A multicentre, double-blind, randomized, placebo-controlled, parallel group study of multiple treatments of botulinum toxin type A (BoNTA) for the prophylaxis of episodic migraine headaches

Nonpharmacologic Treatments for Chronic and Episodic Migraine: A Systematic Review and Meta-Analysis

BACKGROUND

Minimally invasive techniques for treatment-resistant migraine have been developed on recent insights into the peripheral pathogenesis of migraines. Although there is a growing body of evidence supporting these techniques, no study has yet compared the effects of these treatments on headache frequency, severity, duration, and cost.

METHODS

PubMed, Embase, and Cochrane Library databases were searched to identify randomized placebo-controlled trials that compared radiofrequency ablation, botulinum toxin type A (BT-A), nerve block, neurostimulation, or migraine surgery to placebo for preventive treatment. Data on changes from baseline to follow-up in headache frequency, severity, duration, and quality of life were analyzed.

RESULTS

A total of 30 randomized controlled trials and 2680 patients were included. Compared with placebo, there was a significant decrease in headache frequency in patients with nerve block ( P = 0.04) and surgery ( P < 0.001). Headache severity decreased in all treatments. Duration of headaches was significantly reduced in the BT-A ( P < 0.001) and surgery cohorts ( P = 0.01). Quality of life improved significantly in patients with BT-A, nerve stimulator, and migraine surgery. Migraine surgery had the longest lasting effects (11.5 months) compared with nerve ablation (6 months), BT-A (3.2 months), and nerve block (11.9 days).

CONCLUSIONS

Migraine surgery is a cost-effective, long-term treatment to reduce headache frequency, severity, and duration without significant risk of complication. BT-A reduces headache severity and duration, but it is short-lasting and associated with greater adverse events and lifetime cost. Although efficacious, radiofrequency ablation and implanted nerve stimulators have high risks of adverse events and explantation, whereas benefits of nerve blocks are short in duration.

The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

BACKGROUND

Migraine affects 1.1 billion people globally and is the second leading cause of disability worldwide. In clinical trials, treatment efficacy is evaluated by comparing the differential responses in the treatment and placebo arms. Although placebo response in preventive migraine trials has been studied, there is limited research examining temporal trends. This study evaluates the trend of placebo response over thirty years in migraine prevention trials and investigates the association of potential confounders, such as patient, treatment, and study characteristics on placebo response using meta-analysis with regression.

METHODS

We conducted literature searches from January 1990 to August 2021 in bibliographical databases (PubMed, Cochrane Library, and EMBASE). Studies were selected according to PICOS criteria and included randomized, double-blind, placebo-controlled trials evaluating preventive migraine treatments in adult patients diagnosed with episodic or chronic migraine, with or without aura. The protocol was registered with PROSPERO (CRD42021271732). Migraine efficacy outcomes included were either continuous (e.g., monthly migraine days) or dichotomous (e.g., ≥ 50% responder rate (yes/no)). We assessed the correlation of the change in outcome from baseline in the placebo arm, with the year of publication. The relationship between placebo response and year of publication was also assessed after accounting to confounders.

RESULTS

A total of 907 studies were identified, and 83 were found eligible. For the continuous outcomes, the change from baseline in mean placebo response showed an increase over the years (rho = 0.32, p = 0.006). The multivariable regression analysis also showed an overall increase in placebo response over the years. The correlation analysis of dichotomous responses showed no significant linear trend between publication year and mean placebo response (rho = 0.08, p = 0.596). Placebo response also varied by route of administration.

CONCLUSION

Placebo response increased over the past 30 years in migraine preventive trials. This phenomenon should be considered when designing clinical trials and conducting meta-analyses.

Nonsurgical Treatment of Neuralgia and Cervicogenic Headache: A Systematic Review and Meta-analysis

Background:

Extracranial compression of peripheral sensory nerves is one of many origins of chronic headaches. Identifying these patients can be difficult, and they are often diagnosed with neuralgia or cervicogenic headache. The recent literature provides the outcomes of surgical decompression in patients with these headaches. This study aimed to give an overview of the current literature on the nonsurgical treatment options and to evaluate the effectiveness of these treatments in patients with neuralgia and cervicogenic headache.

Methods:

Databases were searched to identify all published clinical studies investigating nonsurgical treatment outcomes in patients with neuralgia or cervicogenic headaches. Studies that reported numerical pain scores, nonnumerical pain scores, headache-free days, or the number of adverse events after nonsurgical treatment were included.

Results:

A total of 22 articles were included in qualitative analysis. The majority of studies included patients who received injection therapy. Treatment with oral analgesics achieved good results in only 2.5% of the patients. Better outcomes were reported in patients who received local anesthetics injection (79%) and corticosteroid injection (87%). Treatment with botulinum toxin injection yielded the highest percentage of good results (97%; 95% CI, 0.81–1.00). The duration of headache relief after injection therapy varied from 30 minutes to 5 months.

Conclusions:

The nonsurgical treatment of patients with neuralgia or cervicogenic headache is challenging. Injection therapy in patients with these types of headaches achieved good pain relief but only for a limited time. Surgical decompression may result in long-lasting pain relief and might be a more sustainable treatment option.

Beyond chronic migraine: a systematic review and expert opinion on the off-label use of botulinum neurotoxin type-A in other primary headache disorders

Introduction: Botulinum neurotoxin type-A (BoNTA) is licensed for the treatment of chronic migraine (CM), but it has been tested off-label as a therapeutic choice in other primary headaches (PHs). We aimed to provide a systematic review and expert opinion on BoNTA use in PHs, beyond CM.Areas covered: After providing an overview on PHs and mechanism of BoNTA action, we report the results of a systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, of BoNTA therapeutic trials in PHs beyond CM. Studies and results were reviewed and discussed, and levels of evidence were graded. We also collected data on relevant ongoing trials.Expert opinion: Although there are contradictory findings on PHs other than CM, BoNTA may represent a therapeutic option for patients who do not respond to conventional prophylactic treatments. Based on limited available evidence, BoNTA may be considered in refractory tension-type headache, trigeminal autonomic cephalalgias, primary stabbing headache, nummular headache, hypnic headache, and new daily persistent headache, after the primary nature of cephalalgia has been documented and other drugs have failed. Experienced physicians in BoNTA treatment are required to guide the therapeutic protocol for each patient to optimize good and safe outcomes.

Percutaneous Interventional Strategies for Migraine Prevention: A Systematic Review and Practice Guideline

OBJECTIVE

To systematically evaluate the efficacy and effectiveness of percutaneous interventional treatments for prevention of migraine through a qualitative and (when possible) quantitative analysis.

