Pharmacological treatment of migraine: CGRP and 5-HT beyond the triptans

Real-world experience with monthly and quarterly dosing of fremanezumab for the treatment of patients with migraine in Japan

Background

The effectiveness of fremanezumab in treating migraine has been demonstrated in randomized controlled trials. However, real-world study results are still limited.

Methods

We conducted a single-center, observational study that included patients with episodic migraine (EM) and chronic migraine (CM) who received fremanezumab monthly or quarterly over 6-month periods. The primary outcome of this study was to evaluate changes in monthly migraine days (MMD) and responder achievement after treatment with fremanezumab. The secondary aim was to characterize the predictors of responder at 6 months. We also evaluated the effectiveness of fremanezumab in the patients who switched from other calcitonin gene-related peptide (CGRP) monoclonal antibodies, and compared the effectiveness of fremanezumab between the monthly and quarterly dosing groups. One hundred twenty-seven patients with migraine (age, 45.2 ± 12.6 years; 96 women) who received at least one dose of fremanezumab with ≥3 months of follow-up were included. The number of MMD was assessed by headache diary.

Results

The changes in MMD from baseline at 1, 3, and 6 months were -6.1 ± 4.7, -7.7 ± 4.4, and - 8.5 ± 4.5 days in the total cohort, respectively (p < 0.001). The ≥50%, ≥ 75 and 100% responder rates at 6 months were 67.6, 22.5, and 5.4% in the total cohort, 90.4, 36.5, and 9.6% in the EM group, and 52.2, 14.9, and 1.5% in the CM group, respectively. Fremanezumab was also effective in 35 patients who switched from other CGRP monoclonal antibodies. Quarterly and monthly fremanezumab doses were equally effective in MMD reduction in the EM and CM groups. In the CM group, 65.1% experienced remission to EM after 6 months. Adverse reactions were mild and occurred in 9.5% of total patients. An at least ≥50% reduction in MMD from months 1 to 3 better predicted a ≥ 50% reduction in MMD at 6 months with 90.5% sensitivity and 80.6% specificity (p < 0.001).

Conclusion

In our real-world study, quarterly and monthly fremanezumab dosing showed both favorable effectiveness and tolerability in patients with migraine.

Network pharmacology and experimental verification to explore the anti-migraine mechanism of Yufeng Ningxin Tablet

ETHNOPHARMACOLOGICAL RELEVANCE

Yufeng Ningxin Tablet (YNT) is a traditional Chinese medicine formula, that has been used clinically to treat migraine for many years. It is composed of one herb Pueraria lobata var. lobata (Willd.) Ohwi (Relevant Chinese name: Gegen). Previously, it has been recorded by traditional Chinese doctor that Gegen could be used as medicine to treat migraine. However, the underlying mechanism of action remains to be investigated.

AIM OF THE STUDY

It was to explore the effect and mechanism of YNT on migraine based on network pharmacology and experimental verification.

MATERIALS AND METHODS

First, with the network pharmacology, the effective chemical components and target genes of YNT were filtrated, the YNT-compound-migraine-targets network was constructed. The protein-protein interaction network (PPI) and literature reports were combined to identify potential targets of YNT in the treatment of migraine. Then, the representative compounds of YNT were characterized by LC-MS/MS and the major effect components were identified. Finally, the prediction results of network pharmacology were verified by animal and cell experiments.

RESULTS

7 bioactive components of YNT could act on 97 migraine potential targets. The 5 bioactive components could be characterized comprehensively of YNT. The key therapeutic targets and pathways were collected including 5-HT, CGRP, inflammation and nociceptive factors, and NF-κB signaling pathway. Animal experiments showed that YNT could increase the expression level of 5-HT and reduce the expression of CGRP, NF-κB, c-fos and IL-1β. YNT could inhibit LPS-induced neuroinflammation by NF-κB in BV2 cells in vitro. Western blotting analysis results showed YNT inhibited the NF-κB and phospho-NF-κB levels.

CONCLUSIONS

It is the first time to verify the consistency between the metabolic components of YNT by LC-MS/MS and the active components predicted by network pharmacology. Meanwhile, the potential mechanism of YNT in the treatment of migraine was studied by combining network pharmacology and in vitro and in vivo experiments.

Clinical efficacy and safety of rimegepant in the treatment of migraine: a meta-analysis of randomized controlled trials

Background

This study aims to evaluate the clinical efficacy and safety of rimegepant for the treatment of migraine in adult patients using a meta-analysis.

Methods

The PubMed, EMBASE, and Cochrane Library were searched up to March 2022. Only randomized controlled trials (RCTs) that evaluated migraine and other comparator treatments in adult patients were included. The clinical response at the post-treatment evaluation, including acute pain free and relief effect, whereas the secondary outcomes were the risk of adverse events (AEs).

Results

A total of 4 RCTs involving 4,230 patients with episodic migraine were included. Outcome indicators for the number of pain free and relief patients at 2 h, 2-24 h, 2-48 h post-dose showed that rimegepant had better effects relative to the placebo [free at 2 h: OR = 1.84, 95% CI (1.55, 2.18), P < 0.00001; relief at 2 h: OR = 1.80, 95% CI (1.59, 2.04), P < 0.00001]. And there was no significant difference between the occurrence of adverse events in the experimental and control groups [OR = 1.29, 95% CI (0.99, 1.67), P = 0.06].

Conclusion

Rimegepant has better therapeutic effects compared to placebo and no significant difference in adverse events.

Targeting Nociceptive Neurons and Transient Receptor Potential Channels for the Treatment of Migraine

Migraine is a neurovascular disorder that affects approximately 12% of the global population. While its exact causes are still being studied, researchers believe that nociceptive neurons in the trigeminal ganglia play a key role in the pain signals of migraine. These nociceptive neurons innervate the intracranial meninges and convey pain signals from the meninges to the thalamus. Targeting nociceptive neurons is considered promising due to their accessibility and distinct molecular profile, which includes the expression of several transient receptor potential (TRP) channels. These channels have been linked to various pain conditions, including migraine. This review discusses the role and mechanisms of nociceptive neurons in migraine, the challenges of current anti-migraine drugs, and the evidence for well-studied and emerging TRP channels, particularly TRPC4, as novel targets for migraine prevention and treatment.

CGRP physiology, pharmacology, and therapeutic targets: migraine and beyond

Calcitonin gene-related peptide (CGRP) is a neuropeptide with diverse physiological functions. Its two isoforms (α and β) are widely expressed throughout the body in sensory neurons as well as in other cell types, such as motor neurons and neuroendocrine cells. CGRP acts via at least two G protein-coupled receptors that form unusual complexes with receptor activity-modifying proteins. These are the CGRP receptor and the AMY1 receptor; in rodents, additional receptors come into play. Although CGRP is known to produce many effects, the precise molecular identity of the receptor(s) that mediates CGRP effects is seldom clear. Despite the many enigmas still in CGRP biology, therapeutics that target the CGRP axis to treat or prevent migraine are a bench-to-bedside success story. This review provides a contextual background on the regulation and sites of CGRP expression and CGRP receptor pharmacology. The physiological actions of CGRP in the nervous system are discussed, along with updates on CGRP actions in the cardiovascular, pulmonary, gastrointestinal, immune, hematopoietic, and reproductive systems and metabolic effects of CGRP in muscle and adipose tissues. We cover how CGRP in these systems is associated with disease states, most notably migraine. In this context, we discuss how CGRP actions in both the peripheral and central nervous systems provide a basis for therapeutic targeting of CGRP in migraine. Finally, we highlight potentially fertile ground for the development of additional therapeutics and combinatorial strategies that could be designed to modulate CGRP signaling for migraine and other diseases.

