Calcitonin gene-related peptide monoclonal antibodies for migraine prevention: comparisons across randomized controlled studies

Analysis to retreatment with monoclonal antibodies in chronic/episodic migraine: Real world data

OBJECTIVE

To analyze the response to retreatment in patients with chronic/episodic migraine who discontinued therapy with erenumab/fremanezumab after one year of treatment.

METHODS

Observational, retrospective, single-center, multidisciplinary study in patients with chronic/episodic migraine who received therapy with erenumab/fremanezumab for at least one year and discontinued it after achieving an adequate response (optimization). The evaluation of the response after retreatment included the following variables: migraine days per month, MIDAS and HIT-6 scales at the beginning of retreatment and 3 months later. The response was evaluated in different subgroups (episodic/chronic, erenumab/fremanezumab and time until retreatment).

RESULTS

48 patients were included. 70.8% (n=34) required retreatment with mAb, with a median of 3.9 (2.9-6.4) months until reintroduction. Clinical response after retreatment was achieved in 67.6% (n=23) of patients. No statistically significant differences were found in the analyzed subgroups.

CONCLUSION

Interruption of treatment with erenumab/fremanezumab for chronic/episodic migraine produces a clinical worsening of the disease requiring retreatment in most cases, approximately after 4 months. Two out of three patients respond positively after restarting monoclonal therapy. This response does not appear to be related to the type of migraine, the specific monoclonal antibody prescribed, or the time to retreatment.

Analysis of retreatment with monoclonal antibodies in chronic/episodic migraine: Real world data

OBJECTIVE

To analyze the response to retreatment in patients with chronic/episodic migraine who discontinued therapy with erenumab/fremanezumab after 1 year of treatment.

METHODS

Observational, retrospective, single-center, multidisciplinary study in patients with chronic/episodic migraine who received therapy with erenumab/fremanezumab for at least 1 year and discontinued it after achieving an adequate response (optimization). The evaluation of the response after retreatment included the following variables: DMM, MIDAS, and HIT-6 scales at the beginning of retreatment and 3 months later. The response was evaluated in different subgroups (episodic/chronic, erenumab/fremanezumab, and time until retreatment).

RESULTS

48 patients were included. 70.8% (n=34) required retreatment with mAb, with a median of 3.9 (2.9-6.4) months until reintroduction. Clinical response after retreatment was achieved in 67.6% (n=23) of patients. No statistically significant differences were found in the analyzed subgroups.

CONCLUSION

Interruption of treatment with erenumab/fremanezumab for chronic/episodic migraine produces a clinical worsening of the disease requiring retreatment in most cases, approximately after 4 months. Two out of three patients respond positively after restarting monoclonal therapy. This response does not appear to be related to the type of migraine, the specific monoclonal antibody prescribed, or the time to retreatment.

Cardiovascular Adverse Drug Reactions of Anti-Calcitonin Gene-Related Peptide Monoclonal Antibodies for Migraine Prevention: An Analysis from the European Spontaneous Adverse Event Reporting System

INTRODUCTION

Anti-calcitonin gene-related peptide monoclonal antibodies (anti-CGRP-mAbs) have recently been approved for the prevention of migraine, and their safety profile is not fully characterized.

OBJECTIVE

The aim of this study was to evaluate the adverse drug reactions (ADRs) of anti-CGRP-mAbs through the analysis of individual case safety reports (ICSRs) collected in the EudraVigilance (EV) database, with a specific focus on cardiovascular (CV) ADRs.

METHODS

Data on ICSRs recorded between July 2018 and December 2022 in the EV database, involving one of the anti-CGRP-mAbs for migraine prevention-erenumab (ERE), galcanezumab (GMB), fremanezumab (FMB), and eptinezumab (EPT)-were included in the analysis. All ICSRs reporting at least one CV ADR, as identified within the MedDRA® System Organ Classes (SOCs) "cardiac disorders" or "vascular disorders," were selected for the analysis. The frequency of disproportionate reporting was expressed as the reporting odds ratio (ROR) with its 95% confidence interval (CI), to evaluate the frequency of reporting of CV ADRs for each anti-CGRP-mAb compared with all other monoclonal antibodies (mAbs). A case-by-case analysis was conducted paying particular attention to serious CV ADR reports, focusing on the type of seriousness, age group, sex, and concomitant drugs.

RESULTS

A total of 9441 ICSRs were recorded in the EV database from 2018 to 2022, of which more than half were related to ERE (58.9%), followed by GMB (21.4%), FMB (19.0%), and EPT (0.7%). CV ICSRs accounted for 1205 cases (12.8%), with a total of 1599 CV ADRs. The CV ICSRs were mainly related to female patients (82.6%) aged 18-64 years (73.4%). Of the reported CV ADRs, 67.5% were considered serious. Among the total number of ICSRs related to each anti-CGRP-mAb, those associated with FMB had a higher percentage of CV ADRs (n = 253; 14.1%), followed by ERE (n = 707; 12.7%), EPT (n = 8; 12.7%), and GMB (n = 237; 11.7%). A higher frequency of reporting hypertension was shown for ERE (ROR = 1.45; 95% CI = 1.14-1.85). Pallor was mainly observed with FMB (5.00; 1.68-14.89), as well as deep vein thrombosis (3.86; 1.57-9.51), hot flush (2.16; 1.43-3.25), and palpitations (1.48; 1.05-2.08). Atrial fibrillation (2.36; 1.02-5.46) and myocardial infarction (2.21; 1.37-3.58) were mostly reported for GMB.

CONCLUSION

The analysis of anti-CGRP-related CV ADRs was consistent with the information reported in the literature. However, hypertension with ERE, atrial fibrillation and myocardial infarction with GMB, as well as pallor, deep vein thrombosis, hot flush, and palpitations with FMB were not reported in the Summary of Product Characteristics (SmPCs). Considering this, more post-marketing analyses are needed to improve knowledge on the CV safety profiles of anti-CGRP-mAbs, especially for the last approved medication, EPT.

Preventive treatment patterns in the adult migraine population: an observational UK study over 7 years

BACKGROUND

Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) are recommended by the United Kingdom National Institute of Health and Care Excellence for the prevention of migraine as treatment beyond third line. We report migraine prevalence and preventive treatment patterns in the adult United Kingdom primary care population over a 7.5-year period, focusing on patients ceasing ≥ 3 oral preventive medication classes.

METHODS

Study populations were retrieved from the Clinical Practice Research Datalink GOLD database (study period: 19 September 2012 to 1 January 2020; inclusion criteria: ≥12 months follow-up, current-in-dataset, adult on 1 January 2020). Patients who used ≥ 1 oral preventive medication with ≥ 3-year follow-up after first prescription were considered preventive treatment users; class cessation was defined as cessation without evidence of restart within 6 months from end-of-supply date.

RESULTS

On 1 January 2020, 3.0% of the total study population were diagnosed with migraine (n = 81,190/2,664,306); of these, 42.4% were preventive treatment users (n = 34,448/81,190). The most frequently used oral migraine preventive medication classes were beta-blockers (n = 14,713), tricyclic antidepressants (n = 14,415) and antiepileptics (n = 6497). Among preventive treatment users, 7.7% (n = 2653/34,448) ceased ≥ 3 oral preventive medication classes; of these, 21.7% (n = 576/2653) had been referred to a neurologist.

CONCLUSIONS

Compared to existing population-based estimates of migraine prevalence, our data further corroborates that a considerable proportion of patients with migraine do not seek treatment. Among those who sought primary care within a 7.5-year period, almost half received empirical oral preventive treatment. Importantly, nearly 1 of 10 preventive treatment users ceased ≥ 3 oral preventive medication classes, highlighting a need for additional therapeutic options. These patients may benefit from CGRP antagonists and/or injectable onabotulinumtoxinA; however, only a minority was referred to specialist care, where these options would be more available.

TRIAL REGISTRATION

Not applicable.

