Shaping the future of migraine targeting Calcitonin-Gene-Related-Peptide with the Disease-Modifying Migraine Drugs (DMMDs)

Long-Term Outcome After Discontinuation of CGRP-Targeting Therapy for Migraine

PURPOSE OF REVIEW

Calcitonin gene-related peptide (CGRP)-targeting agents are potential candidates for disease-modifying migraine drugs. However, most studies on CGRP-targeting agents have assessed efficacy outcomes rather than long-term effects after discontinuation. This review aimed to synthesize and scrutinize the latest clinical data on the outcomes after the discontinuation of CGRP-targeting therapy in patients with episodic and chronic migraine, with a particular focus on chronic migraine.

RECENT FINDINGS

Real-world studies involving patients with migraine have reported consistent findings of worsened headache frequency and quality of life after the discontinuation of CGRP monoclonal antibodies (CGRP mAbs). Although many patients maintain improvements for up to 4 months after discontinuation compared to baseline (before starting CGRP mAbs), no studies have evaluated the effects of stopping treatment for > 5 months, which is the five-half-life of CGRP mAbs. Several studies have suggested that patients treated with CGRP receptor mAbs experience more rapid deterioration than those treated with CGRP ligand mAbs after discontinuing CGRP mAbs. The results of real-world studies suggest that for many patients with migraine, the benefits of CGRP mAbs diminish months after discontinuation. Therefore, anti-CGRP therapies may not be considered disease-modifying. However, the comprehensive assessment of the disease-modifying potential of these drugs requires studies with extended treatment and cessation durations.

Towards precision medicine in migraine: Recent therapeutic advances and potential biomarkers to understand heterogeneity and treatment response

After 35 years since the introduction of the International Classification of Headache Disorders (ICHD), we are living in the era of the second great revolution in migraine therapies. First, discoveries of triptans provided a breakthrough in acute migraine treatment utilizing bench-to-bedside research results on the role of serotonin in migraine. Next, the discovery of the role of neuropeptides, more specifically calcitonin gene-related peptide (CGRP) in migraine attack led to the development of anti-CGRP therapies that are effective both in acute and preventive treatment, and are also able to reduce migraine-related burden. Here, we reviewed the most recent clinical studies and real-world data on available migraine-specific medications, including triptans, ditants, gepants and anti-CGRP monoclonal antibodies. Novel drug targets, such as PACAP and amylins were also discussed. To address the main challenges of migraine therapy, the high heterogeneity of people with migraine, the prevalent presence of various comorbid disorders, and the insufficient medical care of migraine patients were covered. Promising novel approaches from the fields of omics, blood and saliva biomarker, imaging and provocation studies might bring solutions for these challenges with the potential to identify further drug targets, distinguish more homogeneous patient subgroups, contribute to more optimal drug selection strategies, and detect biomarkers in association with headache features or predicting treatment efficacy. In the future, the combined analysis of data of different biomarker modalities with machine learning algorithms may serve precision medicine in migraine treatment.

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.

Advances in CGRP Monoclonal Antibodies as Migraine Therapy: A Narrative Review

Migraine is a potentially disabling disorder, yet it remains underdiagnosed and undertreated. The release of the neuropeptide calcitonin gene-related peptide (CGRP) in the trigemino-cerebrovascular system plays a vital role in the evolution of migraine. It enhances peripheral sensitization by mediating neurogenic inflammation and also influences central sensitization. The majority of the drug classes available for migraine prophylaxis are nonspecific and associated with numerous side effects and drug interactions. Anti-CGRP monoclonal antibodies (mAb) are an innovative therapeutic class that fulfills the need for more efficacious and tolerable preventive therapy. While erenumab is a mAb to the CGRP receptor, eptinezumab, fremanezumab, and galcanezumab bind to the CGRP molecule. They decrease the number of headache days and improve disability. Upper respiratory tract infection, nausea, constipation, pain at the site of injection, and fatigue are the associated side effects. CGRP mAbs are an excellent advancement in translational research and are a promising addition in migraine therapy. This article discusses the recent advances in the development of the CGRP mAbs.

