Efficacy, safety, and tolerability of rimegepant orally disintegrating tablet for the acute treatment of migraine: a randomised, phase 3, double-blind, placebo-controlled trial

Calcitonin gene relating peptide inhibitors in combination for migraine treatment: A mini-review

The discovery of calcitonin gene-related peptide (CGRP) and its role in migraine pathophysiology has led to advances in the treatment of migraine. Since 2018, the Food and Drug Administration (FDA) has approved four monoclonal antibody (mab) therapies targeting either the CGRP ligand or receptor and 3 oral small molecule CGRP receptor antagonists. These targeted therapies have been shown to be safe and effective for either preventive or acute treatment of migraine in adults. Given their efficacy and tolerability profile, CGRP inhibitors have revolutionized the approach to migraine treatment. Theoretically, combining therapies within this therapeutic class could lead to more CGRP blockade and, subsequently, improved patient outcomes. There are providers currently combining CGRP therapies in clinical practice. However, limited data are available regarding the efficacy and safety of this practice. This mini-review provides a summary of available data and poses important considerations when combining CGRP therapies for migraine treatment.

Efficacy, safety and indirect comparisons of lasmiditan, rimegepant, and ubrogepant for the acute treatment of migraine: A systematic review and network meta-analysis of the literature

BACKGROUND

We performed a random-effects network meta-analysis to study the efficacy and safety of newly developed drugs for the acute treatment of migraine attacks.

METHODS

MEDLINE via PubMed, Embase and The Cochrane Register of Controlled Trials were searched from inception to 11 February 2022. Phase 3 randomized controlled trials examining all formulations of lasmiditan, rimegepant and ubrogepant for the acute treatment of adults with migraine, were included. Data were extracted following the PRISMA guidelines.

RESULTS

Seven studies (SAMURAI, SPARTAN, CENTURION, Study 302, Study 303, ACHIEVE I and II) involving n = 12,859 patients were included. All treatments were superior in efficacy to placebo. Lasmiditan 200 mg showed the highest two-hour pain freedom, while two-hour freedom from most bothersome symptom was equally achieved by the higher doses of lasmiditan (100 and 200 mg), rimegepant and the higher doses of ubrogepant (50 and 100 mg). The odds of treatment-emergent adverse events were greatest with all doses of lasmiditan.

CONCLUSION

Lasmiditan 200 mg was the most effective intervention in the treatment of migraine attacks, although it was associated with high degrees of dizziness, nausea and somnolence. Rimegepant showed slightly lower, but similar efficacy rates to lasmiditan. Ubrogepant had overall the best tolerability profile. These conclusions are limited by the absence of head-to-head comparisons, limitations of individual trials and of the meta-analysis methodology itself.PROSPERO trial registration: CRD42022308224.

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

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

Pharmacokinetics and Safety of Single and Multiple Daily Dosing of 75-mg Rimegepant Orally Disintegrating Tablets in Healthy Chinese Adults: A Randomized Placebo-Controlled Trial

Rimegepant is an oral small-molecule calcitonin gene-related peptide antagonist for acute migraine treatment with or without aura and prevention of episodic migraine in adults. This was a rimegepant single- and multiple-dose phase 1, randomized, placebo-controlled, double-blind study to evaluate the pharmacokinetics and confirm safety in healthy Chinese participants. Participants received a 75-mg rimegepant orally disintegrating tablet (ODT) (N = 12) or matching placebo (N = 4) ODT on days 1 and 3-7 after fasting for pharmacokinetic assessments. Safety assessments included 12-lead electrocardiograms, vital signs, clinical laboratory data, and adverse events (AEs). After a single dose (9 females, 7 males) median time to maximum plasma concentration was 1.5 hours; mean values were 937 ng/mL (maximum concentration), 4582 h*ng/mL (area under the concentration-time curve, 0 to infinity), 7.7 hours (terminal elimination half-life), and 19.9 L/h (apparent clearance). Similar results were seen after 5 daily doses, with minimal accumulation. Six (37.5%) participants experienced ≥1 treatment-emergent AE: 4 (33.3%) had received rimegepant and 2 (50.0%) had received placebo. All AEs were grade 1 and resolved by the end of the study with no deaths, serious/significant AEs, or AEs leading to discontinuation. Overall, single- and multiple-dose rimegepant ODT 75 mg was safe and well-tolerated in healthy Chinese adults with similar pharmacokinetics to non-Asian healthy participants. Trial registration: This trial is registered with the China Center for Drug Evaluation (CDE): CTR20210569.