The NMDA receptor antagonists memantine and ketamine as anti-migraine agents

Migraine is a debilitating disorder affecting females more frequently than males. There is some evidence that drugs targeting glutamate receptors: memantine and ketamine might be beneficial in the therapy of this entity. Therefore, the purpose of this work is to present NMDA receptor antagonists, memantine and ketamine, as potential anti-migraine agents. We searched PubMed/MEDLINE, Embase, and clinical trials submitted to ClinicalTrials.gov to find publications describing eligible trials published between database inception and December 31, 2021. This comprehensive literature review summarizes data on the use of the NMDA receptor antagonists memantine and ketamine in the pharmacotherapy of migraine. Results from 20 previous and recent preclinical experiments are discussed and correlated with 19 clinical trials (including case series, open-label, and randomized placebo-controlled trials). For the purposes of this review, the authors hypothesized that the propagation of SD is a major mechanism in the pathophysiology of migraine. In several animal studies and in vitro studies, memantine and ketamine inhibited or reduced propagation of the SD. In addition, the results of clinical trials suggest that memantine or ketamine may be an effective treatment option for migraine. However, most studies on these agents lack control group. Although further clinical trials are needed, the results suggest that ketamine or memantine may be promising molecules for the treatment of severe migraine. Particular attention should be paid to people who have a treatment-resistant form of migraine with aura or have exhausted existing treatment options. For them, the drugs under discussion could represent an interesting alternative in the future.

Nanospanlastics as a Novel Approach for Improving the Oral Delivery of Resveratrol in Lipopolysaccharide-Induced Endotoxicity in Mice

Purpose

Resveratrol (RSV) is a natural polyphenolic compound that has numerous biological effects. Owing to its poor bioavailability, only trace concentrations of RSV could be found at the site of action. Therefore, the present study was aimed at developing RSV-loaded nanospanlastics to improve its oral delivery and therapeutic activity.

Methods

RSV-loaded nanospanlastics were prepared using the thin film hydration technique. The developed formulations were characterized via vesicular size (VS), polydispersity index (PDI), zeta potential (ZP) measurements, fourier transform infrared (FT-IR) spectroscopy analysis and transmission electron microscopy (TEM). In vitro release profile was carried out using dialysis bag diffusion technique. In vivo study was carried out using lipopolysaccharide (LPS)-induced endotoxicity model in mice to evaluate the formulations activity.

Results

The results revealed the successful development of RSV-loaded nanospanlastics which exhibited EE% ranging from 45 to 85%, particle sizes ranging from 260.5 to 794.3 nm; negatively charged zeta potential (≤ − 20 mV) and TEM revealed their spherical shape. An in vitro release study showed biphasic pattern with sustained release of drug up to 24 h. In vivo results showed the superiority of RSV-loaded nanospanlastics over conventional niosomes in attenuating serum levels of liver and kidney functions (aspartate transaminase (AST), alanine transaminase (ALT), and creatinine) in LPS-induced endotoxic mice. Furthermore, both of them suppressed the elevated oxidative stress and inflammatory markers (malondialdehyde (MDA), nitric oxide (NO), and interleukin-1beta (IL-1β)) estimated in the liver and kidney tissues. However, the nanospanlastics showed a prevalence effect over conventional niosomes in kidney measurements and the histopathological examinations.

Conclusions

These findings reveal the potential of nanospanlastics in improving the oral delivery and therapeutic efficacy of RSV.

Safety and tolerability of monoclonal antibodies targeting the CGRP pathway and gepants in migraine prevention: A systematic review and network meta-analysis

BACKGROUND

Direct comparisons of the tolerability and safety of migraine preventive treatments targeting the calcitonin gene-related peptide pathway are lacking. This study aimed to compare the safety and tolerability of anti-calcitonin gene-related peptide monoclonal antibodies and gepants in migraine prevention.

METHODS

A network meta-analysis of phase 3 randomized controlled trials assessing the safety and tolerability of anti-calcitonin gene-related peptide monoclonal antibodies (erenumab, eptinezumab, fremanezumab, or galcanezumab) and gepants (atogepant, rimegepant) in migraine prevention was performed. Primary outcomes were treatment-emergent adverse events and serious adverse events. Secondary outcomes included any adverse events, adverse events leading to treatment discontinuation and individual adverse events.

RESULTS

We included 19 randomized controlled trials, comprising 14,584 patients. Atogepant 120 mg (OR 2.22, 95% CI [1.26, 3.91]) and galcanezumab 240 mg (OR 1.63, 95% CI [1.33, 2.00]) showed the largest odds of treatment-emergent adverse events compared to placebo. While eptinezumab 30 mg had greater odds of adverse events leading to treatment discontinuation (OR 2.62, 95% CI [1.03,6.66]). No significant differences in serious adverse events were found between active treatments and placebo. Eptinezumab was associated with the lowest odds of treatment-emergent adverse events and serious adverse events compared to placebo, whereas erenumab was associated with the lowest odds of any adverse events and quarterly fremanezumab with the lowest odds of treatment discontinuation due to adverse events.

CONCLUSION

Monoclonal antibodies targeting the calcitonin gene-related peptide pathway and gepants are a safe and well tolerated option for migraine prevention.

Rimegepant: A Review in the Acute Treatment and Preventive Treatment of Migraine

Rimegepant [Nurtec^® ODT (USA); Vydura^® (EU)] is a calcitonin gene-related peptide (CGRP) receptor antagonist approved for the acute treatment of migraine with or without aura in adults, and for the preventive treatment of episodic migraine in adults. Rimegepant is available as an orally disintegrating tablet (ODT), which offers convenience and a potentially faster response time than the conventional tablet formulation. In pivotal phase III trials, rimegepant was more effective than placebo at relieving pain and the most bothersome symptom when taken as needed for the acute treatment of migraine. Rimegepant was also more effective than placebo at reducing the number of monthly migraine days when taken every other day for the preventive treatment of migraine. The beneficial effects of rimegepant in reducing migraine frequency and improving quality of life were maintained over the longer term (up to 52 weeks). Rimegepant was generally well tolerated, with no evidence of hepatotoxicity or cardiovascular toxicity in clinical trials. As the first dual agent approved for both treatment and prevention of migraine, rimegepant represents a useful option for the management of migraine in adults.

