Therapeutic patterns and migraine disease burden in switchers of CGRP-targeted monoclonal antibodies - insights from the German NeuroTransData registry.

BACKGROUND: Monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway have shown good efficacy in migraine prophylaxis. However, a subset of patients does not respond to the first mAb treatment and switches among the available mAbs. The goal of this study is to characterize the switching pattern of migraine patients treated with anti-CGRP(-receptor, -R) mAbs, and to describe the headache burden of those who did not switch, switched once, and switched twice. METHODS: This study used real world data from the NeuroTransData Cohort, a registry of migraine patients treated at outpatient neurology clinics across Germany. Patients who had received at least one anti-CGRP(-R) mAb were included. Headache diaries were collected at baseline and during treatment, along with quality of life measures every three months. Results were summarized for the subgroups of patients who did not switch and those with one and two switches. RESULTS: Of the 655 eligible patients, 479 did not switch, 135 switched once, 35 twice, and 6 three or more times. The ≥ 50% response rates for monthly migraine days were 64.7%, 50.7%, and 25.0% for the no switch, one switch, and two switches groups in their last treatment cycles, respectively. Quality of life measures improved for the no switch and one switch groups, but not for the two switches group. CONCLUSION: Patients who switched among anti-CGRP(-R) mAbs during the course of their treatment still benefited overall but to a lesser extent than those who did not switch. Treatment response in patients who switched twice was markedly lower compared to the no switch and one switch subgroup.

Switching CGRP(r) MoAbs in migraine: what evidence?

INTRODUCTION: Approximately 50% of patients that receive a CGRP(r) MoAb for the preventative treatment of migraine are expected to discontinue therapy. For patients that discontinue CGRP(r) MoAb therapy, few clinical options are available. One potential option is to switch CGRP(r) MoAbs, however, data concerning the efficacy of this intervention is scarce. AREAS COVERED: This manuscript aims to summarize all available data concerning the potential efficacy of switching CGRP(r) MoAbs following previous medication discontinuation. Data was sourced by completing a database search for the terms: 'CGRP monoclonal antibody switch OR CGRP monoclonal antibody switching.' EXPERT OPINION: While data considering the potential efficacy of CGRP(r) switching continues to grow, our expert opinion supports the most recent European Headache Federation statement regarding CGRP(r) MoAb prescribing practices, concluding that there remains insufficient data to determine the efficacy of this intervention. As this topic is of significant clinical importance, we recommend a call-to-action to expand on current data considering the therapeutic options for patients that discontinue CGRP(r) MoAb therapy.

Calcitonin Gene-Related Peptide (CGRP)-Targeted Monoclonal Antibodies and Antagonists in Migraine: Current Evidence and Rationale.

Calcitonin gene-related peptide (CGRP), a 37 amino-acid neuropeptide found mostly in peptidergic sensory C-fibers, has been suggested to be implicated in the pathogenesis of migraine, which is one of the most common neurological disorders seen in medical practice, affecting almost 16% of the US population. While previously thought to be a vascular condition, migraine attacks are the result of neurogenic inflammation and peripheral/central sensitization through dysfunctional activation of the trigeminovascular system. To date, two classes of therapeutic agents have been developed to interrupt the function of CGRP: CGRP-targeted monoclonal antibodies (mAbs) and small-molecule antagonists (gepants). There are currently four CGRP-targeted mAbs and three gepants that are US Food and Drug Administration (FDA) approved for the treatment of migraine. Multiple phase II and III studies have established the efficacies and tolerability of these treatments. Previously, we reviewed the fundamental role of CGRP in migraine pathogenesis. Here, we discuss in depth the clinical evidence (randomized controlled trials and real-world studies), safety, and tolerability of CGRP-targeted mAbs and gepants for treating migraine.

Migraine evolution after the cessation of CGRP(-receptor) antibody prophylaxis: a prospective, longitudinal cohort study.