METHODS

An expert panel was asked to develop recommendations for the multidisciplinary preventive treatment of migraine, including interventional strategies. The committee conducted a systematic review and (when evidence was sufficient) a meta-analytic review using GRADE criteria and the modified Cochrane risk of bias analysis available in the Covidence data management program. Clinical questions addressed adults with migraine who should be offered prevention. Examined outcomes included headache days, acute medication use, and functional impairment. Acute management of migraine was outside the scope of this guideline.

RESULTS

The committee screened 1195 studies and assessed 352 by full text, yielding 16 randomized controlled trials that met inclusion criteria.

RECOMMENDATIONS/CONCLUSIONS

As informed by evidence related to the preselected outcomes, adverse event profile, cost, and values and preferences of patients, onabotulinumtoxinA received a strong recommendation for chronic migraine prevention and a weak recommendation against use for episodic migraine prevention. Greater occipital nerve blocks received a weak recommendation for chronic migraine prevention. For greater occipital nerve block, steroid received a weak recommendation against use vs local anesthetic alone. Occipital nerve with supraorbital nerve blocks, sphenopalatine ganglion blocks, cervical spine percutaneous interventions, and implantable stimulation all received weak recommendations for chronic migraine prevention. The committee found insufficient evidence to assess trigger point injections in migraine prevention and highly discouraged use of intrathecal medication.

CGRP-antibodies, topiramate and botulinum toxin type A in episodic and chronic migraine: A systematic review and meta-analysis

Background

The approval of monoclonal antibodies for prevention of migraine has revolutionized treatment for patients. Oral preventatives are still considered first line treatments as head-to-head trials comparing them with antibodies are lacking.

Methods

The main purpose of this study was to provide a comparative overview of the efficacy of three commonly prescribed migraine preventative medication classes. For this systematic review and meta-analysis, we searched the databases CENTRAL, EMBASE, and MEDLINE until 20 March 2020. We included RCTs reporting the 50% response rates for topiramate, Botulinum Toxin Type A and monoclonal antibodies against CGRP(r). Studies were excluded if response rates were not reported, treatment allocation was unclear, or if study quality was insufficient. Primary outcome measure were the 50% response rates. The pooled odds ratios with 95% confidence intervals were calculated with the random effects model. The study was registered at PROSPERO (CRD42020222880).

Findings

We identified 6552 reports. Thirty-two were eligible for our review. Studies assessing monoclonal antibodies included 13,302 patients and yielded pooled odds ratios for the 50% response rate of 2.30 (CI: 2.11–2.50). Topiramate had an overall effect estimate of 2.70 (CI: 1.97–3.69) with 1989 included patients and Botulinum Toxin Type A achieved 1.28 (CI: 0.98–1. 67) with 2472 patients included.

Interpretation

Topiramate, botulinum toxin type A and monoclonal antibodies showed higher odds ratios in achieving a 50% response rate compared to placebo. Topiramate numerically demonstrated the greatest effect size but also the highest drop-out rate.

OnabotulinumtoxinA injection in the treatment of chronic migraine

The earliest descriptions of botulism were in the early 19th century, and was reported by the German physician Justinus Kerner. The term "botulism" was derived from the Latin word botulus, indicating its original association with sausages. It took another 150 years or so to come into clinical use. The first clinical application was strabismus, and was developed by the American ophthalmologist Alan B. Scott, whose effort led to the pharmaceutical product known as onabotulinumtoxinA today. The therapeutic benefit in migraine was an incidental finding in a report by the American plastic surgeon William J. Binder, which inspired a series of clinical studies in headache disorders. The doses and injection techniques in the earlier reports were variable, so were the results. It was until the Phase III REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) 1 and 2 studies when its efficacy and safety, as well as the indication, i.e., chronic migraine (CM), were ascertained. Even though there were criticisms regarding the heterogeneities in the results between the PREEMPT 1 and 2 studies, the data on efficacy endpoints and safety were generally consistent, which were subsequently confirmed by the open-label extension of the PREEMPT 1 and 2 studies, and three open-label studies, namely the Chronic Migraine OnabotulinuMtoxinA Prolonged Efficacy open Label (COMPEL), the REal-life use of botulinum toxin for the symptomatic treatment of adults with chronic migraine, measuring healthcare resource utilization, and Patient-reported OutcomeS observed in practice (REPOSE) studies, and the CM Post-Authorization Safety Study (CM PASS) studies. On the other hand, the results were challenged by the Chronification and Reversibility of Migraine (CHARM) study, which involved CM patients with medication overuse. It was concluded that the clinical improvement was attributed to early withdrawal of the overused acute medications, rather than onabotulinumtoxinA injections. However, fundamental differences in the patient profile and methodology between the CHARM and PREEMPT studies existed, and cautious should be exercised when interpreting and comparing the results. According to the practical guidelines and reimbursement regulations in many countries, its use is limited to CM patients, and is reserved for those who fail at least 2-3 preventive medications, due to either lack of efficacy or intolerability. Cessation of treatment is recommended in patients who do not respond to 2-3 injection cycles, or in patients whose headache frequency has dropped to <10-15 days a month. Even in the era of calcitonin-gene-related peptide monoclonal antibodies, onabotulinumtoxinA injection remains a treatment option of reasonable cost-effectiveness in carefully selected patients.

Efficacy of Botulinum Toxin Type A in Trigeminal Neuralgia in a South Asian Cohort

Introduction:

The antinociceptive effect of botulinum toxin-A (BTX-A) in trigeminal neuralgia (TN) has been described. We evaluated effects of BTX-A in relieving pain in patients with refractory TN at National Hospital of Sri Lanka.

Materials and Methods:

Pain in patients with TN was assessed using a visual analog from 0 to 10. Three months after commencement of drug therapy with ≥2 drugs including one first-line drug (carbamazepine/oxcarbazepine), pain scores were re-assessed. Twenty-two patients who did not report improvement of ≥50% at 90 days’ posttreatment were recruited. They were given adjunct BTX-A directly to the trigger point (if identified) or intradermal. Pain scores were assessed at 10, 20, 30, 60, and 90 days’ posttreatment.

Results:

There was a statistically significant improvement in mean pain scores at 10, 20, 30, 60, and 90 days’ posttreatment (5.59 [standard deviation (SD) = 2.7], 5.68 [SD = 2.6], 5.27 [SD = 3.2], 4.77 [SD = 3.7], and 5.32 [SD = 4.0]) compared to pre-BTX-A treatment (7.14, SD = 2.2). Percentage reduction in mean pain score ranged from 20.4% to 33.1%. Maximum response was at day 60 post-BTX-A (50% had ≥50% reduction in pain). No significant difference was found in response with higher doses and injection strategy.

