Safety and efficacy of ALD403, an antibody to calcitonin gene-related peptide, for the prevention of frequent episodic migraine: a randomised, double-blind, placebo-controlled, exploratory phase 2 trial

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.

Revolutionizing migraine management: advances and challenges in CGRP-targeted therapies and their clinical implications

Migraine, a prevalent neurological disorder, affects approximately 14.1% of the global population and disproportionately impacts females. This debilitating condition significantly compromises quality of life, productivity, and incurs high healthcare costs, presenting a challenge not only to individuals but to societal structures as a whole. Despite advances in our understanding of migraine pathophysiology, treatment options remain limited, necessitating ongoing research into effective therapies. This review delves into the complexity of migraine management, examining the roles of genetic predisposition, environmental influences, personalized treatment approaches, comorbidities, efficacy and safety of existing acute and preventive treatments. It further explores the continuum between migraine and tension-type headaches and discusses the intricacies of treating various migraine subtypes, including those with and without aura. We emphasize the recent paradigm shift toward trigeminovascular activation and the release of vasoactive substances, such as calcitonin gene-related peptide (CGRP), which offer novel therapeutic targets. We assess groundbreaking clinical trials, pharmacokinetic and pharmacodynamic perspectives, safety, tolerability, and the real-world application of CGRP monoclonal antibodies and gepants. In the face of persisting treatment barriers such as misdiagnosis, medication overuse headaches, and limited access to specialist care, we discuss innovative CGRP-targeted strategies, the high cost and scarcity of long-term efficacy data, and suggest comprehensive solutions tailored to Turkiye and developing countries. The review offers strategic recommendations including the formulation of primary care guidelines, establishment of specialized outpatient clinics, updating physicians on novel treatments, enhancing global accessibility to advanced therapies, and fostering patient education. Emphasizing the importance of lifestyle modifications and holistic approaches, the review underscores the potential of mass media and patient groups in disseminating critical health information and shaping the future of migraine management.

Treatment Outcome After Switching From Galcanezumab to Fremanezumab in Patients With Migraine

BACKGROUND AND PURPOSE

Monoclonal antibodies (mAbs) targeting calcitonin-gene-related peptide (CGRP) or its receptor (anti-CGRP-R) have been widely administered to patients with migraine who show inadequate responses to preventive medications. Among patients in whom a particular anti-CGRP-R mAb is ineffective, switching between different anti-CGRP-R mAbs can be the next option. Few studies have investigated treatment outcomes for antibody switching, especially between mAbs with the same target of the CGRP ligand. We aimed to determine the treatment outcome after switching between two anti-CGRP mAbs (galcanezumab to fremanezumab).

METHODS

We identified migraine patients in a prospective headache clinic registry who received galcanezumab for ≥3 months and were switched to fremanezumab for a further ≥3 months at a single university hospital. We defined a treatment response as a ≥50% reduction in the number of days with a moderate or severe headache at the third month of treatment relative to baseline. The treatment response after switching to fremanezumab was compared with the initial treatment response to galcanezumab.

RESULTS

Among 21 patients identified in the registry, 7 (33.3%) were initial responders to galcanezumab. After switching to fremanezumab, 7 (33.3%) showed a treatment response. The treatment response rate was 28.6% in the initial responders and 71.4% in the nonresponders to galcanezumab (p>0.999).

CONCLUSIONS

Switching between anti-CGRP mAbs (galcanezumab to fremanezumab) yielded a treatment outcome comparable to that reported previously when switching from an anti-CGRP-R mAb (erenumab) to an anti-CGRP mAb (galcanezumab or fremanezumab). The treatment response to fremanezumab seems to be independent of the prior treatment response to galcanezumab. Our findings suggest that switching to another anti-CGRP mAb can be considered when a particular anti-CGRP mAb is ineffective or intolerable.

Efficacy and safety of eptinezumab 300mg versus 100mg for migraine patients: a meta-analysis of randomized controlled studies

Introduction: Eptinezumab holds important promise in treating migraine patients, but its ideal dose is unknown. This meta-analysis aims to compare the efficacy and safety of eptinezumab 300 mg versus 100 mg for migraine patients.Methods: Several databases including PubMed, Web of science, EBSCO, EMbase and Cochrane library databases have been systematically searched and we included the randomized controlled trials (RCTs) assessing the effect of eptinezumab 300 mg versus 100 mg for migraine patients. This meta-analysis was conducted using the random-effect model.Results: Five RCTs and 1989 patients were included in the meta-analysis. Compared with eptinezumab 100 mg in migraine patients, eptinezumab 300 mg was associated with substantially reduced monthly migraine days (MD=-0.50; 95% CI=-0.56 to -0.44; p < 0.00001), increased 75% responder rate (OR = 1.32; 95% CI = 1.07 to 1.62; p = 0.008) and 50% responder rate (OR = 1.24; 95% CI = 1.04 to 1.48; p = 0.02), but unraveled no remarkable influence on migraine 1 day after dosing (OR = 0.92; 95% CI = 0.72 to 1.18; p = 0.52), adverse events (OR = 1.07; 95% CI = 0.81 to 1.42; p = 0.62) or serious adverse events (OR = 1.60; 95% CI = 0.68 to 3.74; p = 0.40).Conclusions: Eptinezumab 300 mg was superior to eptinezumab 100 mg for the treatment of migraine patients.

Reporting Quality and Risk of Bias Analysis of Published RCTs Assessing Anti-CGRP Monoclonal Antibodies in Migraine Prophylaxis: A Systematic Review

Objective: Phase II/III randomized clinical trials (RCTs) are vulnerable to many types of bias beyond randomization. Insights into the reporting quality of RCTs involving migraine patients treated with monoclonal antibodies targeting the calcitonin gene-related peptide system (anti-CGRP MAbs) are currently lacking. Our aim was to analyze the reporting quality of phase II/III RCTs involving migraine patients treated with anti-CGRP MAbs. Methods: A systematic search was performed on the PubMed and EMBASE databases, according to PRISMA guidelines, for relevant RCTs in either episodic or chronic migraine prevention. Additionally, an adapted version of the 2010 CONSORT statement checklist was utilized. The ROBvis online tool was used to document the risk of bias. Results: From the initially identified 179 articles, we finally found 31 RCTs that were eligible for evaluation. The average CONSORT compliance was 88.7% (69.7-100%), while 93.5% (N = 29) of the articles had a compliance greater than 75%. Twenty-eight CONSORT items were reported in more than 75% of the articles. The average compliance of the analyzed RCTs was 93.9% for Galcanezumab, 91.3% for Fremanezumab, followed by 85.4% for Erenumab and Eptinezumab studies. Implementation of the ROB2 tool showed some concerning "missing information" arising from the inadequate reporting. Specifically, 50% of the studies (N = 16) were categorized as having inadequate information regarding the randomization process. Conclusions: Adequate reporting quality was disclosed in the evaluated RCTs with anti-CGRP MAbs in migraine prevention. However, some methodological issues need to be highlighted to be addressed in future studies assessing the efficacy of new molecules targeting CGRP or other candidate pathways implicated in migraine pathophysiology.

Long-Term Treatment with the Calcitonin Gene-Related Peptide Receptor Antagonist Erenumab in CADASIL: Two Case Reports

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of cerebral small vessel disease, caused by a mutation in the NOTCH3 gene on chromosome 19. The main clinical features include migraine (often with aura), early onset, recurrent subcortical ischemic strokes, mood disturbances, and cognitive impairment, frequently leading to dementia and disability with a reduction in life expectancy. Cerebral chronic global hypoperfusion, due to impaired cerebrovascular reactivity, seems to play a primary role in CADASIL. Migraine is the most common early feature of the disease, and to date, there are no consensus guidelines for treatment. Given the vasomodulatory influence of many antimigraine drugs, there is concern about their use in this disease. In particular, the calcitonin gene-related peptide (CGRP) system serves as a vasodilatory protective mechanism during cerebral and cardiac ischemia. Blocking this system could exacerbate ischemic events. Herein, we describe two CADASIL patients who were treated with the calcitonin gene-related peptide (CGRP) receptor antagonist erenumab for chronic migraine, reporting a significant reduction in the frequency of attacks and intensity of pain, and an improvement in quality of life without adverse effects.