Medication overuse headache

Medication overuse headache (MOH) is a secondary headache disorder attributed to overuse of acute headache medications by a person with an underlying headache disorder, usually migraine or tension-type headache. MOH is common among individuals with 15 or more headache days per month. Although MOH is associated with substantial disability and reductions in quality of life, this condition is often under-recognized. As MOH is both preventable and treatable, it warrants greater attention and awareness. The diagnosis of MOH is based on the history and an unremarkable neurological examination, and is made according to the diagnostic criteria of the International Classification of Headache Disorders third edition (ICHD-3). Pathophysiological mechanisms of MOH include altered descending pain modulation, central sensitization and biobehavioural factors. Treatment of MOH includes the use of headache preventive therapies, but essential to success is eliminating the cause, by reducing the frequency of use of acute headache medication, and perhaps withdrawing the overused medication altogether. Appropriate treatment is usually highly effective, leading to reduced headache burden and acute medication consumption.

Long-term open-label and real-world studies of lasmiditan, ubrogepant, and rimegepant for the acute treatment of migraine attacks

BACKGROUND

Long-term data helps assess the consistency of efficacy, tolerability, and safety of acute treatment over repeated use for different attacks. Real-world studies help assess tolerability, safety, and efficacy in patients with possibly refractory chronic migraine, more comorbidities, other diseases such as cardiovascular diseases, and polypharmacy.

METHODS

This is a narrative review of the long-term open-label and real-world studies of lasmiditan, ubrogepant, and rimegepant for the acute treatment of migraine. Both manuscripts and abstracts were reviewed.

RESULTS

The efficacy and tolerability of lasmiditan, ubrogepant, and rimegepant are maintained over time. No significant cardiovascular adverse events were thought to be related to any of these medications. The rare instances of palpitations and/or tachycardia occurred within 48 hours of lasmiditan. One participant with a history of supraventricular tachycardia had sinus tachycardia thought to be related to ubrogepant which did not recur despite continued use. One case of thrombocytopenia and two cases of increased aspartate aminotransferase and alanine transaminase were thought to be possibly related, but the alanine transaminase and aspartate aminotransferase levels normalized despite continued use of ubrogepant. A case of first-degree atrioventricular block was considered possibly related to rimegepant. Acute use of rimegepant was associated with a decrease in monthly migraine days over time. The three medications were associated with improvement in function and/or productivity.

CONCLUSION

Long-term and real-world data of tolerability, safety and efficacy of lasmiditan, ubrogepant, and rimegepant is thus far consistent with prior studies, but more longitudinal data that clarifies long-term safety as well as consistency and predictors of response is needed.

Efficacy of rimegepant for the acute treatment of migraine based on triptan treatment experience: Pooled results from three phase 3 randomized clinical trials

BACKGROUND

This post-hoc analysis from three phase 3 treatment trials of rimegepant 75 mg - an oral small molecule calcitonin gene-related peptide receptor antagonist for acute and preventive treatment of migraine - assessed efficacy in adults with migraine based on triptan treatment experience.

METHODS

Participants were assigned to one of four groups based on triptan treatment experience: insufficient response (e.g. lack of efficacy and/or poor tolerability) to 1 triptan, insufficient response to ≥2 triptans, current triptan users, and triptan-naïve participants. The co-primary efficacy endpoints were pain freedom and most bothersome symptom freedom at two hours postdose.

