Targeting CGRP for the Prevention of Migraine and Cluster Headache: A Narrative Review

One-step ultra-rapid immunoassay of calcitonin gene-related peptide for migraine diagnosis

Migraine is known to be caused by calcitonin gene-related peptide (CGRP), prompting the need for quantitative analysis of CGRP for the clinical treatment of monoclonal antibodies targeting CGRP. Since CGRP is cleaved by proteolytic enzymes post-blood collection, rapid analysis methods are required. In this study, a one-step immunoassay for CGRP was developed using chemically mimicking peptides (mimotopes) with an analysis time of 32 min. Four clones from an Fv-antibody library were screened using two types of monoclonal antibodies against CGRP. Mimotopes for each monoclonal antibody were synthesized into peptides of 15 residues. The binding affinity (KD) was estimated, and the interaction with monoclonal antibodies was analyzed using docking simulations. Finally, a one-step immunoassay for CGRP was demonstrated using migraine patient samples (n = 57) and healthy volunteer controls (n = 18). The limit of detection (LOD) of one-step immunoassay based on Fremanezumab (mimotope F1) was estimated to be 8.8 pg/mL with the limit of quantification (LOQ) of 125.9 pg/mL. And, the one-step immunoassay based on Galcanezumab (mimotope G7) showed the LOD of 9.4 pg/mL and the LOQ of 84.7 pg/mL. The total analysis time was estimated to be approximately 32 min and the assay results were estimated to be statistically consistent with conventional CGRP assay.

Comprehensive list of preventative migraine headache medications without significant drug-drug interactions

Background/objective

Preventive medications are crucial in migraine prevention. In cases of refractory migraine headaches, multiple medications may be required. We seek to identify a comprehensive list of preventive migraine headache medications that can be used as two, three, and four drug combinations without drug-drug interactions.

Methods

We compiled a list of prevention medications from Szperka et al.'s "Migraine Care in the Era of COVID-19" as well as American Headache Society's 2018 and 2021 "Consensus Statements on Integrating New Migraine Treatments into Clinical Practice." We obtained all possible two to four combinations of prevention medications through this list. We then filtered out all combinations containing at least one interaction based on DrugBank database and also identified least to most interacting medications.

Results

A total of 26 unique prevention medications are identified. This results in a total of 325 combinations of two preventives, 2,600 combinations of three preventives, and 14,950 combinations of four preventives. There are a total of 124, 146, and 0 non-interacting two, three, and four preventive combinations, respectively. All except 16 combinations of pick-twos can be placed within a pick-three combinations. The resulting distinct non-interacting medications can be represented by a condensed list of 162 unique combinations of medications. CGRP antagonists, Botulinum toxin A, melatonin, and candesartan are least interacting.

Conclusion

This list of migraine preventive medications without drug-drug interactions is a useful tool for clinicians seeking to manage refractory headaches more effectively by implementing an evidence-based polypharmacy.

Cluster headache: understandings of current knowledge and directions for whole process management

Cluster headache (CH) is a common primary headache that severely impacts patients' quality of life, characterized by recurrent, severe, unilateral headaches often centered around the eyes, temples, or forehead. Distinguishing CH from other headache disorders is challenging, and its pathogenesis remains unclear. Notably, patients with CH often experience high levels of depression and suicidal tendencies, necessitating increased clinical attention. This comprehensive assessment combines various reports and the latest scientific literature to evaluate the current state of CH research. It covers epidemiology, population characteristics, predisposing factors, and treatment strategies. Additionally, we provide strategic insights into the holistic management of CH, which involves continuous, individualized care throughout the prevention, treatment, and rehabilitation stages. Recent advances in the field have revealed new insights into the pathophysiology of CH. While these findings are still evolving, they offer a more detailed understanding of the neurobiological mechanisms underlying this disorder. This growing body of knowledge, alongside ongoing research efforts, promises to lead to the development of more targeted and effective treatments in the future.

CGRP promotes osteogenic differentiation by regulating macrophage M2 polarization through HDAC6/AKAP12 signaling pathway

Aim: To determine the mechanism of Calcitonin gene-related peptide (CGRP) in bone healing.Materials & methods: Alkaline phosphatase (ALP) activity and inflammatory-factor levels were detected using ELISA. Osteogenic differentiation was assessed using Alizarin red staining technique. The interaction between histone deacetylase 6 (HDAC6) and A-kinase anchoring protein 12 (AKAP12) was investigated through Co- immunoprecipitation.Results: CGRP treatment promoted rat bone marrow-derived macrophages (BMDMs) M2 polarization. CGRP facilitated osteogenic differentiation by enhancing M2 polarization of BMDMs. Mechanistically, CGRP promoted AKAP12 acetylation to activate the extracellular regulated protein kinases pathway by HDAC6 inhibition.Conclusion: CGRP promoted M2 polarization of rat BMDMs and facilitated osteogenic differentiation through the HDAC6/AKAP12/extracellular regulated protein kinases signaling pathway, thereby promoting bone healing.

A real-world prospective observational study of eptinezumab in Asian patients with migraine

OBJECTIVE

To evaluate the real-world effectiveness of eptinezumab for migraine prevention in Asian patients.

BACKGROUND

Eptinezumab is a monoclonal antibody that targets calcitonin gene-related peptide (CGRP), a potent vasodilator with an important role in migraine pathophysiology. Although there is robust clinical evidence from pivotal Phase 3 placebo-controlled trials of the efficacy of eptinezumab for migraine prevention, there are limited data on the real-world effectiveness of eptinezumab in Asian patient cohorts.

METHODS

This was a non-interventional, prospective, multisite cohort study of adults with migraine (International Classification of Headache Disorders, 3rd edition criteria) in Singapore who were prescribed eptinezumab (100 mg at baseline and Month 3, administered intravenously) and were followed until Month 6. The primary endpoint was change from baseline in monthly migraine days (MMDs) at Month 3 and Month 6. Secondary endpoints were ≥30% and ≥50% responder rates, and change from baseline in the Headache Impact Test-6 (HIT-6), Migraine Disability Assessment (MIDAS), Migraine-Specific Quality of Life (MSQ), patient-identified most bothersome symptom (PI-MBS), acute medication use at Month 3 and Month 6, and safety.

RESULTS

Enrolled patients (completed = 29/30) had on average 3.4 (SD 2.9) previous preventive treatments; 29/30 of the patients had trialed at least one previous preventive treatment without benefit. Most had previously trialed oral preventives (87%, 26/30) and anti-CGRP (70%, 21/30). Relative to baseline, mean MMDs decreased by 4.3 days (95% CI 2.1-6.4; p < 0.001) at Month 3 and 4.9 days (95% CI 2.1-7.7; p < 0.001) at Month 6. At Month 3 and Month 6, 14/30 (47%) and 15/29 (52%) of the patients were ≥30% responders, and 6/30 (20%) and 8/29 (28%) patients were ≥50% responders, respectively. The number of patients with severe life impairment based on the HIT-6 score (total score 60-78) decreased from 24/30 (80%) at baseline to 19/30 (63%) at Month 3 and 19/29 (66%) at Month 6. The mean MIDAS score decreased by 24.6 points (95% CI 2.82-46.38; p = 0.028) at Month 6, and the mean MSQ score increased by 12.2 points (95% CI 5.18-19.20; p = 0.001) at Month 3 and 13.6 points (95% CI 4.58-22.66; p = 0.004) at Month 6. Most patients reported improvement in the PI-MBS at Month 3 (73%, 22/30) and Month 6 (55%, 16/29). Acute medication use for headache relief decreased by 3.3 days/month (95% CI 1.0-5.6; p = 0.007) at Month 3 and 4.7 days/month (95% CI 1.7-7.7; p = 0.003) at Month 6. Treatment-emergent adverse events (TEAEs) were reported in 16/30 (54%) patients, mostly mild/moderate in severity. No serious TEAEs led to treatment discontinuation.

CONCLUSION

Quarterly eptinezumab administration was effective and well-tolerated in Asian patients with chronic migraine.

