive eye closure. This produces significant disability through functional blindness. Botulinum neurotoxins (BoNT) have become the treatment of choice for blepharospasm; the impressive response rate and the tolerable safety profile have been proven through multiple clinical studies. There are currently four BoNT approved in the United States for different indications - we review the data on blepharospasm for each of these drugs. Currently, incobotulinumtoxinA and onabotulinumtoxinA have the most evidence of benefit for patients with blepharospasm. Current evidence, recent development and future directions are discussed.

Comparison of the efficacy of onabotulinumtoxinA and abobotulinumtoxinA at the 1: 3 conversion ratio for the treatment of asymmetry after long-term facial paralysis

BACKGROUND

Botulinum toxin A injection into the nonparalyzed side is used to treat asymmetry resulting from facial palsy. OnabotulinumtoxinA and abobotulinumtoxinA units are not equivalent. The authors compared the conversion ratio of 1:3 in patients with facial palsy.

METHODS

Fifty-five patients (age, 16 to 67 years; 43 women) with longstanding facial palsy were randomly treated with either onabotulinumtoxinA (n = 25) or abobotulinumtoxinA (n = 30) injections into the nonparalyzed side. Adverse effects, facial symmetry, subjective satisfaction, and Facial Disability Index were assessed after 1 and 6 months.

RESULTS

The incidence of adverse effects was higher with abobotulinumtoxinA (93.3 percent versus 64.0 percent; p = 0.007). Clinical scores of the nonparalyzed side decreased after 1 month and increased again at 6 months, with no between-group differences. Scores of the paralyzed side were lower in the onabotulinumtoxinA group before treatment, but similar in both groups thereafter. The paralyzed side scores increased after 1 month, and at 6 months were still higher than the pretreatment scores in both groups. Subjective assessment improved at all time points compared with pretreatment scores and differed between the two groups only at 1 month, when the abobotulinumtoxinA group was a bit too paralyzed. The physical function and social/well-being function subscales of the Facial Disability Index did not differ between the two groups.

CONCLUSIONS

Both toxins efficiently reduced asymmetry in patients with facial palsy. Adverse effects were higher with abobotulinumtoxinA at an equivalence ratio of 1:3.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Botulinum toxin for the treatment of refractory erythema and flushing of rosacea

BACKGROUND

Persistent erythema and severe rosacea flushing can cause significant physical discomfort and emotional stress to patients. Currently, no satisfactory treatments are available.

METHODS

We report two cases of refractory flushing and erythema of rosacea that were successfully treated with intradermal botulinum toxin injections.

RESULTS

Good cosmetic results were achieved for both patients. The side effects during and after treatment were mild pain and localized bruising; these symptoms resolved within several days without further treatment.

CONCLUSION

Intradermal botulinum toxin injection may be an effective treatment for refractory erythema and rosacea flushing that deserves further study in a larger patient population.

Fractionated microneedle radiofrequency for treatment of primary axillary hyperhidrosis: A sham control study

BACKGROUND/ OBJECTIVE

Primary axillary hyperhidrosis (PAH) creates social stress in patients. Although there are several options for treating PAH, only surgical modalities have conferred a permanent solution. This study evaluated the clinical effectiveness of fractionated microneedle radiofrequency (FMR) treatment for PAH.

METHODS

This study is based on a single-blind, sham control comparative design. In all, 25 patients with severe PAH underwent three sessions of FMR at 3-week intervals. One side was treated with FMR while the other was sham controlled. Efficacy was evaluated using the hyperhidrosis disease severity scale (HDSS), sweating intensity visual analogue scale (VAS) and patient satisfaction at baseline, 3 weeks after each session and at 3 months after the last. Skin biopsies were obtained from two enrolled patients.

RESULTS

The HDSS and VAS demonstrated significant improvement after treatment on the treated side in comparison with the control side. The mean ± SD of the HDSS after 21 weeks were 1.87 ± 0.61 and 3.38 ± 0.49 (P < 0.001) for the treated and the controlled side, respectively. The follow-up evaluation revealed that 79% of the patients showed a 1 or 2-score decrease in HDSS. In total, 80% of patients reported more than 50% satisfaction at the end of the study. Histopathological findings showed a decrease of the number of the sweat glands in the treated side, confirming the above findings.

CONCLUSIONS

Treatment of PAH with FMR as a non-invasive modality can be a safe option with positive therapeutic effects on HDSS without any long-lasting side effects.