Place of next generation acute migraine specific treatments among triptans, non-responders and contraindications to triptans and possible combination therapies

Background: For many years triptans have been the cornerstone of acute migraine treatment. Nevertheless, treatment with triptans may not always be initiated due to contraindications (seen in approximately one fifth of patients) or inadequate response (seen in approximately one third of patients). New acute therapies, including 5-hydroxytryptamine (5-HT)_1F receptor agonists, also known as ditans (lasmiditan) and small molecule antagonists of the calcitonin gene-related peptide receptor, also known as gepants (rimegepant and ubrogepant), may be an effective alternative. Methods: We searched Pubmed for keywords, summarized the literature and provided a comprehensive review on the place of next generation acute migraine specific treatments among triptans. Results and conclusion: Post-hoc analyses reported no differences in efficacy of gepants/ditans between responders and non-responders to triptans, but research is hampered by lack of consensus on the definition of non-responder. Due to (partially) overlapping mechanisms of action, it remains unknown whether combination therapy with lasmiditan, gepants and triptans will have added value over monotherapy. Preclinical studies and post-hoc analyses cautiously indicate that these new drugs are safe for patients with cardiovascular risk factors. However, long-term studies are needed to prove cardiovascular safety. The risk of developing medication overuse headache may differ between triptans, ditans and gepants, but further studies are needed to confirm this difference. Head-to-head randomized controlled trials of acute therapies and combinations of therapies are needed to determine their place in migraine treatment among established therapies.

Migraine genetics: Status and road forward

BACKGROUND

Migraine is considered a multifactorial genetic disorder. Different platforms and methods are used to unravel the genetic basis of migraine. Initially, linkage analysis in multigenerational families followed by Sanger sequencing of protein-coding parts (exons) of genes in the genomic region shared by affected family members identified high-effect risk DNA mutations for rare Mendelian forms of migraine, foremost hemiplegic migraine. More recently, genome-wide association studies testing millions of DNA variants in large groups of patients and controls have proven successful in identifying many dozens of low-effect risk DNA variants for the more common forms of migraine with the number of associated DNA variants increasing steadily with larger sample sizes. Currently, next-generation sequencing, utilising whole exome and whole genome sequence data, and other omics data are being used to facilitate their functional interpretation and the discovery of additional risk factors. Various methods and analysis tools, such as genetic correlation and causality analysis, are used to further characterise genetic risk factors.

FINDINGS

We describe recent findings in genome-wide association studies and next-generation sequencing analysis in migraine. We show that the combined results of the two most recent and most powerful migraine genome-wide association studies have identified a total of 178 LD-independent (r² < 0.1) genome-wide significant single nucleotide polymorphisms (SNPs), of which 99 were unique to Hautakangas et al., 11 were unique to Choquet et al., and 68 were identified by both studies. When considering that Choquet et al. also identified three SNPs in a female-specific genome-wide association studies then these two recent studies identified 181 independent SNPs robustly associated with migraine. Cross-trait and causal analyses are beginning to identify and characterise specific biological factors that contribute to migraine risk and its comorbid conditions.

CONCLUSION

This review provides a timely update and overview of recent genetic findings in migraine.

Biodegradable double-network GelMA-ACNM hydrogel microneedles for transdermal drug delivery

As a minimally invasive drug delivery platform, microneedles (MNs) overcome many drawbacks of the conventional transdermal drug delivery systems, therefore are favorable in biomedical applications. Microneedles with a combined burst and sustained release profile and maintained therapeutic molecular bioactivity could further broaden its applications as therapeutics. Here, we developed a double-network microneedles (DN MNs) based on gelatin methacrylate and acellular neural matrix (GelMA-ACNM). ACNM could function as an early drug release matrix, whereas the addition of GelMA facilitates sustained drug release. In particular, the double-network microneedles comprising GelMA-ACNM hydrogel has distinctive biological features in maintaining drug activity to meet the needs of application in treating different diseases. In this study, we prepared the double-network microneedles and evaluated its morphology, mechanical properties, drug release properties and biocompatibility, which shows great potential for delivery of therapeutic molecules that needs different release profiles in transdermal treatment.

Preclinical Studies of Posttraumatic Headache and the Potential Therapeutics

Posttraumatic headache (PTH) attributed to traumatic brain injury (TBI) is a secondary headache developed within 7 days after head injury, and in a substantial number of patients PTH becomes chronic and lasts for more than 3 months. Current medications are almost entirely relied on the treatment of primary headache such as migraine, due to its migraine-like phenotype and the limited understanding on the PTH pathogenic mechanisms. To this end, increasing preclinical studies have been conducted in the last decade. We focus in this review on the trigeminovascular system from the animal studies since it provides the primary nociceptive sensory afferents innervating the head and face region, and the pathological changes in the trigeminal pathway are thought to play a key role in the development of PTH. In addition to the pathologies, PTH-like behaviors induced by TBI and further exacerbated by nitroglycerin, a general headache inducer through vasodilation are reviewed. We will overview the current pharmacotherapies including calcitonin gene-related peptide (CGRP) monoclonal antibody and sumatriptan in the PTH animal models. Given that modulation of the endocannabinoid (eCB) system has been well-documented in the treatment of migraine and TBI, the therapeutic potential of eCB in PTH will also be discussed.

Circulating Insulin-Like Growth Factor 1 Levels and Migraine Risk: A Mendelian Randomization Study

INTRODUCTION

Preclinical studies have indicated insulin-like growth factor 1 (IGF1) as a novel therapeutic target in the treatment of migraines. We aimed to investigate the causal effect of circulating IGF1 levels on migraine risk using the two-sample Mendelian randomization method.

METHODS

A total of 431 independent variants from 363,228 unrelated individuals in the UK Biobank were used as genetic instruments for circulating IGF1 levels. Summary-level data for migraines were obtained from two independent studies with 10,536 and 28,852 migraine cases, respectively.

RESULTS

Mendelian randomization using inverse-variance weighting showed that increased IGF1 levels were significantly associated with decreased risk of migraines in both outcome datasets (odds ratio 0.905, 95% confidence interval 0.842-0.972, p = 0.006; odds ratio 0.929, 95% confidence interval 0.882-0.979, p = 0.006). Although some other robust Mendelian randomization methods did not demonstrate a significant association, no unbalanced horizontal pleiotropy was found by Mendelian randomization-Egger regression (p values for horizontal pleiotropy 0.232 and 0.435). The effect was confirmed in additional analyses including multivariable Mendelian randomization analyses.

CONCLUSION

This two-sample Mendelian randomization study showed that genetically determined increased IGF1 levels are causally associated with decreased migraine risk. Future randomized controlled trials are warranted to confirm the benefits of IGF1 administration on migraines.

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.

Rimegepant, Ubrogepant, and Lasmiditan in the Acute Treatment of Migraine Examining the Benefit-Risk Profile Using Number Needed to Treat/Harm

OBJECTIVES

To develop and compare benefit-risk profiles for rimegepant, ubrogepant, and lasmiditan based on a network meta-analysis (NMA) of published clinical trials.

METHODS

A fixed-effects Bayesian NMA of randomized controlled trials of lasmiditan, rimegepant, and ubrogepant for the acute treatment of adults with migraine were used to determine risk differences for efficacy and safety outcomes of the 3 treatments compared with pooled placebo. Risk differences were used to calculate number needed to treat (NNT) for pain relief and pain freedom at 2 and 2 to 24 hours and freedom from most bothersome symptoms at 2 hours; and number needed to harm (NNH) for dizziness and nausea, relative to placebo.

