A Retrospective, Single-Center Comparative Cost Analysis of OnabotulinumtoxinA and AbobotulinumtoxinA for Cervical Dystonia Treatment

Use of AbobotulinumtoxinA in Adults with Cervical Dystonia: A Systematic Literature Review

Cervical dystonia (CD) is a neurological movement disorder characterized by sustained involuntary muscle contractions. First-line therapy for CD is intramuscular injections of botulinum neurotoxin (e.g., abobotulinumtoxinA) into the affected muscles. The objective of this systematic literature review is to assess the clinical evidence regarding the effects of abobotulinumtoxinA for treatment of CD in studies of safety, efficacy, patient-reported outcomes, and economic outcomes. Using comprehensive electronic medical literature databases, a search strategy was developed using a combination of Medical Subject Heading terms and keywords. Results were reviewed by two independent reviewers who rated the level of evidence. The search yielded 263 publications, of which 232 were excluded for being duplicate publications, not meeting the selection criteria, or failing to meet predefined eligibility criteria, leaving a total of 31 articles. Clinical efficacy, patient-reported outcomes, and safety data were in 6 placebo-controlled trials (8 articles), 6 active-controlled trials, and 16 observational studies (17 articles). Data on health economic outcomes were provided in one of the clinical trials, in two of the observational studies, and in one specific cost-analysis publication. This review demonstrated that the routine use of abobotulinumtoxinA in CD is well-established, effective, and generally well-tolerated, with a relatively low cost of treatment.

Economic evaluation of AbobotulinumtoxinA vs OnabotulinumtoxinA in real-life clinical management of cervical dystonia

Background

Botulinum neurotoxins type A (BoNT-As) are commonly used treatments for cervical dystonia (CD). Clinical trials have demonstrated the benefits of them in these patients, but data from real-life clinical practice as well as comparative data on the cost and outcome of different BoNT-A formulations are limited. The aim of this study was to compare abobotulinumtoxinA (aboBoNT-A) and onabotulinumtoxinA (onaBoNT-A) on their clinical outcomes and drug costs in real-life clinical practice.

Methods

This analysis included 356 adult patients with idiopathic CD treated with aboBoNT-A (n = 253) or onaBoNT-A (n = 103) from 38 centres across Europe and Australia (NCT00833196). The clinical outcome measures were treatment responses, changes in TWSTRS scores and changes in health utility scores from baseline to study visit 2 and 3. Health utility score was mapped from the TWSTRS total scale, using a previous publication. Costs included drug cost for France.

Results

The aboBoNT-A treated group had 2.06 (95% CI: 1.15 to 3.69) times higher odds of achieving treatment response than the onaBoNT-A treated group. The adjusted mean change in TWSTRS total score from baseline to visit 3 were - 6.42 (95% CI: - 7.52 to - 5.33) for aboBoNT-A and - 3.94 (95% CI: - 5.68 to - 2.2) for onaBoNT-A, with a difference of - 2.48 (95% CI: - 4.57 to - 0.39). The corresponding difference in the adjusted mean change for health utility score was 0.008 (95% CI: 0.001 to 0.014). Mean treatment costs for aboBoNT-A and onaBoNT-A were 314.1 (95% CI: 299.1 to 329.0) and 346.6 (95% CI: 322.9 to 370.4) Euros, respectively.

Conclusions

This comparative analysis indicated that treatment with aboBoNT-A may be less costly and lead to improved clinical outcomes when compared with onaBoNT-A, from a French healthcare system perspective. Additional comparative clinical data from larger patient cohorts, as well as more information about cost consequences of an improvement in clinical outcome would be of value to further confirm the findings.

Contemporary Review and Case Report of Botulinum Resistance in Facial Synkinesis

BACKGROUND

Botulinum resistance poses significant treatment challenges for both patients and healthcare practitioners. We first present a case highlighting botulinum resistance in a patient who failed to respond to alternative formulations but who responded remarkably to incobotulinum toxinA, an identical toxin free of complexing proteins. Secondly, we provide a treatment algorithm and a review of the literature detailing clinical and immunochemical botulinum resistance.

RESULTS

Patients with botulinum resistance show a predisposition to failure on subsequent injections and possess a propensity toward neutralizing and nonneutralizing antibody development. The mechanisms of resistance are not entirely understood but thought to be secondary to an immunologic response. Risk factors for resistance include higher botulinum doses, more frequent injections, and high total lifetime dosage. Patients may still respond to other botulinum formulations or subtypes; however, this effect may be temporary.

CONCLUSION

This case report describes a patient who responded to incobotulinum toxinA after failing treatment with the identical toxin compounded with buffer proteins, ultimately supporting the possibility of immune-mediated resistance to the surrounding proteins and not the toxin itself. Often, impending treatment resistance is preceded by a poor or limited clinical response. Antibody testing is not indicated because it is neither sensitive nor specific and does not change clinical practice. Initially, higher doses of botulinum may overcome resistance without increasing treatment frequency, and side effects are far less common in those with clinical resistance. If higher dosages fail to produce a response, alternative botulinum formulations or subtypes can be considered. Laryngoscope, 129:2269-2273, 2019.

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.