Botulinum toxin A (Dysport®): in dystonias and focal spasticity

Efficacy of botulinum toxin A combined with extracorporeal shockwave therapy in post-stroke spasticity: a systematic review

Objectives

In recent years, there has been an increase in the number of randomized clinical trials of BTX-A combined with ESWT for the treatment of post-stroke spasticity. This has made it possible to observe the benefits of combination therapy in clinical practice. Therefore, this paper reviews the effectiveness of BTX-A in combination with ESWT for the treatment of post-stroke spasticity.

Methods

By October 2023, a systematic review was conducted in the databases PubMed, Cochrane, Embase, Medline, Web of Science, China National Knowledge Infrastructure, Wan Fang Database, China Biology Medicine disc and China Science and Technology Journal Database were systematically searched. We included randomized controlled trials that reported outcome metrics such as MAS, FMA, and MBI score. Studies were excluded if MAS was not reported. The quality of the included studies was assessed by the Cochrane Collaboration's tool for assessing risk of bias, and the AMSTAR quality rating scale was selected for self-assessment.

Results

A total of 70 articles were included in the initial search, and six were ultimately included. The results of the included studies showed that the combination therapy was effective in reducing MAS scores and improving FMA and MBI scores in patients with spasticity compared to the control group. Combination therapy has also been shown to improve joint mobility and reduce pain in spastic limbs.

Conclusion

Cumulative evidence from clinical randomized controlled trial studies suggests that the combination therapy is effective in reducing lower limb spasticity and improving mobility after stroke. However, more clinical trials are still needed to corroborate the evidence regarding the efficacy of BTX-A combined with shockwave therapy.

Systematic Review Registration

The system review can be searched in the PROSPERO database (CRD42023476654).

Botulinum Toxin A Treatment in HIV Infected Patients-A Long-Term Observational Study

OBJECTIVE

It is unknown whether interactions between HIV infection and the safety of botulinum toxin A (BTX) exist.

METHODS

We studied eight patients with HIV infection who were treated with BTX every three months for up to nine years. All patients were on antiretroviral treatment. The efficacy and safety of BTX were evaluated.

RESULTS

Indications for BTX treatment (including off-label use), dosage of BTX, and frequency of application did not differ as compared to non-HIV infected patients. BTX treatment was effective in all HIV infected patients during a long-term observation period without loss of efficacy and without clinically relevant side effects. Only one of the eight patients showed mild side effects due to BTX, and no clinical signs of antibody development were noted. We also observed no signs of interaction with antiretroviral treatment. CD4+ cell count and viral load remained stable during the observation period.

CONCLUSIONS

We conclude that BTX treatment is safe and effective in the treatment of HIV infected patients who suffer also from a condition which can be treated by BTX. It is a therapeutic option in addition to oral medication for HIV infected patients.

AbobotulinumtoxinA: A Review in Pediatric Lower Limb Spasticity

AbobotulinumtoxinA (Dysport^®) is currently the only botulinum toxin A formulation approved by the US FDA for the treatment of lower limb spasticity in pediatric patients aged ≥2 years. Intramuscular abobotulinumtoxinA was approved based on the results of a pivotal phase 3 trial in children with lower limb spasticity due to cerebral palsy. In this trial, a single treatment cycle with abobotulinumtoxinA 10-15 U/kg/leg injected into the gastrocnemius and soleus muscles significantly improved ankle plantar flexor muscle tone (primary endpoint), with abobotulinumtoxinA recipients showing a significant response to treatment relative to placebo. AbobotulinumtoxinA treatment also improved spasticity grade. The improvements in muscle tone and spasticity were associated with an improved ability to attain functional goals. Clinical benefits of abobotulinumtoxinA treatment lasted for 16-22 weeks in most patients, and were maintained with multiple treatment cycles during 1 year in an open-label extension study. AbobotulinumtoxinA was generally well tolerated, with a relatively low incidence of treatment-related adverse events. In summary, abobotulinumtoxinA is an effective and generally well tolerated treatment option for children with lower limb spasticity.

Botulinum toxin therapy for treatment of spasticity in multiple sclerosis: review and recommendations of the IAB-Interdisciplinary Working Group for Movement Disorders task force

Botulinum toxin (BT) therapy is an established treatment of spasticity due to stroke. For multiple sclerosis (MS) spasticity this is not the case. IAB-Interdisciplinary Working Group for Movement Disorders formed a task force to explore the use of BT therapy for treatment of MS spasticity. A formalised PubMed literature search produced 55 publications (3 randomised controlled trials, 3 interventional studies, 11 observational studies, 2 case studies, 35 reviews, 1 guideline) all unanimously favouring the use of BT therapy for MS spasticity. There is no reason to believe that BT should be less effective and safe in MS spasticity than it is in stroke spasticity. Recommendations include an update of the current prevalence of MS spasticity and its clinical features according to classifications used in movement disorders. Immunological data on MS patients already treated should be analysed with respect to frequencies of MS relapses and BT antibody formation. Registration authorities should expand registration of BT therapy for spasticity regardless of its aetiology. MS specialists should consider BT therapy for symptomatic treatment of spasticity.