RESULTS

Results were based on 5 randomized controlled trials (NCT03461757, NCT02828020, NCT02867709, NCT02439320, and NCT02605174). NNT to achieve sustained pain relief at 2 to 24 hours was lowest for rimegepant 75 mg (5; 95% credible interval [Crl]: 4, 7) and ubrogepant 100 mg (5; 95% Crl: 4, 8) and highest for ubrogepant 25 mg (8; 95% Crl: 5, 16). Rimegepant had the lowest NNT to achieve sustained pain freedom at 2 to 24 hours and lasmiditan 50 mg had the highest (7; 95% Crl: 5, 12 vs. 26; 95% Crl: 13, 95). NNH for dizziness and nausea was highest for ubrogepant 25 mg (28; 95% Crl: 15, 62 and 99; 95% Crl: -2580, 2378, respectively). Lasmiditan 200 mg had the lowest NNH for dizziness and rimegepant 75 mg had the lowest NNH for nausea.

CONCLUSIONS

The benefit-risk profiles of lasmiditan, rimegepant, and ubrogepant may improve clinical decision-making.

Vascular Risk Score and Associations With Past, Current, or Future Migraine in Women: Cohort Study

BACKGROUND AND OBJECTIVES

Migraine has consistently been associated with an increased risk of cardiovascular disease (CVD) events. It remains, however, unclear to what extent cardiovascular risk profiles might be linked with migraine activity status and how these profiles relate to the development of migraine.

METHODS

We used data from a cohort study of female health professionals (Women's Health Study, n = 27,539, age ≥45 years at baseline) without a history of CVD or other major diseases and who provided a blood sample at baseline. Framingham risk scores (FRSs) estimating the 10-year risk of coronary heart disease calculated at baseline were used to create vascular risk categories. The presence or development of self-reported migraine was assessed by questionnaires. Women were classified as having no migraine, history of migraine (experienced migraine in the past but did not experience any migraine attacks in the year before enrollment), active migraine at baseline (active), or incident migraine (first report of migraine during follow-up but not at baseline). We used multinomial logistic regression models to calculate ORs for the association between FRS categories and migraine status.

RESULTS

Of the 27,539 participants, a total of 21,927 women did not report migraine, 1,500 women reported a history of migraine, 3,579 had migraine at baseline, and 533 reported migraine for the first time during follow-up. The odds of the probability of having a history of migraine at baseline (vs never migraine) was 76% higher among those with FRS ≥10% compared with FRS ≤1% after adjustment (OR = 1.76, 95% CI 1.39-2.23). In contrast, having FRS ≥10% was associated with reduced odds of having active migraine at baseline (OR = 0.64, 95% CI 0.52-0.80) and with newly reported migraine during follow-up (OR = 0.42, 95% CI 0.22-0.81) when compared with women with FRS category ≤1% and those not reporting migraine. A similar association pattern was observed for FRS categories 5%-9% and 2%-4%.

DISCUSSION

High FRS categories were only observed among women with a history of migraine but not with active migraine at baseline or incident migraine after baseline. Our results suggest that the life course of migraine should be considered when studying associations with the vascular system. Our data further suggest that a relatively healthy vascular system, as assessed by the FRS, is associated with active migraine status or developing migraine in the future.

Rimegepant for the treatment of migraine

Migraine is a common form of primary headache, affecting up to 1 in every 6 Americans. The pathophysiology is an intricate interplay of genetic factors and environmental influence and is still being elucidated in ongoing studies. The trigeminovascular system is now known to have a significant role in the initiation of migraines, including the release of pain mediators such as CGRP and substance P. Traditional treatment of migraine is usually divided into acute and preventive treatment. Acute therapy includes non-specific therapy, such as NSAIDs and other analgesics, which may provide relief in mild to moderate migraines. 5-HT1 agonists may provide relief in severe migraine, but are not universally effective and carry a significant side-effect profile with frequent redosing requirement. Prophylactic therapy may reduce the occurrence of acute migraine attacks in selected patients, but does not completely eliminate it. More recently, CGRP antagonism has been studied and shown to be effective in both abortion and prevention of migraine. Novel medications, targeting CGRP, divide into CGRP antibodies and receptor antagonists (gepants). Rimegepant, a second-generation gepant, has shown efficacy in several clinical trials in treating acute migraine. Ongoing trials are also evaluating its role in migraine prophylaxis, and results are promising. It is also generally safer for use than existing options, does not appear to increase the chance of developing chronic migraines, and carries a very tolerable side effects profile. It is a part of a growing arsenal in migraine treatment, and may present the silver bullet for treatment of this disease.

European Headache Federation (EHF) consensus on the definition of effective treatment of a migraine attack and of triptan failure

Background

Triptans are migraine-specific acute treatments. A well-accepted definition of triptan failure is needed in clinical practice and for research. The primary aim of the present Consensus was to provide a definition of triptan failure. To develop this definition, we deemed necessary to develop as first a consensus definition of effective treatment of an acute migraine attack and of triptan-responder.

Main body

The Consensus process included a preliminary literature review, a Delphi round and a subsequent open discussion. According to the Consensus Panel, effective treatment of a migraine attack is to be defined on patient well-being featured by a) improvement of headache, b) relief of non-pain symptoms and c) absence of adverse events. An attack is considered effectively treated if patient’s well-being, as defined above, is restored within 2 hours and for at least 24 hours. An individual with migraine is considered as triptan-responder when the given triptan leads to effective acute attack treatment in at least three out of four migraine attacks. On the other hand, an individual with migraine is considered triptan non-responder in the presence of failure of a single triptan (not matching the definition of triptan-responder). The Consensus Panel defined an individual with migraine as triptan-resistant in the presence of failure of at least 2 triptans; triptan refractory, in the presence of failure to at least 3 triptans, including subcutaneous formulation; triptan ineligibile in the presence of an acknowledged contraindication to triptan use, as specified in the summary of product characteristics.

Conclusions

The novel definitions can be useful in clinical practice for the assessment of acute attack treatments patients with migraine. They may be helpful in identifying people not responding to triptans and in need for novel acute migraine treatments. The definitions will also be of help in standardizing research on migraine acute care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01502-z.

Calcitonin gene-related peptide and neurologic injury: An emerging target for headache management

Calcitonin gene-related peptide (CGRP) is a 37-amino acid neuropeptide known to be involved in the trigeminovascular system and to function as a potent vasodilator. Although it has emerged as a viable target for headache management with targeted treatments developed for migraine, a highly disabling neurovascular disorder, less is known about CGRP's role in other neurologic conditions such as traumatic brain injury and subarachnoid hemorrhage. The literature has shown that during these injury cascades, CGRP receptors are modulated in varying ways. Therefore, CGRP or its receptors might be viable targets to manage secondary injuries following acute brain injury. In this review, we highlight the pathophysiology of the CGRP pathway and its relation to migraine pathogenesis. Using these same principles, we assess the existing preclinical data for CGRP and its role in acute brain injury. The findings are promising, and set the basis for further work, with specific focus on the therapeutic benefit of CGRP modulation following neurologic injury.

Association between sleep quality, migraine and migraine burden

Background

The relationship between sleep and migraine is well known to be bidirectional. However, few studies have systematically assessed the association between sleep quality and the risk of developing migraine, and its gender and age differences are unclear. And there is currently limited evidence on the associations between sleep quality and migraine-related burdens.