Distribution and Chemistry of Phoenixin-14, a Newly Discovered Sensory Transmission Molecule in Porcine Afferent Neurons

Phoenixin-14 (PNX), initially discovered in the rat hypothalamus, was also detected in dorsal root ganglion (DRG) cells, where its involvement in the regulation of pain and/or itch sensation was suggested. However, there is a lack of data not only on its distribution in DRGs along individual segments of the spinal cord, but also on the pattern(s) of its co-occurrence with other sensory neurotransmitters. To fill the above-mentioned gap and expand our knowledge about the occurrence of PNX in mammalian species other than rodents, this study examined (i) the pattern(s) of PNX occurrence in DRG neurons of subsequent neuromeres along the porcine spinal cord, (ii) their intraganglionic distribution and (iii) the pattern(s) of PNX co-occurrence with other biologically active agents. PNX was found in approximately 20% of all nerve cells of each DRG examined; the largest subpopulation of PNX-positive (PNX+) cells were small-diameter neurons, accounting for 74% of all PNX-positive neurons found. PNX+ neurons also co-contained calcitonin gene-related peptide (CGRP; 96.1%), substance P (SP; 88.5%), nitric oxide synthase (nNOS; 52.1%), galanin (GAL; 20.7%), calretinin (CRT; 10%), pituitary adenylate cyclase-activating polypeptide (PACAP; 7.4%), cocaine and amphetamine related transcript (CART; 5.1%) or somatostatin (SOM; 4.7%). Although the exact function of PNX in DRGs is not yet known, the high degree of co-localization of this peptide with the main nociceptive transmitters SP and CGRP may suggests its function in modulation of pain transmission.

Numbers needed to treat or harm and likelihood of being helped versus harmed for fremanezumab in patients who had prior inadequate response to two to four classes of migraine preventive medications: A post hoc analysis

OBJECTIVE

This study aimed to determine the number needed to treat (NNT), number needed to harm (NNH), and likelihood of being helped or harmed (LHH) in a post hoc analysis of the phase 3b FOCUS trial.

BACKGROUND

Fremanezumab, a humanized monoclonal antibody that selectively targets calcitonin gene-related peptide (CGRP), has demonstrated efficacy, tolerability, and safety in adults with episodic migraine (EM) or chronic migraine (CM), with documented previous inadequate response to two to four classes of migraine preventive medications.

METHODS

In the 12-week double-blind period of the FOCUS study, patients were randomized (1:1:1) to quarterly fremanezumab, monthly fremanezumab, or matched monthly placebo. NNT was based on responder analysis, defined as ≥50% reduction in monthly average number of migraine days at 12 weeks. NNH was based on discontinuations due to adverse events (AEs).

RESULTS

Among patients with CM (n = 509), response rates and discontinuation rates were 27% (45/169) and 0 for quarterly fremanezumab, 29% (50/173) and 2% (3/173) for monthly fremanezumab, and 8% (13/167) and <1% (1/167) for placebo, respectively. These results translated to NNTs of 5.3 and 4.7, NNHs of 1000 and 88, and LHHs of 188 and 19 for quarterly and monthly fremanezumab, respectively. Among patients with EM (n = 328), response rates were 47% (50/107) for quarterly fremanezumab, 43% (47/110) for monthly fremanezumab, and 10% (11/111) for placebo. Discontinuation rates were <1% (n = 1) in all three groups. These results translated to NNTs of 2.7 and 3.0, NNHs of 1000 and 1000, and LHHs of 368 and 328 for quarterly and monthly fremanezumab, respectively.

CONCLUSIONS

The NNT, NNH, and LHH for quarterly and monthly fremanezumab compare favorably with those for traditional oral preventive medications, including topiramate, valproate, and propranolol.

Real-world effectiveness of fremanezumab in patients with migraine switching from another mAb targeting the CGRP pathway: a subgroup analysis of the Finesse Study

BACKGROUND

Monoclonal antibodies targeting the CGRP pathway are effective and safe for prophylactic treatment of episodic (EM) and chronic migraine (CM). In case of treatment failure of a CGRP pathway targeting mAb, physician has to decide whether using another anti-CGRP pathway mAb is useful. This interim analysis of Finesse Study evaluates effectiveness of the anti-CGRP mAb fremanezumab in patients with a history of other prior anti-CGRP pathway mAb treatments (switch patients).

METHODS

FINESSE, a non-interventional, prospective, multicentre, two-country (Germany-Austria) study observing migraine patients receiving fremanezumab in clinical routine. This subgroup analysis presents data on documented effectiveness over 3 months after the first dose of fremanezumab in switch patients. Effectiveness was evaluated based on reduction in average number of migraine days per month (MMDs), MIDAS and HIT-6 scores changes as well as in number of monthly days with acute migraine medication use.

RESULTS

One hundred fifty-three out of 867 patients with a history of anti-CGRP pathway mAb treatment prior to initiation of fremanezumab were analysed. Switch to fremanezumab led to ≥ 50% MMD reduction in 42.8% of migraine patients, with higher response rate in EM (48.0%) than in CM patients (36.5%). A ≥ 30% MMD reduction was achieved by 58.7% in CM patients. After three months, monthly number of migraine days decreased by 6.4 ± 5.87 (baseline: 13.6 ± 6.5; p < 0.0001) in all patients, 5.2 ± 4.04 in EM and 7.7 ± 7.45 in CM patients. MIDAS scores decreased from 73.3 ± 56.8 (baseline) to 50.3 ± 52.9 (after 3 months; p = 0.0014), HIT-6 scores decreased from 65.9 ± 5.0 to 60.9 ± 7.2 (p < 0.0001). Concomitant use of acute migraine medication had decreased from 9.7 ± 4.98 (baseline) to 4.9 ± 3.66 (3 months) (p < 0.0001).

CONCLUSIONS

Our results show that about 42.8% of anti-CGRP pathway mAb-non-responder benefit from switching to fremanezumab. These results suggest that switching to fremanezumab may be a promising option for patients experiencing poor tolerability or inadequate efficacy with prior other anti-CGRP pathway mAb use.

TRIAL REGISTRATION

FINESSE Study is registered on the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (EUPAS44606).

Hemodynamic and neurobiological factors for the development of chronic pelvic pain in patients with pelvic venous disorder

OBJECTIVE

The study was aimed at the identification of hemodynamic and neurobiological factors for the development of chronic pelvic pain (CPP) in patients with pelvic venous disorder (PeVD) using ultrasound, radionuclide, and enzyme immunoassay methods.

METHODS

This cohort study included 110 consecutive patients with PeVD and 20 healthy controls. Seventy patients with PeVD had symptoms (CPP in 100% of cases, discomfort in hypogastrium, dyspareunia, vulvar varices, and dysuria), and 40 were asymptomatic. Patients underwent clinical examination, duplex ultrasound study of the pelvic veins and lower extremities, and single-photon emission computed tomography of the pelvic veins with in vivo labeled red blood cells. The prevalence, duration, severity, and pattern of reflux in the pelvic veins, as well as the severity of pelvic venous congestion, were evaluated. Healthy controls underwent only clinical and duplex ultrasound examination. All 130 patients were assessed using enzyme immunoassays to determine plasma levels of calcitonin gene-related peptide (CGRP) and substance P (SP).

RESULTS

Symptomatic patients with PeVD had a higher prevalence of reflux in the ovarian veins (OVs) than asymptomatic ones (45.7% vs 10%, respectively; P = .001) and a greater reflux duration (4.1 ± 1.7 seconds vs 1.4 ± 0.3 seconds; P = .002), although no differences in the OV diameter were found. Similar results were obtained when comparing the diameters of the parametrial veins (PVs) and the duration of reflux in them. Type II/III reflux (greater than 2 seconds) was identified in 41.4% of symptomatic and in only 5% of asymptomatic patients (P = .001). Among patients with CPP, 24.2% had a combined reflux in the OVs, PVs, and uterine veins, and 45.7% had a combined reflux in the OVs and PVs, whereas 90% of patients without CPP had only an isolated reflux in the PVs. The pelvic venous congestion was moderate or severe in 95.7% of patients with CPP and in only 15% patients without CPP (P = .001). In patients with PeVD, the presence of CPP was associated with higher levels of CGRP and SP compared with asymptomatic patients (CGRP: 0.48 ± 0.06 vs 0.19 ± 0.02 ng/mL, respectively, P = .001; SP: 0.38 ± 0.08 vs 0.13 ± 0.03 ng/mL, P = .001).