Eptinezumab for the preventive treatment of episodic and chronic migraine: a narrative review

Eptinezumab, a monoclonal antibody that targets calcitonin gene-related peptide (CGRP), was recently approved in Europe for the prophylactic treatment of migraine in adults who have at least four migraine days a month. Eptinezumab is administered by intravenous infusion every 12 weeks. During recent months, a considerable amount of evidence from eptinezumab trials has been published. The aim of this review is to describe the existing evidence on the tolerability, safety and efficacy of eptinezumab in patients with migraine. Data from randomized (PROMISE-1, PROMISE-2, RELIEF and DELIVER) and open-label (PREVAIL) phase 3 clinical trials have demonstrated the favorable effect of eptinezumab in migraine symptoms from first day of treatment. These studies showed that eptinezumab results in an overall reduction in mean monthly migraine days (MMDs), increases in the ≥50% and ≥ 75% migraine responder rates (MRRs) and improvements in patient-reported outcome measures in both patients with episodic migraine (EM) and with chronic migraine (CM), including patients who failed previous preventive treatments. The RELIEF trial also showed that eptinezumab, within 2 h of administration, reduced headache pain, migraine-associated symptoms and acute medication use when administered during a migraine attack. Eptinezumab benefits manifested as early as day 1 after dosing and with the subsequent doses lasted up to at least 2 years. Treatment-emergent adverse events reported by ≥2% of patients included upper respiratory tract infection and fatigue. Current evidence demonstrates that eptinezumab has a potent, fast-acting, sustained migraine preventive effect in patients with EM and CM. Eptinezumab has also shown to be well tolerated, supporting its use in the treatment of patients with migraine and inclusion in the current migraine therapeutic options.

Efficacy and Safety of Anti-CGRP Monoclonal Antibodies in Prevention of Chronic Migraine: A Bayesian Network Meta-analysis

Due to the unmet needs in the management of migraine, a primary headache, and disabling disorder, the past decade has focused on developing monoclonal antibodies (mAbs) against the calcitonin-gene-related peptide (CGRP) as migraine prophylactic agents. The objective of the study was to evaluate the efficacy and safety of various anti-CGRP mAbs in the prevention of chronic migraine. Network meta-analysis (NMA) was performed using the Bayesian framework to estimate the efficacy and safety of mAbs after performing a literature search in PubMed, MEDLINE, Cochrane database, and International Clinical Trial Registry Platform (ICTRP). The outcomes calculated were in terms of mean difference (MD) or odds ratio (OR) with a 95% credible interval (95%CrI). Network graphs were constructed and node-split analysis was done to analyze the inconsistency. The NMA included a total of 10 clinical trials. Galacanezumab (120 mg) (MD: -2.7; 95%CrI: -4.8 to -0.83) was found to be better than other mAbs in terms of the difference in mean migraine days (MMD). Fremanezumab quarterly dose administration showed the best response (OR: 2.9; 95%CrI: 1.9 to 4.6) in terms of responder rate. Eptinezumab was found to be safer (OR: 0.88; 95%CrI: 0.61-1.3) as compared to other mAbs in terms of the rate of adverse events. Fremanezumab (quarterly) ranked better in terms of response rate, and eptinezumab was found to be the safest in the prophylactic management of migraine. Galacenequmab was better at reducing MMD. Further studies are needed to evaluate the long-term safety, efficacy, and use of mAbs in migraine patients.

Effectiveness of Switching CGRP Monoclonal Antibodies in Non-Responder Patients in the UAE: A Retrospective Study

Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) have shown promising effectiveness in migraine management compared to other preventative treatment options. Many questions remain regarding switching between antibody classes as a treatment option in patients with migraine headaches. This preliminary retrospective real-world study explored the treatment response of patients who switched between CGRP mAb classes due to lack of efficacy or poor tolerability. A total of 53 patients with migraine headache switched between three of the CGRP mAbs types due to lack of efficacy of the original prescribed CGRP mAbs, specifically eptinezumab, erenumab, and galcanezumab. Fremanezumab was not included due to unavailability in the UAE. Galcanezumab and eptinezumab target the CGRP ligand (CGRP/L), while erenumab targets CGRP receptors (CGRP/R). The analysis of efficacy demonstrated that some improvements were seen in both class switch cohorts (CGRP/R to CGRP/L and CGRP/L to CGRP/R). The safety of switching between CGRP classes was well observed, as any adverse events presented before the class switch did not lead to the discontinuation of treatment following the later switch. The findings of this study suggest that switching between different classes of CGRP mAbs is a potentially safe and clinically viable practice that may have some applications for those experiencing side effects on their current CGRP mAb or those witnessing suboptimal response.

Drug-related side effects and adverse reactions in the treatment of migraine: a bibliometric and visual analysis

Background

Migraine imposes a substantial global burden, impacting patients and society. Pharmacotherapy, as a primary treatment, entails specific adverse reactions. Emphasizing these reactions is pivotal for improving treatment strategies and enhancing patients' well-being. Thus, we conducted a comprehensive bibliometric and visual analysis of relevant literature.

Methodology

We conducted a comprehensive search on the Science Citation Index Expanded within the Web of Science, restricting the literature for analysis based on criteria such as document type, publication date, and language. Subsequently, we utilized various analytical tools, including VOSviewer, Scimago Graphica, the R package 'bibliometrix', CiteSpace, and Excel programs, for a meticulous examination and systematic organization of data concerning journals, authors, countries/regions, institutions, keywords, and references.

Results

By August 31, 2023, the literature was distributed across 379 journals worldwide, authored by 4,235 individuals from 1726 institutions. It featured 2,363 keywords and 38,412 references. 'HEADACHE' led in publication count, with 'SILBERSTEIN S' as the most prolific author. The United States ranked highest in publication volume, with 'UNIV COPENHAGEN' leading among institutions.

Conclusion

Our research findings indicate that researchers in the field continue to maintain a focus on the calcitonin gene-related peptide (CGRP) system and explore diverse mechanisms for drug development through the application of novel biotechnological approaches. Furthermore, it is imperative to enhance the assessment of clinical trial outcomes, consistently monitor the efficacy and safety of prominent drugs such as Erenumab and Fremanezumab. There is a need for further evaluation of acute and preventive treatments tailored to different populations and varying types of migraine.

Drug-related side effects and adverse reactions in the treatment of migraine: a bibliometric and visual analysis

BACKGROUND

Migraine imposes a substantial global burden, impacting patients and society. Pharmacotherapy, as a primary treatment, entails specific adverse reactions. Emphasizing these reactions is pivotal for improving treatment strategies and enhancing patients' well-being. Thus, we conducted a comprehensive bibliometric and visual analysis of relevant literature.

METHODOLOGY

We conducted a comprehensive search on the Science Citation Index Expanded within the Web of Science, restricting the literature for analysis based on criteria such as document type, publication date, and language. Subsequently, we utilized various analytical tools, including VOSviewer, Scimago Graphica, the R package 'bibliometrix', CiteSpace, and Excel programs, for a meticulous examination and systematic organization of data concerning journals, authors, countries/regions, institutions, keywords, and references.

RESULTS

By August 31, 2023, the literature was distributed across 379 journals worldwide, authored by 4,235 individuals from 1726 institutions. It featured 2,363 keywords and 38,412 references. 'HEADACHE' led in publication count, with 'SILBERSTEIN S' as the most prolific author. The United States ranked highest in publication volume, with 'UNIV COPENHAGEN' leading among institutions.