Quantitative proteomics reveals CLR interactome in primary human cells

The G protein-coupled receptor (GPCR) calcitonin receptor-like receptor (CLR) mediates essential functions in several cell types and is implicated in cardiovascular pathologies, skin diseases, migraine, and cancer. To date, the network of proteins interacting with CLR ("CLR interactome") in primary cells, where this GPCR is expressed at endogenous (physiologically relevant) levels, remains unknown. To address this knowledge gap, we established a novel integrative methodological workflow/approach for conducting a comprehensive/proteome-wide analysis of Homo sapiens CLR interactome. We used primary human dermal lymphatic endothelial cells and combined immunoprecipitation utilizing anti-human CLR antibody with label-free quantitative nano LC-MS/MS and quantitative in situ proximity ligation assay. By using this workflow, we identified 37 proteins interacting with endogenously expressed CLR amongst 4902 detected members of the cellular proteome (by quantitative nano LC-MS/MS) and revealed direct interactions of two kinases and two transporters with this GPCR (by in situ proximity ligation assay). All identified interactors have not been previously reported as members of CLR interactome. Our approach and findings uncover the hitherto unrecognized compositional complexity of the interactome of endogenously expressed CLR and contribute to fundamental understanding of the biology of this GPCR. Collectively, our study provides a first-of-its-kind integrative methodological approach and datasets as valuable resources and robust platform/springboard for advancing the discovery and comprehensive characterization of physiologically relevant CLR interactome at a proteome-wide level in a range of cell types and diseases in future studies.

Calcitonin Gene-Related Peptide Level in Cystic Fibrosis Patients

Calcitonin gene-related peptide (CGRP) has long been implicated in both the physiology and pathophysiology of the respiratory tract. The objective of our study was to determine the serum concentration of alpha CGRP (αCGRP) in cystic fibrosis (CF) that arises from mutations in the gene responsible for encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Currently, there are not many data in the literature about the role of CGRP in CF. The serum level of αCGRP was estimated using the enzyme-linked immunosorbent assay among 64 patients with CF and 31 healthy controls. The αCGRP concentration in the CF group was 62.51 ± 15.45 pg/mL, while in the control group it was 47.43 ± 8.06 pg/mL (p < 0.001). We also compared the level of αCGRP in CF patients according to the type of CFTR mutation. Homozygotes for ΔF508 had higher αCGRP levels than heterozygotes (67.9 ± 10.2 vs. 54.5 ± 18.3 pg/mL, p < 0.01). The level of this neuropeptide was statistically higher in patients with severe disease than in those with mild CF (p = 0.003) when patients were divided into three groups by spirometry results. αCGRP concentration was not correlated with age, sex, clinical parameters, and pulmonary function test results in the study participants. The results of our study suggest a significant increase in the concentration of αCGRP in the serum of patients with CF compared to the control group. This observation opens interesting possibilities for understanding the role of αCGRP in the context of CF pathophysiology.

Safety and Tolerability of Combining CGRP Monoclonal Antibodies with Gepants in Patients with Migraine: A Retrospective Study

INTRODUCTION

The introduction of clacitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) has revolutionized the treatment of migraines. In clinical practice gepants might be considered as a valid option to treat acute attacks in patients with migraine who are treated with mAbs. However, the safety and tolerability of such a combination is not well addressed in the real-world setting. We designed this study to evaluate the safety and tolerability of combining CGRP mAbs with gepants in the management of migraines.

METHODS

This was a retrospective, real-world, exploratory study. The participants included within the study were adult (≥ 18 years) patients diagnosed with migraine. Screening for patients who were treated with at least one GCRP mAbs was done. Data was collected from one site, the American Center for Psychiatry and Neurology, Abu Dhabi UAE. A total of 516 patients taking CGRP mAbs were identified. Extracted data from patients' electronic medical records included patient demographics, migraine characteristics, prescribed treatments, and adverse events (AEs). The tolerability and safety of the combination therapy was evaluated on the basis of documented AEs.

RESULTS

Among the identified 516 patients, 234 were administered gepants in addition to the CRGP mAb (215, rimegepant; 19, ubrogepant). Eleven of the 234 patients switched from rimegepant to urogepant as a result of lack of efficacy; one patient switched from urogepant to zolmitriptan because of the lack of insurance coverage of the former medication. Among all the patients included in this study, three AEs were documented. These AEs were generally mild and transient and hence did not lead to discontinuation of treatment. Moreover, 42 of the 234 (17.9%) patients were switched from one class of CGRP mAbs to another at least once while continuing treatment with the assigned gepants.

CONCLUSION

The findings of this study demonstrate that combining CGRP mAbs with gepants is a safe and well-tolerated treatment approach for migraine. Future studies are warranted to further validate these findings and explore long-term outcomes.

Cluster headache: an update on clinical features, epidemiology, pathophysiology, diagnosis, and treatment

Cluster headache (CH) is one of the worst primary headaches that remain underdiagnosed and inappropriately treated. There are recent advances in the understanding of this disease and available treatments. This paper aims to review CH's recent clinical and pathophysiological findings, diagnosis, and treatment. We performed a narrative literature review on the socio-demographics, clinical presentations, pathophysiological findings, and diagnosis and treatment of CH. CH affects 0.1% of the population with an incidence of 2.07-9.8/100,00 person-years-habitants, a mean prevalence of 53/100,000 inhabitants (3-150/100,000 inhabitants). The male-to-female ratio remains inconclusive, as the ratio of 4.3:1 has recently been modified to 1.3-2.6, possibly due to previous misdiagnosis in women. Episodic presentation is the most frequent (80%). It is a polygenetic and multifactorial entity that involves dysfunction of the trigeminovascular system, the trigeminal autonomic reflex, and the hypothalamic networks. An MRI of the brain is mandatory to exclude secondary etiologies. There are effective and safe pharmacological treatments oxygen, sphenopalatine, and great occipital nerve block, with the heterogeneity of clinical trial designs for patients with CH divided into acute, transitional, or bridge treatment (prednisone) and preventive interventions. In conclusion, CH remains underdiagnosed, mainly due to a lack of awareness within the medical community, frequently causing a long delay in reaching a final diagnosis. Recent advances in understanding the principal risk factors and underlying pathophysiology exist. There are new therapeutic possibilities that are effective for CH. Indeed, a better understanding of this challenging pathology will continue to be a subject of research, study, and discoveries in its diagnostic and therapeutic approach.

Evaluating physiochemical properties of FDA-approved orally administered drugs

INTRODUCTION

Analyses of orally administered FDA-approved drugs from 1990 to 1993 enabled the identification of a set of physiochemical properties known as Lipinski's Rule of Five (Ro5). The original Ro5 and extended versions still remain the reference criteria for drug development programs. Since many bioactive compounds do not conform to the Ro5, we validated the relevance of and adherence to these rulesets in a contemporary cohort of FDA-approved drugs.

AREAS COVERED

The authors noted that a significant proportion of FDA-approved orally administered parent compounds from 2011 to 2022 deviate from the original Ro5 criteria (~38%) or the Ro5 with extensions (~53%). They then evaluated if a contemporary Ro5 criteria (cRo5) could be devised to better predict oral bioavailability. Furthermore, they discuss many case studies showcasing the need for and benefit of increasing the size of certain compounds and cover several evolving strategies for improving oral bioavailability.

EXPERT OPINION

Despite many revisions to the Ro5, the authors find that no single proposed physiochemical rule has universal concordance with absolute oral bioavailability. Innovations in drug delivery and formulation have dramatically expanded the range of physicochemical properties and the chemical diversity for oral administration.

The role of calcitonin gene-related peptide and substance P in the pathogenesis of dialysis headache

AIM

The present study aims to establish the role of serum CGRP and SP levels in the disease pathophysiology in patients with dialysis headache not accompanied by primary or secondary headaches, and also whether there is a correlation between these vasoactive peptides and the severity of headache.

METHOD

This study was designed as prospective and multicenter. A total of 30 dialysis headache patients and 30 patients without headache as the control group in the Nephrology outpatient clinics which implement similar dialysis procedures were included in the study. Blood samples were taken from all the patients before hemodialysis, and post-hemodialysis samples were collected. CGRP and SP contents in serum samples were measured using the ELISA method with detection kits.