Objective

The objectives of this study were to: (1) explore the association between sleep quality and the risk of developing migraine, and its gender and age differences; (2) investigate the associations between sleep quality and the total pain burden, severity, disability, headache impact, quality of life, anxiety, and depression of migraine patients.

Methods

This study consecutively enrolled 134 migraine patients and 70 sex- and age-matched healthy control subjects. Sleep quality was assessed through the Pittsburgh Sleep Quality Index (PSQI). Logistic regression and linear regression analyses were used to explore the associations between sleep quality with the risk of developing migraine and the migraine-related burdens.

Results

The prevalence of poor sleep quality in migraine patients was significantly higher than that in subjects without migraine (P &lt; 0.001). After adjusting for various confounding factors, the risk of migraine with poor sleep quality remained 3.981 times that of those with good sleep quality. The subgroup analysis showed that there were significant additive interactions between poor sleep quality and the risk of migraine in gender, age, and education level (P for interaction &lt; 0.05), and the stronger correlations were found in females, populations with ages more than 35 years old, and with lower education levels. In addition, multivariate linear regression analysis showed that poor sleep quality was significantly and independently associated with the total pain burden, severity, headache impact, quality of life, anxiety, and depression in migraine patients (P trend &lt; 0.05).

Conclusion

Poor sleep quality was significantly independently associated with an increased risk of developing migraine and the migraine-related burdens. Strengthening PSQI assessment is valuable for the early prevention and treatment of migraine patients.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2021

The second year of the COVID-19 pandemic had no adverse effect on the number of new drug approvals by the US Food and Drug Administration (FDA). Quite the contrary, with a total of 50 new drugs, 2021 belongs to the most successful FDA years. We assign these new drugs to one of three levels of innovation: (1) first drug against a condition ("first-in-indication"), (2) first drug using a novel molecular mechanism ("first-in-class"), and (3) "next-in-class", i.e., a drug using an already exploited molecular mechanism. We identify 21 first-in-class, 28 next-in-class, and only one first-in-indication drugs. By treatment area, the largest group is once again cancer drugs, many of which target specific genetic alterations. Every second drug approved in 2021 targets an orphan disease, half of them being cancers. Small molecules continue to dominate new drug approvals, followed by antibodies and non-antibody biopharmaceuticals. In 2021, the FDA continued to approve drugs without strong evidence of clinical effects, best exemplified by the aducanumab controversy.

Citalopram Neuroendocrine Challenge Shows Altered Tryptophan and Kynurenine Metabolism in Migraine

Altered tryptophan (TRP) metabolism may have an important role in migraine susceptibility through its main metabolites, serotonin and kynurenine (KYN). Both affect pain processing and stress response by interfering with neural and brain hypersensitivity and by interacting with chemokines and cytokines that control vascular and inflammatory processes. The involvement of these pathways in migraine has been widely studied, but acute citalopram neuroendocrine challenge on TRP metabolism and cytokine profile has not been investigated yet. In our study, females with episodic migraine without aura and healthy controls were studied before and after acute citalopram or placebo in a double-blind setting. At baseline, increased TRP/large neutral amino acid (LNAA) ratio and decreased RANTES chemokine concentration were detected in migraine patients compared to controls. The challenge induced a significant increase in TRP, KYN, and TRP/LNAA in healthy controls, but not in migraine patients. Furthermore, migraine attack frequency negatively correlated with KYN/TRP ratio and positively correlated with the neuroendocrine-challenge-induced KYN concentration increase. Our results support a decreased breakdown of TRP via KYN pathway and a failure to modulate TRP–KYN pathway during citalopram-induced acute stress together with an increased vascular sensitivity in migraine. These mechanisms may provide useful drug targets for future drug development.

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.

Myocardial infarction associated with erenumab: A case report

Background

Monoclonal antibodies acting on the calcitonin gene‐related peptide or its receptor (CGRP‐mabs) are novel drugs for resistant migraine prophylaxis. As CGRP‐mabs cause inhibition of vasodilatation, their use is reserved to patients with no recent history of cardiovascular diseases. We report a case of myocardial infarction associated with erenumab.

Case

A 57‐year‐old woman with a familial history of coronaropathy was first treated with erenumab 70 mg for 6 months and then increased to 140 mg. Almost 5 months after, the patient presented chest pain, increased troponin, and abnormal electrocardiogram. A myocardial infarction without coronarography abnormality was diagnosed through MRI.

Conclusion

Further evidence is needed to assess the risk of myocardial infarction in patients treated with a CGRP‐mab. In patients over 40 years of age, the risk of coronary or cardiovascular events should be assessed using risk tables or algorithms to take into account cardiovascular risk factors. This may be complemented by appropriate examinations to measure the burden of coronary atherosclerosis, if necessary.

Safety evaluation of oral calcitonin-gene-related peptide receptor antagonists in patients with acute migraine: a systematic review and meta-analysis

OBJECTIVE

Calcitonin gene-related peptide (CGRP) receptor antagonists have been suggested as novel treatments for acute migraine. This study aimed to use meta-analysis to compare the safety and tolerability of five existing oral CGRP receptor antagonists (BI44370TA, MK-3207, rimegepant, telcagepant, and ubrogepant) with that of a placebo or triptans against acute migraine.

METHODS

Five prominent databases were searched to identify randomized controlled trials on this topic. The primary safety outcomes of interest were any adverse events (AEs) and treatment-related adverse events (TRAEs), and secondary outcomes were individual events, namely diarrhea, dizziness, dry mouth, fatigue, nausea, paresthesia, somnolence, upper abdominal pain, and vomiting.

RESULTS

Fifteen studies met the eligibility criteria and were examined in detail. Although, compared to placebo, oral CGRP receptor antagonists significantly increased the incidence of any AEs (risk ratio [RR] = 1.15; 95% confidence interval [CI] = 1.07-1.23), there was no difference in the incidence of TRAEs (RR = 1.18; 95% CI = 1.00-1.38). Moreover, CGRP receptor antagonists were safer than triptans with respect to primary safety outcomes, such as any AEs (RR = 0.78; 95% CI = 0.63-0.98) and TRAEs (RR = 0.68; 95% CI = 0.58-0.79).

CONCLUSION

Despite oral CGRP receptor antagonists posing a significantly higher risk of AEs when compared to placebo, CGRP receptor antagonists have a favorable safety profile compared to triptans. Our findings inform strategies to enhance safety and tolerability in the treatment of acute migraine.

Assessment and Characteristics of Erenumab therapy on migraine management

Background

Methods

Results

Conclusion

Drug Safety in Episodic Migraine Management in Adults Part 1: Acute Treatments

PURPOSE OF REVIEW

The aim of this review is to aid in choosing safe options when assessing potential risks of acute migraine treatments based on known mechanisms of action and anticipated safety concerns.

RECENT FINDINGS

Part 1 highlights safety issues associated with commonly used medications to treat acute migraine attacks. Strategies to mitigate cardiovascular and gastrointestinal risks of nonsteroidal anti-inflammatory drugs, evaluation of cardiovascular risks of triptan and ergot alkaloids, and precautions with use of antiemetics and the novel drugs gepants and ditans are discussed to help practitioners in clinical decision-making. When available, we included recommendations from professional societies and data from pharmacovigilance systems. While guidelines on efficacy are available, one must also consider the possible risks and adverse effects of a drug when creating treatment plans.

