Spotlight on Anti-CGRP Monoclonal Antibodies in Migraine: The Clinical Evidence to Date

Anti-CGRP mAbs for the Preventive Treatment of Migraine: An Overview Review and a Cost Saving Analysis in the Global Scenario

Objectives: Migraine is a neurological disease with a high frequency of incidence. The new monoclonal antibodies selective for the calcitonin gene-related peptide and its ligand (anti-CGRP mAbs) have been marketed both in the USA and EU based on the positive efficacy results in the prevention of migraine. This search has been carried out with the aim of collecting real-world evidence on the effectiveness of anti-CGRP mAbs, performing a cost-savings analysis, and comparing performances among anti-CGRP mAbs medicines marketed in the American and European market. Methods: The literature review has been performed in PubMed database on 31 December 2022; the cost of the unitary dose of anti-CGRP mAbs has been extracted consulting an American national database. Results: The results confirm efficacy and good tolerability of anti-CGRP mAbs, determining a difference in the purchase price. In fact, all extracted studies showed a protective risk factor exposure in monthly migraine days reduction for all the anti-CGRP mAbs, whereas the cost analysis showed that using eptinezumab, in a quarter there is a cost saving of at least $425 per patient, compared with the other anti-CGRP mAbs. Conclusions: With equal efficacy and equal safety, anti-CGRP mAbs should be prescribed also regard to the cost established at the negotiation, making sure to guarantee the best treatment to the patients, but at the same time impacting as little as possible to the healthcare services resources.

Effectiveness, tolerability, and response predictors of preventive anti-CGRP mAbs for migraine in patients over 65 years old: a multicenter real-world case-control study

OBJECTIVE

To evaluate clinical characteristics, effectiveness, and tolerability of preventive anti- calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) in the elderly. Anti-CGRP mAbs have demonstrated efficacy and safety in patients with migraine although there is limited information regarding the elderly.

DESIGN

We performed a multicenter case-control study of cases (patients over 65 years old) and controls (sex-matched patients under 55 years old) with migraine receiving anti-CGRP mAbs.

METHODS

We included the demographic characteristics, effectiveness-reduction in the number of monthly headache days (MHD) and monthly migraine days (MMD), 30%, 50%, and 75% responder rates-and treatment emergent adverse events (TEAEs). The primary endpoint was the 50% response rate regarding MHD at weeks 20-24; exploratory 50% response predictors in the elderly were evaluated.

RESULTS

In total, 228 patients were included: 114 cases , 114 controls-. Among cases 84.2% (96/114) were women, 79.8% (91/114) CM; mean age of cases 70.1 years old (range: 66-86); mean age of controls was 42.9 years old(range: 38-49). Cases had a higher percentage of vascular risk factors (P < .05),older age of onset (P < .001) and more reported prior preventive treatments (P < .001). Regarding effectiveness in cases, 50% response rate was achieved by 57.5% (42/73) at 20-24 weeks, with lower reduction in the MHD at 8-12 weeks (5 [7.2], 8 [9.1]; P = .001) and a higher reduction in MMD at 20-24 weeks (10.7 [9.1], 9.2 [7.7]; P = .04) compared to the control group. The percentage of TEAEs was similar in the 2 groups. Diagnosis of episodic migraine (EM) (P = .03) and lower number of MHD at baseline (P = .001) were associated with a 50% response in the elderly in univariate analysis.

CONCLUSIONS

Our study provides real world evidence of effectiveness and safety of anti-CGRP mAbs for migraine in patients without upper age-limit and possible predictors of anti-CGRP response in the elderly.

CGRP Antagonism and Ketogenic Diet in the Treatment of Migraine

The study of migraine is based on the complexity of the pathology, both at the pathophysiological and epidemiological levels. Although it affects more than a billion people worldwide, it is often underestimated and underreported by patients. Migraine must not be confused with a simple headache; it is a serious and disabling disease that causes considerable limitations in the daily life of afflicted people, including social, work, and emotional effects. Therefore, it causes a daily state of suffering and discomfort. It is important to point out that this pathology not only has a decisive impact on the quality of life of those who suffer from it but also on their families and, more generally, on society as a whole. The clinical picture of migraine is complex, with debilitating unilateral or bilateral head pain, and is often associated with characteristic symptoms such as nausea, vomiting, photophobia, and phonophobia. Hormonal, environmental, psychological, dietary, or other factors can trigger it. The present review focuses on the analysis of the physiopathological and pharmacological aspects of migraine, up to the correct dietary approach, with specific nutritional interventions aimed at modulating the symptoms. Based on the symptoms that the patient experiences, targeted and specific therapy is chosen to reduce the frequency and severity of migraine attacks. Specifically, the role of calcitonin gene-related peptide (CGRP) in the pathogenesis of migraine is analyzed, along with the drugs that effectively target the corresponding receptor. Particularly, CGRP receptor antagonists (gepants) are very effective drugs in the treatment of migraine, given their high diffusion in the brain. Moreover, following a ketogenic diet for only one or two months has been demonstrated to reduce migraine attacks. In this review, we highlight the diverse facets of migraine, from its physiopathological and pharmacological aspects to prevention and therapy.

What is new in migraine management in children and young people?

For this narrative review, we found recent publications on the use and effectiveness of old therapies including nutraceuticals, such as riboflavin, vitamin D, magnesium, melatonin and talking therapies. Recent large trials of established conventional pharmaceuticals such as propranolol, pizotifen, topiramate and amitriptyline for childhood migraine have failed, but the use of a quasi-placebo in future trials could help. We reviewed the evidence for angiotensin antagonists including candesartan in adults, but found a lack of evidence for their use in children. There have been new developments in pharmaceuticals recently, including a more selective 5-HT1F agonist, lasmiditan, an effective acute treatment with no vasoconstrictor activity in adults, currently being tested in children. Also, a number of new calcitonin gene-related peptide (CGRP) antibodies and antagonists, with proven efficacy in acute treatment and/or prevention of migraine in adults, are undergoing trials in children. Peripheral nerve blocks and botulinum toxin are gaining popularity in adult practice, but we really need more good quality evidence for their effectiveness in children. Finally, electroceuticals, that is, therapeutic electric devices, are now marketed for acute and or preventative treatment, including an external trigeminal nerve stimulator (e-TNS), a non-invasive vagal nerve stimulator (nVNS), a single-pulse transcranial magnetic stimulator (sTMS) and a remote electrical neuromodulation device (REN). At the moment, evidence for their effectiveness in children is still lacking. So, there has been much progress, but mostly for adults. We are in urgent need of more migraine trials in children.

Managing migraine on the frontline: Identifying disease, understanding burden, and incorporating CGRP pathway-targeting therapies in primary care

Migraine is a common neurologic disorder with clinical phenotypes encompassing a variety of symptoms which all contribute to the burden felt by patients. In addition to negative impacts on a patient's quality of life, migraine has both direct medical costs and indirect costs related to missed work and decreased productivity that affect individuals as well as society at large. Unfortunately, migraine diagnoses are often missed, and many patients do not receive appropriate treatment. Primary care providers are in a key position to provide timely diagnosis and effectively manage migraine for many patients. This review aims to be a guide for improving migraine management in the primary care setting by providing strategies to overcome common challenges in migraine diagnosis; summarizing current knowledge on the mechanism of action, efficacy, and safety of calcitonin gene-related peptide (CGRP) pathway-targeting therapies; and reviewing approaches to incorporate traditional and emerging treatment options into a patient-centric migraine management strategy.

Recently approved and emerging drug options for migraine prophylaxis

INTRODUCTION

: Migraine occupies the first position regarding to the disability caused in female working population (15-49 years). Research in the field of prophylaxis of this pathology has made enormous strides in recent years.