RESULTS

A total of 60 patients were included in the study with 17 female and 13 male patients in the dialysis headache group and 18 female and 12 male patients in the control group, and there were no significant differences in sex and age between the groups. CGRP levels in the headache group were found to be significantly higher compared with the control group both before and after hemodialysis. Furthermore, pre-hemodialysis CGRP levels were significantly higher than post-hemodialysis CGRP levels in both the headache and control groups. Serum SP levels in the headache group were found to be higher compared with the control group both before and after hemodialysis, there was no significant difference between the groups. Even though SP levels in both groups decreased after hemodialysis, there was again no significant difference between the groups. No correlation was found between the patients' severity of headache and serum CGRP and SP levels.

CONCLUSION

This study concludes that CGRP and SP, even though the latter is not statistically significant, play a role in the pathophysiology of the dialysis headache, and further studies with a larger and more specific patient population may reveal the relationship between the neuropeptides and dialysis headache more clearly.

What to do with non-responders to CGRP(r) monoclonal antibodies: switch to another or move to gepants?

In this editorial we aim to provide potential therapeutic options in patients who do not benefit from treatment with CGRP(r) monoclonal antibodies. Based on current real-life studies and analysis of practical and economic aspects, we will analyze the potential benefits of changing CGRP-targeted treatment.

Efficacy and safety of eptinezumab for migraine: A systematic review and meta-analysis

Background

Calcitonin gene-related peptides (CGRP) have been considered a new effective means to prevent and treat migraine. Eptinezumab is a new class of CGRP antagonists that has been ratified for clinical treatment. The purpose of this systematic review was to assess and contrast the therapeutic effect and safety of eptinezumab in the management of migraine in comparison with a placebo.

Materials and Methods

We systematically searched PubMed, Embase, Cochrane Library, and the US National Institutes of Health Clinical Trials Registry from the earliest date to February 16, 2023, for randomized controlled trials (RCTs). The mean difference (MD) and risk ratio (RR) were chosen to assess clinical indicators.

Results

In total, there were 2, 739 patients in four RCTs, who were ultimately included. Our summarized results showed that eptinezumab had better healing efficacy compared to placebo with respect to monthly migraine days (MD = -1.56, 95% confidence interval [CI]: -2.32, -0.79, P < 0.001), improving ≥75% migraine responder rate (RR = 1.80, 95% CI: 1.40, 2.33, P < 0.001), ≥50% migraine responder rate (RR = 1.46, 95% CI: 1.33, 1.61, P < 0.001), and 100% migraine responder rate (RR = 2.41, 95% CI: 1.08, 5.38, P < 0.001). Furthermore, compared with placebo, there was no significant increase for treatment-related adverse events (RR = 1.01, 95% CI 0.94, 1.10, P = 0.71) and serious AEs (RR = 0.93, 95% CI 0.46, 1.90, P = 0.84). It was found that all dosages except for 10 mg had significant efficacy compared with placebo, especially 300 mg (P < 0.001).

Conclusion

Eptinezumab has good healing efficacy and insignificant adverse effects in treating migraine, particularly the dosage of 300 mg.

Garlic prevents the oxidizing and inflammatory effects of sepsis induced by bacterial lipopolysaccharide at the systemic and aortic level in the rat. Role of trpv1

Garlic (Allium sativum) possesses healing properties for diseases like systemic arterial hypertension, cancer and diabetes, among others. Its main component, allicin, binds to the Transient Receptor Potential Vanilloid Type 1 (TRPV1). In this study, we investigated TRPV1's involvement in the regulation of various molecules at the systemic and aortic levels in Wistar rats treated with bacterial lipopolysaccharide (LPS) and garlic to activate the receptor. The experimental groups were as follows: 1) Control, 2) LPS, 3) Garlic, and 4) LPS + Garlic. Using Uv-visible spectrophotometry and capillary zone electrophoresis, we measured the levels of nitric oxide (NO), biopterins BH2 and BH4, total antioxidant capacity (TAC) and oxidizing capacity (OXCA). We also analyzed molecules related to vascular homeostasis such as angiotensin Ang 1-7 and Ang II, as well as endothelin ET-1. In addition, we assessed the inflammatory response by determining the levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and galectin-3 (GTN-3). For cell damage assessment, we measured levels of malondialdehyde (MDA), malonate (MTO) and 8-hydroxy-2-deoxyguanosine (8HO2dG). The results showed that LPS influenced the NO pathway at both systemic and aortic levels by increasing OXCA and reducing TAC. It also disrupted vascular homeostasis by increasing Ang-II and ET-1, while decreasing Ang1-7 levels. IL-6, TNFα, GTN-3, as well as MDA, MTO, and 8HO2dG were significantly elevated compared to the control group. The expression of iNOS was increased, but TRPV1 remained unaffected by LPS. However, garlic treatment effectively mitigated the effects of LPS and significantly increased TRPV1 expression. Furthermore, LPS caused a significant decrease in calcitonin gene-related peptide (CGRP) in the aorta, which was counteracted by garlic treatment. Overall, TRPV1 appears to play a crucial role in regulating oxidative stress and the molecules involved in damage and inflammation induced by LPS. Thus, studying TRPV1, CGRP, and allicin may offer a potential strategy for mitigating inflammatory and oxidative stress in sepsis.

[WITHDRAWN] Neuron-dependent tuft cell expansion initiates sinonasal allergic Type 2 inflammation

The authors have withdrawn this manuscript owing to inaccuracies in the calculation of tuft cell numbers and errors in the selection of immunofluorescence images used to support our claims. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Management of cluster headache: Treatments and their mechanisms

BACKGROUND

The management of cluster headache is similar to that of other primary headache disorders and can be broadly divided into acute and preventive treatments. Acute treatments for cluster headache are primarily delivered via rapid, non-oral routes (such as inhalation, nasal, or subcutaneous) while preventives include a variety of unrelated treatments such as corticosteroids, verapamil, and galcanezumab. Neuromodulation is becoming an increasingly popular option, both non-invasively such as vagus nerve stimulation when medical treatment is contraindicated or side effects are intolerable, and invasively such as occipital nerve stimulation when medical treatment is ineffective. Clinically, this collection of treatment types provides a range of options for the informed clinician. Scientifically, this collection provides important insights into disease mechanisms.

METHODS

Two authors performed independent narrative reviews of the literature on guideline recommendations, clinical trials, real-world data, and mechanistic studies.

RESULTS

Cluster headache is treated with acute treatments, bridge treatments, and preventive treatments. Common first-line treatments include subcutaneous sumatriptan and high-flow oxygen as acute treatments, corticosteroids (oral or suboccipital injections) as bridge treatments, and verapamil as a preventive treatment. Some newer acute (non-invasive vagus nerve stimulation) and preventive (galcanezumab) treatments have excellent clinical trial data for episodic cluster headache, while other newer treatments (occipital nerve stimulation) have been specifically tested in treatment-refractory chronic cluster headache. Most treatments are suspected to act on the trigeminovascular system, the autonomic system, or the hypothalamus.

CONCLUSIONS

The first-line treatments have not changed in recent years, but new treatments have provided additional options for patients.

Safety and Efficacy of Zavegepant in Treating Migraine: A Systematic Review

Drugs that act on the calcitonin gene-related peptide (CGRP) pathway herald the dawn of a new era in the management of migraine headaches. The blockade of CGRP alleviates neural inflammation and has been associated with reduced pain sensitization. Zavegepant is a third-generation drug and is the first intranasal CGRP antagonist to be developed. This systematic review aims to assess the safety, efficacy, pharmacokinetics, and tolerability of Zavegepant as an abortive treatment for migraine. Studies that assessed the safety, tolerability, and efficacy of Zavegepant for migraine were identified through a systematic literature review of PubMed, Clinicaltrials.gov, and Cochrane databases in April 2023. Our systematic review yielded a total of six studies that fit our inclusion criteria. Of these, data from only two randomized control trials (RCTs) was homogenous; hence, forest plots of results pooled from the included studies were not reported. The included studies showed that Zavegepant is an efficacious and well-tolerated abortive treatment modality for episodic migraine in adult patients. Zavegepant showed safety and efficacy in migraine treatment according to various parameters throughout the six included studies. These parameters include adverse events, pharmacokinetic properties, CGRP inhibition, effect on blood pressure/electrocardiogram, pain freedom, and freedom from most bothersome symptoms.

