Prognosis Following Discontinuation of OnabotulinumA Therapy in "Super-responding" Chronic Migraine Patients

The sense of stopping migraine prophylaxis

INTRODUCTION

Migraine prophylactic therapy has changed over recent years with the development and approval of monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway. As new therapies emerged, leading headache societies have been providing guidelines on the initiation and escalation of such therapies. However, there is a lack of robust evidence looking at the duration of successful prophylaxis and the effects of therapy discontinuation. In this narrative review we explore both the biological and clinical rationale for prophylactic therapy discontinuation to provide a basis for clinical decision-making.

METHODS

Three different literature search strategies were conducted for this narrative review. These include i) stopping rules in comorbidities of migraine in which overlapping preventives are prescribed, notably depression and epilepsy; ii) stopping rules of oral treatment and botox; iii) stopping rules of antibodies targeting the CGRP (receptor). Keywords were utilized in the following databases: Embase, Medline ALL, Web of Science Core collection, Cochran Central Register of Controlled Trials, and Google Scholar.

DISCUSSION

Reasons to guide decision-making in stopping prophylactic migraine therapies include adverse events, efficacy failure, drug holiday following long-term administration, and patient-specific reasons. Certain guidelines contain both positive and negative stopping rules. Following withdrawal of migraine prophylaxis, migraine burden may return to pre-treatment level, remain unchanged, or lie somewhere in-between. The current suggestion to discontinue CGRP(-receptor) targeted mAbs after 6 to 12 months is based on expert opinion, as opposed to robust scientific evidence. Current guidelines advise the clinician to assess the success of CGRP(-receptor) targeted mAbs after three months. Based on excellent tolerability data and the absence of scientific data, we propose if no other reasons apply, to stop the use of mAbs when the number of migraine days decreases to four or fewer migraine days per month. There is a higher likelihood of developing side effects with oral migraine preventatives, and so we suggest stopping these drugs according to the national guidelines if they are well tolerated.

CONCLUSION

Translational and basic studies are warranted to investigate the long-term effects of a preventive drug after its discontinuation, starting from what is known about the biology of migraine. In addition, observational studies and, eventually, clinical trials focusing on the effect of discontinuation of migraine prophylactic therapies, are essential to substantiate evidence-based recommendations on stopping rules for both oral preventives and CGRP(-receptor) targeted therapies in migraine.

Effectiveness and Safety of Chronic Migraine Preventive Treatments: A Systematic Literature Review

INTRODUCTION

Numerous medications are used for the preventive treatment of chronic migraine (CM), including oral treatments, onabotulinumtoxinA (onabotA; BOTOX), and calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs). Despite substantial clinical trial evidence, less is published about the real-world experience of these treatments based on data routinely collected from a variety of sources. This systematic review assessed real-world evidence on the effectiveness and safety of preventive treatments for CM in adults.

METHODS

A systematic search of MEDLINE, Embase, and the Cochrane library with back-referencing and supplementary searches retrieved data published between January 2010 and February 2020. Publications were screened, extracted, and quality assessed. Data were narratively synthesized. Search criteria included preventive medications for CM. Evidence was available for topiramate, onabotulinumtoxinA, CGRP mAbs (erenumab, galcanezumab, and fremanezumab). OnabotulinumtoxinA was most commonly assessed (55 studies), followed by erenumab (six studies), multiple CGRP mAbs (one study), and topiramate (one study). Long-term data (> 1 year) were available for onabotulinumtoxinA only, with erenumab reported up 6 months, topiramate up to 3 months, and multiple CGRP mAbs up to 12 months.

RESULTS

Substantial data demonstrated that onabotulinumtoxinA reduces the number/frequency of headaches, concomitant acute medication use, and impact of headaches on well-being and daily activity. More limited evidence showed benefits for the same parameters with erenumab. Single studies suggested topiramate and multiple CGRP mAbs decrease the number/frequency of headaches and impact of headaches. To date, onabotulinumtoxinA is the only preventive treatment for CM that has long-term safety data in real-world settings reporting treatment-related adverse events of up to 3 years.

CONCLUSION

While substantial real-world evidence supports the long-term effectiveness and safety of onabotulinumtoxinA, real-world data on other preventive treatments of CM are currently limited to short term effectiveness due to their more recent approvals.

OnabotulinumtoxinA: Still the Present for Chronic Migraine

OnabotulinumtoxinA (BT-A) is one of the few drugs approved for the preventive treatment of chronic migraine (CM). Despite this, some aspects of its mechanism of action are still a matter of debate, and the precise magnitude of BT-A effects needs to be completely elucidated. BT-A acts primarily upon trigeminal and cervical nerve endings, by inhibiting the release of inflammatory mediators such as calcitonin gene-related peptide, as well as reducing the insertion of ionotropic and metabotropic receptors into the neuronal membrane. These actions increase the depolarization threshold of trigeminal and cervical nerve fibers, thus reducing their activation. The central actions of BT-A are still a matter of debate: a retrograde axonal transport has been postulated, but not clearly assessed in humans. Clinically, the efficacy of BT-A in CM has been assessed by large, randomized placebo-controlled trials, such as the Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) trials. Those results were also confirmed in a wide range of open-label studies, even for long-term periods. Recently, novel findings have led to a better understanding of its pharmacological actions and clinical usefulness in migraine prevention. This narrative review summarizes, updates and critically revises the available data on BT-A and its possible implementation in chronic migraine. Moreover, the current role of BT-A in CM treatment has been discussed.