CONCLUSION

Our research findings indicate that researchers in the field continue to maintain a focus on the calcitonin gene-related peptide (CGRP) system and explore diverse mechanisms for drug development through the application of novel biotechnological approaches. Furthermore, it is imperative to enhance the assessment of clinical trial outcomes, consistently monitor the efficacy and safety of prominent drugs such as Erenumab and Fremanezumab. There is a need for further evaluation of acute and preventive treatments tailored to different populations and varying types of migraine.

Characteristics associated with response to subcutaneously administered anti-CGRP monoclonal antibody medications in a real-world community cohort of persons living with migraine: A retrospective clinical and genetic study

OBJECTIVE

To evaluate response to anti-calcitonin gene-related peptide (CGRP) migraine preventives in a real-world community cohort of persons living with migraine and to identify clinical and genetic characteristics associated with efficacious response.

BACKGROUND

Erenumab-aooeb, fremanezumab-vrfm, and galcanezumab-gnlm target CGRP or its receptor; however, many patients are non-responsive.

METHODS

In this retrospective clinical and genetic study, we identified 1077 adult patients who satisfied the International Classification of Headache Disorders, 3rd edition, criteria for migraine without aura, migraine with aura, or chronic migraine and who were prescribed an anti-CGRP migraine preventive between May 2018 and May 2021. Screening of 558 patients identified 289 with data at baseline and first follow-up visits; data were available for 161 patients at a second follow-up visit. The primary outcome was migraine days per month (MDM). In 198 genotyped patients, we evaluated associations between responders (i.e., patients with ≥50% reduction in MDM at follow-up) and genes involved in CGRP signaling or pharmacological response, and genetic and polygenic risk scores.

RESULTS

The median time to first follow-up was 4.4 (0.9-22) months after preventive start. At the second follow-up, 5.7 (0.9-13) months later, 145 patients had continued on the same preventive. Preventives had strong, persistent effects in reducing MDM in responders (follow-up 1: η2  = 0.26, follow-up 2: η2  = 0.22). At the first but not second follow-up: galcanezumab had a larger effect than erenumab, while no difference was seen at either follow-up between galcanezumab and fremanezumab or fremanezumab and erenumab. The decrease in MDM at follow-up was generally proportional to baseline MDM, larger in females, and increased with months on medication. At the first follow-up only, patients with prior hospitalization for migraine or who had not responded to more preventive regimens had a smaller decrease in MDM. Reasons for stopping or switching a preventive varied between medications and were often related to cost and insurance coverage. At both follow-ups, patient tolerance (1: 92.2% [262/284]; 2: 95.2% [141/145]) and continued use (1: 77.5% [224/289]; 2: 80.6% [116/145]) were high and similar across preventives. Response consistency (always non-responders: 31.7% [46/145]; always responders: 56.5% [82/145], and one-time only responders: 11.7% [17/145]) was also similar across preventives. Non-responder status had nominally significant associations with rs12615320-G in RAMP1 (odds ratio [95% confidence interval]: 4.7 [1.5, 14.7]), and rs4680-A in COMT (0.6[0.4, 0.9]). Non-responders had a lower mean genetic risk score than responders (1.0 vs. 1.1; t(df) = -1.75(174.84), p = 0.041), and the fraction of responders increased with genetic and polygenic risk score percentile.

CONCLUSIONS

In this real-world setting, anti-CGRP preventives reduced MDM persistently and had similar and large effect sizes on MDM reduction; however, clinical and genetic factors influenced response.

The history and rationale of the development of new drugs for migraine treatment

Migraine is one of the most prevalent and disabling diseases in the world. Migraine attack treatments and prophylactic treatments of this disease are essential to lessen its individual, social, and economic impact. This is a narrative review of the main drugs used for treating migraine, as well as the experimental models and the theoretical frameworks that led to their development. Ergot derivatives, triptans, non-steroid anti-inflammatory drugs, tricyclic antidepressants, beta-blockers,: flunarizine,: valproic acid,: topiramate, onabotulinumtoxin A, ditans, monoclonal antibodies against CGRP and its receptor, and gepants are discussed. Possible therapeutic targets for the development of new drugs that are under development are also addressed. Many of the drugs currently in use for treating migraine were developed for the treatment of other diseases, but have proven effective for the treatment of migraine, expanding knowledge about the disease. With a better understanding of the pathophysiology of migraine, new drugs have been and continue to be developed specifically for the treatment of this disease.

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.

Migraine: Advances in the Pathogenesis and Treatment

This article presents a comprehensive review on migraine, a prevalent neurological disorder characterized by chronic headaches, by focusing on their pathogenesis and treatment advances. By examining molecular markers and leveraging imaging techniques, the research identifies key mechanisms and triggers in migraine pathology, thereby improving our understanding of its pathophysiology. Special emphasis is given to the role of calcitonin gene-related peptide (CGRP) in migraine development. CGRP not only contributes to symptoms but also represents a promising therapeutic target, with inhibitors showing effectiveness in migraine management. The article further explores traditional medical treatments, scrutinizing the mechanisms, benefits, and limitations of commonly prescribed medications. This provides a segue into an analysis of emerging therapeutic strategies and their potential to enhance migraine management. Finally, the paper delves into neuromodulation as an innovative treatment modality. Clinical studies indicating its effectiveness in migraine management are reviewed, and the advantages and limitations of this technique are discussed. In summary, the article aims to enhance the understanding of migraine pathogenesis and present novel therapeutic possibilities that could revolutionize patient care.

Migraine Treatment: Towards New Pharmacological Targets

Migraine is a debilitating neurological condition affecting millions of people worldwide. Until a few years ago, preventive migraine treatments were based on molecules with pleiotropic targets, developed for other indications, and discovered by serendipity to be effective in migraine prevention, although often burdened by tolerability issues leading to low adherence. However, the progresses in unravelling the migraine pathophysiology allowed identifying novel putative targets as calcitonin gene-related peptide (CGRP). Nevertheless, despite the revolution brought by CGRP monoclonal antibodies and gepants, a significant percentage of patients still remains burdened by an unsatisfactory response, suggesting that other pathways may play a critical role, with an extent of involvement varying among different migraine patients. Specifically, neuropeptides of the CGRP family, such as adrenomedullin and amylin; molecules of the secretin family, such as pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP); receptors, such as transient receptor potential (TRP) channels; intracellular downstream determinants, such as potassium channels, but also the opioid system and the purinergic pathway, have been suggested to be involved in migraine pathophysiology. The present review provides an overview of these pathways, highlighting, based on preclinical and clinical evidence, as well as provocative studies, their potential role as future targets for migraine preventive treatment.

Molecular Mechanisms of Migraine: Nitric Oxide Synthase and Neuropeptides

Migraine is a common condition with disabling attacks that burdens people in the prime of their working lives. Despite years of research into migraine pathophysiology and therapeutics, much remains to be learned about the mechanisms at play in this complex neurovascular condition. Additionally, there remains a relative paucity of specific and targeted therapies available. Many sufferers remain underserved by currently available broad action preventive strategies, which are also complicated by poor tolerance and adverse effects. The development of preclinical migraine models in the laboratory, and the advances in human experimental migraine provocation, have led to the identification of key molecules likely involved in the molecular circuity of migraine, and have provided novel therapeutic targets. Importantly, the identification that vasoconstriction is neither necessary nor required for headache abortion has changed the landscape of migraine treatment and has broadened the therapy targets for patients with vascular risk factors or vascular disease. These targets include nitric oxide synthase (NOS) and several neuropeptides that are involved in migraine. The ability of NO donors and infusion of some of these peptides into humans to trigger typical migraine-like attacks has supported the development of targeted therapies against these molecules. Some of these, such as those targeting calcitonin gene-related peptide (CGRP), have already reached clinical practice and are displaying a positive outcome in migraineurs for the better by offering targeted efficacy without significant adverse effects. Others, such as those targeting pituitary adenylate cyclase activating polypeptide (PACAP), are showing promise and are likely to enter phase 3 clinical trials in the near future. Understanding these nitrergic and peptidergic mechanisms in migraine and their interactions is likely to lead to further therapeutic strategies for migraine in the future.