RESULTS

In the three trials (N = 3507; rimegepant n = 1749, placebo n = 1758), 1235 (35.2%) participants had a history of insufficient response to 1 triptan (n = 910 [25.9%]) or ≥2 triptans (n = 325 [9.3%]), and 2272 (64.8%) had no history of insufficient response to triptans (current use = 595 [17.0%], naïve = 1677 [47.8%]). Rimegepant was effective on the co-primary endpoints in all subgroups (p ≤ 0.013), except for freedom from the most bothersome symptom in the triptan-naïve group (p = 0.06). No differences on co-primary endpoints were found in pairwise comparisons of rimegepant-treated participants.

CONCLUSIONS

Rimegepant was effective for the acute treatment of migraine in adults with a history of insufficient response to 1 or ≥2 triptans and in current triptan users. Efficacy on co-primary endpoints did not differ based on the number of insufficient triptan responses.Trial registration: Clinicaltrials.gov: NCT03235479, NCT03237845, NCT03461757.

Revisiting Migraine: The Evolving Pathophysiology and the Expanding Management Armamentarium

Migraine affects about one billion people worldwide yearly and is one of the most common neurologic illnesses, with a high prevalence and morbidity, particularly among young adults and females. Migraine is associated with many comorbidities, including stress, sleep difficulties, and suicidal ideation. Migraine, despite its widespread occurrence, is underdiagnosed and undertreated. Because of the complicated and primarily unknown mechanisms of migraine formation, several social and biological risk factors, such as hormone imbalances, genetic and epigenetic impacts, and cardiovascular, neurological, and autoimmune illnesses, have been proposed. Through the mid-20th century diversion of the now-defunct vascular theory, the pathophysiology of migraine has developed from a historical study of the "humours" to a distinct entity as a neurological disorder. The range of therapeutic targets has broadened significantly, increasing the number of specialized clinical trials. Understanding the biology of migraine through careful research has resulted in the identification of major therapeutic classes: (i) triptans, serotonin 5-HT1B/1D receptor agonists, (ii) gepants, calcitonin gene-related peptide (CGRP) receptor antagonists, (iii) ditans, 5-HT1F receptor agonists, (iv) CGRP monoclonal antibodies, and (v) glurants, mGlu5 modulators, with further targets being explored. This review provides a comprehensive overview of the most recent literature on epidemiology and risk factors and exposes knowledge gaps.

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

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

Health State Utility Mapping of Rimegepant for the Preventive Treatment of Migraine: Double-Blind Treatment Phase and Open Label Extension (BHV3000-305)

INTRODUCTION

The objectives of this study were to (1) report long-term health-related quality of life (HRQoL) outcomes among patients using rimegepant preventatively in BHV3000-305 (NCT03732638) open-label extension (OLE) and (2) map Migraine-Specific Quality of Life questionnaire version 2.1 (MSQv2) to EQ-5D-3L utility values over the double-blind treatment (DBT; 0-12 weeks) and the OLE (13-64 weeks) to assess the influence of treatment on these values.

METHODS

This was a post hoc analysis using data from a rimegepant study for the prevention of migraine (BHV3000-305). Adult patients with migraine took either rimegepant 75 mg or placebo every other day (EOD) during the DBT phase. All patients received rimegepant during the OLE. MSQv2 was measured at baseline, weeks 12, 24, and 64. A validated algorithm was used to map MSQv2 scores to EQ-5D utilities.

RESULTS

Baseline data were available for 347 patients treated with placebo and 348 treated with rimegepant in the DBT period, who continued to the OLE. Baseline EQ-5D utilities were similar between trial arms: 0.598 for placebo and 0.614 for rimegepant. EQ-5D improved from baseline to week 12 and utilities increased by + 0.09 for placebo and + 0.10 for rimegepant (p value = 0.011). By 24 weeks, at which point patients who were originally randomized to placebo had received rimegepant 75 mg EOD for 12 weeks, HRQoL measures (MSQv2 and EQ-5D) were similar across groups, demonstrating rapid onset of treatment effect. This HRQoL improvement was durable out to 64 weeks.

CONCLUSION

Compared to placebo, treatment with rimegepant 75 mg was associated with greater improvement in EQ-5D utilities during the 12-week DBT phase. Patients originally randomized to placebo experienced a similar improvement in EQ-5D utilities after switching to rimegepant during the OLE, demonstrating that benefits are realized within 12 weeks of active treatment. This preventive effect was durable out to 64 weeks and was associated with an additional increase in HRQoL over time.