CONCLUSIONS

In patients with PeVD, significant hemodynamic and neurobiological factors for the CPP development were found to be reflux in the pelvic veins greater than 2 seconds, involvement of several venous collectors, and increased plasma levels of CGRP and SP.

Comprehensive overview of the venous disorder known as pelvic congestion syndrome

Pelvic venous disorders (PeVD) also known as Pelvic Congestion Syndrome (PCS) affect a great number of women worldwide and often remain undiagnosed. Gynecological symptoms caused by vascular background demand a holistic approach for appropriate diagnosis. This is a relevant cause of chronic pelvic pain and atypical varicose veins. The diagnosis is based on imaging studies and their correlation with clinical presentation. Although the aetiology of PCS still remains unclear, it may result from a combination of factors including genetic predisposition, anatomical abnormalities, hormonal factors, damage to the vein wall, valve dysfunction, reverse blood flow, hypertension and dilatation. The following paper describes an in-depth overview of anatomy, pathophysiology, symptoms, diagnosis and treatment of PCS. In recent years, minimally invasive interventions have become the method of first choice for the treatment of this condition. The efficacy of a percutaneous approach is high and it is rarely associated with serious complications.Key MessagesPelvic venous disorders demand a holistic approach for appropriate diagnosis.This article takes an in-depth look at existing therapies of Pelvic Congestion Syndrome and pathophysiology of this condition.Embolisation is an effective and safe treatment option.

Eptinezumab-jjmr, a humanized monoclonal specific to Calcitonin Gene Related Peptide, for the preventive treatment of migraine in adults

Purpose of Review

Migraines are prevalent and cause significant morbidity, decline in quality of life and healthcare costs universally. Treatment options are varied, but efficacy is limited. This review centers on Eptinezumab-jjmr, a humanized monoclonal specific to CGRP for the prevention of migraines in adults. Herein presented are the science and mechanism of action, indication and clinical evidence for use.

Recent Findings

Migraines are severe, recurrent headaches, which are either episodic or chronic in nature. The pain is severe, often accompanied by co-morbid symptoms, such as photophobia, phonophobia, nausea and emesis, and is limiting in nature. It is a prevalent disorder that causes significant, worldwide disability, morbidity, suffering, and costs.

The pathophysiology of migraines is actively studied, though recent research points to an initiating event causing migraine generation, that is then propagated by other brain regions, a significant one being the trigeminocervical complex. This is driven by biochemical transmitters, chiefly CGRP. This discovery led to the development of CGRP-targeting drugs, including gepants (small molecular antagonists) and anti-CGRP antibodies, such as Eptinezumab-jjmr.

Traditional therapy includes preventative and abortive treatment; however, adherence with preventative treatment has been historically poor, and certain types of abortive therapy carry risks and side effects that preclude them from a large patient population. Moreover, traditional therapy often falls short in migraine therapy. CGRP antagonist, including Eptinezumab, aims to cover the gaps in migraine therapy. We present here evidence to support the safe and effective use of Eptinezumab for the prevention of migraines.

Summary

Migraines are a prevalent primary headache disorder causing significant morbidity worldwide. Traditional abortive and preventative treatments fall short for many patients. Eptinezumab is part of new generation of CGRP-targeting medications and has shown significant evidence to support its use for the prevention of migraines. Further research is required to properly compare eptinezumab with existing pharmacotherapy and update guidelines on the appropriate combinations of therapies that are not available and the correct patient selection for each.

Management of Chronic Migraine in Children and Adolescents: Where are We in 2022?

Migraine is a neurological disorder that affects millions of children and adolescents worldwide. Chronic migraine is a subtype of migraine in which patients experience headaches for more days than not each month, with accompanying symptoms of phonophobia, photophobia, nausea or vomiting for most of these headaches. The burden and impact of chronic migraine in the daily lives of children and adolescents is substantial, requiring a holistic, multidisciplinary, and biopsychosocial approach to conceptualization and treatment. The purpose of this review is to provide a comprehensive “2022” overview of acute and preventive treatments for the management of chronic migraine in youth. We first describe diagnostic criteria for chronic migraine and highlight the state of evidence for acute and preventive treatment in children and adolescents. We then discuss emerging treatments currently receiving rigorous clinical research effort, special considerations for the treatment of chronic migraine in children and adolescents, and avenues for improving existing treatments and expanding access to evidence-based care.

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.

Advances in pharmacotherapy for the prophylactic treatment of resistant and refractory migraine

INTRODUCTION

Refractory migraine is associated with low quality of life and great socioeconomic burden. Despite high need for effective, tolerable preventive therapies, there has been little research on potential therapeutic options. Monoclonal antibodies (mAbs) against Calcitonin Gene-Related Peptide (CGRP) are the first preventive therapeutic approach for migraine based on the underlying pathophysiology.

AREAS COVERED

Following a brief introduction into the term 'refractory migraine,' the authors reviewavailable treatment options, focusing on current phase III trials of substances acting on the CGRP pathway.

EXPERT OPINION

No uniform definition for refractory migraine is available. The vast majority of proposals recommend treatment failure of 2-4 drug classes as a key diagnostic criterion. Phase III studies on CGRP-(receptor) mAbs demonstrated excellent efficacy and tolerability in patients with chronic and episodic migraine including subjects with multiple unsuccessful conventional therapy attempts. However, more comparator trials showing superiority of mAbs versus oral preventatives, such as the HER-MEs study are needed. In summary, with the CGRP antibodies, a group of drugs has entered the market which will most likely not only significantly improve the quality of life of many individual migraine patients but could also reduce indirect health-care costs associated with migraine by reducing recurrent medical consultations.

Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

INTRODUCTION

It has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.

DEVELOPMENT

The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.

CONCLUSIONS

The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.

Assessment and Characteristics of Erenumab therapy on migraine management

Background

Methods

Results

Conclusion

Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

INTRODUCTION

It has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.

DEVELOPMENT

The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.

CONCLUSIONS

The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.

Treatment of migraine with monoclonal antibodies

INTRODUCTION

: In the few last years, a new family of drugs, anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs), has been developed for migraine therapy. Anti-CGRP mAbs are highly effective, but the current limited experience with their use and their high-cost warrant establishing certain rules of use.

AREAS COVERED

The present review provides an overview of the management of migraine patients, especially those who are undergoing treatment with anti-CGRP mAbs.

EXPERT OPINION

Thanks to new research focused on the pathophysiology of migraine, and the discovery that CGRP plays a key role in its etiopathogenesis, new drugs targeting CGRP have been developed. These drugs have led to a paradigm shift, anticipating new and stimulating possibilities in migraine treatment. While physicians and patients are full of expectation about the advantages of this new family of drugs, there are still obstacles to overcome in order to make the best use of them. It is essential to form multidisciplinary teams that can identify patients who will benefit from these therapies, conducting cost-effective treatments. The follow-up of these therapies in the coming years is paramount due to the lack of experience in the management of these drugs and the peculiarity of disease evolution in migraine patients.