Meningeal Mechanisms and the Migraine Connection

Migraine is a complex neurovascular pain disorder linked to the meninges, a border tissue innervated by neuropeptide-containing primary afferent fibers chiefly from the trigeminal nerve. Electrical or mechanical stimulation of this nerve surrounding large blood vessels evokes headache patterns as in migraine, and the brain, blood, and meninges are likely sources of headache triggers. Cerebrospinal fluid may play a significant role in migraine by transferring signals released from the brain to overlying pain-sensitive meningeal tissues, including dura mater. Interactions between trigeminal afferents, neuropeptides, and adjacent meningeal cells and tissues cause neurogenic inflammation, a critical target for current prophylactic and abortive migraine therapies. Here we review the importance of the cranial meninges to migraine headaches, explore the properties of trigeminal meningeal afferents, and briefly review emerging concepts, such as meningeal neuroimmune interactions, that may one day prove therapeutically relevant.

The ATP sensitive potassium channel (KATP) is a novel target for migraine drug development

Migraine is one of the leading causes of disability worldwide, affecting work and social life. It has been estimated that sales of migraine medicines will reach 12.9 billion USD in 2027. To reduce social impact, migraine treatments must improve, and the ATP-sensitive potassium (K_ATP) channel is a promising target because of the growing evidence of its implications in the pathogenesis of migraine. Strong human data show that opening of the K_ATP channel using levcromakalim is the most potent headache and migraine trigger ever tested as it induces headache in almost all healthy subjects and migraine attacks in 100% of migraine sufferers. This review will address the basics of the K_ATP channel together with clinical and preclinical data on migraine implications. We argue that K_ATP channel blocking, especially the Kir6.1/SUR2B subtype, may be a target for migraine drug development, however translational issues remain. There are no human data on the closure of the K_ATP channel, although blocking the channel is effective in animal models of migraine. We believe there is a good likelihood that an antagonist of the Kir6.1/SUR2B subtype of the K_ATP channel will be effective in the treatment of migraine. The side effects of such a blocker may be an issue for clinical use, but the risk is likely only moderate. Future clinical trials of a selective Kir6.1/SUR2B blocker will answer these questions.

Methodological considerations on real-world evidence studies of monoclonal antibodies against the CGRP-pathway for migraine: a systematic review

BACKGROUND

Real-world data are accumulating on the effectiveness, tolerability and safety of anti-calcitonin gene-related peptide pathway monoclonal antibodies for the preventive treatment of migraine. We performed a systematic review of the methodology of prospective, observational, clinic-based real-world evidence studies with these drugs in both episodic and chronic migraine.

METHODS

The objectives were to evaluate the definitions and reported outcomes used, and to perform a risk of bias assessment for each of the different studies. PubMed and EMBASE were systematically queried for relevant scientific articles. Study quality assessment of the included studies was conducted using the "National Heart, Lung and Blood Institute (NHLBI) Study Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group".

RESULTS

Forty-six studies fitted the criteria for the systematic review and were included in the analysis. Ten studies (21.7%) defined a migraine day for the study, while only 5 studies defined a headache day for the study (10.9%). The most common primary endpoint/objective of the studies was change in monthly migraine days (n = 16, 34.8%), followed by responder rate (n = 15, 32.6%) and change in monthly headache days (n = 5, 10.9%). Eight studies (17.4%) did not define the primary endpoint/objective. Thirty-three studies were graded as "good" quality and 13 studies were graded as "fair".

CONCLUSION

Our analysis shows rather significant heterogeneity and/or lack of predefined primary outcomes/objectives, definitions of outcomes measures and the use of longitudinal monitoring (e.g. headache diaries). Standardization of terminology, definitions and protocol procedures for real-world evidence studies of preventive treatments for migraine are recommended.

TRIAL REGISTRATION

This study was registered with PROSPERO with ID CRD42022369366.

Gender bias in clinical trials of biological agents for migraine: A systematic review

Migraine is considered one of the most disabling diseases. Currently, there are few studies on clinical migraine treatment based on sex-related differences, despite the important role of sex in migraine. Our aim was to evaluate gender bias in published clinical trials on monoclonal antibodies (erenumab, galcanezumab, fremanezumab and eptinezumab). We performed a systematic review of controlled clinical trials of erenumab, galcanezumab, fremanezumab and eptinezumab, searching the PubMed/MEDLINE database for articles published before December 2021. The search identified 760 articles, 25 of which met the inclusion criteria. Of all the patients included in these trials, 85.1% were women. Only one study had female lead authors. Two of the 25 studies included a sex-based analysis of the primary endpoint. None of the articles discussed the results separately for men and for women. The proportion of men recruited in trials is scarce and more studies are needed to guarantee the safety and tolerability of monoclonal antibodies used in male migraine. As observed in our study, despite the high number of women recruited, only 2 studies analysed the results separately by sex. Thus, a potential risk of gender bias was found in these clinical trials.

Safety and efficacy of rimegepant orally disintegrating tablet for the acute treatment of migraine in China and South Korea: a phase 3, double-blind, randomised, placebo-controlled trial

BACKGROUND

No acute treatments targeting calcitonin gene-related peptide (CGRP) have been approved for use in China or South Korea. We aimed to compare the efficacy and safety of rimegepant-an orally administered small molecule CGRP antagonist-with placebo in the acute treatment of migraine among adults in these countries.

METHODS

This double-blind, randomised, placebo-controlled, multicentre phase 3 trial was done at 86 outpatient clinics at hospitals and academic medical centres (73 in China and 13 in South Korea). Participants were adults (≥18 years) with at least a 1-year history of migraine who had two to eight moderate or severe attacks per month and fewer than 15 headache days per month within the 3 months before the screening visit. Participants were randomly assigned (1:1) to 75 mg rimegepant or placebo to treat a single migraine attack of moderate or severe pain intensity. Randomisation was stratified by the use of preventive medication and by country. The allocation sequence was generated and implemented by study personnel using an interactive web-response system accessed online from each study centre. All participants, investigators, and the sponsor were masked to treatment assignment. The coprimary endpoints of freedom from pain and freedom from the most bothersome symptom (nausea, phonophobia, or photophobia) 2 h after dosing were assessed in the modified intention-to-treat (mITT) population (randomly assigned participants who took study medication for a migraine attack of moderate or severe pain intensity, and provided at least one efficacy datapoint after treatment) using Cochran-Mantel Haenszel tests. Safety was assessed in all participants who received rimegepant or placebo. The study is registered with ClinicalTrials.gov, number NCT04574362, and is completed.

FINDINGS

1431 participants were randomly assigned (716 [50%] to rimegepant and 715 [50%] to placebo). 668 (93%) participants in the rimegepant group and 674 (94%) participants in the placebo group received treatment. 1340 participants were included in the mITT analysis (666 [93%] in the rimegepant group and 674 [94%] in the placebo group). 2 h after dosing, rimegepant was superior to placebo for pain freedom (132 [20%] of 666 vs 72 [11%] of 674, risk difference 9·2, 95% CI 5·4-13·0; p<0·0001) and freedom from the most bothersome symptom (336 [50%] of 666 participants vs 241 [36%] of 674 participants, 14·8, 9·6-20·0; p<0·0001). The most common (≥1%) adverse events were protein in urine (8 [1%] of 668 participants in the rimepegant group vs 7 [1%] of 674 participants in the placebo group), nausea (7 [1%] of 668 vs 18 [3%] of 674), and urinary tract infection (5 [1%] of 668 vs 8 [1%] of 674). There were no rimegepant-related serious adverse events.

INTERPRETATION

Among adults living in China or South Korea, a single dose of 75 mg rimegepant was effective for the acute treatment of migraine. Safety and tolerability were similar to placebo. Our findings suggest that rimegepant might be a useful new addition to the range of medications for the acute treatment of migraine in China and South Korea, but further studies are needed to support long-term efficacy and safety and to compare rimegepant with other medications for the acute treatment of migraine in this population.