AREAS COVERED

In this narrative review we retrace the most important scientific evidence regarding recently approved and emerging drug for prophylactic treatment of migraine. The purpose of this article is in fact to evaluate currently approved or emerging pharmacological agents for migraine prophylaxis. This review is based on literature published in peer review journal obtained through PubMed, Cochrane library, Clinicaltrials.gov and US FDA.

EXPERT OPINION

: Monoclonal antibodies (mAbs) that target the calcitonin gene-related peptide signalling pathway (CGRP) have marked an innovation in prophylactic migraine therapy. The combination of Onabotulinumtoxin-A (OBTA) and mAbs appears to be an effective, but costly, therapeutic option for resistant cases. New classes of molecules like gepants and ditans seem to give exceptional results. In addition, new prophylactic drugs are emerging with several targets: the pituitary adenylate cyclase-activating polypeptide (PACAP), ion channels, several receptors coupled to G proteins, orexin, and glutamate. All these therapies will implement and improve migraine management, as well as personalized medicine for each patient.

A Comprehensive Review of Zavegepant as Abortive Treatment for Migraine

Migraine headache is a widespread and complex neurobiological disorder that is characterized by unilateral headaches that are often accompanied by photophobia and phonophobia. Migraine is one of the leading chief complaints in the emergency department with negative impacts on quality of life and activities of daily living. The high number of emergency presentations also results in a significant economic burden. Its risk factors include family history, genetics, sex, race, socioeconomics, the existence of comorbid conditions, and level of education. Triggers include stress, light, noise, menstruation, weather, changes in sleep pattern, hunger, dehydration, dietary factors, odors, and alcohol. The International Headache Society has defined criteria for the diagnosis of migraine with and without aura. The pathophysiology of migraine headaches is multifactorial so there are a variety of treatment approaches. The current treatment approach includes abortive medications and prophylactic medications. Abortive medications include the first-line treatment of triptans, followed by ergot alkaloids, and calcitonin gene-related peptide (CGRP) receptor antagonists along with supplemental caffeine and antiemetics. Trigeminal afferents from the trigeminal ganglion innervate most cranial tissues and many areas of the head and face. These trigeminal afferents express certain biomarkers such as calcitonin gene-related peptide (CGRP), substance P, neurokinin A, and pituitary adenylate cyclase-activating polypeptide that are important to the pain and sensory aspect of migraines. In this comprehensive review, we discuss Zavegepant, a calcitonin gene-related peptide receptor antagonist, as a new abortive medication for migraine headaches.

Machine-learning based approach to predict anti-CGRP response in patients with migraine: multicenter Spanish study

BACKGROUND

To date, several variables have been associated with anti-CGRP receptor or ligand-antibody response with disparate results. Our objective is to determine whether machine learning (ML)-based models can predict 6, 9 and 12 months response to anti-CGRP receptor or ligand therapies among migraine patients.

METHODS

We performed a multicenter analysis of a prospectively collected data cohort of patients with migraine receiving anti-CGRP therapies. Demographic and clinical variables were collected. Response rate defined in the 30% to 50% range -or at least 30%-, in the 50% to 75% range -or at least 50%-, and response rate over 75% reduction in the number of headache days per month at 6, 9 and 12 months. A sequential forward feature selector was used for variable selection and ML-based predictive models response to anti-CGRP therapies at 6, 9 and 12 months, with models' accuracy not less than 70%, were generated.

RESULTS

A total of 712 patients were included, 93% women, aged 48 years (SD=11.7). Eighty-three percent had chronic migraine. ML models using headache days/month, migraine days/month and HIT-6 variables yielded predictions with a F1 score range of 0.70-0.97 and AUC (area under the receiver operating curve) score range of 0.87-0.98. SHAP (SHapley Additive exPlanations) summary plots and dependence plots were generated to evaluate the relevance of the factors associated with the prediction of the above-mentioned response rates.

CONCLUSIONS

According to our study, ML models can predict anti-CGRP response at 6, 9 and 12 months. This study provides a predictive tool to be used in a real-world setting.

Rapid resolution of migraine symptoms after initiating the preventive treatment eptinezumab during a migraine attack: results from the randomized RELIEF trial

BACKGROUND

Eptinezumab is an anti-calcitonin gene-related peptide (CGRP) monoclonal antibody approved for the preventive treatment of migraine. In the phase 3 RELIEF study, eptinezumab resulted in shorter time to headache pain freedom and time to absence of most bothersome symptom (MBS; including nausea, photophobia, or phonophobia) compared with placebo when administered during a migraine attack. The objective of this exploratory analysis was to examine the earliest time points that eptinezumab separated from placebo (P < .05) on headache- and migraine-associated symptoms when administered during a migraine attack.

METHODS

RELIEF, a multicenter, parallel-group, double-blind trial, occurred from November 7, 2019, through July 8, 2020. Adults considered candidates for preventive treatment were randomized to eptinezumab 100 mg (N = 238) or placebo (N = 242) administered intravenously over 30 min within 1-6 h of migraine onset. Outcome measures included headache pain freedom/relief and absence of MBS, patient's choice of photophobia, phonophobia, or nausea, at regular intervals from 0.5 to 48 h after infusion start. Censoring was applied at time of acute rescue medication use.

RESULTS

At hour 1, more eptinezumab-treated patients achieved headache pain freedom (9.7%), headache pain relief (38.7%), and absence of MBS (33.2%) versus placebo (4.1%, 26.9%, and 22.1%, respectively; P < .05 all), with separation from placebo (P < .05) through hour 48. Eptinezumab separated from placebo (P < .05) at hour 1 in absence-of-photophobia (29.4% vs 17.0%) and absence-of-phonophobia (41.2% vs 27.2%) and through hour 48. Initial separation from placebo (P < .05) in absence-of-nausea occurred at end-of-infusion (0.5 h; 36.7% vs 25.4%, respectively).

CONCLUSION

Preventive treatment with eptinezumab initiated during a migraine attack resulted in more patients achieving headache pain freedom/relief and absence of MBS, with separation from placebo (P < .05) as early as 0.5-1 h following the start of infusion. Rapid resolution of headache- and migraine-associated symptoms by a peripherally acting, intravenously administered antibody suggest a peripheral site of pharmacological action for CGRP blockade.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04152083 .

Effectiveness and safety of erenumab and galcanezumab in the prevention of chronic and episodic migraine: A retrospective cohort study

WHAT IS KNOWN AND OBJECTIVE?: Erenumab and galcanezumab have shown great results for migraine prevention. However, strict inclusion criteria, absence of concomitant medication and selective outcome report of clinical trials may sometimes be barely representative of the real-world daily practice. Therefore, this study was designed to evaluate effectiveness and safety of these two monoclonal antibodies targeting calcitonin gene-related peptide in real-world patients. METHODS: This observational, retrospective study evaluated the effectiveness and safety of erenumab 140 mg and galcanezumab 120 mg in 142 real-world patients who had previously not responded to three well-established pharmacological alternatives for migraine prevention. To do so, a combination of objective parameters (monthly headache days and acute migraine-specific medication days) and subjective measurements (Migraine Disability Assessment questionnaire, Headache Impact Test and Visual Analogue Scale), validated for clinical research in migraine, were assessed during clinical interview. RESULTS AND DISCUSSION: Findings here reported show that erenumab and galcanezumab reduced monthly headache days, acute migraine specific medication days per month, Headache Impact Test score, Migraine Disability Assessment Test score and Visual Analogue Scale score after 3 and 6 doses (p < 0.01). Additionally, more than 25% of the patients enrolled in the study experienced a reduction by a half in monthly headache days, and more than 50% of the patients also reported a reduction by a half in the number of migraine specific medication days. Both treatments exhibited a great safety profile, rarely leading to discontinuation because of poor tolerance. WHAT IS NEW AND CONCLUSIONS?: Altogether, these results support previous real-life studies regarding effectiveness and safety and provide an interesting insight in how these preventive therapies are also effective in patients diagnosed with difficult to treat migraine who have previously failed, at least, three different drug classes stablished by current neurology guidelines for migraine prevention. Moreover, these data may suggest that erenumab and galcanezumab are able to not only diminish frequency, but also migraine intensity, and that it should be also considered as an effectiveness measure in line with other authors suggestion.