Conclusion:

Consistent statistically significant reductions in pain scores at the aforesaid intervals compared to pretreatment means that there is a place for BTX in refractory TN.

Botulinum Toxin a Valuable Prophylactic Agent for Migraines and a Possible Future Option for the Prevention of Hormonal Variations-Triggered Migraines

BACKGROUND

In 1989, Botulinum toxin (BoNT) was accepted by the FDA for the management of some ophthalmic disorders. Although it was initially considered a lethal toxin, in recent times, Botulinum toxin A (BoNT-A), which is the more used serotype, has expanded to cover different clinical conditions, primarily characterized by neuropathic pain, including migraines and headaches. Evidence suggests that migraines are influenced by hormonal factors, particularly by estrogen levels, but very few studies have investigated the prevalence and management strategies for migraines according to the hormonal status. The effects of several therapeutic regimens on migraines have been investigated, but the medications used varied widely in proven efficacies and mechanisms of action. BoNT-A is increasingly used in the management of migraine and several placebo-controlled trials of episodic and chronic migraine are currently underway. This paper is a review of the recently published data concerning the administration of BoNT-A in the prevention of chronic migraines. Considering the lack of population-based studies about the effectiveness of BoNT-A in the alleviation of premenstrual and perimenopausal migraines, this study proposes a new perspective of the therapeutic approach of migraine syndrome associated with menopausal transition and the premenstrual period.

METHODS

We selected the reviewed papers from CrossRef, PubMed, Medline, and GoogleScholar, and a total of 21 studies met our inclusion criteria.

RESULTS

To date, no specific preventive measures have been recommended for menopausal women with migraines. BoNT-A often reduces the frequency and intensity of migraine attacks per month; the treatment is well tolerated and does not exhibit a significantly higher rate of treatment-related side effects. No population-based studies were conducted in order to highlight the role of BoNT-A in menopause-related migraines, neither in menstrual migraines.

CONCLUSION

There is a need for further research in order to quantify the real burden of menstrual and perimenopausal migraines and to clarify if BoNT-A could be used in the treatment of refractory postmenopausal and premenstrual migraines.

Cochrane systematic review and meta-analysis of botulinum toxin for the prevention of migraine

OBJECTIVES

To assess the effects of botulinum toxin for prevention of migraine in adults.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

CENTRAL, MEDLINE, Embase and trial registries.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) of botulinum toxin compared with placebo, active treatment or clinically relevant different dose for adults with chronic or episodic migraine, with or without the additional diagnosis of medication overuse headache.

DATA EXTRACTION AND SYNTHESIS

Cochrane methods were used to review double-blind RCTs. Twelve week post-treatment time-point data was analysed.

RESULTS

Twenty-eight trials (n=4190) were included. Trial quality was mixed. Botulinum toxin treatment resulted in reduced frequency of -2.0 migraine days/month (95% CI -2.8 to -1.1, n=1384) in chronic migraineurs compared with placebo. An improvement was seen in migraine severity, measured on a numerical rating scale 0 to 10 with 10 being maximal pain, of -2.70 cm (95% CI -3.31 to -2.09, n=75) and -4.9 cm (95% CI -6.56 to -3.24, n=32) for chronic and episodic migraine respectively. Botulinum toxin had a relative risk of treatment related adverse events twice that of placebo, but a reduced risk compared with active comparators (relative risk 0.76, 95% CI 0.59 to 0.98) and a low withdrawal rate (3%). Although individual trials reported non-inferiority to oral treatments, insufficient data were available for meta-analysis of effectiveness outcomes.

CONCLUSIONS

In chronic migraine, botulinum toxin reduces migraine frequency by 2 days/month and has a favourable safety profile. Inclusion of medication overuse headache does not preclude its effectiveness. Evidence to support or refute efficacy in episodic migraine was not identified.

Entrapment Neuropathy: A Concept for Pathogenesis and Treatment of Headaches-A Narrative Review

Entrapment neuropathy is a known cause of neurological disorders. In the head and neck area, this pathophysiological mechanism could be a trigger for headache. Over the last few decades, injection of botulinum toxin type A in the muscles that are causing the compression as well as surgical decompression have proved to be effective treatment methods worldwide for large numbers of patients with daily headaches. In particular the entrapment of the supraorbital nerves in the glabellar musculature and the occipital nerves in the neck musculature are triggers for headache disorders for which many patients are still seeking an effective treatment. This article reviews the literature and aims to bring the concept of neural entrapment to the attention of a wider audience. By doing so, we hope to give more exposure to an effective and relatively safe headache treatment.

Botulinum toxins for the prevention of migraine in adults

BACKGROUND

Migraine occurs in around 15% of adults and is ranked as the seventh most disabling disease amongst all diseases globally. Despite the available treatments many people suffer prolonged and frequent attacks which have a major impact on their quality of life. Chronic migraine is defined as 15 or more days of headache per month, at least eight of those days being migraine. People with episodic migraine have fewer than 15 headache days per month. Botulinum toxin type A has been licensed in some countries for chronic migraine treatment, due to the results of just two trials.

OBJECTIVES

To assess the effects of botulinum toxins versus placebo or active treatment for the prevention or reduction in frequency of chronic or episodic migraine in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE & MEDLINE in Process, Embase, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry (to December 2017). We examined reference lists and carried out citation searches on key publications. We sent correspondence to major manufacturers of botulinum toxin.

SELECTION CRITERIA

Randomised, double-blind, controlled trials of botulinum toxin (any sero-type) injections into the head and neck for prophylaxis of chronic or episodic migraine in adults. Eligible comparators were placebo, alternative prophylactic agent or different dose of botulinum toxin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. For continuous outcomes we used mean change data when available. For dichotomous data we calculated risk ratios (RRs). We used data from the 12-week post-treatment follow-up time point. We assessed the evidence using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