Neurogenic inflammation as a novel treatment target for chronic pain syndromes

Chronic pain syndrome is a heterogeneous group of diseases characterized by several pathological mechanisms. One in five adults in Europe may experience chronic pain. In addition to the individual burden, chronic pain has a significant societal impact because of work and school absences, loss of work, early retirement, and high social and healthcare costs. Several anti-inflammatory treatments are available for patients with inflammatory or autoimmune diseases to control their symptoms, including pain. However, patients with degenerative chronic pain conditions, some with 10-fold or more elevated incidence relative to these manageable diseases, have few long-term pharmacological treatment options, limited mainly to non-steroidal anti-inflammatory drugs or opioids. For this review, we performed multiple PubMed searches using keywords such as "pain," "neurogenic inflammation," "NGF," "substance P," "nociception," "BDNF," "inflammation," "CGRP," "osteoarthritis," and "migraine." Many treatments, most with limited scientific evidence of efficacy, are available for the management of chronic pain through a trial-and-error approach. Although basic science and pre-clinical pain research have elucidated many biomolecular mechanisms of pain and identified promising novel targets, little of this work has translated into better clinical management of these conditions. This state-of-the-art review summarizes concepts of chronic pain syndromes and describes potential novel treatment strategies.

Calcitonin gene-related peptide-targeting drugs and Raynaud's phenomenon: a real-world potential safety signal from the WHO pharmacovigilance database

BACKGROUND

Migraine is responsible for significant disability and societal burden. Recently, drugs targeting the calcitonin gene-related peptide (CGRP) pathway raised new hopes. CGRP, a potent vasodilator, plays a key role in the pathogenesis of migraine attacks. The deficiency of CGRP is involved in Raynaud's phenomenon, which consists of abnormal vasoconstriction of the digits. We aimed to assess the potential association of Raynaud's phenomenon with CGRP-targeting drugs, analyzing real-world data from the World Health Organization (VigiBase®).

METHODS

We queried all reports of Raynaud's phenomenon involving a CGRP-targeting drug. We sought disproportionate reporting of Raynaud's phenomenon with these drugs. For this purpose, we relied on the calculation of the Information Component (IC). A positive lower end of the 95% confidence interval (CI) of the IC defines a statistically significant association. As migraine patients are prone to Raynaud's phenomenon, we also calculated the IC of Raynaud's phenomenon with CGRP-targeting drugs compared to 5HT1B/D agonists (triptans), and beta-blockers used in the treatment of migraine.

RESULTS

Overall, 99 reports of Raynaud's phenomenon involving CGRP-targeting drugs have been yielded in VigiBase®. The most reported CGRP-targeting drug was erenumab, with 56 reports (56.6%). The median time to onset was 84 days. No fatality was notified, but one patient suffered from gangrene and extremity necrosis. As a whole, CGRP-targeting drugs were significantly associated with Raynaud's phenomenon, with an IC of 3.3 (95%CI: 3.0-3.5). There was a disproportionate reporting of Raynaud's phenomenon with CGRP-targeting drugs compared to triptans (IC 0.4; 95%CI: 0.1-0.6) and to beta-blockers (IC 0.5; 95%CI: 0.2-0.7) as well.

CONCLUSIONS

There is a significant disproportionality signal of Raynaud's phenomenon with CGRP-targeting. This signal stands out when CGRP-targeting drugs are compared to other drugs used in patients with migraine. This study is limited by missing data in pharmacovigilance reports. CGRP-targeting drugs may be subject to Weber effect and reporting bias. Nonetheless, CGRP blockade might be the last straw that disrupts the physiological balance of vascular response in patients at-risk of Raynaud's phenomenon. Pending further data regarding vascular safety of CGRP-targeting drugs, caution is warranted in these patients.

Self-administered subcutaneous diclofenac sodium in acute migraine attack: A randomized, double-blind, placebo-controlled dose-finding pilot study

BACKGROUND

A novel formulation of diclofenac, complexed with hydroxypropyl-β-cyclodextrin (HPβCD) as a solubility enhancer, in a prefilled syringe for self-administered subcutaneous injection may overcome the limitations of acute migraine treatments administered by oral, rectal, intramuscular, or intravenous routes.

METHODS

This multicentre, phase 2, double-blind, randomized, placebo-controlled, dose-finding pilot study evaluated the efficacy, safety and tolerability of three different doses (25/50/75 mg/1 mL) of subcutaneous diclofenac sodium in the treatment of an acute migraine attack in 122 subjects. The primary efficacy endpoint was the percentage of patients pain-free at 2 hours after the study drug injection.

RESULTS

A significantly higher percentage of patients in the 50 mg diclofenac group 14 (46.7%) were pain-free at 2 hours when compared with placebo: 9 (29.0%) (p = 0.01). The 50 mg dose proved superior to placebo also in the majority of the secondary endpoints. The overall global impression favoured diclofenac vs placebo. There were no adverse events leading to study withdrawal. The majority of treatment-emergent adverse events were mild.

CONCLUSIONS

The 50 mg dose of this novel formulation of diclofenac represents a valuable self-administered option for the acute treatment of migraine attacks.Trial registration: EudraCT Registration No. 2017-004828-29.

Rapid response to galcanezumab and predictive factors in chronic migraine patients: A 3-month observational, longitudinal, cohort, multicenter, Italian real-life study

BACKGROUND AND PURPOSE

A rapid response to preventive therapy is of pivotal importance in severely disabled patients with chronic migraine (CM) and diverse preventive treatment failures. This prospective, observational, multicenter real-life study aimed at investigating the effectiveness of galcanezumab in the first 3 months of treatment of CM patients at 14 Italian headache centers.

METHODS

All consecutive adult patients with CM diagnosis with the clinical indication for galcanezumab were considered. We collected patients' baseline characteristics, monthly headache days, monthly painkiller intake, migraine clinical characteristics, and disability scale scores during a 1-month run-in period (baseline) and the first 3 months of therapy. Possible predictive factors of treatment were considered.

RESULTS

A total of 156 patients (82.4% female, aged 47.3 ± 12.3 years) were enrolled. The 65 (41.7%) patients with a consecutive ≥50% response rate (RR) in the 3 months of therapy presented a lower body mass index (p = 0.004) and more frequently presented unilateral migraine pain (p = 0.002) and good response to triptans (p = 0.003). Persistent conversion from CM to episodic migraine was observed in 55.8% (87/156) of patients. They more frequently presented a good response to triptans (p = 0.003) and unilateral pain (p = 0.046). At baseline, 131 of 156 (83.9%) patients presented medication overuse (MO). Of these, 61.8% (81/131) no longer displayed MO consistently during the 3 months. These patients were more frequently responders to triptans (p = 0.002) and less frequently suffered from gastrointestinal comorbidity (p = 0.007).

CONCLUSIONS

Unilateral pain, good response to triptans, and normal weight may be associated with a persistent positive response in the first 3 months of therapy with galcanezumab in CM patients.