BACKGROUND: National and international guidelines recommend stopping migraine prophylaxis with CGRP(-receptor) monoclonal antibodies after 6-12 months of successful therapy. In this study, we aimed to analyze the course of migraine for four months after the cessation of CGRP(-receptor) antibodies use. METHODS: This longitudinal cohort study included patients with migraine who received a CGRP-(receptor) antibody for ≥8 months before treatment cessation. We analyzed headache data in the four-week period prior to mAb treatment initiation (baseline), in the month before the last mAb injection, in weeks 5-8 and 13-16 after last treatment. Primary endpoint of the study was the change of monthly migraine days from the month before last treatment to weeks 13-16. Secondary endpoints were changes in monthly headache days and monthly days with acute medication use. RESULTS: A total of 62 patients equally distributed between prophylaxis with the CGRP-receptor antibody erenumab and the CGRP antibodies galcanezumab or fremanezumab participated in the study. Patients reported 8.2 ± 6.6 monthly migraine days in the month before last treatment. Monthly migraine days gradually increased to 10.3 ± 6.8 in weeks 5-8 (p = 0.001) and to 12.5 ± 6.6 in weeks 13-16 (p < 0.001) after drug cessation. Monthly migraine days in weeks 13-16 were not different from baseline values (-0.8 ± 5.4; p > 0.999). Monthly headache days and monthly days with acute medication use showed a similar pattern. CONCLUSIONS: The cessation of CGRP(-receptor) antibodies migraine prophylaxis was associated with a significant increase of migraine frequency and acute medication intake over time.

The impact of CGRPergic monoclonal antibodies on prophylactic antimigraine therapy and potential adverse events.

Migraine is a prevalent medical condition and the second most disabling neurological disorder. Regarding its pathophysiology, calcitonin gene-related peptide (CGRP) plays a key role, and, consequently, specific antimigraine pharmacotherapy has been designed to target this system. Hence, apart from the gepants, the recently developed monoclonal antibodies (mAbs) are a novel approach to treat this disorder. In this review we consider the current knowledge on the mechanisms of action, specificity, safety, and efficacy of the above mAbs as prophylactic antimigraine agents, and examine the possible adverse events that these agents may trigger. Antimigraine mAbs act as direct scavengers of CGRP (galcanezumab, fremanezumab, and eptinezumab) or against the CGRP receptor (erenumab). Due to their long half-lives, these molecules have revolutionized the prophylactic treatment of this neurovascular disorder. Moreover, because of their physicochemical properties, these agents are hepato-friendly and do not cross the blood-brain barrier (highlighting the relevance of peripheral mechanisms in migraine). Nevertheless, apart from potential cardiovascular side effects, the interaction with AMY1 receptors and immunogenicity induced by autoantibodies against mAbs could be a concern for the safety of long-term treatment with these molecules.

Cluster headache: state of the art of pharmacological treatments and therapeutic perspectives.

Cluster headache (CH) is the most common form of trigeminal autonomic cephalalgia. Current treatments have several limitations, and new drugs are required. This article first briefly reviews present acute and preventive treatments in CH, their mechanism of action and limitations, then describes the state of the art in recent clinical drug trials since 2015, and ends with a critique of trials in the CH field. Research is limited by lack of knowledge of pathophysiology and lack of animal models. In the past 5 years, no brand-new treatment has emerged, but promising drugs, such as CGRP(R) antibodies, are under study. According to the literature and guidelines, clinicians and researchers should be aware of many limitations in study protocols: concomitant medication, patient sample size, patients' protocol compliance, and study designs that tend to restrict patient recruitment.

Central effects of erenumab in migraine patients: An event-related functional imaging study.

OBJECTIVE: To determine whether erenumab, a new monoclonal antibody to the calcitonin gene-related peptide (CGRP) receptor, exerts functional central effects in migraineurs by performing functional imaging scans on patients treated with erenumab. METHODS: We conducted an fMRI study on 27 patients with migraine using a well-established trigeminal nociceptive paradigm, examining patients before and 2 weeks after administration of the CGRP receptor antibody erenumab 70 mg. RESULTS: Comparing both visit days in all patients (n = 27) revealed that erenumab leads to a decrease in activation in the right thalamus (i.e., contralateral to the stimulated side), right middle temporal gyrus, right lingual gyrus, left operculum, and several clusters on both sides of the cerebellum. Furthermore, when responders (n = 9) and nonresponders (n = 8) of the respective same headache state were compared, we found a significant reduction of hypothalamic activation after the administration of erenumab in responders only (t = 4.78; contrast estimate 29.79 [90% confidence interval 19.53-40.05]). This finding of reduced hypothalamic activation was confirmed when absolute headache days was used as a regressor. INTERPRETATION: These findings suggest that erenumab may not be an exclusively peripheral migraine treatment but has additional central effects. Whether this is due to secondary changes after peripheral modulation of sensory input or indeed represents a direct central mode of action is discussed.