TRIAL REGISTRATION

NCT03732638.

Ubrogepant and rimegepant: systematic review, meta-analysis, and meta-regression of clinical studies

OBJECTIVES

This study aimed at providing pooled estimates of the incidence of adverse drug reactions (ADRs) of ubrogepant and rimegepant and to use meta-regression to identify correlations between the occurrence of selected ADRs, socio-demographic, and clinical characteristics from data published in clinical studies.

METHODS

Ovid MEDLINE (up to 03/02/2022) was searched along with the references listed in the reviews identified with the research query. Random intercept and slope logistic regression models were used to estimate the logit transformation of the pooled incidence. To examine how selected clinical and socio-demographic characteristics correlated with the pooled incidence rates, we performed random-effects meta-regression.

RESULTS

Significant heterogeneity of incidence estimates was observed in clinical studies along with correlations between ADRs and the sociodemographic and clinical characteristics of patients exposed to ubrogepant. In particular, we observed a correlation between ubrogepant dosage and muscle strain and between Body Mass Index (BMI) and liver function values. For rimegepant, significant correlations were observed between age and infections and having aura symptoms at baseline and nausea/dizziness/diarrhea/muscle strain.

CONCLUSION

This study provided pooled incidence estimates of ubrogepant and rimegepant's ADRs and highlighted new safety aspects of the pharmacological treatment with ubrogepants and rimigepants from correlations obtained from the meta-regression.

Gepants for Acute and Preventive Migraine Treatment: A Narrative Review

Calcitonin gene-related peptide (CGRP) antagonists are a class of medications that act as antagonists of the CGRP receptor or ligand. They can be divided into monoclonal antibodies and non-peptide small molecules, also known as gepants. CGRP antagonists were the first oral agents specifically designed to prevent migraines. The second generation of gepants includes rimegepant (BHV-3000, BMS-927711), ubrogepant (MK-1602), and atogepant (AGN-241689, MK-8031). Zavegepant (BHV-3500, BMS-742413) belongs to the third generation of gepants characterized by different administration routes. The chemical and pharmacological properties of this new generation of gepants were calculated. The clinical trials showed that the new generation of CGRP antagonists is effective for the acute and/or preventive treatment of migraines. No increased mortality risks were observed to be associated with the second- and third-generation gepants. Moreover, the majority of the serious adverse events reported probably occurred unrelated to the medications. Interesting facts about gepants were highlighted, such as potency, hepatotoxicity, concomitant use with monoclonal antibodies targeting the CGRP, comparative analysis with triptans, and the "acute and preventive" treatment of migraine. Further studies should include an elderly population and compare the medications inside this class and with triptans. There are still concerns regarding the long-term side effects of these medications, such as chronic vascular hemodynamic impairment. Meanwhile, careful pharmacovigilance and safety monitoring should be performed in the clinical practice use of gepants.

Variability in recurrence rates with acute treatments for migraine: why recurrence is not an appropriate outcome measure

BACKGROUND

Headache recurrence is a common feature of acute therapies, whether approved or still in development, and continues to be a significant problem for both the patient and the clinician. Further complicating this issue is lack of standardization in definitions of recurrence used in clinical trials, as well as disparity in patient characteristics, rendering a comparison of different acute medications challenging. Recurrence has serious clinical implications, which can include an increased risk for new-onset chronic migraine and/or development of medication overuse headache. The aim of this review is to illustrate variability of recurrence rates depending on prevailing definitions in the literature for widely used acute treatments for migraine and to emphasize sustained response as a clinically relevant endpoint for measuring prolonged efficacy. BODY: A literature search of PubMed for articles of approved acute therapies for migraine that reported recurrence rates was performed. Study drugs of interest included select triptans, gepants, lasmiditan, and dihydroergotamine mesylate. An unpublished post hoc analysis of an investigational dihydroergotamine mesylate product that evaluated recurrence rates using several different definitions of recurrence common in the literature is also included. Depending on the criteria established by the clinical trial and the definition of recurrence used, rates of recurrence vary considerably across different acute therapies for migraine, making it difficult to compare results of different trials to assess the sustained (i.e., over a single attack) and the prolonged (i.e., over multiple attacks) efficacy of a particular study medication.