Description of trialsWe found 90 articles describing 28 trials (4190 participants), which were eligible for inclusion. The longest treatment duration was three rounds of injections with three months between treatments, so we could not analyse long-term effects. For the primary analyses, we pooled data from both chronic and episodic participant populations. Where possible, we also separated data into chronic migraine, episodic migraine and 'mixed group' classification subgroups. Most trials (21 out of 28) were small (fewer than 50 participants per trial arm). The risk of bias for included trials was low or unclear across most domains, with some trials reporting a high risk of bias for incomplete outcome data and selective outcome reporting.Botulinum toxin versus placeboTwenty-three trials compared botulinum toxin with placebo. Botulinum toxin may reduce the number of migraine days per month in the chronic migraine population by 3.1 days (95% confidence interval (CI) -4.7 to -1.4, 4 trials, 1497 participants, low-quality evidence). This was reduced to -2 days (95% CI -2.8 to -1.1, 2 trials, 1384 participants; moderate-quality evidence) when we removed small trials.A single trial of people with episodic migraine (N = 418) showed no difference between groups for this outcome measure (P = 0.49).In the chronic migraine population, botulinum toxin reduces the number of headache days per month by 1.9 days (95% CI -2.7 to -1.0, 2 trials, 1384 participants, high-quality evidence). We did not find evidence of a difference in the number of migraine attacks for both chronic and episodic migraine participants (6 trials, N = 2004, P = 0.30, low-quality evidence). For the population of both chronic and episodic migraine participants a reduction in severity of migraine rated during clinical visits, on a 10 cm visual analogue scale (VAS) of 3.3 cm (95% CI -4.2 to -2.5, very low-quality evidence) in favour of botulinum toxin treatment came from four small trials (N = 209); better reporting of this outcome measure from the additional eight trials that recorded it may have improved our confidence in the pooled estimate. Global assessment and quality-of-life measures were poorly reported and it was not possible to carry out statistical analysis of these outcome measures. Analysis of adverse events showed an increase in the risk ratio with treatment with botulinum toxin over placebo 30% (RR 1.28, 95% CI 1.12 to 1.47, moderate-quality evidence). For every 100 participants 60 experienced an adverse event in the botulinum toxin group compared with 47 in the placebo group.Botulinum toxin versus other prophylactic agentThree trials studied comparisons with alternative oral prophylactic medications. Meta-analyses were not possible for number of migraine days, number of headache days or number of migraine attacks due to insufficient data, but individually trials reported no differences between groups for a variety of efficacy measures in the population of both chronic and episodic migraine participants. The global impression of disease measured using Migraine Disability Assessment (MIDAS) scores were reported from two trials that showed no difference between groups. Compared with oral treatments, botulinum toxin showed no between-group difference in the risk of adverse events (2 trials, N = 114, very low-quality evidence). The relative risk reduction (RRR) for withdrawing from botulinum toxin due to adverse events compared with the alternative prophylactic agent was 72% (P = 0.02, 2 trials, N = 119).Dosing trialsThere were insufficient data available for the comparison of different doses.Quality of the evidenceThe quality of the evidence assessed using GRADE methods was varied but mostly very low; the quality of the evidence for the placebo and active control comparisons was low and very low, respectively for the primary outcome measure. Small trial size, high risk of bias and unexplained heterogeneity were common reasons for downgrading the quality of the evidence.

AUTHORS' CONCLUSIONS

In chronic migraine, botulinum toxin type A may reduce the number of migraine days per month by 2 days compared with placebo treatment. Non-serious adverse events were probably experienced by 60/100 participants in the treated group compared with 47/100 in the placebo group. For people with episodic migraine, we remain uncertain whether or not this treatment is effective because the quality of this limited evidence is very low. Better reporting of outcome measures in published trials would provide a more complete evidence base on which to draw conclusions.

Percutaneous Closure of Patent Foramen Ovale in Patients With Migraine: The PREMIUM Trial

BACKGROUND

Migraine is a prevalent and disabling disorder. Patent foramen ovale (PFO) has been associated with migraine, but its role in the disorder remains poorly understood.

OBJECTIVES

This study examined the efficacy of percutaneous PFO closure as a therapy for migraine with or without aura.

METHODS

The PREMIUM (Prospective, Randomized Investigation to Evaluate Incidence of Headache Reduction in Subjects With Migraine and PFO Using the AMPLATZER PFO Occluder to Medical Management) was a double-blind study investigating migraine characteristics over 1 year in subjects randomized to medical therapy with a sham procedure (right heart catheterization) versus medical therapy and PFO closure with the Amplatzer PFO Occluder device (St. Jude Medical, St. Paul, Minnesota). Subjects had 6 to 14 days of migraine per month, had failed at least 3 migraine preventive medications, and had significant right-to-left shunt defined by transcranial Doppler. Primary endpoints were responder rate defined as 50% reduction in migraine attacks and adverse events. Secondary endpoints included reduction in migraine days and efficacy in patients with versus without aura.

RESULTS

Of 1,653 subjects consented, 230 were enrolled. There was no difference in responder rate in the PFO closure (45 of 117) versus control (33 of 103) groups. One serious adverse event (transient atrial fibrillation) occurred in 205 subjects who underwent PFO closure. Subjects in the PFO closure group had a significantly greater reduction in headache days (-3.4 vs. -2.0 days/month, p = 0.025). Complete migraine remission for 1 year occurred in 10 patients (8.5%) in the treatment group versus 1 (1%) in the control group (p = 0.01).

CONCLUSIONS

PFO closure did not meet the primary endpoint of reduction in responder rate in patients with frequent migraine. (Prospective, Randomized Investigation to Evaluate Incidence of Headache Reduction in Subjects With Migraine and PFO Using the AMPLATZER PFO Occluder to Medical Management [PREMIUM]; NCT00355056).

Evidence and experience with onabotulinumtoxinA in chronic migraine: Recommendations for daily clinical practice

OnabotulinumtoxinA has been demonstrated to be effective as a preventive treatment in patients with chronic migraine (CM). Five years after the approval of onabotulinumtoxinA in Spain, the Headache Study Group of the Spanish Society of Neurology considered it worthwhile to gather a group of experts in treating patients with CM in order to draw up, based on current evidence and our own experience, a series of guidelines aimed at facilitating the use of the drug in daily clinical practice. For this purpose, we posed 12 questions that we ask ourselves as doctors, and which we are also asked by our patients. Each author responded to one question, and the document was then reviewed by everyone. We hope that this review will constitute a practical tool to help neurologists treating patients with CM.