Erenumab Discontinuation After 12-Month Treatment: A Multicentric, Observational Real-Life Study

Objective

To assess migraine outcome after 12-month treatment with erenumab and compare patients who underwent 3-month erenumab discontinuation following the first treatment cycle with those who continued monthly administrations.

Methods

This is a multicentric observational study in patients with migraine in treatment with erenumab. After a full 12-month treatment cycle (T¹²), patients could either continue or discontinue erenumab for at least 3 months. Patients who underwent treatment discontinuation were assessed after 3 months (T¹⁵) to decide whether to start retreatment. Patients were then assessed following at T¹⁶ and T¹⁸.

Results

Thirty consecutive patients were enrolled. Nineteen patients underwent treatment suspension at T¹² up to T¹⁵, whereas 11 continued prophylaxis. At T¹⁵, patients who discontinued treatment documented significantly more migraine days (17.06 ± 6.5 vs 4.8 ± 2.5; p < 0.0001) and analgesics consumption (14.8 ± 9.2 vs 4.6 ± 2.5; p = 0.002), compared with those who continued treatment. After retreatment, at T¹⁶, patients who had previously undergone discontinuation documented a significant improvement in terms of migraine days (9.01 ± 4.4 vs 17.06 ± 6.5; p < 0.0001) and analgesics consumption (9.6 ± 7.3 vs 14.8 ± 9.2; p = 0.004). Such improvement was even greater at T¹⁸, comparable with T¹².

Conclusion

After treatment discontinuation, a rapid migraine worsening was found, despite the high clinical response during treatment and at retreatment, which might be secondary to an untimely interruption of a potentially disease-modifying pharmacologic intervention. Although clinical improvement was documented after retreatment, given the high frequency and degree of worsening during discontinuation, it seems plausible-even ethical-to re-evaluate current timing of discontinuation.

Classification of Evidence

This study provides Class III evidence that people with migraine discontinuing erenumab migraine prophylaxis after 12 months were more likely to have an increase in nonresponder status and migraine days than those who continued treatment.

Roles of calcitonin gene-related peptide in the skin, and other physiological and pathophysiological functions

Skin immunity is regulated by many mediator molecules. One is the neuropeptide calcitonin gene-related peptide (CGRP). CGRP has roles in regulating the function of components of the immune system including T cells, B cells, dendritic cells (DCs), endothelial cells (ECs), and mast cells (MCs).

Herein we discuss actions of CGRP in mediating inflammatory and vascular effects in various cutaneous models and disorders.

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CGRP can help to recruit immune cells through endothelium-dependent vasodilation.

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CGRP plays an important role in the pathogenesis of neurogenic inflammation.

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Functions of many components in the immune system are influenced by CGRP.

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CGRP regulates various inflammatory processes in human skin by affecting different cell-types.

New and sex-specific migraine susceptibility loci identified from a multiethnic genome-wide meta-analysis

Migraine is a common disabling primary headache disorder that is ranked as the most common neurological cause of disability worldwide. Women present with migraine much more frequently than men, but the reasons for this difference are unknown. Migraine heritability is estimated to up to 57%, yet much of the genetic risk remains unaccounted for, especially in non-European ancestry populations. To elucidate the etiology of this common disorder, we conduct a multiethnic genome-wide association meta-analysis of migraine, combining results from the GERA and UK Biobank cohorts, followed by a European-ancestry meta-analysis using public summary statistics. We report 79 loci associated with migraine, of which 45 were novel. Sex-stratified analyses identify three additional novel loci (CPS1, PBRM1, and SLC25A21) specific to women. This large multiethnic migraine study provides important information that may substantially improve our understanding of the etiology of migraine susceptibility.

Efficacy of calcitonin gene-related peptide (CGRP) receptor blockers in reducing the number of monthly migraine headache days (MHDs): A network meta-analysis of randomized controlled trials

The Global burden of disease study ranked migraine as the sixth most common disorder worldwide in 2016, with significant social and economic sequelae. In this study, we assessed the efficacy of different Calcitonin gene-related peptide (CGRP) receptor blockers as potential pharmacological approaches and compare them to placebo using the systematic review (SR) and network meta-analysis (NMA) approach. We performed a computerized search of SCOPUS, PubMed, Cochrane central, and Embase databases through January 2019 and included randomized controlled trials (RCTs), which were performed on episodic and chronic migraine patients who used Erenumab, Eptinezumab, Fremanezumab, or Galcanezumab. The combined analysis revealed that after six, eight, and twelve weeks of intervention, the medications with the most potent effects in comparison to placebo were Fremanezumab 900 mg, (SMD = -0.55, 95% CI [-0.97, -0.12]); Erenumab 140 mg, (SMD = -0.51, 95% CI [-0.61, 0.41]); and Erenumab 140 mg, (SMD = -0.48, 95% CI [-0.571, 0.39]), respectively. For chronic migraine patients, Fremanezumab 900 mg, Erenumab 140 mg, in addition to Erenumab 70 mg, were associated with the highest efficacy after 6, 8, and 12 weeks, correspondingly. The analysis of combined groups data (Chronic and Episodic) showed that Fremanezumab was the most effective drug after six weeks, where Erenumab was the most effective after 8 and 12 weeks. The current evidence retrieved from this NMA suggests that Fremanezumab was the most effective anti-migraine medication in decreasing MHDs per month after six weeks in both chronic and episodic patients.

Calcitonin Gene-Related Peptide Monoclonal Antibody Versus Botulinum Toxin for the Preventive Treatment of Chronic Migraine: Evidence From Indirect Treatment Comparison

Background: The previously approved botulinum toxin and nowadays promising calcitonin gene-related peptide (CGRP) monoclonal antibody have shown efficacy for preventing chronic migraine (CM). However, there is no direct evidence for their relative effectiveness and safety. In this study, we conducted an indirect treatment comparison to compare the efficacy and safety of CGRP monoclonal antibody with botulinum toxin for the preventive treatment of chronic migraine.

Methods: Up to August 31, 2020, we systematically searched PubMed, Embase, and Cochrane Library Central Register of Controlled Trials (Central). Weighted mean difference (WMD) and relative risk (RR) were used to evaluate clinical outcomes. Indirect treatment comparison (ITC) software was used to conduct indirect treatment comparison.

Results: Ten studies were pooled with 6,325 patients in our meta-analysis. Both botulinum toxin and CGRP monoclonal antibody demonstrated favorable efficacy in the change of migraine days, headache days, HIT-6 score, and 50% migraine responder rate compared with placebo. In indirect treatment comparison, CGRP monoclonal antibody was superior to botulinum toxin in the frequency of acute analgesics intake (WMD = −1.31, 95% CI: −3.394 to 0.774, p = 0.02113), the rate of treatment-related adverse events (AEs) (RR = 0.664, 95% CI: 0.469 to 0.939, p = 0.04047), and the rate of treatment-related serious adverse events (RR = 0.505, 95% CI: 0.005 to 46.98, p < 0.001).

Conclusion: For chronic migraine patients, CGRP monoclonal antibody was slightly better than botulinum toxin in terms of efficacy and safety. In the future, head-to-head trials would be better to evaluate the efficacy and safety between different medications in the prevention of chronic migraine.

Pituitary adenylate cyclase-activating polypeptide/vasoactive intestinal peptide (Part 2): biology and clinical importance in central nervous system and inflammatory disorders

PURPOSE OF REVIEW

To discuss recent advances of vasoactive intestinal peptide/pituitary adenylate cyclase-activating polypeptide (VIP/PACAP) receptors in the selected central nervous system (CNS) and inflammatory disorders.