[Consensus statement of the migraine and headache societies (DMKG, ÖKSG, and SKG) on the duration of pharmacological migraine prophylaxis]

Migraine is the most common neurological disorder and can be associated with a high degree of disability. In addition to non-pharmacological approaches to reduce migraine frequency, pharmacological migraine preventatives are available. Evidence-based guidelines from the German Migraine and Headache Society (DMKG), and German Society for Neurology (DGN), Austrian Headache Society (ÖKSG), and Swiss Headache Society (SKG) are available for indication and application. For therapy-relevant questions such as the duration of a pharmacological migraine prevention, no conclusions can be drawn from currently available study data. The aim of this review is to present a therapy consensus statement that integrates the current data situation and, where data are lacking, expert opinions. The resulting current recommendations on the duration of therapy for pharmacological migraine prophylaxis are shown here.

[Consensus statement of the migraine and headache societies (DMKG, ÖKSG, and SKG) on the duration of pharmacological migraine prophylaxis]

Migraine is the most common neurological disorder and can be associated with a high degree of disability. In addition to non-pharmacological approaches to reduce migraine frequency, pharmacological migraine preventatives are available. Evidence-based guidelines from the German Migraine and Headache Society (DMKG), and German Society for Neurology (DGN), Austrian Headache Society (ÖKSG), and Swiss Headache Society (SKG) are available for indication and application. For therapy-relevant questions such as the duration of a pharmacological migraine prevention, no conclusions can be drawn from currently available study data. The aim of this review is to present a therapy consensus statement that integrates the current data situation and, where data are lacking, expert opinions. The resulting current recommendations on the duration of therapy for pharmacological migraine prophylaxis are shown here.

Excellent Response to OnabotulinumtoxinA: Different Definitions, Different Predictors

The identification of patients who can benefit the most from the available preventive treatments is important in chronic migraine. We explored the rate of excellent responders to onabotulinumtoxinA in a multicenter European study and explored the predictors of such response, according to different definitions. A pooled analysis on chronic migraineurs treated with onabotulinumtoxinA and followed-up for, at least, 9 months was performed. Excellent responders were defined either as patients with a ≥75% decrease in monthly headache days (percent-based excellent responders) or as patients with <4 monthly headache days (frequency-based excellent responders). The characteristics of excellent responders at the baseline were compared with the ones of patients with a <30% decrease in monthly headache days. Percent-based excellent responders represented about 10% of the sample, whilst frequency-based excellent responders were about 5% of the sample. Compared with non-responders, percent-based excellent responders had a higher prevalence of medication overuse and a higher excellent response rate even after the 1st and the 2nd injection. Females were less like to be frequency-based excellent responders. Chronic migraine sufferers without medication overuse and of female sex may find fewer benefits with onabotulinumtoxinA. Additionally, the excellent response status is identifiable after the first cycle.

OnabotulinumtoxinA in Migraine: A Review of the Literature and Factors Associated with Efficacy

The efficacy of onabotulinumtoxinA (OnaB-A) as a preventative treatment for chronic migraine, emerging fortuitously from clinical observation is now supported by class one evidence and over two decades of real-world clinical data. There is still limited ability to predict a clinically meaningful response to OnaB-A for individual patients, however. This review summarises briefly the proposed mechanism of OnaB-A in chronic migraine, the literature of predictors of clinical response, and recent developments in the field.

Chronic Migraine and Medication Overuse Headache Worsening After OnabotulinumtoxinA Withdrawn Due to the Severe Acute Respiratory Syndrome-Coronavirus-2 Pandemic

Introduction: OnabotulinumtoxinA (BT-A) is a preventive treatment for chronic migraine (CM), which needs to be administered regularly by a trained clinician every 3 months. The spread of the severe acute respiratory syndrome coronavirus-2 pandemic has forced many patients to momentarily stop the scheduled BT-A injections. The goal of this study was to explore whether those patients experienced a worsening of their CM and, if any, the clinical predictors of migraine worsening after BT-A withdrawal.

Methods: This was a retrospective, multicenter study. Patients' clinical data were obtained from their clinical documentation stored at each center. In particular, the following variables were collected: the mean number of headache days in the last month (NHD), the average number of painkillers taken in the last month (AC), the average number of days in which patients took, at least, one painkiller in the last month (NDM), the average intensity of migraine using the numeric rating scale (NRS) score in the last month, and the average score obtained at the six-item Headache Impact Test. The variables mentioned earlier were compared before and after BT-A withdrawal.

