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

Insights from 25 years of onabotulinumtoxinA in migraine - mechanisms and management

OnabotulinumtoxinA (BTX-A) was first linked to beneficial effects in migraine 25 years ago and was approved by the FDA for preventive treatment of chronic migraine in 2010. The treatment has since had a major impact on the well-being of people with chronic migraine. The clinical development programme for BTX-A and research since its approval have provided insights into the neuromodulatory sensory effect of BTX-A, how it can control chronic migraine despite its peripheral action, and the underlying biology of migraine as a disease. In this Review, we consider the impact that BTX-A has had on the management of chronic migraine and on the research field. We discuss the insights provided by clinical research, encompassing the clinical trials and subsequent real-world evidence, and the mechanistic insights provided by preclinical and translational research. We also provide an overview of future directions of research in the field BTX-A in migraine and the clinical translation of this research.

Open label experience of repeated OnabotulinumtoxinA injections towards the sphenopalatine ganglion in patients with chronic cluster headache and chronic migraine

BACKGROUND

A novel technique for injection of OnabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) has shown promise in refractory chronic migraine (CM) and chronic cluster headache (CCH). Open label safety and efficacy data are presented here.

METHODS

Patients with refractory CM or CCH who had received at least one injection and completed headache diaries were included. Efficacy was defined as ≥50% reduction in moderate-to-severe headache days for CM, or ≥50% reduction in attack frequency for CCH, at weeks five to eight.

RESULTS

Over 261 injections, there were 123 adverse events (AE), of which one was serious. Most (93%) AEs were mild and all were transient. The 50% response to one injection was 81% for CM and 69% for CCH. The response gradually reduced over subsequent months for CM but stayed between 55% and 67% for CCH. Repeated injections were beneficial.

CONCLUSIONS

Injections resulted in improvement for both groups and was maintained with repeated injections. Repeat injection after three months may be beneficial in CM. Adverse events were not uncommon, but universally transient, presumably as a result of the mechanism of action of BTA. Repeated BTA injection towards the SPG could be an effective treatment for refractory CM and CCH. Larger, randomised, placebo-controlled trials are required.

Substance P-Botulinum Mediates Long-term Silencing of Pain Pathways that can be Re-instated with a Second Injection of the Construct in Mice

Chronic pain presents an enormous personal and economic burden and there is an urgent need for effective treatments. In a mouse model of chronic neuropathic pain, selective silencing of key neurons in spinal pain signalling networks with botulinum constructs resulted in a reduction of pain behaviours associated with the peripheral nerve. However, to establish clinical relevance it was important to know how long this silencing period lasted. Now, we show that neuronal silencing and the concomitant reduction of neuropathic mechanical and thermal hypersensitivity lasts for up to 120d following a single injection of botulinum construct. Crucially, we show that silencing and analgesia can then be reinstated with a second injection of the botulinum conjugate. Here we demonstrate that single doses of botulinum-toxin conjugates are a powerful new way of providing long-term neuronal silencing and pain relief. PERSPECTIVE: This research demonstrates that botulinum-toxin conjugates are a powerful new way of providing long-term neuronal silencing without toxicity following a single injection of the conjugate and have the potential for repeated dosing when silencing reverses.

Pericranial Muscle Stiffness, Pain Thresholds, and Tenderness during a Treatment Cycle of OnabotulinumtoxinA for Chronic Migraine Prevention

BACKGROUND

Treatment with OnabotulinumtoxinA (BoNT-A) is effective as a preventive treatment for chronic migraine (CM). Preclinical studies suggest that the mechanism of action of BoNT-A in migraine is based on blocking unmyelinated C fibers. We aimed to investigate whether the muscle-relaxing effect of BoNT-A is associated with the preventive mechanism in patients with chronic migraine by measuring the stiffness, pain thresholds, and tenderness of the BoNT-A-applied muscles.