Efficacy and safety of abobotulinumtoxinA liquid formulation in cervical dystonia: A randomized-controlled trial

BACKGROUND

Approved botulinum toxin A products require reconstitution. AbobotulinumtoxinA solution for injection is a ready-to-use liquid formulation of abobotulinumtoxinA.

OBJECTIVES

The objective of this study was to demonstrate the superior efficacy of abobotulinumtoxinA solution for injection to placebo and to test the noninferior efficacy of abobotulinumtoxinA solution for injection versus abobotulinumtoxinA (dry formulation) in cervical dystonia.

METHODS

This was a phase-3, multicenter, prospective, double-blind, randomized, active, and placebo-controlled study (N = 369). Patients with cervical dystonia were randomized (3:3:1) to abobotulinumtoxinA solution for injection 500 U, abobotulinumtoxinA 500 U, or placebo. Following the double-blind phase, patients received abobotulinumtoxinA solution for injection, open-label, for up to 4 cycles. The primary outcome was change from baseline at week 4 of the Toronto Western Spasmodic Torticollis Rating Scale total score. Secondary measures included change from baseline or cycle baseline in Toronto Western Spasmodic Torticollis Rating Scale scores.

RESULTS

At week 4, both products were superior to placebo (Toronto Western Spasmodic Torticollis Rating Scale total score least square mean decrease from baseline, abobotulinumtoxinA solution for injection 500 U -12.5, abobotulinumtoxinA 500 U -14.0, placebo -3.9; P < .0001 vs placebo). The noninferiority limit of 3 points in the Toronto Western Spasmodic Torticollis Rating Scale total score at week 4 was not met for abobotulinumtoxinA solution for injection versus abobotulinumtoxinA. Toronto Western Spasmodic Torticollis Rating Scale total score reductions were maintained for up to 4 cycles of abobotulinumtoxinA solution for injection open-label follow-up treatment. Safety profiles of abobotulinumtoxinA solution for injection and abobotulinumtoxinA were similar, with dysphagia and injection-site pain the most frequent drug-related adverse events.

CONCLUSIONS

Although the predefined noninferiority criterion was not met, abobotulinumtoxinA solution for injection was similarly effective to freeze-dried abobotulinumtoxinA in reducing Toronto Western Spasmodic Torticollis Rating Scale total scores with a similar safety profile. AbobotulinumtoxinA solution for injection efficacy was maintained with chronic open-label treatment, and this novel formulation may add convenience as well as dosing accuracy to treatment with abobotulinumtoxinA. © 2016 International Parkinson and Movement Disorder Society.

Simultaneous loss of bilateral voluntary eyelid opening and sustained winking response following bilateral posterior cerebral artery infarction

Spontaneous opening and closing of both eyes usually occurs in the normal awake state, unless a deliberate and voluntary attempt is made to open only one eye. We present a rare case of a male patient who was unable to open both eyes simultaneously after bilateral posterior cerebral artery infarction. He was able to close both eyes voluntarily. However, he was unable to keep both eyes open simultaneously and either the right or left eye remained closed. Upon a verbal command to open both eyes, the opened eye closed and the contralateral eye opened. When the closed eye was forced open, the opened eye closed. We thus presented a case of right-left dissociation of voluntary eyelid opening following bilateral posterior cerebral artery infarction, which was treated with botulinum toxin type A injection. Differential diagnosis to other movement disorders of the eyelids was discussed.

Evaluation of the cost per patient per injection of botulinum toxin A in upper limb spasticity: comparison of two preparations in 19 countries

Background

Botulinum toxin A injections are indicated for the management of movement disorders, including upper limb spasticity. The aim of this study was to compare the cost per patient per injection for two botulinum toxin A preparations in 19 countries.

Methods

Doses of botulinum toxin A are expressed in noninterchangeable units (U), ie, Botox^® in 100 Allergan units (100 U) and Dysport^® in 500 Speywood units (500 U). Recommended dosages were derived from country-specific summaries of product characteristics or prescribing information. Cost analysis was based on official list prices and expressed in 2011 Euros. The cost per patient per injection was calculated using the recommended dosage in upper limb spasticity combined with price per vial in each country.

Results

For upper limb spasticity, the recommended dosage for Dysport in the summary of product characteristics is 1000 U per patient, whereas for Botox the recommended dosage when recommendations were made is 300 U. Allowing for different prices per vial in each country, the cost per patient per injection for upper limb spasticity was less for Dysport than for Botox in 18 (95%) of the 19 countries (mean 17% less across countries). The difference was 20% or higher in nearly half (47%) of the countries. Sensitivity analyses considering available “real-world” dosing showed consistent results, with Dysport being less costly than Botox in all 19 countries.

Conclusion

Considering costs per patient per injection based on analysis of recommended dosages in the summary of product characteristics, Dysport remains cheaper than Botox in most countries. Thus, when extrapolated to a national level, substantial savings could be realized by using Dysport in the treatment of upper limb spasticity.