FUNDING

BioShin Limited.

TRANSLATIONS

For the Chinese and Korean translations of the abstract see Supplementary Materials section.

The comparative effectiveness of migraine preventive drugs: a systematic review and network meta-analysis

OBJECTIVE

While there are several trials that support the efficacy of various drugs for migraine prophylaxis against placebo, there is limited evidence addressing the comparative safety and efficacy of these drugs. We conducted a systematic review and network meta-analysis to facilitate comparison between drugs for migraine prophylaxis.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and clinicaltrials.gov from inception to August 13, 2022, for randomized trials of pharmacological treatments for migraine prophylaxis in adults. Reviewers worked independently and in duplicate to screen references, extract data, and assess risk of bias. We performed a frequentist random-effects network meta-analysis and rated the certainty (quality) of evidence as either high, moderate, low, or very low using the GRADE approach.

RESULTS

We identified 74 eligible trials, reporting on 32,990 patients. We found high certainty evidence that monoclonal antibodies acting on the calcitonin gene related peptide or its receptor (CGRP(r)mAbs), gepants, and topiramate increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, compared to placebo. We found moderate certainty evidence that beta-blockers, valproate, and amitriptyline increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, and low certainty evidence that gabapentin may not be different from placebo. We found high certainty evidence that, compared to placebo, valproate and amitriptyline lead to substantial adverse events leading to discontinuation, moderate certainty evidence that topiramate, beta-blockers, and gabapentin increase adverse events leading to discontinuation, and moderate to high certainty evidence that (CGRP(r)mAbs) and gepants do not increase adverse events.

CONCLUSIONS

(CGRP(r)mAbs) have the best safety and efficacy profile of all drugs for migraine prophylaxis, followed closely by gepants.

The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

BACKGROUND

Migraine affects 1.1 billion people globally and is the second leading cause of disability worldwide. In clinical trials, treatment efficacy is evaluated by comparing the differential responses in the treatment and placebo arms. Although placebo response in preventive migraine trials has been studied, there is limited research examining temporal trends. This study evaluates the trend of placebo response over thirty years in migraine prevention trials and investigates the association of potential confounders, such as patient, treatment, and study characteristics on placebo response using meta-analysis with regression.

METHODS

We conducted literature searches from January 1990 to August 2021 in bibliographical databases (PubMed, Cochrane Library, and EMBASE). Studies were selected according to PICOS criteria and included randomized, double-blind, placebo-controlled trials evaluating preventive migraine treatments in adult patients diagnosed with episodic or chronic migraine, with or without aura. The protocol was registered with PROSPERO (CRD42021271732). Migraine efficacy outcomes included were either continuous (e.g., monthly migraine days) or dichotomous (e.g., ≥ 50% responder rate (yes/no)). We assessed the correlation of the change in outcome from baseline in the placebo arm, with the year of publication. The relationship between placebo response and year of publication was also assessed after accounting to confounders.

RESULTS

A total of 907 studies were identified, and 83 were found eligible. For the continuous outcomes, the change from baseline in mean placebo response showed an increase over the years (rho = 0.32, p = 0.006). The multivariable regression analysis also showed an overall increase in placebo response over the years. The correlation analysis of dichotomous responses showed no significant linear trend between publication year and mean placebo response (rho = 0.08, p = 0.596). Placebo response also varied by route of administration.

CONCLUSION

Placebo response increased over the past 30 years in migraine preventive trials. This phenomenon should be considered when designing clinical trials and conducting meta-analyses.

Efficacy and safety of eptinezumab for migraine prevention in patients with prior preventive treatment failures: subgroup analysis of the randomized, placebo-controlled DELIVER study

BACKGROUND

Migraine is a disabling neurological disease adversely affecting many aspects of life. Most patients are still required to have failed several older oral preventive therapies before being reimbursed for a preventive, migraine-specific anti-calcitonin gene-related peptide treatment. In the 24-week placebo-controlled portion of DELIVER, eptinezumab was shown to reduce migraine frequency and resulted in higher migraine responder rates compared with placebo in patients with two to four previous preventive treatment failures. This subgroup analysis assessed if demographic or clinical characteristics were associated with differences in preventive benefits.

METHODS

Migraine frequency reductions and responder rates (i.e., the proportion of patients reaching a ≥50% and ≥75% reduction in monthly migraine days relative to baseline) were determined in the total population and predefined subgroups by sex, age, migraine frequency (chronic migraine, episodic migraine, high-frequency episodic migraine, low-frequency episodic migraine), medication overuse, medication-overuse headache, and previous preventive treatment failures (2, >2). The primary endpoint was change from baseline in monthly migraine days over weeks 1-12.

RESULTS

Eptinezumab 100 and 300 mg reduced monthly migraine days more than placebo over weeks 1-12 (-4.8 and -5.3 vs -2.1, respectively; p < 0.0001). In most subgroups, eptinezumab-treated patients demonstrated larger monthly migraine days reductions from baseline over weeks 1-12 than patients receiving placebo, with reductions maintained or increased over weeks 13-24. For ≥50% and ≥75% migraine responder rates, the odds ratios versus placebo all numerically favored eptinezumab.

CONCLUSION

Eptinezumab had larger monthly migraine days reductions and higher responder rates than placebo across clinically relevant subgroups showing that, across different demographic populations and clinical characteristics, eptinezumab is effective in patients with migraine and prior preventive treatment failures.Trial Registration: ClinicalTrials.gov (Identifier: NCT04418765).

Emerging drugs for the preventive treatment of migraine: a review of CGRP monoclonal antibodies and gepants trials

INTRODUCTION

Migraine is a leading cause of years lived with disability and preventive strategies represent a mainstay to reduce health-related disability and improve quality of life of migraine patients. Until a few years ago, migraine prevention was based on drugs developed for other clinical indications and relocated in the migraine therapeutic armamentarium, characterized by unfavourable tolerability profiles. The advent of monoclonal antibodies against Calcitonin Gene-Related Peptide (CGRP) and gepants, CGRP receptor antagonists, has been a turning point in migraine prevention owing to advantageous efficacy, safety and tolerability profiles.Nevertheless, while in an ideal scenario a drug characterized by significant greater efficacy and tolerability compared to existing therapeutic strategies should be adopted as a first-line treatment, cost-effectiveness analyses available for monoclonal antibodies against CGRP pathway tend to limit their administration to more severe migraine phenotypes.

AREAS COVERED

The present narrative review aim to provide a critical appraisal of phase II and III CGRP-mAbs and gepants trials to analyse their use in clinical practice.

EXPERT OPINION

Despite monoclonal antibodies against CGRP pathway and gepants can be undoubtedly considered top-of-the-range treatments, there are still issues deserving to be addressed in the coming years as the risk of off-target effects as well as their economic sustainability based on the considerable migraine burden.

Shared and independent roles of CGRP and PACAP in migraine pathophysiology

The neuropeptides calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) have emerged as mediators of migraine pathogenesis. Both are vasodilatory peptides that can cause migraine-like attacks when infused into people and migraine-like symptoms when injected into rodents. In this narrative review, we compare the similarities and differences between the peptides in both their clinical and preclinical migraine actions. A notable clinical difference is that PACAP, but not CGRP, causes premonitory-like symptoms in patients. Both peptides are found in distinct, but overlapping areas relevant to migraine, most notably with the prevalence of CGRP in trigeminal ganglia and PACAP in sphenopalatine ganglia. In rodents, the two peptides share activities, including vasodilation, neurogenic inflammation, and nociception. Most strikingly, CGRP and PACAP cause similar migraine-like symptoms in rodents that are manifested as light aversion and tactile allodynia. Yet, the peptides appear to act by independent mechanisms possibly by distinct intracellular signaling pathways. The complexity of these signaling pathways is magnified by the existence of multiple CGRP and PACAP receptors that may contribute to migraine pathogenesis. Based on these differences, we suggest PACAP and its receptors provide a rich set of targets to complement and augment the current CGRP-based migraine therapeutics.