Dysport and Botox at a ratio of 2.5:1 units in cervical dystonia: a double-blind, randomized study

We aimed to compare Dysport (abobotulinumtoxinA, Ipsen Biopharm, Slough, UK) and Botox (onabotulinumtoxinA, Allergan, Irvine, CA, USA) at a 2.5:1 ratio in the treatment of cervical dystonia (CD). A Dysport/Botox ratio of lower than 3:1 was suggested as a more appropriate conversion ratio, considering its higher efficacy and more frequent incidence of adverse effects not only in the treatment of CD but also in other focal movement disorders. A randomized, double-blind, multicenter, non-inferiority, two-period crossover study was done in CD, with a duration of at least 18 months. Patients were randomly assigned to treatment for the first period with Dysport or Botox, and they were followed up for 16 weeks after the injection. After a 4-week washout period, they were switched to the other formulation and then followed up for 16 weeks. The primary outcome was the changes in the Tsui scale between the baseline value and that at 1 month after each injection. A total of 103 patients were enrolled, and 94 completed the study. Mean changes in the Tsui scale between baseline and 4 weeks after each injection tended to favor Botox; however, this was not statistically significant (4.0 ± 3.9 points for the Dysport treatment vs. 4.8 ± 4.1 points for Botox; 95% confidence interval, −0.1-1.7; P = 0.091). The mean change of the Toronto western spasmodic torticollis rating scale score, the proportion of improvement in clinical global impression and patient global impression, and the incidences of adverse events were not significantly different between the two treatments. With regard to safety and efficacy, Dysport was not inferior to Botox in patients with CD at a conversion factor of 2.5:1. [http//clinicaltrial.gov: NCT00950664] © The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Botulinum toxin type A products are not interchangeable: a review of the evidence

Botulinum toxin type A (BoNTA) products are injectable biologic medications derived from Clostridium botulinum bacteria. Several different BoNTA products are marketed in various countries, and they are not interchangeable. Differences between products include manufacturing processes, formulations, and the assay methods used to determine units of biological activity. These differences result in a specific set of interactions between each BoNTA product and the tissue injected. Consequently, the products show differences in their in vivo profiles, including preclinical dose response curves and clinical dosing, efficacy, duration, and safety/adverse events. Most, but not all, published studies document these differences, suggesting that individual BoNTA products act differently depending on experimental and clinical conditions, and these differences may not always be predictable. Differentiation through regulatory approvals provides a measure of confidence in safety and efficacy at the specified doses for each approved indication. Moreover, the products differ in the amount of study to which they have been subjected, as evidenced by the number of publications in the peer-reviewed literature and the quantity and quality of clinical studies. Given that BoNTAs are potent biological products that meet important clinical needs, it is critical to recognize that their dosing and product performance are not interchangeable and each product should be used according to manufacturer guidelines.

Long-term efficacy and safety of botulinum toxin A injections to treat blepharospasm and hemifacial spasm

BACKGROUND

To evaluate efficacy and safety of botulinum toxin A injections after more than 10 consecutive years of treatment for benign essential blepharospasm and hemifacial spasm.

DESIGN

Retrospective chart review at university-affiliated hospital.

PARTICIPANTS

Study consisted of 64 patients treated with botulinum toxin A injections between October 2005 and May 2006.

METHODS

Inclusion criteria included patients treated with at least one annual botulinum toxin-A injection for more than 10 consecutive years. Data collected included diagnoses and patient characteristics, injection dates, doses administered at each visit, response scores, duration of effect, and adverse events.

MAIN OUTCOME MEASURES

Included changes in doses, response scores, duration of effects, and adverse events between the first and last botulinum toxin A injections.

RESULTS

Thirty-two of 64 patients (mean age at first injection, 57.2 ± 12.4 years; 25 women) met the inclusion criteria. The mean duration of follow up was 14.1 ± 3.1 years (range 10-20 years; mean total visits 44.4 ± 19). A higher mean injection dose per visit was administered during the last year compared with the first year (26.8 ± 10.3 vs. 22.5 ± 7.5 units, respectively) (P = 0.003). The mean durations of effect during the first and last years were 12.4 ± 7.1 and 14.6 ± 7.0 weeks, respectively (P = 0.076). There were no significant differences between genders or between benign essential blepharospasm and hemifacial spasm subgroups. The most common adverse events were ptosis, lagophthalmos and dry eye.

CONCLUSIONS

Botulinum toxin A is an effective, safe, long-term treatment for patients with benign essential blepharospasm and hemifacial spasm. Sustained treatment efficacy required higher doses; however, fewer adverse reactions developed.