RECENT FINDINGS

Recent studies provide evidence that PACAP plays an important role in a number of CNS disorders, particularly the pathogenesis of headaches (migraine, etc.) as well as posttraumatic stress disorder and drug/alcohol/smoking addiction. VIP has important therapeutic effects in a number of autoimmune/inflammatory disorder such as rheumatoid arthritis. In some cases, these insights have advanced to therapeutic trials.

SUMMARY

Recent insights from studies of VIP/PACAP and their receptors in both CNS disorders (migraine, posttraumatic stress disorder, addiction [drugs, alcohol, smoking]) and inflammatory disorders [such as rheumatoid arthritis] are suggesting new treatment approaches. The elucidation of the importance of VIP/PACAP system in these disorders combined recent development of specific drugs acting on this system (i.e., monoclonal VIP/PACAP antibodies) will likely lead to importance novel treatment approaches in these diseases.

Long-term safety and tolerability of eptinezumab in patients with chronic migraine: a 2-year, open-label, phase 3 trial

BACKGROUND

Eptinezumab, an anti-calcitonin gene-related peptide monoclonal antibody recently approved in the United States for preventive treatment of migraine in adults, was found to be well tolerated in double-blind, placebo-controlled studies in patients with episodic and chronic migraine. The objective of the PREVAIL study was to evaluate the long-term safety, immunogenicity, and impact on patient-reported outcomes of repeat doses of eptinezumab in patients with chronic migraine.

METHODS

PREVAIL was an open-label, phase 3 trial comprising a 48-week treatment phase followed by a second 48-week treatment phase. Adults with chronic migraine received eptinezumab 300 mg by 30-min intravenous administration every 12 weeks for up to 8 doses. Patients were followed for 20 weeks after the final infusion (end-of-study visit at week 104).

RESULTS

Overall, 128 adults (mean age, 41.5 years) with chronic migraine were included. During the 2 years, the most frequently reported treatment-emergent adverse events were nasopharyngitis (14.1%), upper respiratory tract infection (7.8%), sinusitis (7.8%), influenza (6.3%), bronchitis (5.5%), and migraine (5.5%). The rate of study-drug discontinuation due to adverse events was 6.3%, which included 3 patients with infusion-related hypersensitivity. The incidence of anti-eptinezumab antibodies peaked at week 24 and declined despite continued dosing, to nondetectable levels at week 104. Improvements in patient-reported outcomes were observed at first assessment (week 4) and generally sustained through week 104.

CONCLUSION

In adults with chronic migraine, eptinezumab 300 mg demonstrated a favorable safety profile, limited long-term immunogenicity, early and sustained reductions in migraine-related burden, and improvements in health-related quality of life over 2 years.

TRIAL REGISTRATION

ClinicalTrials.gov (Identifier: NCT02985398 ).

Overcoming Obstacles in Protein Expression in the Yeast Pichia pastoris: Interviews of Leaders in the Pichia Field

The yeast Pichia pastoris (also known as Komagataella pastoris) has been used for over 30 years to produce thousands of valuable, heterologous proteins, such as insulin to treat diabetes and antibodies to prevent migraine headaches. Despite its success, there are some common, stubborn problems encountered by research scientists when they try to use the yeast to produce their recombinant proteins. In order to provide those working in this field with strategies to overcome these common obstacles, nine experts in P. pastoris protein expression field were interviewed to create a written review and video (https://www.youtube.com/watch?v=Q1oD6k8CdG8). This review describes how each respected scientist addressed a specific challenge, such as identifying high expression strains, improving secretion efficiency and decreasing hyperglycosylation. Their perspective and practical advice can be a tool to help empower others to express challenging proteins in this popular recombinant host.

Neuroimmune communication in infection and pain: Friends or foes?

Clinically, a variety of micro-organisms cause painful infections. Before seen as bystanders in the context of infections, recent studies have demonstrated that, as immune cells, nociceptors can sense pathogen-derived products. Nociceptors and immune cells, therefore, have evolved to communicate with each other to control inflammatory and host responses against pathogens in a complementary way. This interaction is named as neuroimmune communication (or axon-axon immune reflex) and initiates after the release of neuropeptides, such as CGRP and VIP by neurons. By this neurogenic response, nociceptors orchestrate the activity of innate and adaptive immune cells in a context-dependent manner. In this review, we focus on how nociceptors sense pathogen-derived products to shape the host response. We also highlight the new concept involving the resolution of inflammation, which is related to an active and time-dependent biosynthetic shift from pro-inflammatory to pro-resolution mediators, the so-called specialized pro-resolving lipid mediators (SPMs). At very low doses, SPMs act on specific receptors to silence nociceptors, limit pain and neurogenic responses, and resolve infections. Furthermore, stimulation of the vagus nerve induces SPMs production to regulate immune responses in infections. Therefore, harnessing the current understanding of neuro-immune communication and neurogenic responses might provide the bases for reprogramming host responses against infections through well balanced and effective immune response and inflammation resolution.

Sustained TNF-α stimulation leads to transcriptional memory that greatly enhances signal sensitivity and robustness

Transcriptional memory allows certain genes to respond to previously experienced signals more robustly. However, whether and how the key proinflammatory cytokine TNF-α mediates transcriptional memory are poorly understood. Using HEK293F cells as a model system, we report that sustained TNF-α stimulation induces transcriptional memory dependent on TET enzymes. The hypomethylated status of transcriptional regulatory regions can be inherited, facilitating NF-κB binding and more robust subsequent activation. A high initial methylation level and CpG density around κB sites are correlated with the functional potential of transcriptional memory modules. Interestingly, the CALCB gene, encoding the proven migraine therapeutic target CGRP, exhibits the best transcriptional memory. A neighboring primate-specific endogenous retrovirus stimulates more rapid, more strong, and at least 100-fold more sensitive CALCB induction in subsequent TNF-α stimulation. Our study reveals that TNF-α-mediated transcriptional memory is governed by active DNA demethylation and greatly sensitizes memory genes to much lower doses of inflammatory cues.

Genes are the instruction manuals of life and contain the information needed to build the building blocks that keep cells alive. To read these instructions, cells use specific signals that activate genes. The process, known as gene expression, is tightly controlled and for the most part, fairly stable. But gene expression can be modified in various ways.

Epigenetics is a broad term for describing reversible changes made to genes to switch them on and off. Sometimes, certain genes even develop a kind of ‘transcriptional memory’ where over time, their expression is enhanced and speeds up with repeated activation signals. But this may also have harmful effects.

For example, the signalling molecule called tumour necrosis factor α (TNF-α) is an essential part of the immune system. But it is also implicated in chronic inflammatory diseases, such as rheumatoid arthritis. In these conditions, cell signalling pathways triggering inflammation are overactive. One possibility is that TNF-α could be inducing the transcriptional memory of certain genes, amplifying their expression. But little is known about which fraction of genes exhibits transcriptional memory, and what differentiates memory genes from genes with stable expression.

Here, Zhao et al. treated cells grown in the laboratory with TNF-α to investigate its role in transcriptional memory and find out what epigenetic features might govern the process. The experiments showed that mimicking a sustained inflammation by stimulating TNF-α, triggered a transcriptional memory in some genes, and enabled them to respond to much lower levels of TNF-α on subsequent exposure.

Zhao et al. also discovered that genes tagged with methyl groups are more likely to show transcriptional memory when stimulated by TNF-α. However, they also found that these groups must be removed to consolidate any transcriptional memory.

This work shows how TNF-α influences can alter the expression of certain genes. It also suggests that transcriptional memory, stimulated by TNF-α, may be a possible mechanism underlying chronic inflammatory conditions. This could help future research in identifying more genes with transcriptional memory.