Hypervigilance, Allostatic Load, and Migraine Prevention: Antibodies to CGRP or Receptor

Migraine involves brain hypersensitivity with episodic dysfunction triggered by behavioral or physiological stressors. During an acute migraine attack the trigeminal nerve is activated (peripheral sensitization). This leads to central sensitization with activation of the central pathways including the trigeminal nucleus caudalis, the trigemino-thalamic tract, and the thalamus. In episodic migraine the sensitization process ends with the individual act, but with chronic migraine central sensitization may continue interictally. Increased allostatic load, the consequence of chronic, repeated exposure to stressors, leads to central sensitization, lowering the threshold for future neuronal activation (hypervigilance). Ostensibly innocuous stressors are then sufficient to trigger an attack. Medications that reduce sensitization may help patients who are hypervigilant and help to balance allostatic load. Acute treatments and drugs for migraine prevention have traditionally been used to reduce attack duration and frequency. However, since many patients do not fully respond, an unmet treatment need remains. Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide involved in nociception and in the sensitization of peripheral and central neurons of the trigeminovascular system, which is implicated in migraine pathophysiology. Elevated CGRP levels are associated with dysregulated signaling in the trigeminovascular system, leading to maladaptive responses to behavioral or physiological stressors. CGRP may, therefore, play a key role in the underlying pathophysiology of migraine. Increased understanding of the role of CGRP in migraine led to the development of small-molecule antagonists (gepants) and monoclonal antibodies (mAbs) that target either CGRP or the receptor (CGRP-R) to restore homeostasis, reducing the frequency, duration, and severity of attacks. In clinical trials, US Food and Drug Administration-approved anti-CGRP-R/CGRP mAbs were well tolerated and effective as preventive migraine treatments. Here, we explore the role of CGRP in migraine pathophysiology and the use of gepants or mAbs to suppress CGRP-R signaling via inhibition of the CGRP ligand or receptor.

Pharmacological, Pharmacokinetic, Pharmacodynamic and Physicochemical Characterization of FE 205030: A Potent, Fast Acting, Injectable CGRP Receptor Antagonist for the Treatment of Acute Episodic Migraine

The neuropeptide calcitonin gene-related peptide (CGRP) is known to play a central role in the underlying pathophysiology of migraine. In comparison to the effective triptan class of antimigraine treatments, the CGRP antagonists possess a comparable efficacy but a superior cardiovascular safety profile in patients. This paper describes the development of selective and potent peptidic CGRP antagonist, FE 205030, that has a fast onset of action and an optimal half-life (subcutaneous T_max ~ 60 min, and t_1/2 ~ 4.4 h in 80 kg pigs, respectively), which is key to prevention of the progression of debilitating migraine symptoms. The in vivo efficacy of this agent has been established a translational pharmacodynamic model (inhibition of capsaicin-induced increase in skin blood flow) in cynomolgus monkeys and shows maximal inhibitory activity at circulating concentrations of 30-100 nM. Antagonist activity of FE 205030 was characterized on CGRP-induced vasodilation in isolated human mesenteric resistance arteries in an ex vivo isometric myograph study, and FE 205030 effectively blocked CGRP-induced vasodilation with a pA₂ of 9.3 ± 0.1, mean ± standard error. Multispecies allometric scaling and modeling of subcutaneous (SC) effective concentrations indicates that a dose of 10-30 mg/day is sufficient to achieve a drug exposure/target coverage of 8h, which is useful to prevent migraine recurrence in patients. The molecule also possesses appropriate physicochemical properties that allows for a convenient dosing form factor of 1 ml injection volume with a sufficient solubility and acceptable short-term stability, optimal for treatment of acute migraine episodes in patients. Hence, FE 205030 may provide an important fast-acting injectable option for patients suffering from frequent acute migraine episodes, complementary to preventative monoclonal antibodies and oral small molecule CGRP-R antagonist therapies.

Insulin-like growth factor-1 inhibits nitroglycerin-induced trigeminal activation of oxidative stress, calcitonin gene-related peptide and c-Fos expression

Migraineurs experience increased oxidative stress which drives the initiation and maintenance of migraine-related pain in animal models and, by extension, migraine in humans. Oxidative stress augments calcitonin gene-related peptide (CGRP) levels, a mediator of migraine pain. Insulin-like growth factor-1 (IGF-1), a neuroprotective growth factor, reduces susceptibility to spreading depression, a preclinical model of migraine, in cultured brain slices by blocking oxidative stress and neuroinflammation from microglia. Similarly, nasal delivery of IGF-1 inhibits spreading depression in vivo. After recurrent cortical spreading depression, nasal administration of IGF-1 also significantly reduces trigeminal ganglion oxidative stress and CGRP levels as well as trigeminocervical c-Fos activation. Here, we probed for the impact of nasal IGF-1 pretreatment on trigeminal system activation using a second well-established preclinical model of migraine, systemic nitroglycerin injection. Adult male rats were treated with one of three doses of IGF-1 (37.5, 75 or 150 μg) and the optimal dose found in males was subsequently used for treatment of female rats. One day later, animals received an intraperitoneal injection of nitroglycerin. Measurements taken two hours later after nitroglycerin alone showed increased surrogate markers of trigeminal activation - oxidative stress and CGRP in the trigeminal ganglion and c-Fos in the trigeminocervical complex compared to vehicle control. These effects were significantly reduced at all doses of IGF-1 for trigeminal ganglion metrics of oxidative stress and CGRP and only at the lowest dose in both males and females for c-Fos. The latter inverted U-shaped or hormetic response is seen in enzyme-targeting drugs. While the specific mechanisms remain to be explored, our data here supports the ability of IGF-1 to preserve mitochondrial and antioxidant pathway homeostasis as means to prevent nociceptive activation in the trigeminal system produced by an experimental migraine model.

Anti-CGRP monoclonal antibodies for migraine prevention: A systematic review and likelihood to help or harm analysis

INTRODUCTION AND OBJECTIVE

Monoclonal antibodies targeting the calcitonin gene-related peptide pathway (anti-CGRP mAbs) have shown promising efficacy in randomised clinical trials for the prevention of episodic and chronic migraine, but no head-to-head comparisons with established treatments are available. We aimed to examine absolute differences in benefit-risk ratios between anti-CGRP mAbs, topiramate and propranolol for the prevention of episodic migraine and between anti-CGRP mAbs, topiramate and onabotulinumtoxinA for the prevention of chronic migraine using a likelihood to help versus harm analysis.

METHODS

The number of patients needed to be treated for a patient to achieve ≥ 50% reduction in migraine days (NNTB_50%) was used as an effect size metric of efficacy. The number of patients needed to be treated for a patient to experience an adverse event that led to treatment discontinuation (NNTH_D-AE) was used as a measure of risk. Likelihood to help versus harm values - which are the ratios of NNTH:NNTB - were calculated using data from phase 3 randomised clinical trials.

RESULTS

All agents tested were more likely to be beneficial than harmful (likelihood to help versus harm > 1) with the exception of topiramate at 200 mg per day for the prevention of episodic migraine. Anti-CGRP mAbs in all tested doses had higher LHH values than propranolol or topiramate for episodic migraine and onabotulinumtoxinA or topiramate for chronic migraine prevention. Fremanezumab had the highest LHH ratio in episodic migraine and galcanezumab in chronic migraine.

CONCLUSION

This analysis showed that anti-CGRP mAbs exhibit a more favourable benefit-risk ratio than established treatments for episodic and chronic migraine. Head-to-head studies are needed to confirm these results.

A population-based survey for disabling headaches in Greece: Prevalence, burden and treatment preferences

OBJECTIVE

To estimate the prevalence, burden and current treatment of disabling primary headaches in a large sample of the Greek population aged 18-70 years old.

METHODS

This is an observational descriptive study, with cross-sectional design performed by quantitative computer-assisted telephone interviews, using a validated 37-item questionnaire for headaches. The prevalence, burden, and current treatment of primary headaches (ICHD-3) were recorded along with participants' treatment preferences.

RESULTS

Out of 10,008 interviewed participants, 1197 (12.0%) reported headaches affecting performance. The annual prevalence of migraine was 8.1% (95% confidence interval, 7.6-8.7, corresponding to 0.6 million Greeks), of chronic migraine 1.0% (95% confidence interval, 0.8-1.2, corresponding to 0.1 million), and of tension-type headache 3.8% (95% confidence interval, 3.4-4.2, corresponding to 0.3 million). The participants with headaches reported 0.5 headache-induced lost workdays per month (corresponding to 5.8 million lost workdays annually) and reductions in performance on 2.8 workdays per month (corresponding to 30.9 million workdays annually). In all, 43.4% of headache participants felt bad/ashamed because of headaches and 21.9% sought professional treatment, most often from a private neurologist. 83.8% of headache participants had never taken pharmacological prophylaxis, and only 5.5% were currently under preventative treatment. For both prophylactic and acute treatment, headache participants prefer oral medication to injection or stimulation devices.