Atogepant: an emerging treatment for migraine

INTRODUCTION

Until recently, only nonspecific and not always well-tolerated medications were available for migraine prophylaxis. Currently, specific drugs such as calcitonin gene-related peptide (CGRP) monoclonal antibodies and second-generation gepants are marketed for migraine treatment. Atogepant, an orally active small molecule, is a potent, selective antagonist of the CGRP receptor and is the only gepant authorized exclusively for episodic migraine prophylaxis in adults.

AREAS COVERED

Using literature obtained from PubMed, Scopus, Web of Science, Cochrane, and ClinicalTrials.gov (up to February 13^rd, 2022), the authors summarize and evaluate the available data on atogepant for the prophylaxis of episodic migraine.

EXPERT OPINION

From pivotal trials, the efficacy and tolerability of atogepant in episodic migraine prophylaxis seem comparable to those of CGRP monoclonal antibodies, even if comparative studies have not been conducted. To date, limited information is available on atogepant, including the optimal dose and duration of therapy; hence, it is difficult to establish whether it could be a first-line drug for migraine prophylaxis. Furthermore, it is important to evaluate if atogepant use is associated with the risk of cardiovascular and cerebrovascular events, which could result from potent and persistent blockade of vasodilation by CGRP.

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.

Dual action of the cannabinoid receptor 1 ligand arachidonyl-2′-chloroethylamide on calcitonin gene-related peptide release

Background

Based on the current understanding of the role of neuropeptide signalling in migraine, we explored the therapeutic potential of a specific cannabinoid agonist. The aim of the present study was to examine the effect of the synthetic endocannabinoid (eCB) analogue, arachidonyl-2′-chloroethylamide (ACEA), on calcitonin gene-related peptide (CGRP) release in the dura and trigeminal ganglion (TG), as cannabinoids are known to activate G_i/o-coupled cannabinoid receptors type 1 (CB1), resulting in neuronal inhibition.

Methods

The experiments were performed using the hemi-skull model and dissected TGs from male Sprague-Dawley rats. CGRP release was induced by either 60 mM K⁺ (for depolarization-induced stimulation) or 100 nM capsaicin (for transient receptor potential vanilloid 1 (TRPV1) -induced stimulation) and measured using an enzyme-linked immunosorbent assay. The analysis of CGRP release data was combined with immunohistochemistry in order to study the cellular localization of CB1, cannabinoid receptor type 2 (CB2), CGRP and receptor activity modifying protein 1 (RAMP1), a subunit of the functional CGRP receptor, in the TG.

Results

CB1 was predominantly expressed in neuronal somas in which colocalization with CGRP was observed. Furthermore, CB1 exhibited colocalization with RAMP1 in neuronal Aδ-fibres but was not clearly expressed in the CGRP-immunoreactive C-fibres. CB2 was mainly expressed in satellite glial cells and did not show substantial colocalization with either CGRP or RAMP1. Without stimulation, 140 nM ACEA per se caused a significant increase in CGRP release in the dura but not TG, compared to vehicle. Furthermore, 140 nM ACEA did not significantly modify neither K⁺- nor capsaicin-induced CGRP release. However, when the TRPV1 blocker AMG9810 (1 mM) was coapplied with ACEA, K⁺-induced CGRP release was significantly attenuated in the TG and dura.

Conclusions

Results from the present study indicate that ACEA per se does not exhibit antimigraine potential due to its dual agonistic properties, resulting in activation of both CB1 and TRPV1, and thereby inhibition and stimulation of CGRP release, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01399-8.

Genome-wide analysis of 102,084 migraine cases identifies 123 risk loci and subtype-specific risk alleles

Migraine affects over a billion individuals worldwide but its genetic underpinning remains largely unknown. Here, we performed a genome-wide association study of 102,084 migraine cases and 771,257 controls and identified 123 loci, of which 86 are previously unknown. These loci provide an opportunity to evaluate shared and distinct genetic components in the two main migraine subtypes: migraine with aura and migraine without aura. Stratification of the risk loci using 29,679 cases with subtype information indicated three risk variants that seem specific for migraine with aura (in HMOX2, CACNA1A and MPPED2), two that seem specific for migraine without aura (near SPINK2 and near FECH) and nine that increase susceptibility for migraine regardless of subtype. The new risk loci include genes encoding recent migraine-specific drug targets, namely calcitonin gene-related peptide (CALCA/CALCB) and serotonin 1F receptor (HTR1F). Overall, genomic annotations among migraine-associated variants were enriched in both vascular and central nervous system tissue/cell types, supporting unequivocally that neurovascular mechanisms underlie migraine pathophysiology.

Brain barriers and their potential role in migraine pathophysiology

Migraine is a ubiquitous neurologic disease that afflicts people of all ages. Its molecular pathogenesis involves peptides that promote intracranial vasodilation and modulate nociceptive transmission upon release from sensory afferents of cells in the trigeminal ganglion and parasympathetic efferents of cells in the sphenopalatine ganglion. Experimental data have confirmed that intravenous infusion of these vasoactive peptides induce migraine attacks in people with migraine, but it remains a point of scientific contention whether their site of action lies outside or within the central nervous system. In this context, it has been hypothesized that transient dysfunction of brain barriers before or during migraine attacks might facilitate the passage of migraine-inducing peptides into the central nervous system. Here, we review evidence suggestive of brain barrier dysfunction in migraine pathogenesis and conclude with lessons learned in order to provide directions for future research efforts.

Insulin sensitizes neural and vascular TRPV1 receptors in the trigeminovascular system

Background

Clinical observations suggest that hyperinsulinemia and insulin resistance can be associated with migraine headache. In the present study we examined the effect of insulin on transient receptor potential vanilloid 1 (TRPV1) receptor-dependent meningeal nociceptor functions in rats.

Methods

The effects of insulin on the TRPV1 receptor stimulation-induced release of calcitonin gene related peptide (CGRP) from trigeminal afferents and changes in meningeal blood flow were studied. Colocalization of the insulin receptor, the TRPV1 receptor and CGRP was also analyzed in trigeminal ganglion neurons.

Results

Insulin induced release of CGRP from meningeal afferents and consequent increases in dural blood flow through the activation of TRPV1 receptors of trigeminal afferents. Insulin sensitized both neural and vascular TRPV1 receptors making them more susceptible to the receptor agonist capsaicin. Immunohistochemistry revealed colocalization of the insulin receptor with the TRPV1 receptor and CGRP in a significant proportion of trigeminal ganglion neurons.

Conclusions

Insulin may activate or sensitize meningeal nociceptors that may lead to enhanced headache susceptibility in persons with increased plasma insulin concentration.