Pain pharmacogenetics

Pain is a significant problem in medicine. The use of PGx markers to personalize postoperative analgesia can increase its effectiveness and avoid undesirable reactions. This article describes the mechanisms of nociception and antinociception and shows the pathophysiological mechanisms of pain in the human body. The main subject of this article is pharmacogenetic approach to the selection of anesthetics. Current review presents data for local and general anesthetics, opioids, and non-steroidal anti-inflammatory drugs. None of the anesthetics currently has clinical guidelines for pharmacogenetic testing. This literature review summarizes the results of original research available, to date, and draws attention to this area.

Monoclonal antibodies blocking CGRP transmission: An update on their added value in migraine prevention

The avenue of effective migraine therapies blocking calcitonin gene-related peptide (CGRP) transmission is the successful outcome of 35 years of translational research. Developed after short-acting, the small antagonists of the CGRP receptor (the "gepants"), the monoclonal antibodies blocking CGRP or its receptor (CGRP/rec mAbs) have changed the paradigm in migraine treatment. Contrary to the classical acute medications like triptans or nonsteroidal anti-inflammatory drugs (NSAIDs) with a transient effect, they act for long durations exclusively in the peripheral portion of the trigeminovascular system and can thus be assimilated to a durable attack treatment, unlike the classical preventives that chiefly act upstream on the central facets of migraine pathophysiology. Randomized controlled trials (RCT) of eptinezumab, erenumab, fremanezumab and galcanezumab have included collectively several thousands of patients, making them the most extensively studied class of preventive migraine treatments. Their results clearly indicate that CGRP/rec mAbs are significantly superior to placebo and have been comprehensively reviewed by Dodick [Cephalalgia 2019;39(3):445-458]. In this review we will briefly summarize the placebo-subtracted outcomes and number-needed-to-treat (NNT) of these pivotal RCTs and analyze new and post-hoc studies published afterwards focusing on effect size, effect onset and sustainability, response in subgroups of patients, safety and tolerability, and cost-effectiveness. We will also summarize our limited real-world experience with one of the CGRP/rec mAbs. Although methodological differences and lack of direct comparative trials preclude any reliable comparison, the overall impression is that there are only minor differences in efficacy and tolerability profiles between the four monoclonals: the average placebo-subtracted 50% responder rates for reduction in migraine headaches are 21.4% in episodic migraine (NNTs: 4-5), 17.4% in chronic migraine (NNTs: 4-8). Patients with an improvement exceeding 50% are rare, chronic migraineurs with continuous headache are unlikely to be responders and migraine auras are not improved. The effect starts within the first week after administration and is quasi maximal at one month. It is sustained for long time periods and may last for several months after treatment termination. CGRP/rec mAbs are effective even after prior preventive treatment failures and in patients with medication overuse, but the effect size might be smaller. They significantly reduce disability and health care resource utilization. The adverse effect profile of CGRP/rec mAbs is close to that of placebo with few minor exceptions and despite concerns related to the safeguarding role of CGRP in ischemia, no treatment-related vascular adverse events have been reported to date. Putting the CGRP/rec mAbs in perspective with available preventive migraine drug treatments, their major advantage seems not to be chiefly their superior efficacy but their unprecedented efficacy over adverse event ratio. Regarding cost-effectiveness, preliminary pharmaco-economic analyses of erenumab suggest that it is cost-effective for chronic migraine compared to no treatment or to onabotulinumtoxinA, but likely not for episodic migraine unless attack frequency is high, indirect costs are considered and its price is lowered.

Migraine and Ischemic Stroke: Deciphering the Bidirectional Pathway

Migraine and stroke are common, disabling neurological conditions with several theories being proposed to explain this bidirectional relationship. Migraine is considered as a benign neurological disorder, but research has revealed a connection between migraine and stroke, predominantly those having migraine with aura (MA). Among migraineurs, females with MA are more susceptible to ischemic stroke and may have a migrainous infarction. Migrainous infarction mostly occurs in the posterior circulation of young women. Although there are several theories about the potential relationship between MA and stroke, the precise pathological process of migrainous infarction is not clear. It is assumed that cortical spreading depression (CSD) might be one of the essential factors for migrainous infarction. Other factors that may contribute to migrainous infarction may be genetic, hormonal fluctuation, hypercoagulation, and right to left cardiac shunts. Antimigraine drugs, such as ergot alkaloids and triptans, are widely used in migraine care. Still, they have been found to cause severe vasoconstriction, which may result in the development of ischemia. It is reported that patients with stroke develop migraines during the recovery phase. Both experimental and clinical data suggest that cerebral microembolism can act as a potential trigger for MA. Further studies are warranted for the treatment of migraine, which may lead to a decline in migraine-related stroke. In this present article, we have outlined various potential pathways that link migraine and stroke.

Efficacy and Safety of Galcanezumab for the Preventive Treatment of Migraine: A Narrative Review

Migraine is a debilitating neurologic disease. People who experience migraine can have substantial disability, impaired functioning and a decreased quality of life (QoL). Expert recommendations suggest that people with frequent migraine attacks or severe impairment related to attacks may benefit from preventive treatment. Despite these recommendations and the existence of evidence-based guidelines for the use of preventive medication, many people who are candidates for preventive therapies do not receive them. Thus, there is still a substantial unmet need for preventive migraine treatment. Calcitonin gene-related peptide (CGRP) has a demonstrated role in the pathophysiology of migraine. Galcanezumab-gnlm (galcanezumab) is a humanized monoclonal antibody that binds to the CGRP ligand and prevents binding to its receptor. It is administered as a once-monthly subcutaneous injection. The aim of this review is to present a comprehensive overview of the existing short- and long-term efficacy and safety data for galcanezumab in patients with migraine. Data from the phase 3, randomized, double-blind, placebo-controlled EVOLVE-1, EVOLVE-2 and REGAIN studies show that galcanezumab treatment for 3 or 6 months results in overall reduction in mean monthly migraine headache days in patients with episodic (EVOLVE-1 and EVOLVE-2) and chronic (REGAIN) migraine. Greater proportions of patients with episodic migraine receiving galcanezumab versus placebo demonstrated a ≥ 50%, ≥ 75% and 100% response to therapy and reported a lower level of disability and an improvement in functioning and QoL. Similarly, when compared with placebo, greater proportions of patients with chronic migraine treated with galcanezumab demonstrated a ≥ 50% and ≥ 75% response and reported improved functioning. A 12-month open-label study demonstrated the continued efficacy of galcanezumab for up to 12 months. In all studies galcanezumab was well tolerated. In conclusion, data from pivotal studies show that galcanezumab may fulfill an unmet need in the treatment of patients with migraine who require preventive therapy.

Migraine is a significant contributor to the global burden of disease. Migraine symptoms can lead to substantial disability and can significantly impact an individual’s ability to perform everyday tasks and their overall quality of life. While individuals with infrequent migraine attacks might have success with acute treatments alone, those with more frequent attacks or who have severe migraine-related impairment may require preventive treatment. Although recommendations on the use of preventive treatment exist, only about one-third of individuals who qualify for preventive therapy actually receive it, resulting in a substantial unmet need. Calcitonin gene-related peptide (CGRP) has a demonstrated role in migraine. Galcanezumab is a humanized monoclonal antibody that binds to the CGRP ligand and prevents receptor binding. In clinical trials of patients with ≥ 4 migraine headache days per month, treatment with galcanezumab was associated with a reduction in the average number of migraine headache days per month. The majority of galcanezumab groups had greater responder rates compared with the placebo groups, and levels of disability and daily functioning were generally improved. Galcanezumab was well tolerated, with the most common adverse events being injection site reactions. The results from the clinical trials of galcanezumab suggest that this drug may fulfill an unmet need in the treatment of individuals with migraine who require preventive therapy.

Eptinezumab in episodic migraine: A randomized, double-blind, placebo-controlled study (PROMISE-1)

OBJECTIVE

To evaluate the efficacy and safety of eptinezumab, a humanized anti-calcitonin gene-related peptide monoclonal antibody, in the preventive treatment of episodic migraine.