Results: After BT-A suspension, there was a significant increase in the NHD (P = 0.0313, Kruskal–Wallis rank test), AC (P = 0.0421, Kruskal–Wallis rank test), NDM (P = 0.0394, paired t-test), NRS score (P = 0.0069, Kruskal–Wallis rank test), and six-item Headache Impact Test score (P = 0.0372, Kruskal–Wallis rank test). Patients who were not assuming other preventive treatments other than BT-A displayed similar results. Patients who experienced a >30% worsening in NHD after BT-A was withdrawn displayed a longer CM history (P = 0.001, Kruskal–Wallis rank test), a longer MOH duration (P = 0.0017, Kruskal–Wallis rank test), a higher AC value at the baseline (P = 0.0149, Kruskal–Wallis rank test), a higher NDM (P = 0.0024, t-test), and a higher average value of the NRS score (P = 0.0073, Kruskal–Wallis rank test).

Conclusion: BT-A withdrawn during severe acute respiratory syndrome coronavirus-2 pandemic was associated with a general worsening in patients suffering from CM, hence the need to continue BT-A injection to avoid patients' worsening.

Botulinum Toxin in the Treatment of Headache

Botulinum toxin type A has been used in the treatment of chronic migraine for over a decade and has become established as a well-tolerated option for the preventive therapy of chronic migraine. Ongoing research is gradually shedding light on its mechanism of action in migraine prevention. Given that its mechanism of action is quite different from that of the new monoclonal antibodies directed against calcitonin gene-related peptide (CGRP) or its receptor, it is unlikely to be displaced to any major extent by them. Both will likely remain as important tools for patients with chronic migraine and the clinicians assisting them. New types of botulinum toxin selective for sensory pain neurons may well be discovered or produced by recombinant DNA techniques in the coming decade, and this may greatly enhance its therapeutic usefulness. This review summarizes the evolution of botulinum toxin use in headache management over the past several decades and its role in the preventive treatment of chronic migraine and other headache disorders.

Effectiveness, Safety, and Health-Related Quality of Life of Chronic Migraine Patients Treated with Onabotulinum Toxin A

OBJECTIVE

The present study aims to describe the efficacy and safety of onabotulinum toxin A (BonT-A) with evaluation of treatment satisfaction and impact on quality of life in chronic migraine (CM) patients in real life.

METHODS

This study was conducted in CM patients who were treated with BoNT-A with 12 months of follow-up. Data about outcome, adverse events, and patients' pre- and post-treatment status including health-related quality of life data were analyzed. Health-related quality of life scores were measured at baseline and months 6 and 12 after the beginning of BoNT-A administration.

RESULTS

Of 42 enrolled patients, 30 were included in the analysis. At 12 months, all patients showed a reduction in number of headaches and analgesic use per month and none reported adverse events. After BoNT-A supplementation, health-related quality-of-life scores improved significantly. There was a direct association between health-related quality of life with reduction of headache days at the end of study.

CONCLUSION

This study confirms that BoNT-A treatment is effective on CM and improves the functional well-being and quality of life of patients.

Wear-Off of OnabotulinumtoxinA Effect Over the Treatment Interval in Chronic Migraine: A Retrospective Chart Review With Analysis of Headache Diaries

OBJECTIVE

To quantify wear-off of the response to OnabotulinumtoxinA (OnabotA) treatment over the treatment cycle in chronic migraine at group and individual level.

BACKGROUND

OnabotA administered quarterly is an effective treatment for chronic migraine. However, some patients report that headache recurs before the scheduled follow-up injection.

METHODS

In this retrospective chart review performed in 6 university outpatient centers or private practices specialized in headache treatment, 112 patients with a ≥30% response to OnabotA who completed headache diaries over 13 weeks after OnabotA treatment were included (age [mean ± SD] 45 ± 12 years, 82% female, headache days/month at baseline 24 ± 6).

RESULTS

Compared to weeks 5 to 8 after injection, headache days/week increased significantly in weeks 12 (+0.52 ± 1.96, 95% CI [0.15, 0.88], P < .009) and 13 (+1.15 ± 1.95, CI[0.79, 1.52], P < .001), demonstrating significant wear-off of the OnabotA effect. Similarly, acute medication days/week significantly increased in weeks 12 (0.38±1.67, CI [0.06, 0.69], P ≤ .027) and 13 (+0.83 ± 1.76, CI [0.49, 1.16], P < .001). At an individual level, 57 patients (51%) showed ≥30% wear-off by weeks 12 and 13, and 28 patients (25%) showed ≥30% wear-off already by weeks 10 and 11. Age, gender, OnabotA dose or cycle number, or headache center did not predict individual wear-off.

CONCLUSIONS

These data show that in clinical practice, on average the response of chronic migraine patients to OnabotA injection shows a clinically significant wear-off from week 12 after treatment. About 25% of the patients experience wear-off even by weeks 10 and 11. It must be noted that wear-off detected in a real-world study on OnabotA responders can be due to wear-off of a pharmacological OnabotA effect or a placebo effect, or to regression to the mean effects. This wear-off phenomenon may negatively affect quality of life of chronic migraine patients under OnabotA treatment. The best way to counteract wear-off remains to be determined.