Erenumab efficacy in migraine headache prophylaxis: A systematic review

OBJECTIVE

This systematic review aims to show the efficiency of Erenumab in the preventive therapy of episodic and chronic migraine, which is still under research.

BACKGROUND

Migraine is a chronic neurovascular disorder that causes disability and a social burden. There are various medications used for migraine prevention regimens, most of which have unwanted side effects and aren't often quite effective. Erenumab is a monoclonal antibody that targets calcitonin gene-related peptide receptors and was recently approved by the Food and Drug Administration for migraine prevention.

METHODS

For this systematic review, we searched through Scopus and PubMed databases using "Erenumab" or "AMG 334" and "migraine" as keywords, and all the studies from 2016 to March 18, 2022, were included. Original English articles assessing any outcomes referring to the efficacy of Erenumab in migraine headache treatment were included in this study.

RESULTS

We found 53 out of 605 papers eligible to be investigated. Erenumab in both dosages of 70 mg and 140 mg could decrease the mean of monthly migraine days and monthly acute migraine-specific medication days. Erenumab also has a higher rate of ≥ 50 %, ≥ 75 %, and 100 % reduction in monthly migraine days from the baseline in different regions. The efficacy of Erenumab was initiated in the first week of administration and sustained throughout and after treatment. Erenumab was also potent in the treatment of migraine with allodynia, aura, prior preventive therapy failure, medication overuse headache, and menstrual migraine. Erenumab also had favorable outcomes in combination therapy with other preventive drugs like Onabotulinumtoxin-A.

CONCLUSION

Erenumab had remarkable efficacy in the short and long-term treatment of episodic and chronic migraine, notably the patients with difficult-to-treat migraine headaches.

Role of PACAP in migraine: An alternative to CGRP?

Migraine is a widespread and debilitating neurological condition affecting more than a billion people worldwide. Thus, more effective migraine therapies are highly needed. In the last decade, two endogenous neuropeptides, calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide (PACAP), were identified to be implicated in migraine. Recently, introduction of monoclonal antibodies (mAbs) blocking the CGRP is the most important advance in migraine therapy for decades. However, 40% of patients are unresponsive to these new drugs. We believe that PACAP may be involved in these patients. Like CGRP, PACAP is located to sensory nerve fibers, it dilates cranial arteries, it causes migraine when infused into patients and it is a peptide that lends itself to antibody therapy. Also, recent studies suggest that the PACAP pathway is independent of the CGRP pathway. Understanding the signaling pathways of PACAP may therefore lead to identification of novel therapeutic targets of particular interest in patients unresponsive to anti-CGRP therapy. Accordingly, neutralizing mAb to PACAP is currently in clinical phase II development. The aim of the present review is, therefore, to give a thorough account of the existing data on PACAP, its receptors and its relation to migraine.

Assessment of the relative effectiveness of erenumab compared with onabotulinumtoxinA for the prevention of chronic migraine

OBJECTIVE

To assess the available clinical and economic evidence of erenumab vs onabotulinumtoxinA for chronic migraine (CM) and present de-novo indirect treatment comparisons (ITCs) based on available clinical trial data.

METHODS

We conducted ITCs based on results from the pivotal 295 trial (NCT02066415) of erenumab vs placebo and published aggregate data from the PREEMPT 1 (NCT00156910) and PREEMPT 2 (NCT00168428) trials of onabotulinumtoxinA vs placebo. ITCs were conducted for CM patients with and without prior administration of onabotulinumtoxinA and among CM patients with ≥3 prior preventive treatment failures. Efficacy was assessed based on responder rates of ≥50% reductions in monthly headache days (MHDs) and monthly migraine days (MMDs) as well as change from baseline in both MHDs and MMDs.

RESULTS

Among patients with CM, 140 mg erenumab was associated with a reduction of 1.2 MHD (p = .092) and a reduction of 1.0 MMD (p = .174) compared to onabotulinumtoxinA at Week 12. Among onabotulinumtoxinA-naïve patients, erenumab was associated with a reduction of 1.8 MHD (p = .026) and 1.4 MMD (p = .080) at Week 12. Among patients that had received ≥3 prior preventive treatments, the odds ratios comparing erenumab vs onabotulinumtoxinA were 1.7 for ≥50% responder rates based on reductions in MHD (p = .155) and 1.7 for ≥50% responder rates based on reductions in MMD (p = .140).

CONCLUSION

These findings suggest directional benefits (although not reaching the threshold of statistical significance) associated with erenumab vs onabotulinumtoxinA for the preventive treatment of CM. Evidence from this study may inform healthcare stakeholders in treatment selection and optimization for patients with CM.

PACAP signaling is not involved in GTN- and levcromakalim-induced hypersensitivity in mouse models of migraine

BACKGROUND

Calcitonin gene-related peptide (CGRP) antagonizing drugs represents the most important advance in migraine therapy for decades. However, these new drugs are only effective in 50-60% of patients. Recent studies have shown that the pituitary adenylate cyclase-activating peptide (PACAP38) pathway is independent from the CGRP signaling pathway. Here, we investigate PACAP38 signaling pathways in relation to glyceryl trinitrate (GTN), levcromakalim and sumatriptan.

METHODS

In vivo mouse models of PACAP38-, GTN-, and levcromakalim-induced migraine were applied using tactile sensitivity to von Frey filaments as measuring readout. Signaling pathways involved in the three models were dissected using PACAP-inhibiting antibodies (mAbs) and sumatriptan.

RESULTS

We showed that PACAP mAbs block PACAP38 induced hypersensitivity, but not via signaling pathways involved in GTN and levcromakalim. Also, sumatriptan has no effect on PACAP38-induced hypersensitivity relevant to migraine. This is the first study testing the effect of a PACAP-inhibiting drug on GTN- and levcromakalim-induced hypersensitivity.

CONCLUSIONS

Based on the findings in our mouse model of migraine using migraine-inducing compounds and anti-migraine drugs, we suggest that PACAP acts via a distinct pathway. Using PACAP38 antagonism may be a novel therapeutic target of interest in a subgroup of migraine patients who do not respond to existing therapies.

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.

Calcitonin gene-related peptide (CGRP) is a key molecule released in acute migraine attacks-Successful translation of basic science to clinical practice

Migraine is a highly prevalent neurovascular disorder afflicting more than 15% of the global population. Nearly three times more females are afflicted by migraine in the 18-50 years age group, compared to males. Migraine attacks are most often sporadic, but a subgroup of individuals experience a gradual increase in frequency over time; among these, up to 1%-2% of the global population develop chronic migraine. Although migraine symptoms have been known for centuries, the underlying mechanisms remain largely unknown. Two theories have dominated the current thinking-a neurovascular theory and a central neuronal theory with the origin of the attacks in the hypothalamus. During the last decades, the understanding of migraine has markedly advanced. This is supported by the early seminal demonstration of the trigeminovascular reflex 35 years ago and the insight that calcitonin gene-related peptide (CGRP) is a key molecule released in acute migraine attacks. The more recent findings that gepants, small molecule CGRP receptor blockers, and monoclonal antibodies generated against CGRP, or its canonical receptor are useful for the treatment of migraine, are other important issues. CGRP has been established as a key molecule in the neurobiology of migraine. Moreover, monoclonal antibodies to CGRP or the CGRP receptor represent a breakthrough in the understanding of migraine pathophysiology and have emerged as an efficacious prophylactic treatment for patients with severe migraine with excellent tolerability. This review describes the progression of research to reach the clinical usefulness of a large group of molecules that have in common the interaction with CGRP mechanisms in the trigeminal system to alleviate the burden for individuals afflicted by migraine.

A narrative review of the calcitonin peptide family and associated receptors as migraine targets: Calcitonin gene-related peptide and beyond

OBJECTIVE

To summarize the pharmacology of the calcitonin peptide family of receptors and explore their relationship to migraine and current migraine therapies.