METHODS

The PRevention Of Migraine via Intravenous ALD403 Safety and Efficacy-1 (PROMISE-1) study was a phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Adults with episodic migraine were randomized to eptinezumab 30 mg, 100 mg, 300 mg, or placebo for up to four intravenous (IV) doses administered every 12 weeks. The primary endpoint was change from baseline in monthly migraine days (MMDs) over weeks 1-12.

RESULTS

A total of 888 patients received treatment across 84 study sites. Mean MMDs at baseline was ∼8.6 across treatment groups. Eptinezumab 100 mg and 300 mg met the primary endpoint, significantly reducing MMDs across weeks 1-12 compared with placebo (30 mg, -4.0; 100 mg, -3.9, p = 0.0182; 300 mg, -4.3; placebo, -3.2, p = 0.0001). Treatment-emergent adverse events were reported by 58.4% (30 mg), 63.2% (100 mg), 57.6% (300 mg), and 59.5% (placebo) of patients. Treatment-emergent adverse events reported by ≥2% of eptinezumab-treated patients at an incidence greater than placebo included: upper respiratory tract infection (30 mg, 11.4%; 100 mg, 9.9%; 300 mg, 10.3%; placebo, 7.2%), and fatigue (30 mg, 2.3%; 100 mg, 3.6%; 300 mg, 3.6%; placebo, <1%).

CONCLUSION

Eptinezumab (100 mg or 300 mg) significantly reduced migraine frequency, was well tolerated, and had an acceptable safety profile when used for the preventive treatment of migraine in adults with episodic migraine. ClinicalTrials.gov identifier: NCT02559895.

Pain and the immune system: emerging concepts of IgG-mediated autoimmune pain and immunotherapies

The immune system has long been recognised important in pain regulation through inflammatory cytokine modulation of peripheral nociceptive fibres. Recently, cytokine interactions in brain and spinal cord glia as well as dorsal root ganglia satellite glia have been identified important- in pain modulation. The result of these interactions is central and peripheral sensitisation of nociceptive processing. Additionally, new insights and the term 'autoimmune pain' have emerged through discovery of specific IgGs targeting the extracellular domains of antigens at nodal and synaptic structures, causing pain directly without inflammation by enhancing neuronal excitability. Other discovered IgGs heighten pain indirectly by T-cell-mediated inflammation or destruction of targets within the nociceptive pathways. Notable identified IgGs in pain include those against the components of channels and receptors involved in inhibitory or excitatory somatosensory synapses or their pathways: nodal and paranodal proteins (LGI1, CASPR1, CASPR2); glutamate detection (AMPA-R); GABA regulation and release (GAD65, amphiphysin); glycine receptors (GLY-R); water channels (AQP4). These disorders have other neurological manifestations of central/peripheral hyperexcitabability including seizures, encephalopathy, myoclonus, tremor and spasticity, with immunotherapy responsiveness. Other pain disorders, like complex regional pain disorder, have been associated with IgGs against β2-adrenergic receptor, muscarinic-2 receptors, AChR-nicotinic ganglionic α-3 receptors and calcium channels (N and P/Q types), but less consistently with immune treatment response. Here, we outline how the immune system contributes to development and regulation of pain, review specific IgG-mediated pain disorders and summarise recent development in therapy approaches. Biological agents to treat pain (anti-calcitonin gene-related peptide and anti-nerve growth factor) are also discussed.

The Therapeutic Impact of New Migraine Discoveries

BACKGROUND

Migraine is one of the most disabling neurological conditions and associated with high socio-economic costs. Though certain aspects of the pathomechanism of migraine are still incompletely understood, the leading hypothesis implicates the role of the activation of the trigeminovascular system. Triptans are considered to be the current gold standard therapy for migraine attacks; however, their use in clinical practice is limited. Prophylactic treatment includes non-specific approaches for migraine prevention. All these support the need for future studies in order to develop innovative anti-migraine drugs.

OBJECTIVE

The present study is a review of the current literature regarding new therapeutic lines in migraine research.

METHODS

A systematic literature search in the database of PUBMED was conducted concerning therapeutic strategies in a migraine published until July 2017.

RESULTS

Ongoing clinical trials with 5-HT1F receptor agonists and glutamate receptor antagonists offer promising new aspects for acute migraine treatment. Monoclonal antibodies against CGRP and the CGRP receptor are revolutionary in preventive treatment; however, further long-term studies are needed to test their tolerability. Preclinical studies show positive results with PACAP- and kynurenic acid-related treatments. Other promising therapeutic strategies (such as those targeting TRPV1, substance P, NOS, or orexin) have failed to show efficacy in clinical trials.

CONCLUSION

Due to their side-effects, current therapeutic approaches are not suitable for all migraine patients. Especially frequent episodic and chronic migraine represents a therapeutic challenge for researchers. Clinical and preclinical studies are needed to untangle the pathophysiology of migraine in order to develop new and migraine-specific therapies.

The CGRP Pathway in Migraine as a Viable Target for Therapies

The neuropeptide calcitonin gene-related peptide is well established as a key player in the pathogenesis of migraine. Clinical studies show calcitonin gene-related peptide levels correlate with migraine attacks, and decreases in this neuropeptide can indicate antimigraine therapy effectiveness. Research has revealed a wide distribution of expression sites for calcitonin gene-related peptide in the central and peripheral nervous system. Of these, the calcitonin gene-related peptide receptor, which binds calcitonin gene-related peptide with high affinity, has attracted growing interest as a viable target for antimigraine therapies. An incentive to pursue such research is the continuing unmet medical need of patients. Triptans have offered some clinical benefit, but many patients do not respond and these drugs have important safety considerations. Initial calcitonin gene-related peptide-focused research led to development of the "gepant" small-molecule calcitonin gene-related peptide receptor blockers. Positive efficacy reports concerning the gepants have been tempered by safety findings which led to the discontinuation of some of these agents. Currently, there is considerable excitement regarding monoclonal antibodies against calcitonin gene-related peptide (eptinezumab, galcanezumab, fremanezumab) and the calcitonin gene-related peptide receptor (erenumab). To date, these monoclonal antibodies have shown promising efficacy in clinical trials, with no major safety concerns. If ongoing long-term studies show that their efficacy can be maintained, this may herald a new era for effective antimigraine therapies.

Monoclonal antibodies for the prevention of migraine

Introduction: Calcitonin Gene-Related Peptide (CGRP) plays a crucial role in migraine pathophysiology. A novel specific treatment strategy for the prevention of migraine incorporates monoclonal antibodies (mAbs) against CGRP and its canonical receptor. Eptinezumab, fremanezumab and galcanezumab block CGRP mediated effects by binding to the peptide, while erenumab blocks the CGRP receptor.Areas covered: Following a brief overview of pharmacological characteristics, we will review phase III trials for the use of CGRP mAbs in the prevention of episodic and chronic migraine.Expert opinion: All four CGRP mAbs demonstrated an excellent safety, tolerability and efficacy profile in migraine patients. Across all trials mAbs showed superior efficacy for the reduction of monthly migraine days compared to placebo with a net benefit of 2.8 days. Neither cardiovascular nor immunological safety concerns have emerged from clinical trials. Fremanezumab, galcanezumab, and erenumab are approved in the USA and Europe. Based on trial data there is no reason why these mAbs should not become first-line therapies in future. For now, we advocate for the use of mAbs in migraine prevention for patients who failed a minimum of two standard oral treatments based on the novelty and costs of this approach. mAbs are also effective in patients with medication overuse and with comorbid depression or anxiety disorders. Taken together, mAbs are likely to usher in a new era in migraine prevention and provide significant value to patients.