Calcitonin gene-related peptide and its receptor plays important role in nociceptive regulation in the arcuate nucleus of hypothalamus of rats with inflammatory pain

The present study has explored the role of calcitonin gene-related peptide (CGRP) and its receptor in inflammatory pain modulation in arcuate nucleus of hypothalamus (ARC). Our study demonstrated that intra-ARC injection of CGRP induced antinociceptive effects to naïve rats and rats with inflammatory pain, the effect could be inhibited by the selective CGRP receptor antagonist CGRP8-37. Interestingly, the CGRP-induced antinociception effect was decreased in rats with inflammatory pain compared to naïve rats. Similarly, we found that calcitonin receptor like receptor (CLR), a main component of CGRP receptor, had a low decreased expression levels in the ARC regions of rats with inflammatory pain. The CGRP-induced antinociceptive effect was significantly impaired after reducing CLR expression by intra-ARC administration of CLR targeted siRNA. These findings demonstrated that CGRP might play a crucial role in nociceptive modulation in the ARC during inflammatory pain, which was mediated by CGRP receptor in the ARC. This study shed light upon CGRP and its receptor interaction might be valuable strategies for the alleviation of inflammatory pain.

Evaluating the efficacy of CGRP mAbs and gepants for the preventive treatment of migraine: A systematic review and network meta-analysis of phase 3 randomised controlled trials

BACKGROUND

Several novel treatments targeting the calcitonin gene-related peptide pathway have been developed for migraine. We evaluated the efficacy of these medications, including atogepant, rimegepant, erenumab, eptinezumab, fremanezumab, and galcanezumab, for the prevention of migraine via network meta-analysis.

METHODS

Databases, including MEDLINE via PubMed, EMBASE, and Cochrane central, were systematically reviewed, and all eligible phase 3 randomised controlled trials were included.

RESULTS

Nineteen studies (n = 14,584 participants) were included. Studies included episodic (n = 11) and chronic (n = 4) migraine or both (n = 4). All interventions, except for eptinzumab 30 mg, significantly reduced mean monthly migraine days compared to placebo. All medications had a higher ≥50% responder rate than placebo and results were statistically significant in those with the subcutaneous or intravenous route of administrations, but not with the oral one. All medications significantly reduced mean monthly headache days, although no data for this outcome was available for rimegepant, and mean monthly acute medication days, with no data for eptinezumab.

CONCLUSION

The results show that medications targeting calcitonin gene-related peptide were effective in preventing migraine compared to placebo. Considering limitations of single studies, different populations such as episodic and chronic migraine, and the absence of head-to-head trials, all novel treatments decreased mean monthly migraine and headache days, and showed higher 50%, 75% and 100% responder rates than placebo.Trial registration: PROSPERO registration: CRD42022310579.

Costs and Utilization of New-to-Market Neurologic Medications

BACKGROUND AND OBJECTIVES

The objective of this study was to compare the utilization and costs (total and out-of-pocket) of new-to-market neurologic medications with existing guideline-supported neurologic medications over time.

METHODS

We used a healthcare pharmaceutical claims database (from 2001 to 2019) to identify patients with both a diagnosis of 1 of 11 separate neurologic conditions and either a new-to-market medication or an existing guideline-supported medication for that condition. Neurologic conditions included orthostatic hypotension, spinal muscular atrophy, Duchenne disease, Parkinson disease, multiple sclerosis, amyotrophic lateral sclerosis, myasthenia gravis, Huntington disease, tardive dyskinesia, transthyretin amyloidosis, and migraine. New-to-market medications were defined as all neurologic medications approved by the US Food and Drug Administration (FDA) between 2014 and 2018. In each year, we determined the median out-of-pocket and standardized total costs for a 30-day supply of each medication. We also measured the proportion of patients receiving new-to-market medications compared with all medications specific for the relevant condition.

RESULTS

We found that the utilization of most new-to-market medications was small (<20% in all but 1 condition), compared with existing, guideline-supported medications. The out-of-pocket and standardized total costs were substantially larger for new-to-market medications. The median (25th percentile, 75th percentile) out-of-pocket costs for a 30-day supply in 2019 were largest for edaravone ($712.8 [$59.8-$802.0]) and eculizumab ($91.1 [$3.0-$3,216.4]). For new-to-market medications, the distribution of out-of-pocket costs was highly variable and the trends over time were unpredictable compared with existing guideline-supported medications.

DISCUSSION

Despite the increasing number of FDA-approved neurologic medications, utilization of newly approved medications in the privately insured population remains small. Given the high costs and similar efficacy for most of the new medications, limited utilization may be appropriate. However, for new medications with greater efficacy, future studies are needed to determine whether high costs are a barrier to utilization.

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.

CGRP-Targeted Therapy for Episodic and Chronic Cluster Headache

PURPOSE OF REVIEW

Chronic cluster headache (CH) substantially affects patients' quality of life, and treatment remains challenging. The current article reviewed controlled studies for new treatment options targeting calcitonin gene-related peptide (CGRP) or its receptors in CH and discussed the current gaps and future directions for the treatment of chronic CH.

RECENT FINDINGS

Two anti-CGRP monoclonal antibodies (i.e., galcanezumab and fremanezumab) completed randomized-control trials for efficacy for the preventive treatment of episodic and chronic CH. Galcanezumab was effective for preventing episodic CH but not chronic CH. Fremanezumab was ineffective in preventing episodic and chronic CH. Studies for other anti-CGRP monoclonal antibodies and CGRP antagonists are still pending for results. There are no randomized controlled trials for CGRP-targeted therapies that showed efficacy for chronic CH prevention. The different responses to galcanezumab between episodic and chronic CH may be due to the study design, i.e., the allowance of concomitant preventive therapies in the chronic CH study but not in the episodic CH study. Another reason for the discrepancies is the different roles and sensitivity of CGRP in chronic CH.

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.

A Review of Current Perspectives on Facial Presentations of Primary Headaches

Orofacial pain (OFP) has recently been classified and subdivided into a number of groups, similar to headache disorders in the International Classification of Headache Disorders (ICHD). A novel group of OFP has been established whose major feature is that they resemble primary headache disorders occurring in the V2 or V3 dermatomes. These follow the clinical criteria and associated symptoms of the eponymous headache syndromes. Following the recent International Classification of Orofacial Pain (ICOP), three types are differentiated: Headache which spread into the face (type 1), facial pain which replaced headache but maintained the same characteristics and associated symptoms of the former headache (type 2), and de-novo orofacial pain that resembles primary headache types without any involvement of the ophthalmic trigeminal branch (type 3). The epidemiology is unclear: type 1 and 2 are not exactly common, they certainly exist in a notable proportion of headache patients, whereas type 3 may be rather rare. Since effective treatment options are available, it is important for clinicians to recognize such syndromes early to avoid misdiagnosis and unnecessary treatment, which most of these patients still experience. This review gives an up-to-date summary of diagnosis, pathophysiology and treatment of attack-like non-dental facial pain disorders.

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

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

The Arrival of Anti-CGRP Monoclonal Antibodies in Migraine

Remarkable advancements have been made in the field of migraine pathophysiology and pharmacotherapy over the past decade. Understanding the molecular mechanism of calcitonin gene-related peptide (CGRP) has led to the discovery of a novel class of drugs, CGRP functional blocking monoclonal antibodies (mAbs), for migraine prevention. CGRP is a neuropeptide inherently involved in migraine physiology where its receptors are found dispersed throughout the central and peripheral nervous systems. CGRP-targeted mAbs are effective in the preventive treatment of both chronic and episodic migraine. The advantages of mAbs over oral migraine preventives are numerous. Favorable attributes of the mAbs include high affinity and selectivity for CGRP molecular targets, long-circulating plasma half-lives, and limited risk for nonspecific hepatic and renal toxicity. This pharmacological profile leads to fewer off-target (side) effects and drug-drug interactions rendering mAbs an attractive alternative to traditional small molecule therapies, especially for the preventive treatment of migraine. MAbs display minimal drug interaction thus are excellent for patients prescribed with multiple medications. However, the long-term safety of CGRP blockade is incompletely known, and CGRP mAbs use should be avoided during pregnancy. CGRP mAbs represent a radical shift in preventing chronic and episodic migraine.