CONCLUSION

A standardized definition of recurrence is necessary to help physicians evaluate recurrence rates of different abortive agents for migraine. Sustained pain relief or freedom may be more comprehensive efficacy outcome measures than recurrence. Future efficacy studies should be encouraged to use the recommended definition of sustained pain freedom set by the International Headache Society.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Background

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

Main body

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

Conclusions

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

Supplementary Information

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

Rimegepant for the treatment of migraine

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

Atogepant for the prevention of episodic migraine in adults

Objective

Atogepant is a newly approved medication for the prevention of migraine. This review aims to discuss the efficacy, safety, cost, and place in therapy of atogepant.

Methods

The authors performed a systematic search for sources, including articles, abstracts, and poster presentations. Queried databases were the National Institute of Health, US National Library of Medicine Clinical Trials, PubMed, European PMC, and the Cochrane Library. Search terms included atogepant, QULIPTA™, AGN-241689, MK-803, and N02CD07. Full-text, English language, randomized-controlled trials from 1 February 2012 to 1 February 2022 were included in the review. Additional relevant prescribing information, abstracts, and articles identified through the search were considered for inclusion in this review. A total of 193 database entries were evaluated for inclusion in this narrative review. Three articles representing two randomized controlled trials were reviewed.

Results and conclusions

Atogepant, a small-molecule calcitonin gene-related peptide (CGRP) receptor antagonist, is a daily oral treatment for migraine prevention. In placebo-controlled clinical trials, atogepant decreased mean monthly migraine days (MMD) over 12 weeks in patients with episodic migraine. Major treatment-related adverse effects include nausea and constipation. Long-term placebo-controlled efficacy and safety studies, chronic migraine studies, and studies in patients that failed more than two classes of preventive therapies are still pending. Atogepant represents one of many novel therapies for the prevention of migraine. To date, no head-to-head comparisons of atogepant versus other agents indicated for migraine prevention have been published. Atogepant offers patients an alternative therapy to injectable or infusion monoclonal antibody treatments and offers an alternative to non-specific migraine medications that are associated with poor tolerability. Due to its high cost and narrower therapeutic indications, atogepant may be reserved for a small subset of migraineurs who prefer oral therapy.

Focus on zavegepant: the first intranasal third-generation gepant

Migraine is the leading cause of years lived with disability in people under 50 and its burden is increased by calcitonin gene-related peptide (CGRP)-driven chronicity. Newly approved small molecules that antagonize the CGRP receptor, gepants, have advanced from the hepatotoxic first-generation telcagepant to third-generation intranasal zavegepant; during this process of drug development, rimegepant, ubrogepant and atogepant, which are orally administered, have been launched and approved for clinical use with no warning for hepatotoxicity. Real-world, long-term postmarketing data about the efficacy and safety of gepants are awaited. The aim of the present drug evaluation study was to provide an overview of the novel, third-generation intranasal Zavegepant, encompassing its development and future perspectives.

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

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

Calcitonin Gene-Related Peptide (CGRP) and Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in Migraine Pathogenesis

Migraine is a prevalent and debilitating neurologic disorder. Advancements in understanding the underlying pathophysiological mechanisms are spearheading the effort to introduce disease-specific treatment options. In recent years this effort has largely focused on alteration of endogenous neuropeptide signaling, namely the peptides calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP). Human studies into the pathophysiological underpinnings of CGRP and PACAP in migraine are manifold and here we review the works investigating these neuropeptides in patients suffering from migraine in order to elucidate the background for developing new treatment options for this vastly disabling disorder.