BACKGROUND

Therapeutics that dampen calcitonin gene-related peptide (CGRP) signaling are now in clinical use to prevent or treat migraine. However, CGRP belongs to a broader peptide family, including the peptides amylin and adrenomedullin. Receptors for this family are complex, displaying overlapping pharmacologic profiles. Despite the focus on CGRP and the CGRP receptor in migraine research, recent evidence implicates related peptides and receptors in migraine.

METHODS

This narrative review summarizes literature encompassing the current pharmacologic understanding of the calcitonin peptide family, and the evidence that links specific members of this family to migraine and migraine-like behaviors.

RESULTS

Recent work links amylin and adrenomedullin to migraine-like behavior in rodent models and migraine-like attacks in individuals with migraine. We collate novel information that suggests females may be more sensitive to amylin and CGRP in the context of migraine-like behaviors. We report that drugs designed to antagonize the canonical CGRP receptor also antagonize a second CGRP-responsive receptor and speculate as to whether this influences therapeutic efficacy. We also discuss the specificity of current drugs with regards to CGRP isoforms and how this may influence therapeutic profiles. Lastly, we emphasize that receptors related to, but distinct from, the canonical CGRP receptor may represent underappreciated and novel drug targets.

CONCLUSION

Multiple peptides within the calcitonin family have been linked to migraine. The current focus on CGRP and its canonical receptor may be obscuring pathways to further therapeutics. Drug discovery schemes that take a wider view of the receptor family may lead to the development of new anti-migraine drugs with favorable clinical profiles. We also propose that understanding these related peptides and receptors may improve our interpretation regarding the mechanism of action of current drugs.

Alterations in metabolic flux in migraine and the translational relevance

BACKGROUND

Migraine is a highly prevalent disorder with significant economical and personal burden. Despite the development of effective therapeutics, the causes which precipitate migraine attacks remain elusive. Clinical studies have highlighted altered metabolic flux and mitochondrial function in patients. In vivo animal experiments can allude to the metabolic mechanisms which may underlie migraine susceptibility. Understanding the translational relevance of these studies are important to identifying triggers, biomarkers and therapeutic targets in migraine.

MAIN BODY

Functional imaging studies have suggested that migraineurs feature metabolic syndrome, exhibiting hallmark features including upregulated oxidative phosphorylation yet depleted available free energy. Glucose hypometabolism is also evident in migraine patients and can lead to altered neuronal hyperexcitability such as the incidence of cortical spreading depression (CSD). The association between obesity and increased risk, frequency and worse prognosis of migraine also highlights lipid dysregulation in migraine pathology. Calcitonin gene related peptide (CGRP) has demonstrated an important role in sensitisation and nociception in headache, however its role in metabolic regulation in connection with migraine has not been thoroughly explored. Whether impaired metabolic function leads to increased release of peptides such as CGRP or excessive nociception leads to altered flux is yet unknown.

CONCLUSION

Migraine susceptibility may be underpinned by impaired metabolism resulting in depleted energy stores and altered neuronal function. This review discusses both clinical and in vivo studies which provide evidence of altered metabolic flux which contribute toward pathophysiology. It also reviews the translational relevance of animal studies in identifying targets of biomarker or therapeutic development.

Consensus of the Brazilian Headache Society (SBCe) for the Prophylactic Treatment of Episodic Migraine: part I

The Brazilian Headache Society (Sociedade Brasileira de Cefaleia, SBCe, in Portuguese) nominated a Committee of Authors with the aim of establishing a consensus with recommendations regarding prophylactic treatment for episodic migraine based on articles published in the worldwide literature, as well as personal experience. Migraine affects 1 billion people around the world and more than 30 million Brazilians. In addition, it is an underdiagnosed and undertreated disorder. It is well known within the medical community of neurologists, and especially among headache specialists, that there is a need to disseminate knowledge about prophylactic treatment for migraine. For this purpose, together with the need for drug updates and to expand knowledge of the disease itself (frequency, intensity, duration, impact and perhaps the progression of migraine), this Consensus was developed, following a full online methodology, by 12 groups who reviewed and wrote about the pharmacological categories of the drugs used and, at the end of the process, met to read and establish conclusions for this document. The drug classes studied were: anticonvulsants, tricyclic antidepressants, monoclonal anti-calcitonin gene-related peptide (anti-CGRP) antibodies, beta-blockers, antihypertensives, calcium channel inhibitors, other antidepressants (selective serotonin reuptake inhibitors, SSRIs, and dual-action antidepressants), other drugs, and polytherapy. Hormonal treatment and anti-inflammatories and triptans in minimum prophylaxis schemes (miniprophylaxis) will be covered in a specific chapter. The drug classes studied for part I of the Consensus were: anticonvulsants, tricyclic antidepressants, monoclonal anti-CGRP antibodies, and beta-blockers.

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.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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

INTRODUCTION

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

DEVELOPMENT

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

CONCLUSIONS

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

The importance of an early onset of migraine prevention: an evidence-based, hypothesis-driven scoping literature review

Recently approved migraine preventive therapies facilitate rapid control of migraine activity, potentially improving patients’ lives and minimizing the societal burden of migraine. This review synthesizes available evidence on rates and timing of early onset of migraine prevention and identifies patient-level outcomes related to early onset prevention. This evidence-based scoping review identified all available clinical trial evidence regarding the early onset of prevention of migraine, under the hypothesis ‘Patients with migraine (episodic or chronic) report additional benefits when receiving an approved migraine preventive treatment that demonstrates an early onset of prevention’. Early onset of prevention was defined as migraine preventive benefits within 30 days post-administration. PubMed, EMBASE, and CINAHL were searched for publications between 1988 and 2020. Overall, 16 publications described 18 studies. All studies were conducted in approved treatments [four anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies and one chemodenervation agent] in patients with episodic/chronic migraine; no publications were identified for traditional oral agents for early migraine prevention. Compared to placebo, erenumab (three studies) reduced weekly migraine days within 1 week; fremanezumab (six studies) increased reports of no headache of at least moderate severity on Day 1 and significantly reduced migraine frequency within 1 week; galcanezumab (three studies) significantly reduced the mean number of patients with migraine beginning Day 1 and each day of the first week; eptinezumab (four studies) significantly reduced migraine attack likelihood on Day 1 by > 50% versus baseline; and onabotulinumtoxinA (two studies) reduced headache and migraine days within 1 week. Four publications described function, disability, and quality of life improvements as early as Week 4; none reported cost–benefit. Anti-CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab, and eptinezumab) and a chemodenervation agent (onabotulinumtoxinA) provide clinically relevant benefits during the first treatment week. Literature describing clinically relevant benefits regarding early onset of prevention in patients with migraine is limited.

Treatment of resistant chronic migraine with anti-CGRP monoclonal antibodies: a systematic review

Background

Resistant chronic migraine is a highly disabling condition which is very difficult to treat. The majority of the treatments for migraine prophylaxis are nonspecific and present weak safety profiles, leading to low adherence and discontinuation. Currently, monoclonal antibodies (mAb) targeting the trigeminal sensory neuropeptide, calcitonin gene-related peptide (CGRP), are available for migraine prophylaxis being the first drugs developed specifically to target migraine pathogenesis. The main objective of the current work is to carry out a systematic review of randomised controlled trials that specifically analyse the effectivity and safety of anti-CGRP mAb, comparatively to placebo, in patients with resistant chronic migraine and possibly fill the literature gap or be a source of information to health professionals. Additionally the current knowledge on migraine, particularly resistant chronic migraine, was revisited and summarised.

Methods

Literature search was carried out on MEDLINE, Scopus, Science Direct and ClinicalTrials.gov database, from inception to December 2021. Articles were selected according to prespecified criteria of inclusion and exclusion. Efficacy and safety outcomes included were: change from baseline in monthly migraine days (MMD); ≥50% reduction of MMD values from baseline; change from baseline in monthly acute migraine-specific medication days (MAMD); Migraine-specific Quality of Life Questionnaire (MSQ); and registered adverse events. Additionally, we used the Cochrane risk of bias tool (RoB 2) to assess the risk of bias of the included studies.