[Novel migraine treatment with CGRP-related monoclonal antibodies].

Migraine is a common and debilitating neurological disorder characterized by recurrent attacks of moderate to severe throbbing headache accompanied by nausea, vomiting and photophobia/phonophobia. Because of its high prevalence, migraine causes a considerable financial burden on the society as well as impaired quality of life in individual patients. Scientific evidence shows that migraine is a quite complex neurological disorder that involves not only the trigeminovascular and autonomic systems but also the hypothalamus and cerebral cortex. Calcitonin gene-related peptide (CGRP) was originally discovered as a 37-amino acid neuropeptide derived from a calcitonin gene splicing variant. CGRP is found to be expressed in trigeminal ganglion neurons. Much attention has been attracted to this molecule since CGRP was found to be released from trigeminal terminals in animal migraine models. Subsequent studies demonstrated that CGRP administration induced migraine-like headache attacks specifically in migraineurs, thus highlighting a pivotal role of CGRP in the development of migraine attacks. Several CGRP receptor antagonists were shown to be efficacious for the treatment of acute migraine. Among them, telcagepant, was shown to exert a significant migraine prophylactic action as well. Nevertheless, the development of most of these agents were discontinued due to hepatotoxicity. Currently, newer CGRP receptor antagonists are being developed. On the other hand, monoclonal antibodies targeting CGRP and its receptor showed consistent efficacy for migraine prophylaxis with excellent safety profiles in Phase III clinical trials. Furthermore, emerging data support the long-term safety and efficacy of these antibodies. In this review article, the development and perspective of anti-migraine therapeutic strategies using CGRP-related antibodies are discussed.

Patient selection for migraine preventive treatment with anti-CGRP(r) monoclonal antibodies.

Introduction: Migraine is the most common neurological disorder and represents the first cause of disability in under 50s in both genders. Available preventive drugs were primarily developed for indications other than migraine and with an unclear mechanism of action in migraine pathophysiology. Areas covered: This article reviews current preventive treatments and their shortcomings and the road that, through the understanding of calcitonin gene-related peptide (CGRP) role in migraine pathophysiology, carried to the approval of the 3 first-in-class monoclonal antibodies (mAbs) acting on the CGRP pathway. Data from phase 2 and phase 3 clinical trials of erenumab, galcanezumab and fremanezumab, both for episodic and chronic migraine prevention, are consistent for safety and efficacy. Expert opinion: Anti-calcitonin gene-related peptide mAbs have potential advantages over conventional treatments such as ease of use, quick onset of action, persistent efficacy, placebo-like safety profile and absence of pharmacological interactions. Pharmacoeconomic studies should evaluate the economic impact of these drugs taking into account the overall direct and indirect costs related to untreated migraine and to migraine treated with the other available preventive therapies. Given the high cost of these therapies, it is essential to implement all possible strategies to optimize their effectiveness by optimization of patients' selection.

Anti-CGRP and anti-CGRP receptor monoclonal antibodies as antimigraine agents. Potential differences in safety profile postulated on a pathophysiological basis.

Calcitonin gene-related peptide (CGRP) is a peptide neurotransmitter with potent vasodilating properties. CGRP is believed to play a primary role in the pathogenesis of migraine. As such, CGRP and its receptors are obvious druggable targets for novel anti-migraine agents. While the development of small-molecule CGRP receptor antagonists started first, none of these agents is yet available in clinical practice. Conversely, both anti-CGRP and anti-CGRP receptor monoclonal antibodies (mABs) completed clinical development, and the first representatives of these 2 classes are available on the market. MABs are approved for prevention of migraine attacks in chronic or episodic migraine, involving long-term treatments. In light of the physiological role exerted by CGRP in the regulation of vascular tone, the potential risks of a long-term inhibition of CGRP functions raised diffuse concerns. These concerns were correctly addressed by the anti-CGRP receptor mABs erenumab with a 5-year open-label clinical trial; however, this study is currently ongoing and results are not yet available, leaving some uncertainty on the profile of erenumab long-term safety. Similar concerns can be raised with direct anti-CGRP mABs, which entrap the peptide preventing receptor activation. However, evidence exists that plasma CGRP is detectable in patients chronically treated with anti-CGRP mABs. Assuming that plasma CGRP is an indirect marker of peptide levels at the vascular receptor sites, such residual CGRP would maintain a physiological level of receptor stimulation, in spite of a well-established anti-migraine activity of the mABs. This might represent a potential advantage in the safety profile of anti-CGRP mABs, but it needs to be confirmed and expanded with data on free plasma CGRP.