OnabotulinumtoxinA decreases interictal CGRP plasma levels in patients with chronic migraine

OnabotulinumtoxinA (onabotA) has shown efficacy in chronic migraine (CM). Its mechanism of action, however, remains obscure. We have analysed whether treatment with onabotA is able to induce changes in interictal plasma calcitonin gene-related peptide (CGRP) concentrations, which have been shown to be increased in patients with CM. Calcitonin gene-related peptide levels were determined in samples obtained from the right antecubital vein using ELISA, outside a migraine attack and having taken no symptomatic medication in the previous 24 hours, in 83 patients with CM (average age 44 years; 94% females) before and 1 month after treatment with 155 to 195 U of onabotA. CGRP levels after onabotA treatment (median, 51.89 pg/mL; range, 199.4-10.2) were significantly lower as compared with CGRP levels obtained before onabotA treatment (median, 74.09 pg/mL; range, 241.0-11.4; P = 0.001). Pretreatment CGRP levels in responders (76.85 pg/mL) were significantly higher than those seen in nonresponders (50.45 pg/mL; P = 0.001). One month after treatment, the CGRP levels did not change in nonresponders (51.89 pg/mL; P not significant), but significantly decreased in responders (52.48 pg/mL; P = 0.003). A number of demographic factors, clinical features, and comorbidities were not different in responders as compared with those of nonresponders. These results confirm that interictal CGRP levels can be of help in predicting the response to onabotA and suggest that the mechanism of action of onabotA in CM is the reversal of sensitization as a result of the inhibition of CGRP release.

Current status and future directions of botulinum neurotoxins for targeting pain processing

Current evidence suggests that botulinum neurotoxins (BoNTs) A1 and B1, given locally into peripheral tissues such as skin, muscles, and joints, alter nociceptive processing otherwise initiated by inflammation or nerve injury in animal models and humans. Recent data indicate that such locally delivered BoNTs exert not only local action on sensory afferent terminals but undergo transport to central afferent cell bodies (dorsal root ganglia) and spinal dorsal horn terminals, where they cleave SNAREs and block transmitter release. Increasing evidence supports the possibility of a trans-synaptic movement to alter postsynaptic function in neuronal and possibly non-neuronal (glial) cells. The vast majority of these studies have been conducted on BoNT/A1 and BoNT/B1, the only two pharmaceutically developed variants. However, now over 40 different subtypes of botulinum neurotoxins (BoNTs) have been identified. By combining our existing and rapidly growing understanding of BoNT/A1 and /B1 in altering nociceptive processing with explorations of the specific characteristics of the various toxins from this family, we may be able to discover or design novel, effective, and long-lasting pain therapeutics. This review will focus on our current understanding of the molecular mechanisms whereby BoNTs alter pain processing, and future directions in the development of these agents as pain therapeutics.

OnabotulinumtoxinA for trigeminal neuralgia: a review of the available data

Trigeminal neuralgia (TN) patients may develop side effects from centrally acting drugs, have contraindications for neurosurgical procedures, or experience relapse during conventional therapies. OnabotulinumtoxinA (BoNT/A) has been reported to be effective for TN, although this finding has been challenged. An overview of the available evidence based on a narrative/qualitative analysis of the literature is presented. About 90% of patients who receive BoNT/A show an improvement, a higher figure than that reported for the placebo effect of BoNT/A for other headaches. Tolerability of BoNT/A is good, and its few side-effects are transient. The articles reviewed were mainly case reports, case series and open-label trials; however, randomized controlled trials have endorsed the efficacy of BoNT/A for TN. This evidence, together with a better understanding of the analgesic mechanisms of BoNT/A and its proven efficacy in treating other pain syndromes, supports the use of this toxin as a therapeutic option for TN.

Glutamate receptor antagonists in the management of migraine

Migraine is a neurovascular disorder that is associated with severe headache and neurologic symptoms. The pathogenesis of migraine is believed to involve trigeminovascular system activation with the primary dysfunction located in brainstem. Glutamate, the major excitatory neurotransmitter in the central nervous system, and its receptors have since long been suggested in migraine pathophysiology. Different preclinical studies have confirmed their potential role in migraine. Moreover, several glutamate receptor modulators have been studied in clinical studies, some with promising results. In this review, we will give an overview of what is known about the role of glutamate in the pathogenesis of migraine, which will be followed by an overview of available efficacy, safety and tolerability data for glutamate receptor inhibitors in clinical development for the treatment of migraine.

Therapeutic use of botulinum toxin in migraine: mechanisms of action

Migraine pain represents sensations arising from the activation of trigeminal afferents, which innervate the meningeal vasculature and project to the trigeminal nucleus caudalis (TNC). Pain secondary to meningeal input is referred to extracranial regions innervated by somatic afferents that project to homologous regions in the TNC. Such viscerosomatic convergence accounts for referral of migraine pain arising from meningeal afferents to particular extracranial dermatomes. Botulinum toxins (BoNTs) delivered into extracranial dermatomes are effective in and approved for treating chronic migraine pain. Aside from their well-described effect upon motor endplates, BoNTs are also taken up in local afferent nerve terminals where they cleave soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, and prevent local terminal release. However, a local extracranial effect of BoNT cannot account for allthe effects of BoNT upon migraine. We now know that peripherally delivered BoNTs are taken up in sensory afferents and transported to cleave SNARE proteins in the ganglion and TNC, prevent evoked afferent release and downstream activation. Such effects upon somatic input (as from the face) likewise would not alone account for block of input from converging meningeal afferents. This current work suggests that BoNTs may undergo transcytosis to cleave SNAREs in second-order neurons or in adjacent afferent terminals. Finally, while SNAREs mediate exocytotic release, they are also involved in transport of channels and receptors involved in facilitated pain states. The role of such post-synaptic effects of BoNT action in migraine remains to be determined.

OnabotulinumtoxinA treatment for chronic migraine: experience in 52 patients treated with the PREEMPT paradigm

OnabotulinumtoxinA (OnabotA) was approved for treatment of chronic migraine (CM) after publication of PREEMPT trials. Thus, we set out to evaluate the efficacy of OnabotA in a series of patients with CM treated according to the PREEMPT protocol.

In May 2012 we began to offer OnabotA to patients with CM who did not respond to topiramate and at least one other preventive therapy (beta blocker and/or calcium channel antagonist). We prospectively recorded demographic data and the characteristics of migraine, and we assessed the modifications in monthly headache and migraine days, as well as the number of days of symptomatic medication and triptan intake.

By September 2014 we had treated 52 patients (8 male, 44 female), whose age at treatment onset was 42.8 ± 12.7 years (range: 16–71) and age at migraine onset was 16.8 ± 7.8 years (3–32). In 43 of these patients (82.7%) symptomatic overuse of medication was observed at the onset of treatment. A total of 168 procedures were performed and after the first session, we observed a significant reduction in all the variables considered. Twelve (23.1%) patients failed to perceive a positive effect after the first procedure and it was not repeated in 4 of them. By contrast, there was a significant decreasing in all the variables evaluated compared to the baseline in the 39 patients that received a second series of injections.

The use of OnabotA according to the PREEMPT paradigm is an effective treatment in patients with chronic migraine in a real-life setting.