New Approaches to Shifting the Migraine Treatment Paradigm

The standard of care paradigm for migraine treatment has been based almost exclusively on approaches that grew out of the happenstance use of market pharmaceuticals. Only methysergide, which has long since been removed from use for safety concerns, the ergotamine family of drugs, and the triptans were explicitly developed with migraine and other vascular headaches in mind. While the forward and innovative thinking to utilize the broad array of agents to treat migraine served millions well, their therapeutic efficacy was often low, and adverse event profiles were troublesome in the least. Advances in biochemical and molecular biology and the application of advanced "designing drugs" methods have brought about a potentially significant shift in treatment. The gepants have efficacies similar to the triptans but without vascular safety or medication overuse concerns. Preventative gepants offer innovative approaches to prevention and efficacy that exceed even the CGRP monoclonal antibodies. Those monoclonal antibodies brought rapid and highly effective outcomes across the spectrum of migraine. They outpaced older oral medication efficacy and eliminated most adverse events while potentially improving compliance with monthly or quarterly dosing. Other serotonin receptors beyond the 5HT1B and1D receptors have been targeted for decades. They now lead us to better formulations of dihydroergotamine for efficacy, convenience, and tolerability, and a 5HT1F-specific acute treatment like the gepants opens new options for acute management. Neuromodulation goes back to the mid-1800's. Our improved understanding of applied biomedical engineering has brought forward several tantalizing devices, including the application of currents distant from the target and patient regulated. Whether these advances change the paradigm of migraine treatment and standards of care remains to be seen, and issues such as cost and patient acceptance will help mold it.

Real-World Patient Experience of CGRP-Targeting Therapy for Migraine: a Narrative Review

PURPOSE OF REVIEW

To summarize available calcitonin gene-related peptide (CGRP)-targeting therapies for migraine and discuss their use in real-world populations.

BACKGROUND

CGRP has long been a topic of interest in migraine pathophysiology, with new therapies targeting CGRP since 2018 for both the preventive and acute treatment of migraine.

METHODS

We searched PubMed using keywords including "migraine," "CGRP," "real-world," "erenumab," "galcanezumab," "fremanezumab," "eptinezumab," "ubrogepant," "rimegepant," and "atogepant." We reviewed all pertinent studies and summarized main findings. We also compiled detailed patient characteristics (e.g., migraine diagnoses, medication overuse, prior treatment failures) and treatment outcome measures, such as 50% responder rates, reduction in migraine days, and adverse event rates in several tables. Overall, studies reporting real-world patient experiences of CGRP-targeting therapies suggested meaningful effectiveness for migraine treatment with response rates comparable to the numbers reported in clinical trials. Furthermore, studies suggested benefit in patients with multiple prior unsuccessful treatment trials, medication overuse, and complex medical comorbidities. In some studies, adverse event rates have been notably higher than reported in clinical trials. Additional long-term data is needed to further evaluate sustained efficacy, predictors of treatment response, and adverse events.

Sensory Neurotransmitter Calcitonin Gene-Related Peptide Modulates Tumor Growth and Lymphocyte Infiltration in Oral Squamous Cell Carcinoma

Head and neck squamous cell carcinoma are highly innervated by peripheral sensory neurons. Local neurotransmitter release (e.g., calcitonin gene-related peptide (CGRP)) from sensory neurons innervating cancer is linked to tumorigenesis. CGRP-immunoreactive nerve presence comprised 9.53±1.9% of total nerve area across 11 HNSCC patients. A syngeneic tongue tumor transplant mouse model of oral cancer and a global Calca knockout mouse (CGRPKO ) are used to investigate the impact of CGRP signaling on tumor growth and the associated immune response in vivo. In tumor-bearing CGRPKO mice, there is a significant reduction in tumor size over time compared to wildtype mice using two different mouse oral cancer cell lines. Furthermore, tumor tissue from CGRPKO mice had a significant increase in tumor-infiltrating CD4+ T cells, cytotoxic CD8+ T cells, and NK1.1+ NK cells compared to wildtype. Fluorescent-activated cell sorting and real-time qPCR are used to confirm that CD4+ T cells are isolated from tumor-bearing wildtype mice containing a high expression of Ramp1 compared to sham mice. These data suggest that sensory neurotransmitter CGRP may modulate oral cancer progression via tumor immunosurveillance. Understanding the relationship between sensory neurons and cancer will aid in repurposing clinically available nervous system drugs for the treatment of cancer.