CGRP/CGRP Receptor Antibodies: Potential Adverse Effects Due to Blockade of Neovascularization?

Migraine is a severe neurological disorder in which calcitonin gene-related peptide (CGRP) is a key molecule in pathophysiology. Neuronal system-derived CGRP enhances neovascularization in several important pathological conditions and sends a cue to the vascular system. In 2018, the FDA approved erenumab and fremanezumab, antibodies against CGRP receptor and CGRP, as the first new class of drugs for migraine. Treatment of migraine with these antibodies requires great care because neovascularization-related adverse effects may be induced in some patients. Here, we focus on enhancement of neovascularization by CGRP and discuss possible adverse effects resulting from blocking neovascularization. We also suggest that CGRP antibodies may also be used as novel antitumor agents by suppressing tumor-associated angiogenesis.

Basic Considerations for the Use of Monoclonal Antibodies in Migraine.

BACKGROUND: Migraine impacts more than 36 million people in the United States and 1 billion people worldwide. Despite the increasing availability of acute and preventive therapies, there is still tremendous unmet need. Potential treatments in development include monoclonal antibodies (mAbs). Appropriate use of these "biologic" treatments will necessitate an understanding of the aspects that distinguish them from traditional medications. AIM: Many drug classes are prescribed for migraine treatment, but all have limitations. Recently, calcitonin gene-related peptide (CGRP) activity has shown a significant promise as a target for preventive therapy. In this review, we provide an overview of the potential role of CGRP mAbs in migraine, with a focus on their design, pharmacokinetics, safety, and immunogenicity. CONCLUSIONS: The CGRP mAbs are an innovative new therapy for migraine and address the need for effective and tolerable preventive options. MAbs, including those that target CGRP or its receptor, bind to a target with high specificity and affinity and lead to few off-target adverse effects, although mechanism-based adverse reactions may occur. Unlike other therapeutic antibodies used to treat neurologic disease, CGRP mAbs do not have a target within the immune system and have been designed to avoid altering the immune system. The safety and efficacy of mAbs against CGRP or its receptors are being investigated in clinical development programs, and the first of these therapies has received regulatory approval in the United States.

Antigens and Antibodies in Disease With Specifics About CGRP Immunology.

Growth in knowledge about calcitonin gene-related peptide (CGRP) in the pathophysiology of migraine brought CGRP antagonism to headache medicine. Failures in development of small molecule CGRP receptor antagonists and increasing knowledge and use of monoclonal antibodies (mAbs) in medicine led to the breakthrough development of large molecule anti-CGRP mAbs: eptinezumab, erenumab, fremanezumab, and galcanezumab. This specifics about CGRP immunology aims to outline: (1) knowledge needed for CGRP antagonism and (2) developmental issues of specific CGRP antagonists for provider use. This clinically oriented review documents IgG structure and function; state of the art of monoclonal IgG production and ligand-antigen-antibodies in migraine therapeutics contributing to immunogenic risks and off-target toxicities. Specifics to CGRP ligand, receptor, antagonism, and molecules, small and large, complete this review. Completion will facilitate assessment of the similarities, differences, and application of the forthcoming anti-CGRP receptor and ligand antagonists for patients.

Erenumab in the treatment of migraine.

Migraine is a highly prevalent neurological pain syndrome, and its management is limited due to side effects posed by current preventive therapies. Calcitonin gene-related peptide (CGRP) plays a crucial role in the pathogenesis of migraine. In recent years, research has been dedicated to the development of monoclonal antibodies against CGRP and CGRP receptors for the treatment of migraine. This review will focus on the first US FDA-approved CGRP-receptor monoclonal antibody developed for the prevention of migraine: erenumab. Two Phase II trials (one for episodic migraine and one for chronic migraine) and two Phase III trials for episodic migraine have been published demonstrating the efficacy and safety of erenumab in the prevention of migraine.