Focus on zavegepant: the first intranasal third-generation gepant

Migraine is the leading cause of years lived with disability in people under 50 and its burden is increased by calcitonin gene-related peptide (CGRP)-driven chronicity. Newly approved small molecules that antagonize the CGRP receptor, gepants, have advanced from the hepatotoxic first-generation telcagepant to third-generation intranasal zavegepant; during this process of drug development, rimegepant, ubrogepant and atogepant, which are orally administered, have been launched and approved for clinical use with no warning for hepatotoxicity. Real-world, long-term postmarketing data about the efficacy and safety of gepants are awaited. The aim of the present drug evaluation study was to provide an overview of the novel, third-generation intranasal Zavegepant, encompassing its development and future perspectives.

Calcitonin gene-related peptide (CGRP) is a key molecule released in acute migraine attacks-Successful translation of basic science to clinical practice

Migraine is a highly prevalent neurovascular disorder afflicting more than 15% of the global population. Nearly three times more females are afflicted by migraine in the 18-50 years age group, compared to males. Migraine attacks are most often sporadic, but a subgroup of individuals experience a gradual increase in frequency over time; among these, up to 1%-2% of the global population develop chronic migraine. Although migraine symptoms have been known for centuries, the underlying mechanisms remain largely unknown. Two theories have dominated the current thinking-a neurovascular theory and a central neuronal theory with the origin of the attacks in the hypothalamus. During the last decades, the understanding of migraine has markedly advanced. This is supported by the early seminal demonstration of the trigeminovascular reflex 35 years ago and the insight that calcitonin gene-related peptide (CGRP) is a key molecule released in acute migraine attacks. The more recent findings that gepants, small molecule CGRP receptor blockers, and monoclonal antibodies generated against CGRP, or its canonical receptor are useful for the treatment of migraine, are other important issues. CGRP has been established as a key molecule in the neurobiology of migraine. Moreover, monoclonal antibodies to CGRP or the CGRP receptor represent a breakthrough in the understanding of migraine pathophysiology and have emerged as an efficacious prophylactic treatment for patients with severe migraine with excellent tolerability. This review describes the progression of research to reach the clinical usefulness of a large group of molecules that have in common the interaction with CGRP mechanisms in the trigeminal system to alleviate the burden for individuals afflicted by migraine.

Novel Migraine Therapies May Reduce Public and Personal Disadvantages for People with Migraine

The introduction of new drug classes for migraine, such as monoclonal antibodies that target the calcitonin gene-related peptide (CGRP) or its receptor and small-molecule antagonists of CGRP, have opened a new scenario in a large population of individuals suffering from migraines. The provision of an effective and safe therapy can help overcome the high social and personal costs together with the burden of this disease by offering social, work and economic recovery to the people affected by migraine. Whether the satisfaction of personal and collective unmet needs will be achieved in the vast majority of migraine sufferers now depends only on the efficiency of the organizational care structures dedicated to this socially impactful disease. This path will offer personal benefits and significant psychosocial relief that will help to reduce the enormous current healthcare expenditure necessary for the management of the huge number of individuals suffering from migraines. The new pharmacological classes for prevention must be applied as an interdiction to the chronic phase to express their full rehabilitation potential.

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.