CONCLUSION

More than 10% of the Greek adult population up to 70 years old experience disabling headaches, causing a dramatic work loss. More than 80% of these have never taken pharmacological prophylaxis. Thus, enriching the quality of life of people with headaches relies crucially on expanding awareness about headaches and their treatment.

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.

Multidimensional assessment of the effects of erenumab in chronic migraine patients with previous unsuccessful preventive treatments: a comprehensive real-world experience

BACKGROUND

erenumab was safe and effective in clinical trials for the prevention of migraine. However, real-life data are still lacking. Here we report the clinical experience from an Italian real-world setting using erenumab in patients with chronic migraine experiencing previous unsuccessful preventive treatments.

METHODS

Seventy patients with chronic migraine and failure to ≥4 migraine preventive medication classes initially received monthly erenumab 70 mg s.c. Patients without a clinically meaningful improvement, considered as a > 30% reduction in headache days per month, after ≥3 months of therapy switched to monthly erenumab 140 mg. At the first administration and after 3 and 6 months, patients underwent extensive interviews to assess clinical parameters of disease severity and migraine-related disability and impact, and validated questionnaires to explore depression/anxiety, sleep, and quality of life (QoL). Finally, the Pain Catastrophizing Scale, Allodynia Symptom Checklist-12 and MIGraine attacks-Subjective COGnitive impairments scale (MIG-SCOG) were administered.

RESULTS

70% of patients were "responders" after the third administration of erenumab 70 mg, whereas 30% switched to erenumab 140 mg; 29% (6 pts) responded after the sixth administration. The headache-day frequency was reduced from 21.1 ± 0.7 to 11.4 ± 0.9 days after the third administration (p < 0.001) and to 8.9 ± 0.7 days after the sixth administration (p < 0.001). 53% and 70% of patients, respectively, showed a reduction of ≥50% of headache days/month after the third and the sixth administrations. Also improved were headache pain severity, migraine-related disability, and impact on daily living, QoL, pain catastrophizing and allodynia (all p < 0.001), quality of sleep, symptoms of depression or anxiety (p < 0.05) but not MIG-SCOG. There were no new adverse event signals.

CONCLUSION

These real-world data support monthly erenumab 70 or 140 mg s.c. as a safe and effective preventive treatment to reduce headache frequency and severity in chronic migraine patients experiencing previous unsuccessful preventive treatments.

Hospital Burden of Migraine in United States Adults: A 15-year National Inpatient Sample Analysis

Background

Migraine headache is associated with high costs, but changes over time of inpatient burden in the United States are unknown. Understanding longitudinal trends is necessary to determine the costs of evolving inpatient treatments that target biological factors in the generation of pain such as vasodilation and aberrant activity of trigeminal neurotransmitters. We report the migraine hospital burden trend in the United States over 15 years.

Methods

Data from the Nationwide Inpatient Sample of the Hospitalization Cost and Utilization Project databases were analyzed from 1997 to 2012. Inpatient costs were reported in dollars for the cost to the institution, whereas charges reflect the amount billed. These parameters were trended and the average annual percent change was calculated to illustrate year-to-year changes.

Results

Overall discharges for migraine headache reached a low of 30,761 discharges in 1999, and peaked in 2012 with 54,510 discharges. Average length of stay decreased from 3.5 days in 1997 to 2.8 days in 2012. Total inpatient charges increased from $176 million in 1999 to $1.2 billion in 2012. Inpatient costs totaled $322 million in 2012, with an average daily cost of $2,111.

Conclusions

Inpatient burden rapidly increased over the analyzed period, with hospital charges increasing from $5,939 per admission and $176 million nationwide in 1997, to $21,576 per admission and $1.2 billion nationwide in 2012. This trend provides context for research examining cost-effectiveness and quality of life benefits for current treatments. The study of these parameters together with better prevention and improved outpatient treatment may help alleviate the inpatient burden of migraine.

Regulatory mechanisms and therapeutic potential of microglial inhibitors in neuropathic pain and morphine tolerance

Microglia are important cells involved in the regulation of neuropathic pain (NPP) and morphine tolerance. Information on their plasticity and polarity has been elucidated after determining their physiological structure, but there is still much to learn about the role of this type of cell in NPP and morphine tolerance. Microglia mediate multiple functions in health and disease by controlling damage in the central nervous system (CNS) and endogenous immune responses to disease. Microglial activation can result in altered opioid system activity, and NPP is characterized by resistance to morphine. Here we investigate the regulatory mechanisms of microglia and review the potential of microglial inhibitors for modulating NPP and morphine tolerance. Targeted inhibition of glial activation is a clinically promising approach to the treatment of NPP and the prevention of morphine tolerance. Finally, we suggest directions for future research on microglial inhibitors.

Insulin-like growth factor-1 inhibits spreading depression-induced trigeminal calcitonin gene related peptide, oxidative stress & neuronal activation in rat

Migraineurs can show brain hyperexcitability and oxidative stress that may promote headache. Since hyperexcitability can enhance oxidative stress which promotes hyperexcitability, ending this feed-back loop may reduce migraine. Neocortical spreading depression, an animal model of migraine begins with hyperexcitability and triggers oxidative stress in the neocortical area involved and in the trigeminal system, which is important to pain pathway nociceptive activation in migraine. Additionally, oxidative stress causes increased trigeminal ganglion calcitonin gene-related peptide release and oxidative stress can reduce spreading depression threshold. Insulin-like growth factor-1 significantly protects against spreading depression in vitro by reducing oxidative stress and it is effective against spreading depression after intranasal delivery to animals. Here, we used adult male rats and extend this work to study the trigeminal system where insulin-like growth factor-1 receptors are highly expressed. Recurrent neocortical spreading depression significantly increased surrogate markers of trigeminal activation - immunostaining for trigeminal ganglion oxidative stress, calcitonin gene related peptide levels and c-fos in the trigeminocervical complex versus sham. These effects were significantly reduced by intranasal delivery of insulin-like growth factor-1 a day before recurrent neocortical spreading depression. Furthermore, intranasal treatment with insulin-like growth factor-1 significantly reduced naïve levels of trigeminal ganglion calcitonin gene related peptide versus sham with no impact on blood glucose levels. Intranasal delivery of insulin-like growth factor-1 not only mitigates neocortical spreading depression, a cause of migraine hyperexcitability modeled in animals, but also when neocortical spreading depression is triggered by supra-threshold stimuli, insulin-like growth factor-1 effectively reduces nociceptive activation in the trigeminal system.

Placebo and nocebo phenomena in anti- CGRP monoclonal antibody trials for migraine prevention: a meta-analysis

High placebo and low nocebo phenomena mirror high positive expectations for a novel treatment, among other reasons. In a meta-analysis aimed to identify placebo and nocebo phenomena in the placebo-controlled randomized trials (RCTs) with the monoclonal antibodies targeting the calcitonin gene-related peptide pathway (anti-CGRP mAbs) all the placebo-treated patients were pooled and compared with the placebo-treated patients in RCTs with topiramate and onabotulinum toxin A (OBTA). In episodic migraine (EM), the proportion of placebo-treated patients who achieved the 50% responder rate (placebo) was 32.7% (95% CI 28.6%-37.0%) in anti-CGRP mAbs vs. 24.4% (95% CI 20.5%-28.5%) in topiramate trials. The proportion of dropouts due to adverse events in placebo-treated patients (nocebo) was 1.9% (95% CI 1.4%-2.6%) in anti-CGRP mAbs vs. 9.9% (95% CI 7.7%-12.3%) in topiramate RCTs. In chronic migraine (CM), the placebo 50% responder rate was 23.6% (95% CI 11.2%-38.8%) in anti-CGRP mAbs RCTs vs. 36.4% (95% CI 32.6%-39.3%) in RCTs with OBTA. The nocebo dropout in anti-CGRP mAbs and OBTA RCTs was 1.4% (95% CI 0.8%-2.1%) and 0.9 (95% CI 0.3%-1.7%), respectively. The stronger placebo and weaker nocebo phenomena in RCTs with anti-CGRP mAbs vs. those with topiramate in the prophylaxis of EM, may decisively determine anti-CGRP mAbs treatment success. No differences were detected between the anti-CGRP mAbs and OBTA in the treatment of CM.