CGRP Regulates Nucleus Pulposus Cell Apoptosis and Inflammation via the MAPK/NF-κB Signaling Pathways during Intervertebral Disc Degeneration

Chronic low back pain (CLBP) has been proved to be the dominating cause of disability in patients with lumbar degenerative diseases. Of the various etiological factors, intervertebral disc degeneration (IVDD) has been the dominating cause. In the past few decades, the role and changes of nerve systems, especially the peripheral sensory fibers and their neurotransmitters, in the induction and progression of IVDD have attracted growing concerns. The expression of many neuropeptides, such as SP, NPY, and CGRP, in the nociceptive pathways is increased during the progression of IVDD and responsible for the discogenic pain. Here, the role of CGRP in the progression of IVDD was firstly investigated both in vitro and in vivo. Firstly, we confirmed that human degenerated intervertebral disc tissue exhibited elevated expression of CGRP and its receptor. Secondly, in vitro experiments suggested that CGRP could inhibit the proliferation and induce apoptosis in human nucleus pulposus (NP) cells, as well as promote inflammation and degenerated phenotypes through activating NF-κB and MAPK signaling pathways. Thirdly, CGRP receptor antagonist, Rimegepant, can ameliorate the adverse effects of CGRP imposed on NP cells, which were confirmed in vitro and in vivo. Our results will bring about a brand-new insight into the roles of neuromodulation in IVDD and related therapeutic attempts.

Study on the Chemical Constituents and Anti-Migraine Activity of Supercritical CO2 Extracts of Zanthoxylum schinifolium

Background:Zanthoxylum schinifolium is a common herbal medicine in Southwest China. It is also a condiment commonly used in many families. In Chinese folk medicine, Z. schinifolium is considered to have the effect of relieving migraine, but there is no modern evidence on its anti-migraine mechanism.

Objective: The aim of this study was to investigate the chemical constituents of the supercritical carbon dioxide extracts of Z. schinifolium (CO₂-ZSE) and its effects on migraine animals.

Materials and Methods: Supercritical CO₂ extraction technology was applied to extract the dried fruit of Z. schinifolium, and the chemical components were determined by gas chromatography–mass spectrometry (GC-MS). Two migraine animal models were established by subcutaneous injection of nitroglycerin (NTG) and reserpine, respectively, to further evaluate the therapeutic effect of CO₂-ZSE and explore its mechanism. On the basis of the experimental results, the therapeutic effects of linalool in different dosages and different ways of administration on NTG-induced migraine rats have been further investigated.

Results: About 125 peaks were detected in CO₂-ZSE, and the relative content of linalool was 74.16%. CO₂-ZSE decreased the number of head-scratching significantly and the levels of serum nitric oxide (NO), endothelin-1 (ET-1), calcitonin gene–related peptide (CGRP), interleukin-1β (IL-1β), nuclear factor kappa B (NF-κB) p65, and inhibitor of kappa B alpha (IκBα), and increased the level of 5-hydroxytryptamine (5-HT). Linalool has the potential to reduce the frequency of scratching the head and the expressions of NO, ET-1, and CGRP in NTG-induced migraine rats.

Conclusion: CO₂-ZSE has a definite therapeutic effect on migraine by affecting the expression of vasomotor factors and the inflammatory pathway. Linalool has been proven to be the main effective substance against migraine. These findings provide scientific basis for the development of effective and simple migraine therapy.

Design, synthesis and biological evaluation of pyridinylmethylenepiperidine derivatives as potent 5-HT1F receptor agonists for migraine therapy

Migraine is a common neurovascular disease which has been classified as the sixth most disabling disorder. Current migraine therapy was triptans, however, riptans can cause contraction of blood vessels. Therefore, novel drugs without cardiovascular effects emerged, such as CGRP and selective 5-HT1F receptor agonists. In this work, a series of pyridinylmethylenepiperidine derivatives were designed, synthesized and evaluated for their 5-HT1F receptor agonist activity. The results in vitro showed that compound C1-C6 displayed potent agonist activities compared with positive drug lasmiditan. Pharmacokinetic properties in rat indicated that 2,4,6-trifluoro-N-(6-(fluoro(1-methylpiperidin-4-ylidene)methyl)pyridin-2-yl)benzamide (C5) possessed high AUC and good bioavailability. In two rodent models of migraine, C5 significantly inhibited dural plasma protein extravasation and c-fos expression in the trigeminal nucleus caudalis. Moreover, C5 showed no effect on vasoconstriction. Through these studies, we identified C5 as a potent 5-HT1F receptor agonist for migraine therapy.

The involvement of orexin 1 and cannabinoid 1 receptors within the ventrolateral periaqueductal gray matter in the modulation of migraine-induced anxiety and social behavior deficits of rats

Orexin 1 receptors (Orx1R) and cannabinoid 1 receptors (CB1R) are implicated in migraine pathophysiology. This study evaluated the potential involvement of Orx1R and CB1R within the ventrolateral periaqueductal gray matter (vlPAG) in the modulation of anxiety-like behavior and social interaction of migraineurs rats. A rat model of migraine induced by recurrent administration of nitroglycerin (NTG) (5 mg/kg/i.p.). The groups of rats (n = 6) were then subjected to intra-vlPAG microinjection of orexin-A (25, 50 pM), and Orx1R antagonist SB334867 (20, 40 nM) or AM 251 (2, 4 μg) as a CB1R antagonist. Behavioral responses were evaluated in elevated plus maze (EPM), open field (OF) and three-chambered social test apparatus. NTG produced a marked anxiety like behaviors, in both EPM and OF tasks. It did also decrease social performance. NTG-related anxiety and social conflicts were attenuated by orexin-A (25, 50 pM). However, NTG effects were exacerbated by SB334867 (40 nM) and AM251 (2, 4 μg). The orexin-A-mediated suppression of NTG-induced anxiety and social conflicts were prevented by either SB334867 (20 nM) or AM251 (2 μg). The findings suggest roles for Orx1R and CB1R signaling within vlPAG in the modulation of migraine-induced anxiety-like behavior and social dysfunction in rats.

Atogepant: First Approval

Atogepant (Qulipta™) is an orally administered, small-molecule, calcitonin gene-related peptide (CGRP) receptor antagonist being developed by AbbVie for the prophylaxis of migraine. In September 2021, atogepant was approved in the USA for the preventive treatment of episodic migraine in adults. The drug is also in phase 3 clinical development for the preventive treatment of migraine in various other countries. This article summarizes the milestones in the development of atogepant leading to this first approval for the preventive treatment of episodic migraine in adults.

Emodin Interferes With Nitroglycerin-Induced Migraine in Rats Through CGMP-PKG Pathway

The purpose of this research was to explore the effect and mechanism of emodin in interfering with nitroglycerin-induced migraine rats. We carried out behavioral research within 2 h post-nitroglycerin (NTG) injection, and blood samples were collected through the abdominal aorta for measurements of nitric oxide (NO), calcitonin gene-related peptide (CGRP), substance P (SP), tumor necrosis factor (TNF-α) and cyclic guanosine monophosphate (cGMP) levels. Immunohistochemistry was adopted to detect the activation of c-Fos immunoreactive neurons in brain tissues. The number and integrated optical density (IOD) of c-Fos positive cells were measured using Image-Pro Plus. Western blotting was applied to detect the levels of PKG protein in rat brain tissues. The results showed that emodin can alleviate the pain response of migraine rats and significantly reduce the levels of NO, CGRP, SP, TNF-α and cGMP in migraine rats. In addition, emodin can significantly reduce the number of c-Fos positive cells and the IOD value. Moreover, the expression of PKG protein was significantly inhibited by emodin. Therefore, it is inferred that emodin can relieve migraine induced by NTG through the cGMP-PKG pathway, and can be used as a potential botanical medicine for the treatment of migraine.