OnabotulinumtoxinA for the treatment of headache

Botulinum toxin, a potent muscle relaxant, has been found to have analgesic effects in patients with various pain syndromes. Both in vitro and in vivo studies showed the ability of the toxin to block the release of pain neurotransmitters, such as substance P, glutamate, and calcitonin gene-related peptide. The effect of the toxin, and specifically of one of its serotypes, botulinum neurotoxin type A, on headaches, has been extensively studied. This serotype is available in the United States in 3 forms, including as onabotulinumtoxinA. Data from clinical trials confirmed the efficacy, safety, and tolerability of onabotulinumtoxinA in the prophylactic treatment of chronic migraine, the most severe and debilitating type of migraine, in adults. The drug was approved by the Food and Drug Administration for this indication in 2010. The drug was not found to be effective for episodic migraine or tension-type headache. Noncontrolled studies suggest the efficacy of the toxin for headache associated with craniocervical dystonia. Proper injection technique and appropriate patient selection are essential for achieving positive results after treatment with onabotulinumtoxinA. The recommended injection paradigm combines a fixed site/fixed dose and follow the pain approaches, with the toxin injected to multiple sites of the head and neck, at a total dose of 155U-195U. The treatment is given at intervals of 12 weeks on average. The efficacy of onabotulinumtoxinA for some headaches, its long duration of action, and its favorable adverse effect profile make it a viable treatment option for the appropriate headache patients. The drug may be particularly suitable for patients who cannot tolerate, or are not compliant with, the daily intake of oral headache preventive drugs.

Knowledge and attitude of dentists towards the use of botulinum toxin and dermal fillers in dentistry, Riyadh, Saudi Arabia

INTRODUCTION

Botulinum toxin (BTX) and dermal fillers (DFs) are considered as quick and effective non-surgical solutions for enhancing facial appearance.

OBJECTIVE

To evaluate dentists' knowledge and attitude towards using Botulinum toxin and DFs in dental treatment in Riyadh, Saudi Arabia.

METHODS

Five hundred questionnaires were distributed in Riyadh city to government and private sectors to determine awareness and attitude towards using Botulinum toxin and DFs in dental clinics for therapeutic and aesthetics uses.

RESULTS

Botulinum toxin: A total of 1.2% is practising it. Only 34.8% could recognise its composition. Use of Botulinum toxin in wrinkle reduction was the most reported (73.7%). A total of 81.1% believed that Botulinum toxin has side effects; allergic reaction was the most reported (57.5%). A total of 47.8% reported that higher doses are more toxic, and that males need higher doses than females (10.2%). Dermal fillers: A total of 0.9% is practising it. The most reported type (47.8%) was Fat transfer. Filling of wrinkles was the most reported use (57.8%). A total of 69% believed that DFs has side effects; allergic reaction was the most reported (53.4%). Attitude: A total of 37.8% would like to practise Botulinum toxin/DFs, mostly for aesthetic dental reason. However, 60.2% rejected the idea, mainly due to lack of knowledge and experience (44%).

CONCLUSION

Limited knowledge regarding Botulinum toxin and dermal fillers is found among dentists in Riyadh, Saudi Arabia.

Subcutaneous histamine versus botulinum toxin type A in migraine prophylaxis: a randomized, double-blind study

OBJECTIVES

To compare the efficacy and tolerability of the subcutaneous administration of histamine and botulinum toxin type A (BoNTA) in migraine prophylaxis.

BACKGROUND

Histamine has a selective affinity for H3 receptors and it may specifically inhibit the neurogenic edema response involved in migraine pathophysiology.

METHODS

One hundred patients with migraine were selected in a 12-week double-blind controlled clinical trial to evaluate the efficacy of subcutaneous administration of histamine (1-10 ng twice a week) n = 50, compared with administration of 50 U of BoNTA (one injection cycle) n = 50.

RESULTS

The data collected during the 4th week of treatment revealed a significant decrease in all parameters studied, in histamine and BoNTA (P < 0.001). After 4 weeks of treatment, but one injection cycle of 50 U BoNTA had only a 40-day period of efficacy.

CONCLUSIONS

This randomized study demonstrated that both histamine and BoNTA are similarly effective and well tolerated in reducing or eliminating headache in migraine prophylaxis. Low doses of histamine applied subcutaneously may represent a novel and effective therapeutic alternative in migraine patients and lay the clinical and pharmacological groundwork for the use of H3 agonist in migraine prophylaxis.

Insights into the mechanism of onabotulinumtoxinA in chronic migraine

OnabotulinumtoxinA has recently been approved by regulatory agencies in the UK and United States for treatment of chronic migraine based on data generated from the PREEMPT studies. As such, onabotulinumtoxinA is the only prophylactic therapy specifically approved for chronic migraine. Most headache clinicians would agree that acute episodic migraine and chronic migraine differ in their pathophysiology, etiology, diagnosis, and response to pharmacological as well as nonpharmacological therapies. Of the 7 botulinum neurotoxin serotypes, botulinum neurotoxin type A (onabotulinumtoxinA) has been the most thoroughly investigated in preclinical and clinical studies. Based on preclinical studies, onabotulinumtoxinA is known to inhibit the release of excitatory neurotransmitters from both motor and sensory neurons by preventing vesicle fusion to the cell membrane. In addition to the well-documented myorelaxant effects of this neurotoxin, onabotulinumtoxinA can exert a direct analgesic effect that likely involves inhibition of primary and secondary nociceptive neurons. The inhibitory effects of onabotulinumtoxinA are also likely to involve suppressing the activity of myogenic trigger points and decreasing the persistent nociceptive barrage that promotes and maintains central sensitization. This article describes possible mechanisms to explain how onabotulinumtoxinA functions as a therapy for chronic migraine and considers why treatment with the neurotoxin is not effective in some chronic migraineurs.

Prevention and management of medication overuse headache

PURPOSE OF REVIEW

This review provides an update on our knowledge regarding prevention and management of medication overuse headache (MOH).

RECENT FINDINGS

The prevalence of MOH is 1-2% in the general population worldwide, and because of the tremendous socio-economic cost, it is likely to be the most costly neurological disorder known. MOH has similarities with traditional drug addiction. Use of a brochure on medication overuse can prevent MOH. The Severity of Dependence Scale (SDS) score is a significant predictor of medication overuse among headache patients. Withdrawal of medication is essential in the management of MOH, and simultaneous initiation of prophylactic medication may alleviate this process. Short advice on medication overuse by a physician reduced mean medication days from 22 to 6 days; 76% no longer had medication overuse and 42% no longer had chronic headache.