[Neurobiological aspects of venous pelvic pain]

Mechanisms of the development of pain in chronic venous diseases (CVD), including pelvic congestion syndrome (PCS), are understudied. The existing hypotheses of the occurrence of venous pelvic pain (VVP) do not allow to answer the question why some patients have no pain syndrome while others have very pronounced pain despite the same morphofunctional changes in the pelvic veins. This review presents current hypotheses of the VPP development, data on some vasoactive neuropeptides (endothelin, calcitonin gene-related peptide, and substance P), their role in the modulation of vascular tone and sensation of pain, possible association between neurogenic inflammation and VPP and provides a rationale for studying the activity of these neurotransmitters in the treatment of PCS and pelvic pain.

Consensus of the Hellenic Headache Society on the diagnosis and treatment of migraine

More than 0.6 million people suffer from disabling migraines in Greece causing a dramatic work loss, but only a small proportion of migraineurs attend headache centres, most of them being treated by non-experts. On behalf of the Hellenic Headache Society, we report here a consensus on the diagnosis and treatment of adult migraine that is based on the recent guidelines of the European Headache Federation, on the principles of Good Clinical Practice and on the Greek regulatory affairs. The purposes are three-fold: (1) to increase awareness for migraine in Greece; (2) to support Greek practitioners who are treating migraineurs; and (3) to help Greek migraineurs to get the most appropriate treatment. For mild migraine, symptomatic treatment with high dose simple analgesics is suggested, while for moderate to severe migraines triptans or non-steroidal anti-inflammatory drugs, or both, should be administered following an individually tailored therapeutic strategy. A rescue acute treatment option should always be advised. For episodic migraine prevention, metoprolol (50–200 mg/d), propranolol (40–240 mg/d), flunarizine (5–10 mg/d), valproate (500–1800 mg/d), topiramate (25–100 mg/d) and candesartan (16–32 mg/d) are the drugs of first choice. For chronic migraine prevention topiramate (100-200 mg/d), valproate (500–1800 mg/d), flunarizine (5–10 mg/d) and venlafaxine (150 mg/d) may be used, but the evidence is very limited. Botulinum toxin type A and monoclonal antibodies targeting the CGRP pathway (anti-CGRP mAbs) are recommended for patients suffering from chronic migraine (with or without medication overuse) who failed or did not tolerate two previous treatments. Anti-CGRP mAbs are also suggested for patients suffering from high frequency episodic migraine (≥8 migraine days per month and less than 14) who failed or did not tolerate two previous treatments.

Erenumab safety and efficacy in migraine: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Erenumab is a new medicine recently approved in the United States of America for the preventive treatment of migraine among adults. We aimed to conduct a meta-analysis and evaluation of the efficacy and safety of erenumab among patients with migraine.

METHODS

The electronic databases that were searched comprised PubMed, Embase and the Cochrane library, which were independently retrieved by 2 reviewers. Only randomized controlled trials (RCTs) that compared placebo with erenumab were selected. Mean differences (MDs), pooled risk ratios (RRs), and their corresponding 95% confidence intervals (CIs) were calculated for continuous and dichotomous data, respectively.

RESULTS

Five RCTs representing 2928 patients were included. Pooled analysis showed significant reductions in the 50% responder rate (RR 1.55; P < .00001; I = 49%). In addition, the mean monthly migraine days from baseline in the erenumab group compared with placebo (MD-1.32; P < .00001; I = 100%) and migraine-specific medication days) from baseline (MD-1.41; P < .00001; I = 100%) were significantly decreased for the erenumab group as compared with placebo. Furthermore, Migraine-specific medication days from baseline in the 140 mg erenumab group were significantly reduced as compared the 70 mg group (MD = 0.55; P < .00001; I = 90%). Finally, there was no significant difference between the erenumab group and placebo for any adverse event and serious adverse event.

CONCLUSION

Among patients with migraine, both 70 and 140 mg of erenumab were associated with reduced Migraine-specific medication days, Migraine-specific medication days from baseline, and an increased rate of a 50% reduction, in the absence of an increased risk of any serious adverse effect.

A new era for migraine: Pharmacokinetic and pharmacodynamic insights into monoclonal antibodies with a focus on galcanezumab, an anti-CGRP antibody

PURPOSE

To review pharmacokinetic and pharmacodynamic characteristics of antibodies that bind to soluble ligands within the framework of calcitonin gene-related peptide antibodies.

OVERVIEW

Calcitonin gene-related peptide has been implicated in the pathophysiology of migraine. Galcanezumab is an antibody that binds to the ligand calcitonin gene-related peptide. Other antibodies that target calcitonin gene-related peptide include eptinezumab and fremanezumab. To understand how antibodies can affect the extent and duration of free ligand concentrations, it is important to consider the dose and pharmacokinetics of an antibody, and the kinetics of the ligand and antibody-ligand complex. Insights regarding the pharmacokinetic/pharmacodynamic properties of galcanezumab as a probe antibody drug and calcitonin gene-related peptide as its binding ligand regarding its clinical outcomes are provided.

DISCUSSION

Antibodies are administered parenterally because oral absorption is limited by gastrointestinal degradation and inefficient diffusion through the epithelium. The systemic absorption of antibodies following intramuscular or subcutaneous administration most likely occurs via convective transport through lymphatic vessels into blood. The majority of antibody elimination occurs via intracellular catabolism into peptides and amino acids following endocytosis. Binding of ligand to an antibody reduces the free ligand that is available to interact with the receptor and efficacy is driven by the magnitude and duration of the reduction in free ligand concentration. A galcanezumab pharmacokinetic/pharmacodynamic model shows that galcanezumab decreases free calcitonin gene-related peptide concentrations in a dose- and time-dependent manner and continues to suppress free calcitonin gene-related peptide with repeated dosing. The model provides evidence for a mechanistic linkage to galcanezumab therapeutic effects for the preventive treatment of migraine.

Problems with Developments of Breakthrough Analgesics: Recent History via Scientometric Analysis

This study evaluated 13 specific topics representing molecular targets for pain during the period 1982-2016. The evaluation was performed by measuring research efforts via a scientometric approach on one hand and by assessing successful outcomes of these efforts, as indicated by the development of FDA-approved analgesics, on the other. A number of new analgesics were developed during this period, some of them with a completely novel mechanism of action. However, the main problems with approved drugs, as well as drug candidates, are relatively low levels of clinical superiority in effectiveness and narrow spectrum of action in different types of pain, compared to opioids or NSAIDs. The most interesting feature of the scientometric analysis of the 13 analgesic discovery topics is the long-lasting growth in the number of articles. The total number of all PubMed articles persistently increased over each of many 5-year periods in every topic even without any success in the development of new analgesics. Scientometric indices of NIH-supported studies are not better at predicting successes in the discovery of new analgesics than indices applied to all publications without regard to the category of support. Thus, even the highly valued NIH-based funding system did not demonstrate a clear advantage for discovery efforts centered on pain-related molecular targets. The evaluated research efforts did not result in breakthrough analgesics that could demonstrably affect the current use of opioids or NSAIDs. Orthodox thinking-both in research and research funding-might be the main reason for the absence of breakthrough analgesics.

