Targeting Calcitonin Gene-related Peptide Research Articles

Fremanezumab: First Global Approval.

Fremanezumab-vfrm (hereafter referred to as fremanezumab) [AJOVY™] is a fully humanized monoclonal antibody (IgG2Δa) developed by Teva Pharmaceuticals to selectively target calcitonin gene-related peptide (a vasodilatory neuropeptide involved in the pathophysiology of migraine). Its use has been associated with significant reductions in migraine frequency, the requirement for acute headache medication use and headache-related disability compared with placebo in multinational, phase III studies, and in September 2018 fremanezumab was approved by the US FDA for the preventive treatment of migraine in adults. A regulatory assessment for fremanezumab as a preventive treatment of migraine in adults is underway in the EU. Fremanezumab is also undergoing phase III development for the preventive treatment of cluster headache (although a phase III chronic cluster headache study has been suspended due to the results of a prespecified futility analysis) and phase II development for the preventive treatment of post-traumatic headache disorder. This article summarizes the milestones in the development of fremanezumab leading to this first approval in the USA for the preventive treatment of migraine in adults.

PACAP38 and PAC1 receptor blockade: a new target for headache?

Pituitary adenylate cyclase activating polypeptide-38 (PACAP38) is a widely distributed neuropeptide involved in neuroprotection, neurodevelopment, nociception and inflammation. Moreover, PACAP38 is a potent inducer of migraine-like attacks, but the mechanism behind this has not been fully elucidated.Migraine is a neurovascular disorder, recognized as the second most disabling disease. Nevertheless, the antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor are the only prophylactic treatment developed specifically for migraine. These antibodies have displayed positive results in clinical trials, but are not effective for all patients; therefore, new pharmacological targets need to be identified.Due to the ability of PACAP38 to induce migraine-like attacks, its location in structures previously associated with migraine pathophysiology and the 100-fold selectivity for the PAC1 receptor when compared to VIP, new attention has been drawn to this pathway and its potential role as a novel target for migraine treatment. In accordance with this, antibodies against PACAP38 (ALD 1910) and PAC1 receptor (AMG 301) are being developed, with AMG 301 already in Phase II clinical trials. No results have been published so far, but in preclinical studies, AMG 301 has shown responses comparable to those observed with triptans. If these antibodies prove to be effective for the treatment of migraine, several considerations should be addressed, for instance, the potential side effects of long-term blockade of the PACAP (receptor) pathway. Moreover, it is important to investigate whether these antibodies will indeed represent a therapeutic advantage for the patients that do not respond the CGRP (receptor)-antibodies.In conclusion, the data presented in this review indicate that PACAP38 and PAC1 receptor blockade are promising antimigraine therapies, but results from clinical trials are needed in order to confirm their efficacy and side effect profile.

Vascular Contributions to Migraine: Time to Revisit?

Migraine is one of the most prevalent and disabling neurovascular disorders worldwide. However, despite the increase in awareness and research, the understanding of migraine pathophysiology and treatment options remain limited. For centuries, migraine was considered to be a vascular disorder. In fact, the throbbing, pulsating quality of the headache is thought to be caused by mechanical changes in vessels. Moreover, the most successful migraine treatments act on the vasculature and induction of migraine can be accomplished with vasoactive agents. However, over the past 20 years, the emphasis has shifted to the neural imbalances associated with migraine, and vascular changes have generally been viewed as an epiphenomenon that is neither sufficient nor necessary to induce migraine. With the clinical success of peripherally-acting antibodies that target calcitonin gene-related peptide (CGRP) and its receptor for preventing migraine, this neurocentric view warrants a critical re-evaluation. This review will highlight the likely importance of the vasculature in migraine.

Qualitative Change in Migraine Prevention?

A new generation of drugs that target calcitonin gene-related peptide (CGRP) pathways offers a unique opportunity to explore the relationship between responder rates (RRs) and improvement in patient outcomes. The authors hypothesize a "tipping point" exists for patients with a ≥75% migraine response. They propose higher RRs reported in trials with CGRP inhibitory antibodies deliver not only a quantitative change in monthly headache days, but also a qualitative change in function, for a clinically meaningful subpopulation of patients.