Role of Atogepant in the Treatment of Episodic Migraines: Clinical Perspectives and Considerations

Advances in molecular biology and neuroscience have led to the discovery of calcitonin gene-related peptide (CGRP), a 37 amino-acid neuropeptide that plays a critical role in the pathogenesis of migraine. CGRP receptor antagonist, also known as gepant, is an oral medication that inhibits the CGRP-related nociceptive signaling pathway. To date, three gepants are approved by the FDA for migraine treatment. Atogepant is a 2nd-generation gepant that non-competitively antagonizes CGRP receptors inhibiting neurogenic inflammation and pain sensitization. With its long half-life and minimal cardiovascular or liver toxicity, it is the first in its class approved primarily for migraine prevention. This article will discuss the evidence, safety, and rationale of atogepant for use in clinical practice.

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.

A Female-Specific Role for Calcitonin Gene-Related Peptide (CGRP) in Rodent Pain Models

We aimed to investigate a sexually dimorphic role of calcitonin gene-related peptide (CGRP) in rodent models of pain. Based on findings in migraine where CGRP has a preferential pain-promoting effect in female rodents, we hypothesized that CGRP antagonists and antibodies would attenuate pain sensitization more efficaciously in female than male mice and rats. In hyperalgesic priming induced by activation of interleukin 6 signaling, CGRP receptor antagonists olcegepant and CGRP_8-37 both given intrathecally, blocked, and reversed hyperalgesic priming only in females. A monoclonal antibody against CGRP, given systemically, blocked priming specifically in female rodents but failed to reverse it. In the spared nerve injury model, there was a transient effect of both CGRP antagonists, given intrathecally, on mechanical hypersensitivity in female mice only. Consistent with these findings, intrathecally applied CGRP caused a long-lasting, dose-dependent mechanical hypersensitivity in female mice but more transient effects in males. This CGRP-induced mechanical hypersensitivity was reversed by olcegepant and the KCC2 enhancer CLP257, suggesting a role for anionic plasticity in the dorsal horn in the pain-promoting effects of CGRP in females. In spinal dorsal horn slices, CGRP shifted GABA_A reversal potentials to significantly more positive values, but, again, only in female mice. Therefore, CGRP may regulate KCC2 expression and/or activity downstream of CGRP receptors specifically in females. However, KCC2 hypofunction promotes mechanical pain hypersensitivity in both sexes because CLP257 alleviated hyperalgesic priming in male and female mice. We conclude that CGRP promotes pain plasticity in female rodents but has a limited impact in males.SIGNIFICANCE STATEMENT The majority of patients impacted by chronic pain are women. Mechanistic studies in rodents are creating a clear picture that molecular events promoting chronic pain are different in male and female animals. We sought to build on evidence showing that CGRP is a more potent and efficacious promoter of headache in female than in male rodents. To test this, we used hyperalgesic priming and the spared nerve injury neuropathic pain models in mice. Our findings show a clear sex dimorphism wherein CGRP promotes pain in female but not male mice, likely via a centrally mediated mechanism of action. Our work suggests that CGRP receptor antagonists could be tested for efficacy in women for a broader variety of pain conditions.

Synthesis of pyrimidine-containing alkaloids

This review deals with the synthesis of naturally occurring alkaloids containing partially or completely saturated pyrimidine nuclei. The interest in these compounds is associated with their structural diversity, high biological activity and toxicity. The review is divided into four parts, each of which describes a number of synthetic methodologies toward structurally different naturally occurring alkaloids containing saturated cyclic six-membered amidine, guanidine, aminal and urea (thiourea) moieties, respectively. The development of various synthetic strategies for the preparation of these compounds has remarkably increased during the past few decades. This is primarily due to the fact that some of these compounds are isolated only in limited quantities, which makes it practically impossible to study their full structural characteristics and biological activity.

Innovations and advances in modelling and measuring pain in animals

Best practices in preclinical algesiometry (pain behaviour testing) have shifted over the past decade as a result of technological advancements, the continued dearth of translational progress and the emphasis that funding institutions and journals have placed on rigour and reproducibility. Here we describe the changing trends in research methods by analysing the methods reported in preclinical pain publications from the past 40 years, with a focus on the last 5 years. We also discuss how the status quo may be hampering translational success. This discussion is centred on four fundamental decisions that apply to every pain behaviour experiment: choice of subject (model organism), choice of assay (pain-inducing injury), laboratory environment and choice of outcome measures. Finally, we discuss how human tissues, which are increasingly accessible, can be used to validate the translatability of targets and mechanisms identified in animal pain models.

The efficacy and safety of atogepant for the prophylactic treatment of migraine: evidence from randomized controlled trials

BACKGROUND

Migraine is a common neurovascular disorder that has a severe impact on the individual daily life. Atogepant (AGN-241689) is an orally ingested, small-molecule drugs belonging to calcitonin gene-related peptide receptor antagonist, which has been initiated for the prophylactic treatment of migraine. However, there is no comprehensive literature to study the efficacy and safety of atogepant for the treatment of migraine. In this article, we present a meta-analysis of the available studies.

METHODS

MEDLINE, Embase, Cochrane Library and ClinicalTrials.gov were searched before October 20, 2021 for any relevant literature. Eventually, three randomized clinical trials (RCTs) with 2,466 patients were included in our study.

RESULTS

We pooled 2,466 patients from 3 RCTs and primary outcome was mean monthly migraine days, the secondary endpoints were monthly headache days, acute medication use days per month and ≥ 50% reduction in monthly migraine days, baseline to end of trials. It was found that atogepant (10 mg, 30 mg, 60 mg once a day) led to a significant reduction in monthly migraine days (P < 0.00001, P < 0.00001, P = 0.007), monthly headache days (P < 0.00001, P < 0.00001, P = 0.001), and monthly medication use days (P < 0.00001, P < 0.00001, P = 0.0001), and an increase in the proportion of people with ≥ 50% reduction in monthly migraine days (P = 0.0008, P = 0.02, P = 0.04) in comparison with placebo. Moreover, there were no significant differences (P > 0.05) in outcomes of adverse events between atogepant and placebo.

CONCLUSIONS

Atogepant has shown good efficacy and safety in the prophylactic treatment of migraine, and further studies are expected.

The eptinezumab:CGRP complex structure - the role of conformational changes in binding stabilization

To further elucidate the mechanism of action and binding properties of eptinezumab to calcitonin gene-related peptide (CGRP), X-ray crystallography, computational alanine scanning, and molecular dynamics were used. X-ray diffraction data were collected to determine the three-dimensional structures of the unbound eptinezumab antigen-binding fragment (Fab) and the Fab:CGRP complex. Molecular dynamics simulations were performed to analyze the transition between uncomplexed and complex states. The amidated C-terminus of CGRP was shown to bind in a pocket formed by the Fab heavy and light chains. There was extensive contact between all six complementarity-determining regions (CDRs; composed of light-chain [L1, L2, and L3] and heavy-chain [H1, H2, H3]) of eptinezumab and CGRP. The complex demonstrated a high ligand-binding surface area dominated by aromatic residues. CDR L3 contains a disulfide bond that stabilizes the loop, contributes surface area to the binding pocket, and provides van der Waals contacts. Comparison of the uncomplexed and complex structures revealed motion near the binding cleft. The CDR loops H2 and H3 were displaced ~1.4–2.0 Å and residue H-Tyr33 changed conformation, creating a ‘latch-and-lock’ mechanism for binding CGRP and preventing dissociation. Computational alanine scanning of CGRP identified energetic ‘hot spots’ that contribute to binding energy; mutating these positions to residues in homologous neuropeptides resulted in unfavorable binding energies. The attributes of the Fab region and the conformational changes that occur in eptinezumab during binding to CGRP contribute to the specificity, durability, and strength of the interaction, and likely underlie the rapid and sustained migraine preventive effect observed in clinical studies.