Neuropeptide CGRP Limits Group 2 Innate Lymphoid Cell Responses and Constrains Type 2 Inflammation

Innate lymphocytes maintain tissue homeostasis at mucosal barriers, with group 2 innate lymphoid cells (ILC2s) producing type 2 cytokines and controlling helminth infection. While the molecular understanding of ILC2 responses has advanced, the complexity of microenvironmental factors impacting ILC2s is becoming increasingly apparent. Herein, we used single-cell analysis to explore the diversity of gene expression among lung lymphocytes during helminth infection. Following infection, we identified a subset of ILC2s that preferentially expressed Il5-encoding interleukin (IL)-5, together with Calca-encoding calcitonin gene-related peptide (CGRP) and its cognate receptor components. CGRP in concert with IL-33 and neuromedin U (NMU) supported IL-5 but constrained IL-13 expression and ILC2 proliferation. Without CGRP signaling, ILC2 responses and worm expulsion were enhanced. Collectively, these data point to CGRP as a context-dependent negative regulatory factor that shapes innate lymphocyte responses to alarmins and neuropeptides during type 2 innate immune responses.

Characterisation of vasodilatory responses in the presence of the CGRP receptor antibody erenumab in human isolated arteries

BACKGROUND

Migraine is associated with activation of the trigeminovascular system, release of calcitonin gene-related peptide (CGRP) and dilation of dural arteries. Novel treatments target calcitonin gene-related peptide or its receptor, which are present in all vascular beds, raising cardiovascular concerns. Erenumab is a human CGRP-receptor antibody approved for the prophylactic treatment of migraine.

METHODS

We characterised the relaxant responses to CGRP in the absence and presence of erenumab (1 μM) in isolated human middle meningeal, internal mammary and (proximal and distal) coronary arteries. Furthermore, in human internal mammary arteries from cardiovascularly-compromised patients, we assessed the pharmacological specificity of erenumab by investigating whether the vasodilatory responses to acetylcholine, sodium nitroprusside, pituitary adenylate cyclase activating polypeptide-38 (PACAP), vasoactive intestinal peptide and nicardipine, along with the vasoconstrictor responses to dihydroergotamine, were modified by erenumab.

RESULTS

Calcitonin gene-related peptide induced concentration-dependent vasodilatory responses in all vessels studied that were significantly antagonised by erenumab. In human internal mammary arteries from cardiovascularly-compromised patients, the responses to acetylcholine, sodium nitroprusside, PACAP, vasoactive intestinal peptide, nicardipine and dihydroergotamine were unaffected by erenumab.

CONCLUSION

Erenumab inhibits calcitonin gene-related peptide-induced vasodilatory responses in human middle meningeal arteries, human internal mammary arteries and human coronary arteries. Moreover, erenumab shows functional specificity as no interaction was observed with the relaxant responses to several vasodilators, nor the dihydroergotamine-dependent vasoconstrictor responses.

The role of vasoactive neuropeptides in the genesis of venous pelvic pain: A review

Mechanisms of the development of pain in chronic venous diseases, including pelvic congestion syndrome, are not studied in detail so far. The existing hypotheses of the occurrence of venous pelvic pain do not allow to answer the question why some patients have no pain syndrome, while others have very pronounced pain despite the same morphofunctional changes in the pelvic veins. This review presents current hypotheses of the venous pelvic pain development, data on some vasoactive neuropeptides (endothelin, calcitonin gene-related peptide, and substance P), their role in the modulation of vascular tone and sensation of pain, and possible association between neurogenic inflammation and venous pelvic pain, as well as provides rationale for studying the activity of these neurotransmitters in the treatment of pelvic congestion syndrome and pelvic pain.

The Role of Anti-calcitonin Gene-related Peptide in Migraine and its Implication in Developing Countries: A Reasonable Option to Consider Despite Higher Cost

Migraine is among the commonest causes of headache in all ages. It is the second most common cause of neurological disability. Currently, antihypertensive, antidepressants and antiepileptic drugs are reasonable preventable medications for chronic migraine. Despite the higher levels of stigma associated with this disease, fewer attempts were made in past regarding the treatment options for chronic migraine. Recently, a novelty treatment was introduced known as calcitonin gene-related peptide (CGRP) monoclonal antibodies as a possible mechanism for the prevention of migraine attacks. CGRP played an important role in the etiology of migraine headaches and was considered as the major peptide behind the cause of the headache disorders. We have reviewed the benefits of these monoclonal antibodies in terms of their efficacy and adverse effects with the available treatment choices. These drugs showed superior results when compared to the placebo and were considered generally safe in the majority of clinical trials. Earlier versions of CGRP antagonists, known as gepants, were less tolerable due to their tendency to cause liver and cardiovascular complications. Thus, in comparison to the earlier gepants, these CGRP monoclonal antibodies were safer and demonstrated excellent tolerability. Short-term side effects were only limited to mild-moderate injection site rash or pruritus, however, their long-term side effects are still unknown. Despite the higher cost of these drugs, we have analyzed the applicability of this drug in the developing countries. Although the quality-adjusted life year (QALY) gained per cost of the drug is still expensive and majority of people may not afford, its excellent tolerability and less adverse effects should also be considered a reason to implement this drug, particularly for resource-limited countries. Moreover, these medications could also become a prototype for future inventions and creations (cost-effective versions for resource-limited countries). In conclusion, this review suggests that CGRP monoclonal antibodies are safer and excellent alternate option for patients with chronic migraine as it has better efficacy, tolerability, and provides a hope to reduce the stigma associated with migraine. All these benefits should be the deciding factors when opting for this treatment and the decision should not be made solely on the socioeconomic status.

Once-monthly galcanezumab for the prevention of migraine in adults: an evidence-based descriptive review and potential place in therapy

In the last 15 years relevant efforts have been made to demonstrate that calcitonin gene-related peptide (CGRP) antagonism is a valuable and druggable mechanism for treatment or prevention of migraine. Galcanezumab is one of the antibodies developed and studied to prevent migraine by targeting CGRP. The scope of this review is to report data currently available on galcanezumab. According to available data, galcanezumab is safe and efficacious in preventing migraine in episodic migraine patients, also reducing disability and functional impairment due to the disorder. In September 2018, galcanezumab was approved in the USA for the prevention of migraine in adults. The placement of galcanezumab into the current therapeutic scenario will be a revolution for migraine patients, and probably in a less near future also for patients affected by other primary headaches.

Health state utilities associated with attributes of migraine preventive treatments based on patient and general population preferences

Purpose

While previous studies have estimated health state utilities associated with migraine severity and frequency, migraine treatments vary in other ways that may have an impact on patients’ quality of life, preference, and utility. The purpose of this study was to estimate utilities associated with migraine treatment attributes including route of administration and treatment-related adverse events (AEs).

Methods

In time trade-off interviews, migraine patients and general population participants in the UK valued health state vignettes drafted based on literature, medication labels, and clinician interviews. All respondents valued migraine health states varying in route of administration. Each participant also valued eight health states (randomly selected from a total of 15) that added the description of an AE to a migraine health state.

Results

A total of 400 participants completed interviews (200 general population [49.0% female; mean age = 43.6 years]; 200 migraine patients [74.5% female; mean age = 45.8 years]). In the general population sample, mean utilities of health states without aura were 0.79 with daily oral medication, 0.78 with one injection per month, and 0.72 with 31–39 injections once every 3 months. The greatest disutilities (i.e., decreases in utility) were for AEs associated with oral medications (e.g., − 0.060 [fatigue] and − 0.098 [brain fog]). Differences among health states followed the same pattern in the patient sample as in the general population sample.

Conclusions

Utilities estimated from the general population sample may be used to represent route of administration and AEs in cost-utility models. Results from the patient sample indicate that these treatment characteristics have an impact on patient preference.

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.

Calcitonin-gene-related peptide pathway mAbs and migraine prevention

PURPOSE OF REVIEW

Monoclonal antibodies (mAbs) targeting the calcitonin-gene-related peptide (CGRP) pathway have been developed for episodic and chronic migraine prevention, either through binding the CGRP ligand (eptinezumab, fremanezumab, galcanezumab) or the CGRP receptor (erenumab). We provide an update on published Phase 2 and Phase 3 trials, safety/tolerability data, pharmacokinetics and mechanism of action of these biologicals.