Effect of Fremanezumab Compared With Placebo for Prevention of Episodic Migraine

Fremanezumab, a fully humanized monoclonal antibody that targets calcitonin gene-related peptide, may be effective for treating episodic migraine. To assess the efficacy of fremanezumab compared with placebo for prevention of episodic migraine with a monthly dosing regimen or a single higher dose. Randomized, double-blind, placebo-controlled, parallel-group trial conducted at 123 sites in 9 countries from March 23, 2016 (first patient randomized), to April 10, 2017, consisting of a screening visit, 28-day pretreatment period, 12-week treatment period, and final evaluation at week 12. Study participants were aged 18 to 70 years with episodic migraine (6-14 headache days, with at least 4 migraine days, during 28-day pretreatment period). Patients who had previous treatment failure with 2 classes of migraine-preventive medication were excluded. Patients were randomized 1:1:1 to receive subcutaneous monthly dosing of fremanezumab (n = 290; 225 mg at baseline, week 4, and week 8); a single higher dose of fremanezumab, as intended to support a quarterly dose regimen (n = 291; 675 mg of fremanezumab at baseline; placebo at weeks 4 and 8); or placebo (n = 294; at baseline, week 4, and week 8). The primary end point was mean change in mean number of monthly migraine days during the 12-week period after the first dose. Among 875 patients who were randomized (mean age, 41.8 [SD, 12.1] years; 742 women [85%]), 791 (90.4%) completed the trial. From baseline to 12 weeks, mean migraine days per month decreased from 8.9 days to 4.9 days in the fremanezumab monthly dosing group, from 9.2 days to 5.3 days in the fremanezumab single-higher-dose group, and from 9.1 days to 6.5 days in the placebo group. This resulted in a difference with monthly dosing vs placebo of -1.5 days (95% CI, -2.01 to -0.93 days; P < .001) and with single higher dosing vs placebo of -1.3 days (95% CI, -1.79 to -0.72 days; P < .001). The most common adverse events that led to discontinuation were injection site erythema (n = 3), injection site induration (n = 2), diarrhea (n = 2), anxiety (n = 2), and depression (n = 2). Among patients with episodic migraine in whom multiple medication classes had not previously failed, subcutaneous fremanezumab, compared with placebo, resulted in a statistically significant 1.3- to 1.5-day reduction in the mean number of monthly migraine days over a 12-week period. Further research is needed to assess effectiveness against other preventive medications and in patients in whom multiple preventive drug classes have failed and to determine long-term safety and efficacy. clinicaltrials.gov Identifier: NCT02629861.

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

Editorial summarySpecific 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.

New treatments for headache.

Headache disorders are common worldwide and often disabling. Until recently, treatments were borrowed from other branches of neurology and medicine. Monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) ligand and receptor, small molecule CGRP receptor antagonist gepants, serotonin1F agonists, new devices to deliver currently available drugs, and neuromodulation devices have recently been in the forefront of headache treatments that are rather specific for various headache disorders. These novel therapies are changing the field of headache medicine. Herein, we update the latest data available for these therapies.

Role of Calcitonin Gene Related Peptide (CGRP) in Migraine

Migraine is the second most primary headache. The prevalence of Migraine is 12% in the general population, including 18% in women and 6% in men. Migraine can start in childhood and adolescence and continue throughout lifespan. It is most prevalent among people in their 30s and 40s. Migraine is a debilitating hemicranial headache that is pulsating, aggravated by movement, nausea, vomiting and having sensitivity to light and sound, with or without aura. It can affect all aspects of life as work and school, parenting and family relationships and personal and leisure time. There are some theory regarding pathogenesis of migraine which includes cortical spreading depression, cortical spreading oligemia, activation of trigeminocervical complex leading to neuroinflammation &amp; release of vasodialating neuropeptides which include calcitonin gene related peptide (CGRP), substance P, vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and pituitary adenylate cyclase activating peptide (PACAP) &amp; genetic factor. CGRP is a potent vasodilator and causes perivascular plasma protein extravasation and nociceptive pain. Newer medications target CGRP both for acute and preventive treatment of migraine.&#x0D; Bangladesh Journal of Neuroscience 2017; Vol. 33 (1): 39-43

New strategies for the treatment and prevention of primary headache disorders.