External Concurrent Occipital and Trigeminal Neurostimulation Relieves Migraine Headache: A Prospective, Randomized, Double-Blind, Sham-Controlled Trial

INTRODUCTION

Current external peripheral nerve stimulation devices stimulate only one nerve. This prospective, randomized, double-blind, sham-controlled trial assessed efficacy, safety, and tolerability of a novel external combined occipital and trigeminal neurostimulation (eCOT-NS) device as a self-administered home treatment for migraine (Relivion^®MG, Neurolief Ltd; Netanya, Israel).

METHODS

Episodic and chronic migraine subjects (N = 55) were randomized to receive active (n = 27) or sham (n = 28) treatment. Subjects received eCOT-NS devices and performed 60 ± 20-min home treatments within 45 min of migraine episode onset. The primary endpoint was relative (percent) change in mean baseline VAS pain scores 1 h after treatment initiation. Treatment outcomes assessed at 1-, 2-, and 24-h post-treatment initiation were pain reduction and proportion of pain-free subjects and treatment responders, defined as ≥ 50% pain reduction. Categorical pain ratings (none, mild, moderate, and severe pain) were also analyzed.

RESULTS

Active stimulation was significantly more effective than sham stimulation for decreasing pain intensity at 1 h (53% vs. 10%), 2 h (52% vs. 17%), and 24 h (71% vs. 34%). Pain-free ratings were greater for the active treatment arm at 1 h (29.2% vs. 16%), 2 h (41.7% vs. 20%), and 24 h (65.2% vs. 40%). The number of subjects with baseline moderate or severe migraine pain who were pain-free at 2 h was significantly greater among active treatment subjects (43% vs. 10.5%). The responder rate was significantly higher among the active treatment group at 1 h (67% vs. 20%), 2 h (66.7% vs. 32%,), and 24 h (78.3% vs. 48%). Overall headache relief was significantly higher in the active treatment group at 1 h (67% vs. 26%) and 2 h (76% vs. 31.6%). Mild adverse events, reported by a minority of subjects, resolved spontaneously.

CONCLUSIONS

eCOT-NS provides superior clinically meaningful relief and freedom from migraine pain, offering an effective and safe therapy for acute treatment of migraine.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03398668.

Gepants - a long way to cure: a narrative review

Calcitonin gene-related peptide (CGRP) is probably the most potent vasodilator in cerebral circulation. Forty years after its discovery, the new CGRP-targeted therapy monoclonal antibodies, and the small molecule gepants, are now available for clinical practice. While randomized controlled trials and real-world experience consistently demonstrated the high efficacy and tolerability of monoclonal antibodies, limited evidence is available to characterize gepants fully. Depending on pharmacokinetics, these CGRP receptor antagonists can be used for acute (ubrogepant, rimegepant, and the not yet approved zavegepant) or preventive (atogepant and rimegepant) migraine treatment. Randomized placebo-controlled trials demonstrated gepants efficacy in treating acute attacks to obtain 2 h pain freedom in about 20% of patients and pain relief in about 60%, while up to 60% of treated patients with episodic migraine may experience a 50% reduction in monthly migraine days. The most common treatment-related emergent adverse events were gastrointestinal (nausea, constipation) for the acute or preventive use. No vascular or hepatic concerns have emerged so far. More studies are ongoing to investigate gepant tolerability and safety also if associated with monoclonal antibodies targeting CGRP and other therapeutic classes. Gepants are also under investigation to treat other painful and non-painful conditions. Real-life studies are necessary to confirm the trials’ findings and investigate more practical clinical aspects.