Real world considerations for newly approved CGRP receptor antagonists in migraine care

INTRODUCTION

Migraine is the leading cause of years lived with disability in people under 50 . Electrophysiological phenomena at the basis of prodromal and headache attack phases and of chronification processes involve calcitonin-gene related peptide (CGRP) as a fundamental player become a game changer of migraine pharmacotherapy.Areas covered: The purpose of the present review is to retrace fundamental stages of CGRP from its discovery to the role in migraine pathogenesis and therapy to underscore the change of paradigm offered by the newly approved small molecules to antagonize CGRP receptor, the gepants. In particular, the development of this new class is gone over from the initial synthesis of C-terminus truncated CGRP antagonists to the development of the first generation of gepants ending with Zavegepant that can be considered the third generation.Expert opinion: The history of CGRP in migraine draws the successful road to follow for key signaling pathways of modulation of nociceptive facilitation by diencephalic and brainstem nuclei, including dopaminergic neurotransmission, orexin A and the large-conductance calcium-activated potassium (BK_Ca) and ATP-sensitive potassium (K_ATP) channels also investigating the potential of essential oils and the role of polymorphisms. Real-world post marketing long-term data are needed for gepants.

Efficacy and safety of anti-CGRP(r) monoclonal antibodies in real clinical practice: preliminary analysis after three months of therapy

Monoclonal antibodies inhibiting calcitonin gene related peptide (CGRP) or its receptor have been widely used for migraine prophylactic therapy for the past three years. Evaluation of their efficacy and safety of therapy in real clinical practice is needed.Objective: to evaluate the efficacy and safety of Erenumab, a monoclonal antibody inhibiting the CGRP receptor during three months of therapy.Patients and methods. Sixty-eight patients (58 women and 10 men, mean age 37±10.4 years) with episodic or chronic migraine who were treated with Erenumab were observed. Patients were assessed with MIDAS, WPAI, and HADS scales; the presence of cutaneous allodynia was evaluated with ASC-12 questionnaire. Patients kept a headache diary and marked adverse events during the whole treatment period.Results and discussion. 47 patients (69%) had chronic migraine and 32 (71.9%) had medication overuse headache. In 48 patients (70%) after 3 injections of Erenumab the number of days with migraine decreased by 50% or more. In 7 patients (10%), the reduction in headache days was more than 75%; 20 (29%) did not experience sufficient effect after three months of therapy. Nineteen adverse events were noted in 15 (22%) patients. Severe constipation led to discontinuation of treatment in two patients (3%).Conclusion. The study showed the efficacy and safety of Erenumab for migraine prophylaxis in both patients with episodic and chronic migraine.

Preventive treatment with CGRP monoclonal antibodies restores brain stem habituation deficits and excitability to painful stimuli in migraine: results from a prospective case-control study

Background & Objectives

Calcitonin gene-related peptide ligand/receptor (CGRP) antibodies effectively reduce headache frequency in migraine. It is understood that they act peripherally, which raises the question whether treatment merely interferes with the last stage of headache generation or, alternatively, causes secondary adaptations in the central nervous system and might thus possess disease modifying potential. This study addresses this question by investigating the nociceptive blink reflex (nBR), which is closely tied to central disease activity, before and after treatment with CGRP antibodies.

Methods

We enrolled 22 patients suffering episodic migraine (21 female, 46.2 ± 13.8 years of age) and 22 age-/gender-matched controls. Patients received assessments of the nBR (R2 component, 10 trials, 6 stimuli/trial) before (V0) and three months (V3) after treatment with CGRP antibodies started, controls were assessed once. The R2 area (R2a) and habituation (R2h; gradient of R2a against stimulus order) of the stimulated/non-stimulated side (_s/_ns) following repeated supraorbital stimulation provide a direct readout of brainstem excitability and habituation as key mechanisms in migraine.

Results

All patients showed a substantial reduction of headache days/month (V0: 12.4±3.3, V3: 6.6 ± 4.9). R2a_s (F_global=5.86, p<0.001; block 1: R2a_s: -28%, p<0.001) and R2a_ns (F_global=8.22, p<0.001, block 1: R2a_ns: -22%, p=0.003) were significantly decreased, and R2h_ns was significantly enhanced (F_global=3.07, p<0.001; block 6: R2h_ns: r=-1.36, p=0.007) from V0 to V3. The global test for changes of R2h_s was non-significant (F_global=1.46, p=0.095). Changes of R2h significantly correlated with improvement of headache frequency (R2h_s, r=0.56, p=0.010; R2h_ns: r=0.45, p=0.045). None of the nBR parameters assessed at baseline predicted treatment response.