METHODS

A total of 22 patients with CM who were already in BoNT-A treatment participated in this longitudinal prospective study. Pericranial muscle stiffness was measured using ultrasound shear wave elastography, which measures the speed of shear waves propagating through the muscle. Pressure pain thresholds (PPT) were obtained via algometry, and muscle tenderness was measured via manual palpation. Measurements were made before BoNT-A injections and six weeks after the treatment. The measurements were performed while the muscles were maximally relaxed. The patients also completed daily diaries on headache and neck pain.

RESULTS

No change was observed in muscle stiffness (p = 0.737) or pericranial muscle tenderness (p = 0.400). The PPT over the trapezius muscles increased from 250 kPa before treatment to 304 kPa six weeks after treatment (p = 0.027). No change was observed on the temporalis muscles (p = 0.200) nor the non-dominant index finger (p = 0.067). BoNT-A decreased neck pain (p = 0.008) and headache (p = 0.007).

CONCLUSIONS

The findings suggest that BoNT-A leads to the desensitization of cutaneous and muscle nociceptors in the head and neck regions, whereas muscle relaxation might not be an important part of the anti-migraine effect.

A Retrospective Comparison of Onabotulinum Toxin A and Incobotulinum Toxin A in Terms of Efficacy, Tolerability, Duration of Effect, and Pain on Injection Administration Site for the Treatment of Chronic Migraine

Background Onabotulinum toxin A (OnA) is a well-tolerated and effective treatment for chronic migraine (CM). However, based on research indications that incobotulinum toxin A (InA) would be equally effective, a Veterans Health Administration medical center mandated a two-year trial of InA as a more cost-effective alternative to OnA. Although InA is used for many similar indications as OnA, it is not Food and Drug Administration-approved for treating CM, and complications occurred in several patients with CM following this treatment change. We conducted this retrospective analysis to evaluate differences in the efficacy of OnA and InA and identify the reasons for the adverse effects of InA in some of these patients. Methods We performed a retrospective review of 42 patients who had been effectively treated with OnA and were then switched to InA. The differences between treatment responses to OnA and InA were assessed through the evaluation of pain on injection, number of headache days, and duration of action. Patients received injections at 10- to 13-week intervals. Those who reported severe pain on injection of InA were switched back to OnA. Results Severe burning pain on InA injection was reported by 38% of patients (nine males and seven females, i.e., a total of 16 patients out of 42 patients). One male patient reported the same degree of pain from both InA and OnA injections. A total of 66.7% of women with obesity and 83.3% of men with obesity or diabetes experienced severe pain on injection. Neither migraine suppression nor the duration of effect was significantly different between OnA and InA. Conclusions OnA is better tolerated than InA in the treatment of CM. InA appears to effectively suppress migraines, but some patients complain of a severe localized burning sensation during the injections. Some of these patients, all of whom were previously treated with OnA, requested to switch back to OnA. This suggested that InA is not equivalent to OnA in terms of tolerability and effectiveness. The present study found 2.38% of patients experienced an insufficient duration of effect with InA, and none with OnA. However, these lower rates may, in part, be due to variability in injection intervals in this sample, which could be because of scheduling considerations at the Harry S. Truman Veterans Health Administration Medical Center. In cases where OnA fails because of the development of antibodies, it might be reasonable to switch to InA treatment. Reformulation of InA with a pH-buffered solution may eliminate the difference in pain on injection. InA would then be a good alternative to OnA for treating CM.

Early Wearing-Off Effect of OnabotulinumtoxinA in Chronic Migraine: A Prospective Real-Life Study

OBJECTIVE

Chronic migraine (CM) is a significant public health problem that affects 2.2% of the global population. Onabotulinumtoxin A (OnabotA) is a safe and effective prophylactic treatment for patients with CM. The standard injection interval for OnabotA is 12 weeks. Nevertheless, some patients experience a wearing-off effect (WOE) in the weeks preceding the next scheduled cycle. The objectives of this study are to determine the prevalence of early WOE, to analyze variables that could be clinical predictors and to specify which interval is the most appropriate to define the existence of this phenomenon.

METHODS

This is a prospective single-center study of consecutive adult patients with CM who, after failing previous prophylactic therapies, started OnabotA treatment following the PREEMPT protocol between June and December of 2021.