The primary headache disorders, which include migraine, cluster headache and tension-type headache, are among the most common diseases and leading causes of disability worldwide. The available treatment options for primary headache disorders have unsatisfactory rates of efficacy, tolerability and patient adherence. In this Review, we discuss promising new approaches for the prevention of primary headache disorders, such as monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor, and small-molecule CGRP receptor antagonists. Neuromodulation approaches employing noninvasive or implantable devices also show promise for treating primary headache disorders. Noninvasive treatments, such as transcranial magnetic stimulation and transcutaneous peripheral nerve stimulation, are delivered by devices that patients can self-administer. Implantable devices targeting the occipital nerves, sphenopalatine ganglion or high cervical spinal cord are placed using percutaneous and/or surgical procedures, and are powered either wirelessly or by surgically implanted batteries. These new and emerging treatments have the potential to address unmet patient needs and reduce headache-associated disability.

Efficacy of (S)-Lacosamide in preclinical models of cephalic pain.

Migraine is one of the world's most common neurological disorders. Current acute migraine treatments have suboptimal efficacy, and new therapeutic options are needed. Approaches targeting calcitonin gene related peptide (CGRP) signaling are clinically effective, but small molecule antagonists have not been advanced because of toxicity. In this study, we explored the axonal growth/specification collapsin response mediator protein 2 (CRMP2) as a novel “druggable” target for inhibiting CGRP release and for potential relevance for treatment of migraine pain. Collapsin response mediator protein 2 has been demonstrated to regulate N-type voltage-gated Ca2+ channel activity and Ca2+-dependent CGRP release in sensory neurons. The coexpression of CRMP2 with N-type voltage-gated Ca2+ channel and CGRP in trigeminal ganglia (TGs) sensory neurons suggested the possibility of a novel approach to regulate CGRP release in the trigeminal system. Screening protocols surprisingly revealed that (S)-lacosamide ((S)-LCM), an inactive analog of the clinically approved small molecule antiepileptic drug (R)-lacosamide (Vimpat), inhibited CRMP2 phosphorylation by cyclin-dependent kinase 5 in rat TG slices and decreased depolarization-evoked Ca2+ influx in TG cells in culture. (S)-LCM significantly blocked capsaicin-evoked CGRP release from dural nerve terminals in the rat in ex vivo cranial cup preparation. Additionally, cephalic and extracephalic cutaneous allodynia induced in rats by activation of dural nociceptors with a cocktail of inflammatory mediators, was inhibited by oral administration of (S)-LCM. The confirmation of CRMP2 as an upstream mediator of CGRP release, together with the brain penetrance of this molecule suggests (S)-LCM as a potential therapy for acute migraine.

Stroke, Migraine and Triptans: From Bedside to Bench

Stroke, Migraine and Triptans: From Bedside to Bench

CGRP and migraine.

Migraine has been estimated to be the seventh highest cause of disability worldwide, and the third most common disease worldwide after dental caries and tension type headache. However, the use of currently available acute and prophylactic medications to control this condition, such as 5-HT1 agonists (triptans) and beta-blockers, is limited by side effects and efficacy so that alternative and more specific treatments are required. More recently, an improved understanding of the pathophysiology of disease has allowed investigation of new therapeutic targets. The 37 amino acid neuropeptide calcitonin gene-related peptide (CGRP) has been shown to play a crucial role in the trigeminocervical complex pathway for nociception in the head. Studies have demonstrated elevated levels in the external jugular vein during the headache phase of migraine, with reduction following headache resolution. Furthermore, CGRP infusion triggers migraine type headache and subsequent treatment with triptans results in normalization of CGRP levels. This neuropeptide is therefore thought to have a central role in pain modulation as it participates in the neurovascular pathway and contributes to the vasodilation and neurogenic inflammation, which leads to migrainous attacks. Targeting CGRP may provide the ideal therapeutic tool needed for control of this common and debilitating illness. The three studies chosen for this month’s journal club are a small sample of the large amount of research being performed on CGRP. The first investigates whether its measurement can be used to classify migraine. The second and third articles are phase II clinical trials which investigate the use of CGRP antagonists and a monoclonal antibody CGRP