Erenumab: First Global Approval.

Amgen and Novartis are developing erenumab (AIMOVIG™, erenumab-aooe)-a fully human monoclonal antibody calcitonin gene-related peptide (CGRP) receptor antagonist-for the prevention of migraine. CGRP is a vasodilatory neuropeptide implicated in the pathophysiology of migraine and treatment with erenumab was associated with significant reductions in migraine frequency in phase II and III clinical trials. Based on these positive results erenumab was recently approved in the US for the preventive treatment of migraine in adults and has received a positive opinion in the EU for the prophylaxis of migraines in adults who have at least 4 migraine days per month. This article summarizes the milestones in the development of erenumab leading to this first approval.

CGRP and Migraine: The Role of Blocking Calcitonin Gene-Related Peptide Ligand and Receptor in the Management of Migraine.

Migraine is a highly prevalent, complex neurological disorder. The burden of disease and the direct/indirect annual costs are enormous. Thus far, treatment options have been inadequate and mostly based on trial and error, leaving a significant unmet need for effective therapies. While the underlying pathophysiology of migraine is incompletely understood, blocking the calcitonin gene-related peptide (CGRP) using monoclonal antibodies targeting CGRP or its receptor and small molecule CGRP receptor antagonists (gepants) have emerged as a promising therapeutic opportunity for the management of migraine. In this review, we discuss new concepts in the pathophysiology of migraine and the role of CGRP, the current guidelines for treating migraine preventively, the medications that are being used, and their limitations. We then discuss small molecule CGRP receptor antagonists, monoclonal antibodies to CGRP ligand and receptor, as well as the detailed results of Phase II and III trials involving these novel treatments. We conclude with a discussion of the implications of blocking CGRP and its receptor.

CGRP as the target of new migraine therapies - successful translation from bench to clinic.

Treatment of migraine is on the cusp of a new era with the development of drugs that target the trigeminal sensory neuropeptide calcitonin gene-related peptide (CGRP) or its receptor. Several of these drugs are expected to receive approval for use in migraine headache in 2018 and 2019. CGRP-related therapies offer considerable improvements over existing drugs as they are the first to be designed specifically to act on the trigeminal pain system, they are more specific and they seem to have few or no adverse effects. CGRP receptor antagonists such as ubrogepant are effective for acute relief of migraine headache, whereas monoclonal antibodies against CGRP (eptinezumab, fremanezumab and galcanezumab) or the CGRP receptor (erenumab) effectively prevent migraine attacks. As these drugs come into clinical use, we provide an overview of knowledge that has led to successful development of these drugs. We describe the biology of CGRP signalling, summarize key clinical evidence for the role of CGRP in migraine headache, including the efficacy of CGRP-targeted treatment, and synthesize what is known about the role of CGRP in the trigeminovascular system. Finally, we consider how the latest findings provide new insight into the central role of the trigeminal ganglion in the pathophysiology of migraine.

Calcitonin gene-related peptide (receptor) antibodies: an exciting avenue for migraine treatment.

Specific prophylactic migraine treatments are urgently needed because of the unmet needs of many migraine patients. Antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor have recently shown efficacy in episodic and chronic migraine and will be available soon.

CGRP Monoclonal Antibodies for Migraine: Rationale and Progress.

Calcitonin gene-related peptide (CGRP), a neuropeptide abundant in the trigeminal system and widely expressed in both the peripheral and central nervous systems, has recently emerged as a promising target for migraine management. While known as a potent arterial vasodilator, the role of CGRP in migraine is likely mediated by modulating nociception and sustaining neurogenic inflammation that leads to further peripheral and central pain sensitization. Functional blockade of CGRP, which involves either CGRP receptor antagonists or monoclonal antibodies (mAbs) to CGRP or its receptor, has recently shown clinical efficacy in migraine management. The site of action, although still being studied, is likely in nervous system structures outside the blood-brain barrier. To date, four CGRP function-blocking mAbs (three target CGRP and one targets the CGRP receptor) are under clinical investigation for migraine prophylaxis. Phase II and III studies were promising with favorable safety profiles. CGRP function-blocking mAbs may potentially revolutionize the management of migraine. This review discusses in depth the fundamental role of CGRP in migraine pathogenesis as well as the clinical efficacy of CGRP function-blocking mAbs.