Abo-, inco-, ona-, and rima-botulinum toxins in clinical therapy: a primer

Botulinum neurotoxin (BoNT) is an acetylcholine release inhibitor and a neuromuscular-blocking agent used for the treatment of a variety of medical and cosmetic indications. Currently, in the United States, there are four BoNT formulations licensed for use: abobotulinumtoxinA, incobotulinumtoxinA, onabotulinumtoxinA, and rimabotulinumtoxinB. These revised name designations were established to reinforce the understanding that each BoNT product has an individual potency and is not interchangeable with any other BoNT product. The therapeutic use of BoNTs is expanding and new formulations are on the horizon. This article is a primer that describes distinctions among currently available, licensed BoNT formulations. Toxin pharmacology, product characteristics, storage, handling, preparation, and dosages will be reviewed. In addition, issues related to dose equivalency ratios, immunogenicity, potency, and toxin spread will be discussed. Therapeutic indications and safety are discussed briefly. Knowledge of the available and licensed BoNT formulations and the ability to make distinctions in toxin pharmacology, product characteristics, and indications are vital for product selection, preparation, drug information, avoidance of drug errors, quality assurance, and patient safety.

Botulinum toxin for the treatment of movement disorders

After botulinum toxin was initially used to treat strabismus in the 1970s, others started using it to treat movement disorders including blepharospasm, hemifacial spasm, cervical dystonia, spasmodic dysphonia, and oromandibular dystonia. It was discovered that botulinum toxin can be an effective treatment for focal movement disorders with limited side effects. Over the past three decades, various formulations of botulinum toxin have been developed and the therapeutic use of these toxins has expanded in movement disorders and beyond. We review the history and mechanism of action of botulinum toxin, as well as describe different formulations available and their potential therapeutic uses in movement disorders.

Diffusion of botulinum toxins

BACKGROUND

It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion.

METHODS

This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method). It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB).

RESULTS

Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others.

DISCUSSION

Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected.

Critical analysis of the use of onabotulinumtoxinA (botulinum toxin type A) in migraine

OnabotulinumtoxinA, a neurotoxin, has been studied in numerous trials as a novel preventive therapy for migraine headache. The data would support that it may be effective at reducing headache days in patients suffering from chronic migraine (≥15 headache days/month, with eight or more of those migraine headache days). The mechanism by which onabotulinumtoxinA exerts its effects on migraine is not yet understood. It is known to inhibit acetylcholine release at the neuromuscular junction, but this probably does not explain the observed antinociceptive properties noted in preclinical and clinical trials. This review will discuss the known mechanisms of action of botulinum toxin type A, and will review the available randomized, placebo-controlled trials that have looked at its efficacy as a migraine preventative. We also describe the onabotulinumtoxinA injection sites used at our institution.

Retrospective evaluation of the dose equivalence of Botox(®) and Dysport (®) in the management of blepharospasm and hemifacial spasm: a novel paradigm for a never ending story

Botox(®) and Dysport(®) are the preparations of botulinum neurotoxin most widely used for therapeutic purposes. Several studies have addressed the topic of the equivalency ratio (D/B ratio) to be used in clinical practice and whether a reliable value exists is still a matter of debate. To this purpose, we ideated a novel paradigm by retrospectively examining the patients affected by hemifacial spasm and blepharospasm. We compared the pairs of treatments with a switch from one brand to the other undergone by the same patient in consecutive sessions with overlapping clinical outcome. Out of 2006 treatments, we found 51 treatment pairs. D/B ratio was extremely variable (range 1.2-13.3) and in most cases (65%) it was between 1:3 and 1:5. In conclusion, even if the 1:4 ratio might be reliable for clinical purpose, a true bioequivalence between Dysport(®) and Botox(®) might not exist due to the intrinsic difference in their pharmacokinetic properties.

Botulinum toxin has an increased effect when targeted toward the muscle's endplate zone: a high-density surface EMG guided study

OBJECTIVES

To compare the effect of endplate-targeted injections of a low Botulinum neurotoxin type A (BoNT-A) dose with that of injections at defined distances from the motor endplate zone.

METHODS

In eight healthy volunteers, the main endplate zones of the right and left extensor digitorum brevis (EDB) muscles were localized using high-density surface EMG. On the study side BoNT-A was injected at fixed distances from the endplate zone. On the control side, BoNT-A was administered into the endplate zone. Compound muscle action potential (CMAP) prior to the injection and 2, 12, and 24 weeks later were recorded.

RESULTS

On the control side, the mean CMAP reduction 2 weeks after BoNT-A injection was 79.3%. The difference in CMAP reduction between both EDB muscles was significantly related to the injection distance from the endplate zone. Increasing the injection distance by 1cm reduced the effect of BoNT-A by 46%.

CONCLUSIONS

Guided injection of a reduced BoNT-A dose into the muscle's endplate zone(s) is a promising strategy for optimizing the therapeutic effectiveness of BoNT-A and for minimizing side-effects such as unwanted weakness of adjacent muscles.