Chapter 16 - Migraine

This chapter presents an overview of migraine epidemiology and mechanisms. Migraine is a common and disabling neurologic disorder characterized by episodic attacks of severe head pain and other symptoms, including interference with activity, nausea, and sensitivity to light and sound. A number of risk factors for migraine onset and progression have been identified, including the presence of comorbid disorders and overuse of acute headache medications. Though the pathophysiology of migraine is complex and incompletely understood, advances in genetics research and clinical trials methodology offer promise for better understanding the underlying pathophysiologic mechanisms. These advances presently center on genomewide studies, development of antibodies targeting calcitonin gene-related peptide, and understanding the psychologic mechanisms that underlie the efficacy of some interventions. Studies of both pharmacologic and behavioral interventions for migraine and its common comorbidities also offer promise for understanding the neuroepidemiologic mechanisms of migraine. Clinical trials relevant to these mechanisms are reviewed, and methodologic considerations for future trials are discussed.

Targeting Calcitonin Gene-Related Peptide and its Receptor by Monoclonal Antibody, New Developments in the Prevention of Migraine

Burnett School of Biomedical Sciences (BSBS), College of Medicine, University of Central Florida, Orlando, Florida, USA *Corresponding author Mohtashem Samsam, MD, PhD Associate Professor of Medicine Burnett School of Biomedical Sciences Department of Medicine Burnett School of Biomedical Sciences College of Medicine University of Central Florida 4000 Central Florida Blvd., HPA-II 320 Orlando, FL, 32816, USA Tel. 1407823 4810 Fax: 1407823 3095 E-mail: Mohtashem.Samsam@ucf.edu

Therapeutic Monoclonal Antibodies: What Headache Specialists Need to Know.

Monoclonal antibodies (mAbs) are now an important part of the treatment armamentarium for a wide range of conditions including cancer, autoimmune diseases, inflammatory diseases of the joint and bowel, transplant rejection, and multiple sclerosis. Significant progress over the last 30 years in the development of therapeutic mAbs has resulted in improved efficacy and safety. Monoclonal antibodies approved for the treatment of neurological illnesses so far are limited to use in multiple sclerosis. Several therapeutic mAbs have completed phase 2 clinical trials for migraine prevention, and there are phase 3 trials underway for migraine prophylaxis and for cluster headache at the time of this writing. The purpose of this review is to discuss the characteristics of mAbs, including their mechanism of action and safety profile, and briefly describe the mAbs being evaluated for the prevention of migraine and cluster headaches. Monoclonal antibodies have several features that distinguish them from small molecules, including very high selectivity, relatively long half-life that generally allows for once or twice monthly dosing, and significantly reduced potential for drug-drug interactions or other nontarget related toxicities. The clinical development of mAbs that target calcitonin gene-related peptide and its receptor is underway and will evaluate this promising new drug class for the prevention of migraine and cluster headache.

Calcitonin gene-related peptide in the joint: contributions to pain and inflammation.