SUMMARY

A brochure and/or the SDS should be used to prevent MOH. Withdrawal is the cornerstone of MOH management. Short advice on MOH is the current most cost effective management method, a method that can be applied anywhere including third world countries.

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.

Treatment of refractory pain with botulinum toxins--an evidence-based review

OBJECTIVES

To provide updated information on the role of botulinum toxins in the treatment of refractory pain based on prospective, randomized, double-blind, placebo-controlled studies. DESIGN OF THE REVIEW: Class I and class II articles were searched online through PubMed (1966 to the end of January 2011) and OvidSP including ahead-of-print manuscripts.

RESULTS

Level A evidence (two or more class I studies-established efficacy): pain of cervical dystonia, chronic migraine, and chronic lateral epicondylitis. Level B evidence (one class I or two class II studies-probably effective and recommended): post-herpetic neuralgia, post-traumatic neuralgia, pain of plantar fasciitis, piriformis syndrome, and pain in total knee arthroplasty. Level C evidence (one class II study-possibly effective, may be used at discretion of clinician): allodynia of diabetic neuropathy, chronic low back pain, painful knee osteoarthritis, anterior knee pain with vastus lateralis imbalance, pelvic pain, post-operative pain in children with cerebral palsy after adductor hip release surgery, post-operative pain after mastectomy, and sphincter spasms and pain after hemorrhoidectomy. Level U evidence (efficacy not proven due to diverse class I and II results): myofascial pain syndrome and chronic daily headaches. Studies in episodic migraine and tension headaches have shown treatment failure (level A-negative).

CONCLUSION

Evidence-based data indicate that administration of botulinum toxin in several human conditions can alleviate refractory pain. The problems with some study designs and toxin dosage are critically reviewed.

Botulinum toxin type-A effect as a preemptive treatment in a model of acute trigeminal pain: a pre-clinical double-blind and placebo-controlled study

The purpose of this study was to investigate if botulinum neurotoxin type-A (BoNT/A) had a preemptive antinociceptive effect in a formalin-induced orofacial pain model (FT). To test this hypothesis, male Rattus norvegicus were injected with isotonic saline solution 0.9% or BoNT/A administered as a 40 μl bolus, lateral to their nose, at 24 hours, 8, 15, 22, 29 or 36 days pre-FT. The procedures were repeated 42 days later. Influence on motor activity was assessed through the open-field test. Pain scores corresponded to the time spent rubbing and flicking the injected area. Animals pre-treated with BoNT/A at the first protocol (8 days subgroup) showed reduced inflammatory scores (p=0.011). For the other groups no significant results were observed at any phase. Motor activity was similar in both groups. BoNT/A showed to be effective preventing inflammatory pain up to eight days after the first treatment, an effect not reproduced on the second dose administration.

Botulinum toxin type-A in the prophylactic treatment of medication-overuse headache: a multicenter, double-blind, randomized, placebo-controlled, parallel group study

Medication-overuse headache (MOH) represents a severely disabling condition, with a low response to prophylactic treatments. Recently, consistent evidences have emerged in favor of botulinum toxin type-A (onabotulinum toxin A) as prophylactic treatment in chronic migraine. In a 12-week double-blind, parallel group, placebo-controlled study, we tested the efficacy and safety of onabotulinum toxin A as prophylactic treatment for MOH. A total of 68 patients were randomized (1:1) to onabotulinum toxin A (n = 33) or placebo (n = 35) treatment and received 16 intramuscular injections. The primary efficacy end point was mean change from baseline in the frequency of headache days for the 28-day period ending with week 12. No significant differences between onabotulinum toxin A and placebo treatment were detected in the primary (headache days) end point (12.0 vs. 15.9; p = 0.81). A significant reduction was recorded in the secondary end point, mean acute pain drug consumption at 12 weeks in onabotulinum toxin A-treated patients when compared with those with placebo (12.1 vs. 18.0; p = 0.03). When we considered the subgroup of patients with pericranial muscle tenderness, we recorded a significant improvement in those treated with onabotulinum toxin A compared to placebo treated in both primary (headache days) and secondary end points (acute pain drug consumption, days with drug consumption), as well as in pain intensity and disability measures (HIT-6 and MIDAS) at 12 weeks. Onabotulinum toxin A was safe and well tolerated, with few treatment-related adverse events. Few subjects discontinued due to adverse events. Our data identified the presence of pericranial muscle tenderness as predictor of response to onabotulinum toxin A in patients with complicated form of migraine such as MOH, the presence of pericranial muscle tenderness and support it as prophylactic treatment in these patients.

Are the current IHS guidelines for migraine drug trials being followed?

In 2000, the Clinical Trials Subcommittee of the International Headache Society (IHS) published the second edition of its guidelines for controlled trials of drugs in migraine. The purpose of this publication was to improve the quality of such trials by increasing the awareness amongst investigators of the methodological issues specific to this particular illness. Until now the adherence to these guidelines has not been systematically assessed. We reviewed all published controlled trials of drugs in migraine from 2002 to 2008. Eligible trials were scored for compliance with the IHS guidelines by using grading scales based on the most essential recommendations of the guidelines. The primary efficacy measure of each trial was also recorded. A total of 145 trials of acute treatment and 52 trials of prophylactic treatment were eligible for review. Of the randomized, double-blind trials, acute trials scored an average of 4.7 out of 7 while prophylactic trials scored an average of 5.6 out of 9 for compliance. Thirty-one percent of acute trials and 72% of prophylactic trials used the recommended primary efficacy measure. Fourteen percent of the reviewed trials were either not randomized or not double-blinded. Adherence to international guidelines like these of IHS is important to ensure that only high-quality trials are performed, and to provide the consensus that is required for meta analyses. The primary efficacy measure for trials of acute treatment should be “pain free” and not “headache relief”. Open-label or non-randomized trials generally have no place in the study of migraine drugs.

Re-engineering clostridial neurotoxins for the treatment of chronic pain: current status and future prospects

Clostridial neurotoxins from the botulinum neurotoxin (BoNT) family are protein complexes, derived from the bacterium Clostridium botulinum, which potently inhibit acetylcholine release and result in a reversible blockade of the neuromuscular junction. This feature led to the clinical development of BoNT-A for a number of neuromuscular disorders. BoNT-A toxins are commercially available as three different preparations: Dysport/Azzalure, Botox/Vistabel, and Xeomin/Bocouture. Although BoNT-A preparations have not yet been approved for the treatment of pain, a substantial body of preclinical and clinical evidence shows that BoNT-A is effective in treating a number of different types of pain. It is thought to exert an analgesic effect both via muscle-relaxant properties and also directly, via inhibition of nociceptive neuropeptides. This review explores the mechanistic basis of this analgesic effect, summarizing current knowledge of the structure-function relationship of BoNT and discussing effects on both motor and pain neurons. For a complete picture of the analgesic properties of BoNT-A, clinical evidence of efficacy in myofascial pain and neuropathic pain is considered in tandem with a mechanistic rationale for activity. Patients experiencing chronic pain are clear candidates for treatment with a modified clostridial endopeptidase that would provide enduring inhibition of neurotransmitter release. A strong preclinical evidence base underpins the concept that re-engineering of BoNT could be used to enhance the analgesic potential of this neurotoxin, and it is hoped that the first clinical studies examining re-engineered BoNT-A will confirm this potential.