Calcitonin gene-related peptide and brain-derived serotonin are related to bone loss in ovariectomized rats

OBJECTIVES

Postmenopausal osteoporosis (PMO) and osteoporotic fracture seriously impair human health in developed countries. The present study aims to explore whether sensory nerves, calcitonin gene-related peptide (CGRP), and brain-derived serotonin are related to bone loss in ovariectomized (OVX) rats.

METHODS

Female rats were grouped into the ovariectomized (OVX) and sham surgery (SHAM) groups. Immunocytochemistry, western blotting, and qPCR were performed to detect CGRP expression in the femurs. The expression levels of serotonin and CGRP in the spinal cord and brainstem were estimated using western blotting, immunofluorescence, and qPCR. ELISA was used to evaluate the serum biomarkers of bone formation and resorption. Bone mineral density was measured using dual-energy X-ray (DXA) analysis. Femur microstructure was imaged by Micro CT. P values less than 0.05 were considered statistically significant.

RESULTS

ELISA showed that serum bone alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRAP), β-crosslaps, and β-ctx were increased in the OVX group. In the OVX group, in vivo bone mineral density, trabecular bone mineral density, bone volume fraction (BV/TV), and trabecular number (Tb. N) were significantly decreased, while trabecular spacing (Tb. Sp) and trabecular bone pattern factor (Tb. Pf) were markedly increased. In the OVX group, the expression levels of CGRP of the femur were significantly downregulated. In contrast, CGRP and serotonin expression was increased in the spinal cord of the OVX group. Serotonin expression was increased in the brainstem, brainstem nucleus raphe magnus (RMG), and nucleus raphe dorsalis (DRN).

CONCLUSION

Our results indicated that the activation of osteoclast triggered the release of CGRP from nociceptive sensory nerve fibers and transmitted this painful stimulus to the dorsal horn of the spinal cord to release increased CGRP. The descending serotonergic inhibitory system was activated by increased CGRP levels of the spinal cord and promoted serotonin release in the brainstem RMG, DRN, and the spinal cord, contributing to the decreased CGRP level in bone tissue, which revealed a novel mechanism of bone loss in PMO.

Macrophage as a Peripheral Pain Regulator

A neuroimmune crosstalk is involved in somatic and visceral pathological pain including inflammatory and neuropathic components. Apart from microglia essential for spinal and supraspinal pain processing, the interaction of bone marrow-derived infiltrating macrophages and/or tissue-resident macrophages with the primary afferent neurons regulates pain signals in the peripheral tissue. Recent studies have uncovered previously unknown characteristics of tissue-resident macrophages, such as their origins and association with regulation of pain signals. Peripheral nerve macrophages and intestinal resident macrophages, in addition to adult monocyte-derived infiltrating macrophages, secrete a variety of mediators, such as tumor necrosis factor-α, interleukin (IL)-1β, IL-6, high mobility group box 1 and bone morphogenic protein 2 (BMP2), that regulate the excitability of the primary afferents. Neuron-derived mediators including neuropeptides, ATP and macrophage-colony stimulating factor regulate the activity or polarization of diverse macrophages. Thus, macrophages have multitasks in homeostatic conditions and participate in somatic and visceral pathological pain by interacting with neurons.

Proinflammatory and bone protective role of calcitonin gene-related peptide alpha in collagen antibody-induced arthritis

OBJECTIVES

Calcitonin gene-related peptide alpha (αCGRP) represents an immunomodulatory neuropeptide implicated in pain perception. αCGRP also functions as a critical regulator of bone formation and is overexpressed in patients with rheumatoid arthritis (RA). In the present study, we investigated the role of αCGRP in experimental RA regarding joint inflammation and bone remodelling.

METHODS

Collagen II-antibody-induced arthritis (CAIA) was induced in wild type (WT) and αCGRP-deficient (αCGRP-/-) mice. Animals were monitored over 10 and 48 days with daily assessments of the semiquantitative arthritis score and grip strength test. Joint inflammation, cartilage degradation and bone erosions were assessed by histology, gene expression analysis and µCT.

RESULTS

CAIA was accompanied by an overexpression of αCGRP in WT joints. αCGRP-/- mice displayed reduced arthritic inflammation and cartilage degradation. Congruently, the expression of TNF-α, IL-1β, CD80 and MMP13 was induced in WT, but not αCGRP-/- animals. WT mice displayed an increased bone turnover during the acute inflammatory phase, which was not the case in αCGRP-/- mice. Interestingly, WT mice displayed a full recovery from the inflammatory bone disease, whereas αCGRP-/- mice exhibited substantial bone loss over time.

CONCLUSION

This study demonstrates a proinflammatory and bone protective role of αCGRP in CAIA. Our data indicate that αCGRP not only enhances joint inflammation, but also controls bone remodelling as part of arthritis resolution. As novel αCGRP inhibitors are currently introduced clinically for the treatment of migraine, their potential impact on RA progression warrants further clinical investigation.

Migraine pharmacology and brain ischemia

Introduction: The aim of this review article was to analyze in details the mechanism of drugs’ effects in the treatment and prevention of a migraine attack, as well as to discuss the hypotheses of migraine pathogenesis.

Migraine attack treatment agents: The main agents for migraine attack treatment have an anti-nociceptive activity.

Agents for migraine preventive treatment: β-blocker propranolol also has anti-serotonin and analgesic activities, and most drugs used for the prophylactic treatment of migraine have a vasodilating activity.

Vascular hypothesis of migraine pathogenesis: Despite numerous studies that have expanded our understanding of migraine pathogenesis, the importance of the vascular component in the pathogenesis of this disease has not questioned yet.

Neurogenic hypotheses of cortical spreading depression: It is necessary to take into account the points of this hypothesis in the context of the pathophysiology of migraine.

Neurochemical serotonin hypotheses of migraine pathogenesis: Serotonin plays an important role in the pathogenesis of migraine.

Trigemino-vascular hypotheses of migraine pathogenesis: The trigemino-vascular hypothesis claims to solve the problem of migraine pain.

Migraine and ischemic brain damage: Migraine is a risk factor for ischemic stroke and cognitive disorders.

Search for the new anti-ischemic anti-migraine preparations: A methodology for the search for new anti-ischemic anti-serotonin drugs for the treatment of migraine is proposed.

Conclusion: Belonging of a drug to one or another pharmacological group does not always correspond to its therapeutic effect on the pathogenetic processes of migraine. Migraine with its variety of forms cannot fit only one of the proposed hypotheses on the pathogenesis of this disease.

Graphical abstract:

PEARL study protocol: a real-world study of fremanezumab effectiveness in patients with chronic or episodic migraine

Fremanezumab is a humanized monoclonal antibody (IgG2Δa) that selectively targets calcitonin gene-related peptide and is approved in Europe for migraine prevention in adults with ≥4 migraine days/month. The Pan-European Real Life (PEARL) study is a 24-month, prospective, observational study of fremanezumab in chronic or episodic migraine. End points include proportion of patients with ≥50% reduction in monthly migraine days during 6 months of treatment (primary); changes in monthly migraine days, disability scores and acute headache medication use; adherence and persistence; and effectiveness in patients switching from another calcitonin gene-related peptide pathway-targeting monoclonal antibody. PEARL is being conducted in approximately 100 centers in 11 European countries (estimated n = 1100). PEARL will generate important real-world data on effectiveness of fremanezumab and treatment patterns in patients with chronic migraine or episodic migraine.