Arthritis is the commonest cause of disabling chronic pain, and both osteoarthritis (OA) and rheumatoid arthritis (RA) remain major burdens on both individuals and society. Peripheral release of calcitonin gene-related peptide (CGRP) contributes to the vasodilation of acute neurogenic inflammation. Contributions of CGRP to the pain and inflammation of chronic arthritis, however, are only recently being elucidated. Animal models of arthritis are revealing the molecular and pathophysiological events that accompany and lead to progression of both arthritis and pain. Peripheral actions of CGRP in the joint might contribute to both inflammation and joint afferent sensitization. CGRP and its specific receptors are expressed in joint afferents and up-regulated following arthritis induction. Peripheral CGRP release results in activation of synovial vascular cells, through which acute vasodilatation is followed by endothelial cell proliferation and angiogenesis, key features of chronic inflammation. Local administration of CGRP to the knee also increases mechanosensitivity of joint afferents, mimicking peripheral sensitization seen in arthritic joints. Increased mechanosensitivity in OA knees and pain behaviour can be reduced by peripherally acting CGRP receptor antagonists. Effects of CGRP pathway blockade on arthritic joint afferents, but not in normal joints, suggest contributions to sensitization rather than normal joint nociception. CGRP therefore might make key contributions to the transition from normal to persistent synovitis, and the progression from nociception to sensitization. Targeting CGRP or its receptors within joint tissues to prevent these undesirable transitions during early arthritis, or suppress them in established disease, might prevent persistent inflammation and relieve arthritis pain.

Translational Pharmacodynamics of Calcitonin Gene-Related Peptide Monoclonal Antibody LY2951742 in a Capsaicin-Induced Dermal Blood Flow Model

LY2951742, a monoclonal antibody targeting calcitonin gene-related peptide (CGRP), is being developed for migraine prevention and osteoarthritis pain. To support the clinical development of LY2951742, capsaicin-induced dermal blood flow (DBF) was used as a target engagement biomarker to assess CGRP activity in nonhuman primates and healthy volunteers. Inhibition of capsaicin-induced DBF in nonhuman primates, measured with laser Doppler imaging, was dose dependent and sustained for at least 29 days after a single intravenous injection of the CGRP antibody. This information was used to generate a pharmacokinetic/pharmacodynamic model, which correctly predicted inhibition of capsaicin-induced DBF in humans starting at a single subcutaneous 5-mg dose. As expected, the degree of inhibition in capsaicin-induced DBF increased with higher LY2951742 plasma concentrations. Utilization of this pharmacodynamic biomarker with pharmacokinetic data collected in phase I studies provided the dose-response relationship that assisted in dose selection for the phase II clinical development of LY2951742.

Targeting CGRP: A New Era for Migraine Treatment.

Migraine is a highly prevalent headache disease that typically affects patients during their most productive years. Despite significant progress in understanding the underlying pathophysiology of this disorder, its treatment so far continues to depend on drugs that, in their majority, were not specifically designed for this purpose. The neuropeptide calcitonin gene-related peptide (CGRP) has been indicated as playing a critical role in the central and peripheral pathways leading to a migraine attack. It is not surprising that drugs designed to specifically block its action are gaining remarkable attention from researchers in the field with, at least so far, a safe risk profile. In this article, we highlight the evolution from older traditional treatments to the innovative CGRP target drugs that are revolutionizing the way to approach this debilitating neurological disease. We provide a brief introduction on pathophysiology of migraine and details on the characteristic, function, and localization of CGRP to then focus on CGRP receptor antagonists (CGRP-RAs) and CGRP monoclonal antibodies (CGRP mAbs).

Emerging treatments for the primary headache disorders.

Migraine and cluster headache are common, episodic, often chronic and disabling disorders of the brain. Although there are many standard treatment techniques, none are ideal. This article reviews various novel pharmacologic and device-related treatments for migraine and cluster headache. Emphasis is given to recent advances in the development of monoclonal antibodies (mAbs) targeting calcitonin gene-related peptide (CGRP) and its receptor, including promising results from phase 2 trials studying the safety and efficacy of LY2951742, ALD403 and TEV-48125, three anti-CGRP mAbs. Other new pharmacologic treatments discussed include the 5-HT1F receptor agonist lasmiditan and glial cell modulator ibudilast. Also reviewed is neuromodulation for migraine and cluster headache, including promising recent results of randomized controlled trials studying sphenopalatine ganglion stimulation, trigeminal nerve stimulation, transcutaneous vagus nerve stimulation, and transcranial magnetic stimulation. Finally, we discuss patch, inhaled, and intranasal methods of triptan and dihydroergotamine delivery.