RECENT FINDINGS

The efficacy data from Phase 2 trials are corroborated by those from published Phase 3 trials, with a multitude of publications expected in 2018. Review of safety data concluded there was no difference in total adverse events or main adverse events (including upper respiratory tract infection, nasopharyngitis, nausea, injection-site pain and back pain) between the mAbs and placebo injections except apparently for dizziness. The site of action of these mAbs is not fully elucidated but current insight is that their effect resides in the periphery; a contribution of central effect(s) can however not be excluded at present.

SUMMARY

Although efficacy of all four drugs is modest over placebo in episodic and chronic migraine prevention and overall comparable with available oral preventive treatments, current tolerability and (short-term) safety data of this new treatment approach certainly promise a major step forward for migraine patients.

Safety and tolerability of calcitonin-gene-related peptide binding monoclonal antibodies for the prevention of episodic migraine - a meta-analysis of randomized controlled trials

AIM

To systematically evaluate the safety and tolerability of calcitonin-gene-related peptide binding monoclonal antibodies from the results of randomized controlled trials.

METHODS

Online databases were searched on calcitonin-gene-related peptide binding monoclonal antibodies for the prevention of episodic migraine. Overall withdrawal, withdrawal due to adverse events, adverse events, serious adverse events and specific adverse events were extracted from the included studies. A meta-analysis was performed with Revman 5.3.0 software.

RESULTS

Ten studies that investigated four drugs (galcanezumab, erenumab, fremanezumab and eptinezumab) with 5817 participants were included in this study. Serious adverse events, overall withdrawals, withdrawal due to adverse events and any adverse events were not significantly associated with monoclonal antibody treatment. Injection site pain and erythema were significantly higher in the calcitonin-gene-related peptide binding monoclonal antibodies treatment group than in the placebo group. The rates of serious adverse events were significantly higher in the galcanezumab 120 mg group. Injection site erythema was associated with galcanezumab 120 mg and 240 mg. Injection site pain and nasopharyngitis were associated with galcanezumab 150 mg and 5 mg, respectively. Overall adverse events were significantly higher with erenumab 70 mg and 140 mg. Treatment-related adverse events were significantly higher with fremanezumab 225 mg/month and 675 mg/quarter.

CONCLUSIONS

This study provides data on the safety and tolerability profiles of calcitonin-gene-related peptide binding monoclonal antibodies and confirms their potential use as preventive treatments for episodic migraine. In addition to the acceptable withdrawal rates, serious adverse events were rare, and the severity of most adverse events was mild to moderate. Injection site reaction may be the major adverse event associated with galcanezumab.

European headache federation guideline on the use of monoclonal antibodies acting on the calcitonin gene related peptide or its receptor for migraine prevention

BACKGROUND AND AIM

Monoclonal antibodies acting on the calcitonin gene-related peptide or on its receptor are new drugs to prevent migraine. Four monoclonal antibodies have been developed: one targeting the calcitonin gene-related peptide receptor (erenumab) and three targeting the calcitonin gene-related peptide (eptinezumab, fremanezumab, and galcanezumab). The aim of this document by the European Headache Federation (EHF) is to provide an evidence-based and expert-based guideline on the use of the monoclonal antibodies acting on the calcitonin gene-related peptide for migraine prevention.

METHODS

The guideline was developed following the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed systematic review and analysis of the literature, assessed the quality of available evidence, and wrote recommendations. Where the GRADE approach was not applicable, expert opinion was provided.

RESULTS

We found low to high quality of evidence to recommend eptinezumab, erenumab, fremanezumab, and galcanezumab in patients with episodic migraine and medium to high quality of evidence to recommend erenumab, fremanezumab, and galcanezumab in patients with chronic migraine. For several clinical questions, there was not enough evidence to provide recommendations using the GRADE approach and recommendations relied on experts' opinion.

CONCLUSION

Monoclonal antibodies acting on the calcitonin gene-related peptide are new drugs which can be recommended for migraine prevention. Real life data will be useful to improve the use of those drugs in clinical practice.

Understanding CGRP and Cardiovascular Risk

Increasing knowledge about the role of calcitonin gene-related peptide (CGRP) in migraine pathophysiology has led to the development of antibodies against this peptide or its receptor. However, CGRP is widely expressed throughout the body, participating not only in pathophysiological conditions but also in several physiological processes and homeostatic responses during pathophysiological events. Therefore, in this chapter, the risks of long-term blockade of the CGRP pathway will be discussed, with focus on the cardiovascular system, as this peptide has been described to have a protective role during ischemic events, and migraine patients present a higher risk of stroke and myocardial infarction.

The efficacy and safety of calcitonin gene-related peptide monoclonal antibody for episodic migraine: a meta-analysis

OBJECTIVE

This meta-analysis was performed to evaluate the efficacy and safety of monoclonal antibodies against calcitonin gene-related peptide (CGRP) for episodic migraine prevention.

METHODS

MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched from inception to April 2018. Studies considered to be eligible were randomized controlled trials about efficacy and safety of calcitonin gene-related peptide monoclonal antibody for episodic migraine prevention.

RESULTS

Eight randomized controlled trials involving 2292 patients were included. The outcomes of this meta-analysis presented that CGRP monoclonal antibodies for preventive treatment of episodic migraine significantly reduced the monthly migraine days from baseline [weighted mean difference (WMD) = - 1.52; 95%CI, - 1.92 to - 1.11; Z = 7.40; P < 0.001] and monthly acute migraine-specific medication consumption from baseline [WMD = - 1.45; 95%CI, - 2.17 to - 0.72; Z = 3.93; P < 0.001], as compared with placebo group. CGRP monoclonal antibodies for preventive treatment of episodic migraine significantly increased the ≥ 50% reduction from baseline in migraine days per month [RR = 1.54; 95%CI, 1.38 to1.71; Z = 7.88; P < 0.001]. The adverse events were similar between the CGRP monoclonal antibody group and placebo group (P = 0.998). The outcomes of subgroup analysis showed that erenumab, galcanezumab, and fremanezumab significantly reduced the monthly migraine days from baseline and increased the ≥ 50% reduction from baseline in migraine days per month. Both erenumab and fremanezumab significantly reduced from baseline.

CONCLUSIONS

Based on the results of this meta-analysis, CGRP monoclonal antibodies significantly reduced the monthly migraine days and acute migraine-specific medication. CGRP monoclonal antibodies were effective and safe for preventive treatment of episodic migraine.

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.

Characterization of the trigeminovascular actions of several adenosine A2A receptor antagonists in an in vivo rat model of migraine

BACKGROUND

Migraine is considered a neurovascular disorder, but its pathophysiological mechanisms are not yet fully understood. Adenosine has been shown to increase in plasma during migraine attacks and to induce vasodilation in several blood vessels; however, it remains unknown whether adenosine can interact with the trigeminovascular system. Moreover, caffeine, a non-selective adenosine receptor antagonist, is included in many over the counter anti-headache/migraine treatments.

METHODS

This study used the rat closed cranial window method to investigate in vivo the effects of the adenosine A_2A receptor antagonists with varying selectivity over A₁ receptors; JNJ-39928122, JNJ-40529749, JNJ-41942914, JNJ-40064440 or JNJ-41501798 (0.3-10 mg/kg) on the vasodilation of the middle meningeal artery produced by either CGS21680 (an adenosine A_2A receptor agonist) or endogenous CGRP (released by periarterial electrical stimulation).

RESULTS

Regarding the dural meningeal vasodilation produced neurogenically or pharmacologically, all JNJ antagonists: (i) did not affect neurogenic vasodilation but (ii) blocked the vasodilation produced by CGS21680, with a blocking potency directly related to their additional affinity for the adenosine A₁ receptor.

CONCLUSIONS

These results suggest that vascular adenosine A_2A (and, to a certain extent, also A₁) receptors mediate the CGS21680-induced meningeal vasodilation. These receptors do not appear to modulate prejunctionally the sensory release of CGRP. Prevention of meningeal arterial dilation might be predictive for anti-migraine drugs, and since none of these JNJ antagonists modified per se blood pressure, selective A_2A receptor antagonism may offer a novel approach to antimigraine therapy which remains to be investigated in clinical trials.