SIGNIFICANCE

Precise endplate-targeted injections increase the effect of BoNT-A and may thus prove to reduce required dosage and treatment costs.

Prophylactic botulinum type A toxin complex (Dysport®) for migraine without aura

OBJECTIVE

To evaluate the efficacy, safety, and optimum dose of a highly purified Clostridium botulinum type A toxin-hemagglutinin complex (Dysport) for migraine prophylaxis.

BACKGROUND

Botulinum toxin type-A has demonstrated good efficacy in several open-label studies of patients with migraine, involving either individualized or standardized protocols, although data from placebo-controlled trials have been conflicting.

METHODS

A 12-week, double-blind, randomized trial of Dysport (120 or 240 units) vs placebo was conducted in 6 centers in Thailand to evaluate the efficacy, safety, and optimum dose of botulinum toxin type-A (Dysport) for migraine prophylaxis. A total of 128 patients with migraine without aura were enrolled. The primary end point was the change in the mean number of migraine attacks per 4-week period from the pre-treatment period to 8-12 weeks post injection. Secondary efficacy measures included the change in the mean total intensity score from the pre-treatment period to 8-12 weeks, the investigator and patient global assessments of change at each visit compared with pre-treatment, and Migraine Disability Assessment and Short Form-36 scores.

RESULTS

Change in number of migraine attacks from pre-treatment to weeks 8-12 was not significantly different. There was a greater improvement in total intensity score at weeks 8-12 with Dysport-240 (not significant), and interim visit data showed that this was significant at weeks 0-4 (P = .03 Dysport-240 vs placebo). The mean duration of headache during weeks 0-4 was lower with Dysport-240 (P = .04 vs placebo). Improvements in patient and investigator global assessments of change between weeks 0-4 and 8-12 were significant for the Dysport-240 group (both P < .05 vs placebo).

CONCLUSIONS

Limitations in study design and assessment tools employed may have contributed to the inconclusive nature of the primary end point data. Dysport-240 showed significant benefit over placebo at some end points and further trials with more appropriate outcome measures are required to evaluate effectively this treatment.

Dosing, efficacy and safety plus the use of computerized photography for botulinum toxins type A for upper facial lines

INTRODUCTION

Several studies confirm that botulinum toxins type A (BTX-A) are effective for reducing facial lines caused by hyperactive muscles. Two different commercial types of BTX-A currently available are BTX-A-1 (Botox) and BTX-A-2 (Dysport). This paper reports further comparison of dosing, efficacy and safety.

METHODS

Sites treated: glabellar, horizontal forehead lines and crow's feet. Different dilutions and dosages were studied with BTX-A-1 and BTX-A-2. The reduction of facial lines was evaluated by investigators and patients. Computerized photographic numerical assessment was also studied in determining the efficacy of BTX-A for crow's feet lines.

RESULTS

Study 1: Injecting glabellar lines at doses of BTX-A-1 (30 units) and BTX-A-2 (75 units) (2.5:1 ratio BTX-A2:BTX-A1) showed similar efficacy. Study 2: BTX-A-2 (256 units total) was significantly more effective than BTX-A-1 (64 units total) (i.e. a dose ratio of 4:1) for upper face lines. No differences in the side-effect profiles between the two toxins were observed in either study. Study 3: A computerized photographic numerical assay was an objective assessment of crow's feet severity. Using a dose ratio of BTX-A-2 to BTX-A-1 of 3:1 showed a trend towards BTX-A-2 superiority.

CONCLUSION

Two different botulinum toxins type A were shown to be effective and safe for hyperfunctional facial lines. The choice of dose, dilution and placement is critical for each individual toxin. Computerized photography gave numerical severity scores of crow's feet severity.

Temporal characteristics of botulinum neurotoxin therapy

Botulinum neurotoxin is a pharmaceutical treatment used for an increasing number of neurological and non-neurological indications, symptoms and diseases. Despite the wealth of clinical reports that involve the timing of the therapeutic effects of this toxin, few studies have attempted to integrate these data into unified models. Secondary reactions have also been examined including the development of adverse events, resistance to repeated applications, and nerve terminal sprouting. Our primary intent for conducting this review was to gather relevant pharmacodynamic data from suitable biomedical literature regarding botulinum neurotoxins via the use of automated data-mining techniques. We envision that mathematical models will ultimately be of value to those who are healthcare decision makers and providers, as well as clinical and basic researchers. Furthermore, we hypothesize that the combination of this computer-intensive approach with mathematical modeling will predict the percentage of patients who will favorably or adversely respond to this treatment and thus will eventually assist in developing the increasingly important area of personalized medicine.