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

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

Gene expression changes contribute to stemness and therapy resistance of relapsed acute myeloid leukemia: roles of SOCS2, CALCRL, MTSS1, and KDM6A

Relapse is associated with therapy resistance and is a major cause of death in acute myeloid leukemia (AML). It is thought to result from the accretion of therapy-refractory leukemic stem cells. Genetic and transcriptional changes that are recurrently gained at relapse are likely to contribute to the increased stemness and decreased therapy responsiveness at this disease stage. Despite the recent approval of several targeted drugs, chemotherapy with cytosine arabinoside and anthracyclines is still the mainstay of AML therapy. Accordingly, a number of studies have investigated genetic and gene expression changes between diagnosis and relapse of patients subjected to such treatment. Genetic alterations recurrently acquired at relapse were identified, but were restricted to small proportions of patients, and their functional characterization is still largely pending. In contrast, the expression of a substantial number of genes was altered consistently between diagnosis and recurrence of AML. Recent studies corroborated the roles of the upregulation of SOCS2 and CALCRL and of the downregulation of MTSS1 and KDM6A in therapy resistance and/or stemness of AML. These findings spur the assumption that functional investigations of genes consistently altered at recurrence of AML have the potential to promote the development of novel targeted drugs that may help to improve the outcome of this currently often fatal disease.

Ubrogepant in the Acute Management of Migraine: A Narrative Review

Ubrogepant is a small-molecule calcitonin gene-related peptide (CGRP) receptor antagonist that received Food and Drug Administration (FDA) approval for the acute treatment of migraine with and without aura in adults. The ACHIEVE I and ACHIEVE II Phase III clinical trials showed that ubrogepant was superior to placebo for pain freedom and freedom of the most bothersome migraine-associated symptom at 2 hours after medication intake. The 52-week open label extension of the Phase III trials demonstrated safety of ubrogepant. A real-world study conducted at a tertiary headache center also confirmed the efficacy and safety of ubrogepant. Adverse event rates were higher in the real-world population. Studies are needed to evaluate its long-term efficacy and safety, especially in the setting of co-administration with other CGRP modulating therapies such as the CGRP monoclonal antibodies.

An updated brief overview on post-traumatic headache and a systematic review of the non-pharmacological interventions for its management

INTRODUCTION

Post-traumatic headache (PTH), a common type of headache secondary to traumatic brain injury (TBI) or whiplash, carries a relevant burden on patients. PTH is still an undertreated condition because of limited pharmacological treatment options. Therefore, multimodal non-pharmacologic approaches, which account for comorbidities and biopsychosocial factors, are often used in PTH patients.

AREAS COVERED

After providing a brief overview of PTH, a systematic review was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations on recently published (2015-2020) papers on non-pharmacological interventions for PTH. We also collected data on ongoing trials on this topic. Studies and results are reviewed and discussed.

EXPERT OPINION

PTH is one of the most common complications of TBI and accounts for almost 4% of symptomatic headache disorders. The most common clinical presentations of PTH are migraine-like or tension type (TTH)-like headache, neck pain, cognitive complaints, and psychological/psychiatric symptoms. Growing evidence suggests that combined pharmacological and non-pharmacological interventions, encompassing noninvasive neuromodulation, physical therapy, cognitive-behavioral treatment, and education, may be the best approaches for PTH and related comorbidities. Acute/preemptive pharmacological treatments for PTH include drugs used for migraine and TTH. When PTH management is multidisciplinary, the patient benefits most.

N/OFQ modulates orofacial pain induced by tooth movement through CGRP-dependent pathways

BACKGROUND

Nociceptin/orphanin FQ (N/OFQ) has been revealed to play bidirectional roles in orofacial pain modulation. Calcitonin gene-related peptide (CGRP) is a well-known pro-nociceptive molecule that participates in the modulation of orofacial pain. We aimed to determine the effects of N/OFQ on the modulation of orofacial pain and on the release of CGRP.

METHODS

Orofacial pain model was established by ligating springs between incisors and molars in rats for the simulation of tooth movement. The expression level of N/OFQ was determined and pain level was scored in response to orofacial pain. Both agonist and antagonist of N/OFQ receptor were administered to examine their effects on pain and the expression of CGRP in trigeminal ganglia (TG). Moreover, gene therapy based on the overexpression of N/OFQ was delivered to validate the modulatory role of N/OFQ on pain and CGRP expression.

RESULTS

Tooth movement elicited orofacial pain and an elevation in N/OFQ expression. N/OFQ exacerbated orofacial pain and upregulated CGRP expression in TG, while UFP-101 alleviated pain and downregulated CGRP expression. N/OFQ-based gene therapy was successful in overexpressing N/OFQ in TG, which resulted in pain exacerbation and elevation of CGRP expression in TG.

CONCLUSIONS

N/OFQ exacerbated orofacial pain possibly through upregulating CGRP.

A link between gastrointestinal disorders and migraine: Insights into the gut-brain connection

Background

Migraine is a complex, multifaceted, and disabling headache disease that is often complicated by gastrointestinal (GI) conditions, such as gastroparesis, functional dyspepsia, and cyclic vomiting syndrome (CVS). Functional dyspepsia and CVS are part of a spectrum of disorders newly classified as disorders of gut–brain interaction (DGBI). Gastroparesis and functional dyspepsia are both associated with delayed gastric emptying, while nausea and vomiting are prominent in CVS, which are also symptoms that commonly occur with migraine attacks. Furthermore, these gastric disorders are comorbidities frequently reported by patients with migraine. While very few studies assessing GI disorders in patients with migraine have been performed, they do demonstrate a physiological link between these conditions.

Objective

To summarize the available studies supporting a link between GI comorbidities and migraine, including historical and current scientific evidence, as well as provide evidence that symptoms of GI disorders are also observed outside of migraine attacks during the interictal period. Additionally, the importance of route of administration and formulation of migraine therapies for patients with GI symptoms will be discussed.

Methods

A literature search of PubMed for articles relating to the relationship between the gut and the brain with no restriction on the publication year was performed. Studies providing scientific support for associations of gastroparesis, functional dyspepsia, and CVS with migraine and the impact these associations may have on migraine treatment were the primary focus. This is a narrative review of identified studies.

Results

Although the association between migraine and GI disorders has received very little attention in the literature, the existing evidence suggests that they may share a common etiology. In particular, the relationship between migraine, gastric motility, and vomiting has important clinical implications in the treatment of migraine, as delayed gastric emptying and vomiting may affect oral dosing compliance, and thus, the absorption and efficacy of oral migraine treatments.

Conclusions

There is evidence of a link between migraine and GI comorbidities, including those under the DGBI classification. Many patients do not find adequate relief with oral migraine therapies, which further necessitates increased recognition of GI disorders in patients with migraine by the headache community.

Recently available and emerging therapeutic strategies for the acute and prophylactic management of cluster headache: a systematic review and expert opinion

Introduction: Although it causes a huge burden to sufferers, cluster headache (CH), remains an undertreated condition, partly due to the absence of established acute and prophylactic treatment options. New therapeutic approaches providing fast and safe relief from CH are needed. Areas covered: A systematic review was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendation on recently published (last 5 years) papers on CH treatment. The authors also collected preliminary results from ongoing trials on emerging therapeutic/preventive pharmacological and interventional approaches for CH. Studies and results are reviewed and discussed. Expert opinion: The complexity of CH pathophysiology prevents the definition of reliable acute and preventive treatments. In the real-world clinical setting, several treatments are combined to provide relief to patients and increase their quality of life. Drugs targeting neuropeptides or their receptors within the trigeminovascular network are of particular interest to prevent CH attacks. Calcitonin gene-related peptide (CGRP) blockade seems attractive and promising, but studies on anti-CGRP monoclonal antibodies indicated rather modest or even absence of a prophylactic effect. A deeper insight into CH pathophysiology, and combined approaches may lead the path to new, more effective, and personalized CH therapies.

Acupuncture vs. Pharmacological Prophylaxis of Migraine: A Systematic Review of Randomized Controlled Trials

Introduction: Migraine is a chronic paroxymal neurological disorder characterized by attacks of moderate to severe headache and reversible neurological and systemic symptoms. Treatment of migraine includes acute therapies, that aim to reduce the intensity of pain of each attack, and preventive therapies that should decrease the frequency of headache recurrence. The objective of this systematic review was to assess the efficacy and safety of acupuncture for the prophylaxis of episodic or chronic migraine in adult patients compared to pharmacological treatment.