RESULTS

A total of 59 patients (93.2% female, age 44 ± 12 years) were included. A total of 37 patients (64.9%) fulfilled medication overuse criteria. Of the total patients, 40.6% reported WOE and this was more frequent after the first cycle (35.6%). Depression and anxiety disorder was a statistically significant clinical predictor of WOE (OR 3.4; CI 95% 1.22-10.84; p = 0.028). A better cut-off point to consider WOE seems to be at 10 weeks.

CONCLUSIONS

Early WOE is common in patients on OnabotA treatment for CM. Individualizing the standard 12-week injection, using total doses of 195 U, and managing psychiatric comorbidities with pharmacological and non-pharmacological strategies may improve treatment outcomes and reduce OnabotA WOE.

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.

Migraine Prevention with Erenumab: Focus on Patient Selection, Perspectives and Outcomes

Erenumab is a monoclonal antibody targeting the calcitonin gene-related peptide (CGRP) receptor suitable for episodic and chronic migraine prevention. Randomized clinical trials proved the superiority of erenumab to placebo in a strictly selected population, while real-world studies confirmed treatment efficacy in more severe forms of disease – most patients suffered from chronic migraine with medication overuse headache, had prior treatment failures, and long disease duration. According to guidelines, anti-CGRP pathway monoclonal antibodies should be reserved to patients who failed or have contraindication to several classes of preventive treatments. However, their ease of use, tolerability and efficacy make these monoclonal antibodies ideally suitable for most patients with migraine; cost-effectiveness needs to be considered when looking at expanding current prescription criteria. Also, data from open label extensions of randomized control trials confirmed sustained benefits of prolonged treatment up to 5 consecutive years without significant risk of adverse events. Further studies will provide insights on optimal treatment duration to achieve migraine remission and predictors of treatment response. In the present work, we aimed at reviewing design and results of the main studies on erenumab and discussing treatment use in the current migraine prevention scenario; we also summarized the main ongoing research projects and provided clinical perspectives for the future.

FollowTheSutures: Piloting a new way to administer onabotulinumtoxinA for chronic migraine

Background

Anatomical and experimental data indicate that onabotulinimtoxin A could be more efficient and cost-effective for treating chronic migraine with injections targeting the cranial sutures, where collaterals from the meninges penetrate the skull.

Methods

A new injection paradigm (FollowTheSutures) was tested for safety, tolerability and feasibility in a Phase II, open-label, non-controlled, single-center pilot study. Ninety units of onabotulinimtoxin A (Botox®), were injected in 18 sites over the area of the cranial sutures. Adverse events and potential beneficial effects were recorded in a headache diary at least 4 weeks before, and for 12 weeks after the injections. A higher dilution than normal of onabotulinimtoxin A was used to get better diffusion.

Results

Nineteen (of 20 included) women with chronic migraine received the injections and were evaluable. There was only one treatment-related adverse event (reduced power of chewing for some weeks). Otherwise, the procedure was overall well tolerated. Patients improved on most efficacy parameters after the injections. There was little or no effect on glabellar or forehead lines.

Conclusions

The protocol was safe and well tolerated. Lower risk of unblinding due to the absence of cosmetic effects should make the injection procedure well suited for a large, randomized, placebo-controlled study. If efficacy is confirmed, it will be markedly less costly than the standard procedure.

Trial registration: EUDRACT (2017-002516-13), ClinicalTrials.gov (NCT03543254).

Does “wearing off” of efficacy occur in galcanezumab‐treated patients at the end of the monthly treatment cycle? Post hoc analyses of four phase III randomized trials

Objective

The purpose of this study was to propose a definition of “wearing off” at the individual patient‐level and determine the percentage of patients with migraine who experience “wearing off” of efficacy of galcanezumab at the end of a treatment cycle using this predefined threshold.

Background

Anecdotal reports suggest that some patients may experience “wearing off” of efficacy during the last week of their calcitonin gene‐related peptide monoclonal antibody treatment cycle. A previous post hoc analysis of galcanezumab demonstrated consistent efficacy at each week throughout all monthly dosing intervals at the population‐level, but “wearing off” has not been assessed at the individual patient‐level.