OnabotulinumtoxinA for treatment of chronic migraine: pooled results from the double-blind, randomized, placebo-controlled phases of the PREEMPT clinical program

OBJECTIVE

To assess the efficacy, safety, and tolerability of onabotulinumtoxinA (BOTOX) as headache prophylaxis in adults with chronic migraine.

BACKGROUND

Chronic migraine is a prevalent, disabling, and undertreated neurological disorder. Few preventive treatments have been investigated and none is specifically indicated for chronic migraine.

METHODS

The 2 multicenter, pivotal trials in the PREEMPT: Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy clinical program each included a 24-week randomized, double-blind phase followed by a 32-week open-label phase (ClinicalTrials.gov identifiers NCT00156910, NCT00168428). Qualified patients were randomized (1:1) to onabotulinumtoxinA (155-195 U) or placebo injections every 12 weeks. Study visits occurred every 4 weeks. These studies were identical in design (eg, inclusion/exclusion criteria, randomization, visits, double-blind phase, open-label phase, safety assessments, treatment), with the only exception being the designation of the primary and secondary endpoints. Therefore, the predefined pooling of the results was justified and performed to provide a complete overview of between-group differences in efficacy, safety, and tolerability that may not have been evident in individual studies. The primary endpoint for the pooled analysis was mean change from baseline in frequency of headache days at 24 weeks. Secondary endpoints were mean change from baseline to week 24 in frequency of migraine/probable migraine days, frequency of moderate/severe headache days, total cumulative hours of headache on headache days, frequency of headache episodes, frequency of migraine/probable migraine episodes, frequency of acute headache pain medication intakes, and the proportion of patients with severe (> or =60) Headache Impact Test-6 score at week 24. Results of the pooled analyses of the 2 PREEMPT double-blind phases are presented.

RESULTS

A total of 1384 adults were randomized to onabotulinumtoxinA (n = 688) or placebo (n = 696). Pooled analyses demonstrated a large mean decrease from baseline in frequency of headache days, with statistically significant between-group differences favoring onabotulinumtoxinA over placebo at week 24 (-8.4 vs -6.6; P < .001) and at all other time points. Significant differences favoring onabotulinumtoxinA were also observed for all secondary efficacy variables at all time points, with the exception of frequency of acute headache pain medication intakes. Adverse events occurred in 62.4% of onabotulinumtoxinA patients and 51.7% of placebo patients. Most patients reported adverse events that were mild to moderate in severity and few discontinued (onabotulinumtoxinA, 3.8%; placebo, 1.2%) due to adverse events. No unexpected treatment-related adverse events were identified.

CONCLUSIONS

The pooled PREEMPT results demonstrate that onabotulinumtoxinA is an effective prophylactic treatment for chronic migraine. OnabotulinumtoxinA resulted in significant improvements compared with placebo in multiple headache symptom measures, and significantly reduced headache-related disability and improved functioning, vitality, and overall health-related quality of life. Repeat treatments with onabotulinumtoxinA were safe and well tolerated.

OnabotulinumtoxinA for treatment of chronic migraine: results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 1 trial

OBJECTIVES

This is the first of a pair of studies designed to assess efficacy, safety and tolerability of onabotulinumtoxinA (BOTOX) as headache prophylaxis in adults with chronic migraine.

METHODS

The Phase III REsearch Evaluating Migraine Prophylaxis Therapy 1 (PREEMPT 1) is a phase 3 study, with a 24-week, double-blind, parallel-group, placebo-controlled phase followed by a 32-week, open-label phase. Subjects were randomized (1:1) to injections every 12 weeks of onabotulinumtoxinA (155 U-195 U; n = 341) or placebo (n = 338) (two cycles). The primary endpoint was mean change from baseline in headache episode frequency at week 24.

RESULTS

No significant between-group difference for onabotulinumtoxinA versus placebo was observed for the primary endpoint, headache episodes (-5.2 vs. -5.3; p = 0.344). Large within-group decreases from baseline were observed for all efficacy variables. Significant between-group differences for onabotulinumtoxinA were observed for the secondary endpoints, headache days (p = .006) and migraine days (p = 0.002). OnabotulinumtoxinA was safe and well tolerated, with few treatment-related adverse events. Few subjects discontinued due to adverse events.

CONCLUSIONS

There was no between-group difference for the primary endpoint, headache episodes. However, significant reductions from baseline were observed for onabotulinumtoxinA for headache and migraine days, cumulative hours of headache on headache days and frequency of moderate/severe headache days, which in turn reduced the burden of illness in adults with disabling chronic migraine.

OnabotulinumtoxinA for treatment of chronic migraine: results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 2 trial

OBJECTIVES

This is the second of a pair of studies designed to evaluate the efficacy and safety of onabotulinumtoxinA (BOTOX) for prophylaxis of headaches in adults with chronic migraine.

METHODS

PREEMPT 2 was a phase 3 study, with a 24-week, double-blind, placebo-controlled phase, followed by a 32-week, open-label phase. Subjects were randomized (1:1) to injections of onabotulinumtoxinA (155U-195U; n = 347) or placebo (n = 358) every 12 weeks for two cycles. The primary efficacy endpoint was mean change in headache days per 28 days from baseline to weeks 21-24 post-treatment.

RESULTS

OnabotulinumtoxinA was statistically significantly superior to placebo for the primary endpoint, frequency of headache days per 28 days relative to baseline (-9.0 onabotulinumtoxinA/-6.7 placebo, p < .001). OnabotulinumtoxinA was significantly favoured in all secondary endpoint comparisons. OnabotulinumtoxinA was safe and well tolerated, with few treatment-related adverse events. Few patients (3.5% onabotulinumtoxinA/1.4% placebo) discontinued due to adverse events.

CONCLUSIONS

The results of PREEMPT 2 demonstrate that onabotulinumtoxinA is effective for prophylaxis of headache in adults with chronic migraine. Repeated onabotulinumtoxinA treatments were safe and well tolerated.