Galcanezumab in episodic migraine: subgroup analyses of efficacy by high versus low frequency of migraine headaches in phase 3 studies (EVOLVE-1 & EVOLVE-2)

Background

Patients with high-frequency episodic migraine (HFEM) have a greater disease burden than those with low-frequency episodic migraine (LFEM). Acute treatment overuse increases the risk of migraine chronification in patients with HFEM. Galcanezumab, a humanized monoclonal antibody binding calcitonin gene-related peptide (CGRP), is effective for migraine prevention with a favorable safety profile. Here, we investigate whether there are differences in galcanezumab efficacy in patients with LFEM or with HFEM.

Methods

Data were pooled from two double-blind, placebo-controlled phase 3 trials; EVOLVE-1 and EVOLVE-2. Patients were 18–65 years old, experienced 4–14 monthly migraine headache days (MHDs) for ≥1 year prior, with onset at < 50 years of age. Migraine headaches were tracked via electronic patient-reported outcome system and randomization was stratified by low (LFEM; 4–7 monthly MHDs) or high (HFEM; 8–14 monthly MHDs) frequency. Subgroup analysis compared the HFEM and LFEM subgroups with a linear or generalized linear mixed model repeated measures approach.

Results

The intent-to-treat patients (N = 1773) had a mean age of 41.3 years, were mostly white (75%), female (85%), and 66% of patients had HFEM. In both the LFEM and HFEM subgroups, the overall (Months 1–6) and monthly changes from baseline in monthly MHDs and monthly MHDs with acute medication use compared with placebo were statistically significantly reduced for galcanezumab 120-mg and 240-mg. Galcanezumab (120-mg and 240-mg) significantly decreased the overall and monthly MHDs with nausea and/or vomiting, and with photophobia and phonophobia versus placebo in patients with LFEM or HFEM. In both subgroups, the mean overall (Months 1–6) and monthly percentages of patients with ≥50%, ≥75%, and 100% reduction in monthly MHDs from baseline were statistically significantly greater in patients receiving either dose of galcanezumab versus placebo. Galcanezumab (120-mg and 240-mg) significantly improved the Migraine-Specific Quality of Life Questionnaire role function-restrictive domain score as well as the Migraine Disability Assessment total score versus placebo for patients with LFEM or HFEM. There were no significant subgroup-by-treatment interactions.

Conclusions

Galcanezumab was as effective in patients with HFEM as in those with LFEM. Associated symptoms, quality of life, and disability were similarly improved in patients with HFEM or LFEM.

Trial registration

NCT02614183, NCT02614196.

Erenumab and galcanezumab in chronic migraine prevention: effects after treatment termination

Background

Monoclonal antibodies (mAbs) targeting the CGRP pathway are safe and efficacious therapies for the prevention of migraine. In this study we assessed the effects of discontinuation of preventive erenumab and galcanezumab treatment in patients with chronic migraine.

Methods

This retrospective pooled analysis included completers of the open-label extension study phase for the preventive treatment of chronic migraine with galcanezumab (NCT02614261; 9 months) and erenumab (NCT02174861; 12 months) in a single headache center. We compare migraine data until week 12 after open-label treatment completion, when patients did not have any pharmacological preventive medication, to study baseline values of the double-blind trial period, and to the last 4 weeks of the open-label extension. The assessment included changes in monthly migraine days, headache hours, days with severe headache and acute headache medication use.

Results

Data from 16 patients after galcanezumab (n = 9) and erenumab (n = 7) open-label treatment completion were analyzed. The mean number of monthly migraine days was 18.38 ± 3.74 at baseline, and 12.19 ± 4.53 in the last 4 weeks of the open-label extension (p < 0.001). Monthly migraine days remained significantly reduced compared to baseline during the entire 12-week observation period after open-label termination (p = 0.002), with a reduction of 5.38 ± 4.92 in weeks 1–4 (p = 0.001), 4.75 ± 4.15 in weeks 5–8 (p = 0.001), and 3.93 ± 5.45 in weeks 9–12 (p = 0.014). There was no significant difference in monthly migraine days between the 12 weeks after open-label termination and the last 4 weeks of the open-label phase (p = 0.228). All other analyses revealed numerical improvement through week 12 in comparison to baseline.

Conclusions

In this small, self-selected cohort, the results indicate a therapeutic effect of monoclonal antibodies targeting the CRGP pathway in chronic migraine prevention after treatment termination up to 12 weeks.

Optimising migraine treatment: from drug-drug interactions to personalized medicine

Migraine is the most disabling and expensive chronic disorders, the etiology of which is still not fully known. The neuronal systems, (glutammatergic, dopaminergic, serotoninergic and GABA-ergic) whose functionality is partly attributable to genetically determined factors, has been suggested to play an important role. The treatment of acute attacks and the prophylactic management of chronic forms include the use of different category of drugs, and it is demonstrated that not each subject has the same clinical answer to them. The reason of this is to be searched in different functional capacity and quantity of phase I enzymes (such as different isoforms of CYP P450), phase II enzymes (such as UDP-glucuronosyltransferases), receptors (such as OPRM1 for opioids) and transporters (such as ABCB1) involved in the metabolic destiny of each drug, all of these dictated by DNA and RNA variations. The general picture is further exacerbated by the need for polytherapies, often also to treat comorbidities, which may interfere with the pharmacological action of anti-migraine drugs. Personalized medicine has the objective of setting the optimal therapies in the light of the functional biochemical asset and of the comorbidities of the individual patient, in order to obtain the best clinical response. Novel therapeutic perspectives in migraine includes biotechnological drugs directed against molecules (such as CGRP and its receptor) that cause vasodilatation at the peripheral level of the meningeal blood vessels and reflex stimulation of the parasympathetic system. Drug-drug interactions and the possible competitive metabolic destiny should be studied by the application of pharmacogenomics in large scale. Drug-drug interactions and their possible competitive metabolic destiny should be studied by the application of pharmacogenomics in large scale.

Safety and Tolerability of Fremanezumab for the Prevention of Migraine: A Pooled Analysis of Phases 2b and 3 Clinical Trials

OBJECTIVE

Presentation of pooled analysis of safety data for fremanezumab in patients with chronic (CM) or episodic migraine (EM) from 4 placebo-controlled phase 2b and phase 3 studies.

BACKGROUND

There is a need for an effective, safe, and well-tolerated preventive therapy that specifically targets the pathophysiology of migraine to reduce the frequency and severity of migraine attacks in patients with CM or EM who experience 4 or more migraine days per month. Fremanezumab is a fully humanized monoclonal antibody that targets calcitonin gene-related peptide, a neuropeptide involved in the pathophysiology of migraine.

DESIGN/METHODS

The 4 placebo-controlled phases 2b and 3 studies included in this analysis were 16-week, multicenter, randomized, double-blind, placebo-controlled, and parallel-group studies consisting of a screening visit, a 28-day pretreatment baseline period, and a 12-week treatment period with a final evaluation 4 weeks after the final dose of the study drug. Safety endpoints included adverse events (AEs) and immunogenicity.

RESULTS

A total of 2566 patients were randomized across all studies (fremanezumab, n = 1704; placebo, n = 862), and 2563 patients were treated. Common reasons for study discontinuation were withdrawal by patient (n = 78), patient lost to follow-up (n = 60), and AE (n = 50). The mean (standard deviation) duration of exposure was 83.8 (13.6) days for the patients who received fremanezumab, with a total exposure of 390.4 patient years and maximum exposure of 181 days. AEs were mostly mild to moderate in severity and were reported among 48-69% of patients in all treatment groups, and most were injection site reactions (pain, induration, and erythema). Two deaths occurred (chronic obstructive pulmonary disease and intentional overdose of diphenhydramine), both of which were deemed unrelated to study drug by the investigators and sponsor. Cardiovascular adverse events, abnormal liver function tests, and hypersensitivity were uncommon and occurred at similar rates between the placebo and fremanezumab groups.

CONCLUSIONS

Fremanezumab is a generally safe and well-tolerated preventive therapy for migraine in adults.