Methods

Post hoc analyses of clinical trial data from four galcanezumab phase III, randomized, placebo‐controlled studies in a total of 2680 patients with high‐frequency episodic migraine (EVOLVE‐1, EVOLVE‐2, and CONQUER studies) or chronic migraine (CM; REGAIN and CONQUER studies) were conducted. “Wearing off” was defined as an increase of greater than or equal to 2 weekly migraine headache days in the last week of the treatment cycle compared to the second week for at least 2 months. The analyses were conducted (1) in all patients and (2) in patients with a clinically meaningful response to treatment.

Results

The percentage of patients meeting the threshold of “wearing off” was not statistically significantly different among the placebo, galcanezumab 120 mg, and galcanezumab 240 mg treatment groups, both in the total population and in patients with a clinically meaningful response (all ≤9.0%). Although the frequency of “wearing off” in patients with CM and prior preventive failures was numerically greater in the galcanezumab groups (8/89 or 9.0%) compared to placebo (3/95 or 3.2%), these differences were not statistically significant.

Conclusions

Consistent with previous analyses at the population‐level that showed no evidence of decreased efficacy at the end of a treatment cycle, rates of individual patients meeting the threshold of “wearing off” in this analysis were low and similar among placebo, galcanezumab 120 mg, and galcanezumab 240 mg treatment groups.

Botulinum toxin type A wear-off phenomenon in chronic migraine patients: how long does the maximum efficiency last?

BACKGROUND

Botulinum toxin Type A (BoNTA) is a successful treatment for chronic migraine prophylaxis.

OBJECTIVE

We aimed to evaluate the monthly change of effectiveness of BoNTA treatment.

METHODS

A total of 80 patients (70 females and 10 males) with chronic migraine were included. In our study protocol, we applied to 155 U across 31 fixed-sites and if the patient had pain, 40 U dose injections were applied across 8 specific head/neck muscle areas. Headache days and analgesic intake were noted before the BoNTA injection and during the interviews at the first, second, and third months after the BoNTA injection.

RESULTS

The mean age was 37.59 ± 7.60 and 87.5% of the patients were female. The mean number of headache days/month before BoNTA was 18.95±2.69, decreasing to 10.55±3.15 days/month in the first month (p<0.001), 9.31±2.43 days/month in the second month (p<0.001), and increased to 11.97±3.27 days/month in the third month (p<0.001). The mean analgesic intake before BoNTA was 11.48±4.68 tablets/month, while it decreased to 6.53±2.72 tablets/month in the first month (p<0.001) and 5.40±2.46 tablets/month in the second month (p<0.001). In the third month, it was 5.85±2.59 tablets/month (p<0.001). There was a significant increase in pain medication use from the second to the third month (p<0.001).

CONCLUSION

In our study, there was a significant reduction in analgesic intake and headache days in the first and second months after BoNTA injection, and an increase was observed in the third month.

OnabotulinumtoxinA in Chronic Migraine: A Profile of Its Use

OnabotulinumtoxinA (Botox^®; a formulation of botulinum toxin type A (BoNT/A)] is indicated for the prevention of headaches in adults with chronic migraine (CM) in numerous countries, including those of Europe. In clinical trials, intramuscular administration of BoNT/A (155-195 units at 12-week intervals) to patients with CM was generally well tolerated and associated with sustained and clinically meaningful improvements in multiple assessments of headache symptoms, headache-related impact and/or disability and migraine-specific health-related quality of life over a period of 1 year (in the pivotal PREEMPT 1 and 2 studies) and 2 years (in the phase IV COMPEL study). The efficacy and safety of BoNT/A therapy have been confirmed in a number of large, prospective, real-world studies conducted in Europe, including the 2-year REPOSE study. Intramuscular BoNT/A has also demonstrated greater clinical utility than the oral prophylactic medication topiramate in a clinical practice setting (FORWARD study).