Results

Four studies were included in this systematic review, involving 2811 resistant chronic migraine patients, 667 in a study using erenumab, 838 in a study using fremanezumab and 1306 in two studies using galcanezumab. When compared to placebo, all investigated anti-CGRP mAb and respective doses demonstrate effectiveness in decreasing MMD, reducing acute medication use and improving the MSQ scores, including, sometimes, reversion of chronic to episodic migraine (efficacy outcomes). Regarding the safety outcomes, the number and type of adverse events did not differ between anti-CGRP mAb-treated and placebo groups.

Conclusions

Anti-CGRP or anti-CGRP receptor monoclonal antibodies are a promising preventive migraine therapy which can be particularly useful for resistant chronic migraine patients.

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

INTRODUCTION

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

DEVELOPMENT

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

CONCLUSIONS

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

Brazilian descriptive study of 104 consecutive real-world migraine patients treated with monoclonal antibodies

BACKGROUND

Migraine is a highly disabling and prevalent neurological disorder. A peptide, calcitonin gene-related peptide, was identified as involved in migraine pathophysiology and monoclonal anti-CGRP antibodies have been developed.

AIM

To describe the clinical characteristics and therapeutic response of migraine patients treated with monoclonal antibodies.

METHOD

An observational, prospective, uncontrolled and descriptive study was carried out with a sample of 112 consecutive patients with episodic or chronic migraine treated with monoclonal antibodies. Eight patients did not return for the following medical consultation. They were excluded from the study.

RESULTS

A total of 104 patients were described. There was a predominance of episodic migraine. Before treatment, the average frequency of headache was 15.3±8.5 days per month, during the previous three months. Monoclonal antibodies were prescribed at the following frequency: erenumab (49%), galcanezumab (45.2%), and fremanezumab (5.8%). After the third month, the reduction in headache attacks was greater than 50% in 57.7% of patients. Adverse events were referred by 18.3% of patients, in this order of frequency: constipation (7.7%), insomnia (2.9%), vertigo (1.9%), erythema at the injection site (1.9%), arthralgia (1%), nasopharyngitis (1%), facial and hand edema (1%), irritation at the injection site (1%), and paresthesia at the injection site (1%).

CONCLUSIONS

This described analysis of migraine patients who used monoclonal antibodies presented one of the first Brazilian experiences with real-world patients. Our results may enlighten clinicians on the outcomes and ways of prescribing anti-CGRP antibodies.

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.

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.

Alpha-Calcitonin Gene Related Peptide: New Therapeutic Strategies for the Treatment and Prevention of Cardiovascular Disease and Migraine

Alpha-calcitonin gene-related peptide (α-CGRP) is a vasodilator neuropeptide of the calcitonin gene family. Pharmacological and gene knock-out studies have established a significant role of α-CGRP in normal and pathophysiological states, particularly in cardiovascular disease and migraines. α-CGRP knock-out mice with transverse aortic constriction (TAC)-induced pressure-overload heart failure have higher mortality rates and exhibit higher levels of cardiac fibrosis, inflammation, oxidative stress, and cell death compared to the wild-type TAC-mice. However, administration of α-CGRP, either in its native- or modified-form, improves cardiac function at the pathophysiological level, and significantly protects the heart from the adverse effects of heart failure and hypertension. Similar cardioprotective effects of the peptide were demonstrated in pressure-overload heart failure mice when α-CGRP was delivered using an alginate microcapsules-based drug delivery system. In contrast to cardiovascular disease, an elevated level of α-CGRP causes migraine-related headaches, thus the use of α-CGRP antagonists that block the interaction of the peptide to its receptor are beneficial in reducing chronic and episodic migraine headaches. Currently, several α-CGRP antagonists are being used as migraine treatments or in clinical trials for migraine pain management. Overall, agonists and antagonists of α-CGRP are clinically relevant to treat and prevent cardiovascular disease and migraine pain, respectively. This review focuses on the pharmacological and therapeutic significance of α-CGRP-agonists and -antagonists in various diseases, particularly in cardiac diseases and migraine pain.

The Interplay Between Neuroinfections, the Immune System and Neurological Disorders: A Focus on Africa

Neurological disorders related to neuroinfections are highly prevalent in Sub-Saharan Africa (SSA), constituting a major cause of disability and economic burden for patients and society. These include epilepsy, dementia, motor neuron diseases, headache disorders, sleep disorders, and peripheral neuropathy. The highest prevalence of human immunodeficiency virus (HIV) is in SSA. Consequently, there is a high prevalence of neurological disorders associated with HIV infection such as HIV-associated neurocognitive disorders, motor disorders, chronic headaches, and peripheral neuropathy in the region. The pathogenesis of these neurological disorders involves the direct role of the virus, some antiretroviral treatments, and the dysregulated immune system. Furthermore, the high prevalence of epilepsy in SSA (mainly due to perinatal causes) is exacerbated by infections such as toxoplasmosis, neurocysticercosis, onchocerciasis, malaria, bacterial meningitis, tuberculosis, and the immune reactions they elicit. Sleep disorders are another common problem in the region and have been associated with infectious diseases such as human African trypanosomiasis and HIV and involve the activation of the immune system. While most headache disorders are due to benign primary headaches, some secondary headaches are caused by infections (meningitis, encephalitis, brain abscess). HIV and neurosyphilis, both common in SSA, can trigger long-standing immune activation in the central nervous system (CNS) potentially resulting in dementia. Despite the progress achieved in preventing diseases from the poliovirus and retroviruses, these microbes may cause motor neuron diseases in SSA. The immune mechanisms involved in these neurological disorders include increased cytokine levels, immune cells infiltration into the CNS, and autoantibodies. This review focuses on the major neurological disorders relevant to Africa and neuroinfections highly prevalent in SSA, describes the interplay between neuroinfections, immune system, neuroinflammation, and neurological disorders, and how understanding this can be exploited for the development of novel diagnostics and therapeutics for improved patient care.

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.

Cardiovascular outcomes in adults with migraine treated with eptinezumab for migraine prevention: pooled data from four randomized, double-blind, placebo-controlled studies

Background

Patients with migraine have an increased relative risk of cardio- and cerebrovascular events, and some migraine treatments may exacerbate this risk. The primary objective of this analysis was to determine whether the rate of cardiovascular adverse events was higher for patients with migraine treated with the migraine-preventive eptinezumab, compared with patients receiving placebo.

Methods

Cardiovascular outcomes in patients with migraine were pooled across four clinical trials (phase 1b, phase 2, and two phase 3 trials) for use of eptinezumab as a preventive migraine treatment for up to 1 year. In all studies, treatment-emergent adverse events (TEAEs) that occurred after the first dose of study treatment (eptinezumab 100 mg, 300 mg, 1000 mg, or placebo) and vital signs were recorded through study completion.

Results

Cardiovascular TEAEs were rare across all four clinical trials, and rates were similar between patients receiving eptinezumab and those receiving placebo. Cardiovascular TEAEs that did occur were mild or moderate in severity; there were no serious adverse events as per FDA definition. Vital signs (systolic blood pressure, diastolic blood pressure, and heart rate) were not meaningfully different across treatment groups over the course of 56 weeks, compared to placebo. Treatment with eptinezumab did not result in significant new or changed cardiovascular medications used concomitantly compared to placebo.

Conclusions

In this post hoc analysis of four clinical trials for eptinezumab, doses of 100 mg, 300 mg, and 1000 mg (more than 3 times the highest approved dose) were not associated with clinically relevant changes in vital signs or significant changes in concomitant cardiovascular medication usage, and had low incidences of cardiovascular TEAEs, comparable to placebo.

Trial registration

NCT01772524 (Study 2), 01/21/2013; NCT02275117 (Study 5), 10/27/2014; NCT02559895 (PROMISE-1), 09/25/2017; NCT02974153 (PROMISE-2), 11/28/2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01360-1.