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 Antagonists for the Treatment of Chronic Migraines: a Comprehensive Review

PURPOSE OF REVIEW

The purpose of the following review is to summarize the most recent understanding of migraine pathophysiology, as well as of basic and clinical science pharmacologic literature regarding the development of calcitonin gene receptor peptide (CGRP) antagonists as a novel therapeutic modality for the treatment of migraine headaches. A review is provided of erenumab, the first of its class FDA approved CGRP antagonist.

RECENT FINDINGS

Despite its high prevalence, the occurrence and treatment of migraine headaches is poorly understood. Erenumab and CGRP antagonists as a whole significantly reduce the average number of migraine days experienced in migraine sufferers. CGRP antagonists appear to significantly improve treatment outcomes in patients who suffer from episodic and chronic migraines. Erenumab is the first CGRP antagonist to be FDA approved for public use; however, further development of biologics in this class is underway.

Circulating nociceptin and CGRP in medication-overuse headache

BACKGROUND

Previous studies found low serum levels of nociceptin in migraine patients but high serum levels of calcitonin gene-related peptide (CGRP). CGRP can elicit migraine-like headache. Medication-Overuse Headache (MOH) often has migraine features and can mimic chronic migraine. We therefore hypothesized that as in migraine, serum levels of nociceptin would be lower and CGRP serum levels higher in MOH patients compared with those in healthy volunteers. We hypothesized that the serum levels would normalize after detoxification.

METHODS

Seventeen MOH patients, hereof 70.6% with chronic migraine and MOH, and 30 sex and age matched headache-free controls were included. MOH patients underwent a 2-month outpatient detoxification program and after 6 months, 10 patients and 19 controls were retested. Blood samples were analyzed blinded.

RESULTS

We found no differences in the levels of nociceptin and CGRP between MOH patients and controls (P = 0.65 and P = 0.59). The mean headache frequency reduction was 43% and 70% of patients reverted to episodic headache after 6 months, but the levels of nociceptin and CGRP were unchanged (P = 0.71 and P = 0.82).

CONCLUSION

In contrast to previous findings in migraine patients, we found normal serum levels of nociceptin and CGRP in MOH patients. Thus, we find no evidence that the increased headache frequency of MOH patients could be caused by altered nociceptin and CGRP levels. This underlines the importance of identifying medication overuse in chronic headache and treating the MOH.

Diagnosis and treatment of migraine in the patient with depression

BACKGROUND AND PURPOSE

Migraine headache is an enormous health care burden resulting in billions of dollars in workforce revenue lost and millions of lost workdays per year. Migraine headaches and depression are common comorbidities and require expertise in treatment and prevention.

METHODS

The aim of this article is to update the nurse practitioner (NP) on best clinical practices for managing the patient with migraine and previously diagnosed depression. This will include an overview of the pathophysiology of migraine, as well as criteria for diagnosis, treatment, prevention, and patient teaching.

CONCLUSIONS

Migraine and depression are commonly linked and require expertise in treatment to achieve the best patient outcomes.

IMPLICATIONS FOR PRACTICE

Patients with migraine are more likely to have depression than the general population. Both conditions require optimal treatment and patient education to reduce overall disease burden. A better understanding of the relationship between depression and migraine will enable the NP to better manage patients with migraine and comorbid depression.

Peripheral GABAA receptor-mediated signaling facilitates persistent inflammatory hypersensitivity

Unlike in the central nervous system (CNS), in the adult peripheral nervous system (PNS), activation of GABA_A receptors (GABA_AR) is excitatory because of the relatively high concentration of intracellular chloride in these neurons. Indeed, exogenous GABA and muscimol, a GABA_AR agonist, exacerbate acute inflammatory hypersensitivity in rodents. However, it remains unclear whether peripheral GABA_AR and the endogenous GABA play an important role in persistent inflammatory hypersensitivity. In this study, we thus investigated how peripheral GABA_AR affects pain hypersensitivity by using the complete Freund's adjuvant (CFA)-induced persistent inflammatory pain mouse model. We found that intraplantar (i.pl.) administration of GABA_AR antagonists, picrotoxin, and 1(S),9(R)-(-)-bicuculline methiodide significantly inhibited both spontaneous nociceptive (paw licking and flinching) behavior and mechanical hypersensitivity in CFA-injected mice at day 3 (D3), but not in naïve mice. Interestingly, CFA-induced mechanical hypersensitivity was significantly reversed by anti-GABA antibody (anti-GABA, i.pl.). In addition, RT-qPCR revealed that glutamate decarboxylase Gad1 (GAD 67) and Gad2 (GAD 65) mRNA expression was also upregulated in the ipsilateral hind paw of CFA-injected mice at D3. Finally, 5α-pregnan-3α-ol-20-one (3α,5α-THP), a selective positive allosteric modulator of GABA_AR, produced mechanical hypersensitivity in naïve mice in a dose-dependent manner. Taken together, our results indicate that peripheral GABA_AR and endogenous GABA, possibly produced by the inflamed tissue, potentiate CFA-induced persistent inflammatory hypersensitivity, suggesting that they can be used as a therapeutic target for alleviating inflammatory pain.

The Biology of Monoclonal Antibodies: Focus on Calcitonin Gene-Related Peptide for Prophylactic Migraine Therapy

Calcitonin gene-related peptide (CGRP) is 37-amino-acid neuropeptide, crucially involved in migraine pathophysiology. Four monoclonal antibodies (mAbs) targeting the CGRP pathway are currently under evaluation for the prevention of episodic and chronic migraine: eptinezumab (ALD403), fremanezumab (TEV-48125), galcanezumab (LY2951742), and erenumab (AMG334). As reviewed in this article, all 4 antibodies have been proven effective, tolerable, and safe as migraine prophylactic treatments in phase II clinical trials. The mean decrease in migraine days per month was between 3.4 and 6.3 days/month after 8 to 12 weeks of treatment, and the placebo subtracted benefit ranged from 1 to 2.18 days. Notably, up to 32% of subjects experienced total migraine freedom after drug administration. Substance class-specific adverse events and treatment-related serious adverse event did not occur. Further long-term and large-scale trials are currently under way to verify the safety and efficacy profile of mAbs. In particular, the potential risk of vascular adverse events and the role of anti-drug antibodies deserve special attention. Anti-CGRP peptide and anti-CGRP receptor antibodies are the first effective treatments, which were specifically developed for the prevention of migraine. Their site of action in migraine prevention is most likely peripheral due to large molecule size, which prevents the penetration through the blood-brain barrier and thereby shows that peripheral components play a pivotal role in the pathophysiology of a CNS disease.

Side effects associated with current and prospective antimigraine pharmacotherapies

INTRODUCTION

Migraine is a neurovascular disorder. Current acute specific antimigraine pharmacotherapies target trigeminovascular 5-HT1B/1D, 5-HT1F and CGRP receptors but, unfortunately, they induce some cardiovascular and central side effects that lead to poor treatment adherence/compliance. Therefore, new antimigraine drugs are being explored. Areas covered: This review considers the adverse (or potential) side effects produced by current and prospective antimigraine drugs, including medication overuse headache (MOH) produced by ergots and triptans, the side effects observed in clinical trials for the new gepants and CGRP antibodies, and a section discussing the potential effects resulting from disruption of the cardiovascular CGRPergic neurotransmission. Expert opinion: The last decades have witnessed remarkable developments in antimigraine therapy, which includes acute (e.g. triptans) and prophylactic (e.g. β-adrenoceptor blockers) antimigraine drugs. Indeed, the triptans represent a considerable advance, but their side effects (including nausea, dizziness and coronary vasoconstriction) preclude some patients from using triptans. This has led to the development of the ditans (5-HT1F receptor agonists), the gepants (CGRP receptor antagonists) and the monoclonal antibodies against CGRP or its receptor. The latter drugs represent a new hope in the antimigraine armamentarium, but as CGRP plays a role in cardiovascular homeostasis, the potential for adverse cardiovascular side effects remains latent.