Discussion

We provide evidence that three months of treatment with CGRP antibodies restores brain stem responses to painful stimuli and thus might be considered disease modifying. The nociceptive blink reflex may provide a biomarker to monitor central disease activity. Future studies should evaluate the blink reflex as a clinical biomarker to predict treatment response at baseline and to establish the risk of relapse after treatment discontinuation.

Trial registration

This trial was prospectively registered at clinicaltrials.gov (ID: NCT04019496, date of registration: July 15, 2019).

Burden and attitude to resistant and refractory migraine: a survey from the European Headache Federation with the endorsement of the European Migraine & Headache Alliance

BACKGROUND

New treatments are currently offering new opportunities and challenges in clinical management and research in the migraine field. There is the need of homogenous criteria to identify candidates for treatment escalation as well as of reliable criteria to identify refractoriness to treatment. To overcome those issues, the European Headache Federation (EHF) issued a Consensus document to propose criteria to approach difficult-to-treat migraine patients in a standardized way. The Consensus proposed well-defined criteria for resistant migraine (i.e., patients who do not respond to some treatment but who have residual therapeutic opportunities) and refractory migraine (i.e., patients who still have debilitating migraine despite maximal treatment efforts). The aim of this study was to better understand the perceived impact of resistant and refractory migraine and the attitude of physicians involved in migraine care toward those conditions.

METHODS

We conducted a web-questionnaire-based cross-sectional international study involving physicians with interest in headache care.

RESULTS

There were 277 questionnaires available for analysis. A relevant proportion of participants reported that patients with resistant and refractory migraine were frequently seen in their clinical practice (49.5% for resistant and 28.9% for refractory migraine); percentages were higher when considering only those working in specialized headache centers (75% and 46% respectively). However, many physicians reported low or moderate confidence in managing resistant (8.1% and 43.3%, respectively) and refractory (20.7% and 48.4%, respectively) migraine patients; confidence in treating resistant and refractory migraine patients was different according to the level of care and to the number of patients visited per week. Patients with resistant and refractory migraine were infrequently referred to more specialized centers (12% and 19%, respectively); also in this case, figures were different according to the level of care.

CONCLUSIONS

This report highlights the clinical relevance of difficult-to-treat migraine and the presence of unmet needs in this field. There is the need of more evidence regarding the management of those patients and clear guidance referring to the organization of care and available opportunities.

Targeting CGRP for migraine treatment: mechanisms, antibodies, small molecules, perspectives

INTRODUCTION

Calcitonin Gene-Related Peptide (CGRP) has gradually emerged as a suitable therapeutic target to treat migraine. Considering the social and economic burden of migraine, it is fundamental to optimize the disease management with efficacious and safe treatments. In this scenario, drugs targeting GCRP, monoclonal antibodies (MoAbs) and gepants, represent new therapeutic strategies.

AREAS COVERED

In the present work, the authors aim at appraising the main insights and implications of treatments targeting CGRP by reviewing pathophysiology and clinical information.

EXPERT OPINION

Anti-CGRP MoAbs are the first migraine-specific preventive treatments representing a suitable option especially for difficult-to-treat patients. They can be safely administered for long periods even in association with preventatives acting on different targets. Gepants are a safe alternative to triptans for the acute management of migraine and are currently being tested for prevention, thus representing the first transitional molecules for disease therapy. In the future, it might be possible to adapt the treatment according to patients' characteristics and disease phenotype even combining the two treatments targeting the CGRP pathway.