Methods: We included randomized-controlled trials published in western languages that compared any treatment involving needle insertion (with or without manual or electrical stimulation) at acupuncture points, pain points or trigger points, with any pharmacological prophylaxis in adult (≥18 years) with chronic or episodic migraine with or without aura according to the criteria of the International Headache Society.

Results: Nine randomized trials were included encompassing 1,484 patients. At the end of intervention we found a small reduction in favor of acupuncture for the number of days with migraine per month: (SMD: −0.37; 95% CI −1.64 to −0.11), and for response rate (RR: 1.46; 95% CI 1.16–1.84). We found a moderate effect in the reduction of pain intensity in favor of acupuncture (SMD: −0.36; 95% CI −0.60 to −0.13), and a large reduction in favor of acupuncture in both the dropout rate due to any reason (RR 0.39; 95% CI 0.18 to 0.84) and the dropout rate due to adverse event (RR 0.26; 95% CI 0.09 to 0.74). Quality of evidence was moderate for all these primary outcomes. Results at longest follow-up confirmed these effects.

Conclusions: Based on moderate certainty of evidence, we conclude that acupuncture is mildly more effective and much safer than medication for the prophylaxis of migraine.

Erenumab for headaches in idiopathic intracranial hypertension: A prospective open-label evaluation

Objective

To determine the effectiveness of erenumab in treating headaches in idiopathic intracranial hypertension (IIH) in whom papilledema had resolved.

Background

Disability in IIH is predominantly driven by debilitating headaches with no evidence for the use of preventative therapies. Headache therapy in IIH is an urgent unmet need.

Methods

A prospective, open‐label study in the United Kingdom was conducted. Adult females with confirmed diagnosis of IIH now in ocular remission (papilledema resolved) with chronic headaches (≥15 days a month) and failure of ≥3 preventative medications received erenumab 4‐weekly (assessments were 3‐monthly). The primary end point was change in monthly moderate/severe headache days (MmsHD) from baseline (30‐day pretreatment period) compared to 12 months.

Results

Fifty‐five patients, mean (SD) age 35.3 (9) years and mean duration of headaches 10.4 (8.4) years with 3.7 (0.9) preventative treatment failures, were enrolled. Mean baseline MmsHD was 16.1 (4.7) and total monthly headache days (MHD) was (29) 2.3. MmsHD reduced substantially at 12 months by mean (SD) [95% CI] 10.8 (4.0) [9.5, 11.9], p < 0.001 and MHD reduced by 13.0 (9.5) [10.2, 15.7], p < 0.001. Crystal clear days (days without any head pain) increased by 13.1 (9.5) [9.6, 15.3], p < 0.001, headache severity (scale 0–10) fell by 1.3 (1.7) [0.9, 1.9], p < 0.001, and monthly analgesic days reduced by 4.3 (9.2) [1.6, 6.9], p = 0.002. All these measures had improved significantly by 3 months, with a consistent significant response to 12 months. Headache impact test‐6 score and quality of life Short Form‐36 Health Survey significantly improved at 12 months. Sensitivity analysis revealed similar results for patients with and without a prior migraine diagnosis (28/55 (52%) patients) or those with or without medication overuse (27/55 (48%) patients).

Conclusions

This study provides evidence for the effectiveness of erenumab to treat headaches in IIH patients with resolution of papilledema. It provides mechanistic insights suggesting that calcitonin gene‐related peptide is likely a modulator driving headache and a useful therapeutic target.

Emerging themes in idiopathic intracranial hypertension

PURPOSE

Idiopathic intracranial hypertension (IIH) is a rare disorder characterised by raised intracranial pressure. The underlying pathophysiology is mostly unknown and effective treatment is an unmet clinical need in this disease. This review evaluates key emerging themes regarding disease characteristics, mechanisms contributing to raised intracranial pressure and advances in potential therapeutic targets.

FINDINGS

IIH is becoming more common, with the incidence rising in parallel with the global obesity epidemic. Current medical management remains centred around weight management, which is challenging. Metabolic investigations of patients have identified specific androgen profiles in cerebrospinal fluid (CSF), which suggest an endocrine dysfunction impacting CSF secretion in IIH. Glucagon-like peptide-1 (GLP-1) and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have been found to play a role in CSF dynamics in IIH and have formed the basis of the first clinical trials looking at new treatments.

CONCLUSIONS

Identification of novel molecular targets thought to underlie IIH pathology is now being translated to clinical trials.

Galcanezumab for the Management of Migraine: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials

Introduction Migraine is a frequent neurological condition manifested by several episodes of headache. Calcitonin gene-related peptide (CGRP) has been shown to play a key role in the pathophysiology of migraine. Galcanezumab is a monoclonal antibody that binds CGRP and inhibits its action, without affecting the CGRP receptor. The aim of this study is to carry out a systematic review and meta-analysis of all randomized placebo-controlled trials that evaluated the efficacy of galcanezumab (120 mg or 240 mg) for the management of migraine. Methods We screened four databases (PubMed, SCOPUS, Embase, and Cochrane Central) from inception to October 10, 2020. Studies meeting the following criteria were included: (i) Patients: individuals with migraine, (ii) Intervention: galcanezumab at a dose of 120 mg or 240 mg, (iii) Comparator: placebo, (iv) Outcomes: prespecified efficacy and safety outcomes, and (v) Study design: randomized placebo-controlled trials. Efficacy outcomes included change in migraine headache days (MHDs), change in MHDs with acute medication use, patient global impression of severity (PGI-S) score, migraine-specific quality of life role function-restrictive domain (MSQ RF-R) score, and migraine disability assessment (MIDAS) score. Safety outcomes included frequency of injection-site pain, nasopharyngitis, and upper respiratory tract infection (URTI). Moreover, we used the Cochrane Collaboration's risk of bias tool to assess the risk of bias of the included studies. Review Manager Software, version 5.4.1, was used for statistical analysis. Mean difference and risk ratio with 95% confidence interval were used to analyze continuous and dichotomous outcomes, respectively. We used the fixed-effects and random-effects models to analyze homogeneous and heterogeneous data, respectively. Results A total of six studies comprising 4,023 patients were included in this systematic review and meta-analysis. When compared to placebo, both doses of galcanezumab were highly effective in decreasing MHDs (p<0.001), reducing MHDs with acute medication use (p<0.001), and improving the PGI-S score (p<0.001). On the other hand, MSQ RF-R and MIDAS scores were significantly enhanced only in the 240-mg dose group (p<0.001). With regard to side effects, the rates of injection-site pain and nasopharyngitis did not substantially differ between galcanezumab (inclusive of 120 mg and 240 mg) and placebo groups. Nonetheless, when compared to placebo, galcanezumab 120 mg, but not galcanezumab 240 mg, substantially correlated with a higher rate of URTI. Conclusions Galcanezumab is clinically safe and efficient for the management of migraine, and the use of a higher dose increases its efficacy. Future research directions should be geared toward determining the optimal dose of galcanezumab in the management of patients with migraine. Moreover, head-to-head comparative studies between galcanezumab and other related anti-CGRP receptor monoclonal antibodies are warranted.

The impact of midlife on migraine in women: summary of current views

Migraine is three times more common in women than in men and is the 4th leading cause of disability in women. Onset of migraine increases at menarche, with peaks in prevalence in the late 30s, and a rapid decline after menopause. While the prevalence is highest among women of childbearing age the frequency of headache and burden of migraine frequently worsens during midlife. Abundant population data suggest that hormonal factors may trigger headache attacks and influence onset and remission. The midlife worsening of migraine is attributed to hormonal fluctuations characteristic of the menopausal transition. Drops in estrogen presumably lead to increased migraine attacks at the time of menses as well as during the menopausal transition. During the menopausal transition, recommended approaches include both acute and preventive non-hormonal and hormonal options as well as behavioral approaches. Herein, is a brief review on the presentation of migraine in women across the lifespan, with special emphasis on midlife and the menopausal transition and implications for treatment.