Cerebral vascular reactivity and the migraine-stroke relationship: A narrative review

Migraine, and especially migraine with aura, is associated with an increased risk of stroke and vascular events; however, the reasons for this association are unclear. Several studies evaluated cerebral autoregulation and vasomotor reactivity in patients with migraine compared with non-migraineurs, with conflicting results. Our narrative review aimed at summarizing their results to find the most reliable evidence in the field. Studies which used visual stimuli to evoke vascular responses consistently showed an increased vascular reactivity in migraineurs compared with non-migraineurs, while studies which used systemic stimuli such as hyper- or hypocapnia showed inconsistent results. Therefore, central neural mechanisms might be more important than peripheral vascular mechanisms in determining the cerebral vascular responses of patients with migraine. However, a large body of evidence supports the existence of peripheral vascular dysfunction in patients with migraine. Further studies are needed to explain the complex interactions between central neural and peripheral vascular mechanisms in determining migraine and its vascular risk. Migraine preventive treatments, and especially the most recent ones with a peripheral action, might provide important insights in this field.

Real-life data on the efficacy and safety of erenumab in the Abruzzo region, central Italy

Background

We aimed to assess the efficacy and safety of erenumab, a fully human monoclonal antibody inhibiting the calcitonin gene-related peptide receptor (CGRPr), for the prevention of migraine in a real-life setting.

Main body

We included in our observational study all patients with episodic or chronic migraine treated with erenumab during the year 2019 in the Abruzzo region, central Italy, and with a 6-month follow-up. We included 89 patients; 76 (85.4%) received 6 doses of erenumab, 11 (12.4%) autonomously withdrew the drug due to perceived inefficacy, and 2 (2.2%) due to adverse events. Seventy-eight patients (87.6%) were female, with a mean age of 46.8 ± 11.2 years; 84 (94.4%) had chronic migraine, and 64 (71.9%) medication overuse. All patients had ≥2 prior preventive treatment failures. Fifty-three patients (69.7%) had a 50% decrease in monthly migraine days (MMDs) within the first three doses; 46 (71.9%) of 64 patients withdrew medication overuse. In the 76 patients who completed a 6-dose treatment, erenumab decreased median MMDs from 19 (interquartile range [IQR] 12–27.5) to 4 (IQR 2–9.5; P < 0.001), median monthly days of analgesic use from 10 (IQR 4.5–20) to 2 IQR 0–5; P < 0.001), and median monthly days of triptan use from 5 (IQR 0–15.5) to 1 (IQR 0–4; P < 0.001). We recorded 27 adverse events in 20 (22.5%) patients, the most common being constipation (13.5%). One adverse event, i.e. allergic reaction, led to treatment discontinuation in one patient.

Conclusions

Our real-life data confirm the efficacy and tolerability of erenumab for the prevention of migraine in a difficult-to-treat population of patients with a high prevalence of chronic migraine and medication overuse.

The appropriate dosing of erenumab for migraine prevention after multiple preventive treatment failures: a critical appraisal

Background

Erenumab, a fully human monoclonal antibody directed against the calcitonin gene-related peptide receptor, was approved for the prevention of episodic (EM) or chronic migraine (CM) at the monthly dose of 70 mg or 140 mg. We reviewed the available literature to understand if patients with prior preventive treatment failures benefit more from the 140 mg dose than the 70 mg.

Main body

We searched papers indexed in PubMed and conference abstracts published in the last 2 years which assessed the safety and efficacy of erenumab in patients with prior preventive treatment failures. We reviewed the results of 3 randomized controlled trials and their subgroup analyses and open-label extensions. The 140 mg monthly dose of erenumab had a numerical advantage over the 70 mg monthly dose in patients with prior preventive treatment failures, both in EM and CM (with or without medication overuse) during the double blind phases of the trials and their open-label extensions. The numerical difference between the two doses increased with the increase in the number of prior preventive treatment failures.

Conclusions

The available data suggest that erenumab 140 mg monthly might be preferred over the 70 mg monthly dose in patients with EM or CM and prior preventive treatment failures. Further data are needed to assess the long-term efficacy in clinical practice of the two doses of erenumab, while their safety profile is comparable.