Headache: Treatment update

Primary headache disorders in particular migraine are one of the most common causes of disability worldwide. Given the high burden of migraine in terms of disability, there has been an effort to develop migraine specific therapies that has led to the availability of new drugs including 5HT_1F receptor agonists-ditans (lasmiditan), small molecule calcitonin gene-related peptide (CGRP) receptor antagonists-gepants: (ubrogepant, rimegepant, atogepant) and anti-CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab and eptinezumab). However, some of these treatments incur a high cost and may not be a feasible option for most patients in resource limited settings. Lasmiditan and the gepants are a good option for patients with moderate-severe migraine attacks who cannot use triptans due variously to poor tolerability, or cardio- or cerebrovascular disease. For practical purposes, the new anti-CGRP monoclonal antibodies are best reserved for patients who have failed to have efficacy or had intolerable side effects from multiple traditional oral preventives.

Acute Treatment of Headache (Focus on Migraine)

Acute treatments for migraine and cluster headache are necessary to abort attacks, relieve pain and associated symptoms, and restore an individual's ability to function. Acute headache treatments consist of a variety of medication and nonmedication options. In this article, we discuss the approach to acute treatment of migraine and cluster headache. We summarize the level of evidence to support each acute medication class according to recent systematic reviews and meta-analyses, as well as guideline recommendations from the American Headache Society, American Academy of Neurology, and European Federation of Neurological Society.

CGRP-Targeted Therapy for Episodic and Chronic Cluster Headache

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Galcanezumab modulates Capsaicin-induced C-fiber reactivity

Background

The vasodilatory calcitonin-gene related peptide (CGRP) is understood as pivotal mediator in migraine pathophysiology. Blocking CGRP with small molecules or monoclonal antibodies (CGRP-mAb) reduces migraine frequency. However, prescription of CGRP-mAbs is still regulated and possible predictive measures of therapeutic success would be useful.

Methods

Using standardized capsaicin-induced dermal blood flow model, 29 migraine patients underwent a laser speckle imaging measurement before and after administration of galcanezumab. At both sessions dermal blood flow before and after capsaicin stimulation as well as flare size were analyzed over all three trigeminal branches and the volar forearm for extracranial control. Long-term measures were repeated in 14 patients after continuous treatment ranging from 6 to 12 months.

Results

Resting dermal blood flow remained unchanged after administration of galcanezumab. Capsaicin-induced dermal blood flow decreased significantly after CGRP-mAb in all tested areas compared to baseline and this was consistent even after 12 months of treatment. However, following galcanezumab administration, the flare size decreased only in the three trigeminal dermatomes, not the arm and was therefore specific for the trigemino-vascular system. None of these two markers distinguished between responders and non-responders.

Conclusion

CGRP-mAb changed blood flow response to capsaicin stimulation profoundly and this effect did not change over a 12-month application. Neither capsaicin-induced flare nor dermal blood flow can be used as a predictor for treatment efficacy. These data suggest that the mechanism of headache development in migraine is not entirely CGRP-mediated.

Relative efficacy of lasmiditan versus rimegepant and ubrogepant as acute treatments for migraine: network meta-analysis findings

Background

In the absence of head-to-head trials, comprehensive evidence comparing onset of efficacy of novel agents for acute treatment of migraine is lacking. This study aimed to explore the relative efficacy of lasmiditan (serotonin [5-hydroxytryptamine] 1F receptor agonist) versus rimegepant and ubrogepant (calcitonin gene-related peptide antagonists) for the acute oral treatment of migraine through network meta-analysis (NMA).

Methods

Data included in the NMA were identified through a systematic literature search (conducted April 2018, updated May/December 2020) of phase II–IV, randomised controlled trials (RCTs) in adults with chronic/episodic migraine with/without aura. Treatments included: lasmiditan 50, 100, 200 mg; rimegepant 75 mg; ubrogepant 25, 50, 100 mg. Pairwise treatment comparisons from Bayesian fixed-effect/random-effects NMA, adjusted by baseline risk where appropriate, were conducted. Comparisons were reported as odds ratios with 95% credible intervals. Early-onset efficacy endpoints included: pain freedom at 2 hours and pain relief at 1 and 2 hours. Adverse drug reaction (ADR) profiles were summarised. Heterogeneity and inconsistency in the network were explored; sensitivity analyses investigated robustness of findings.

Results

Across 12 RCTs included in the base case, females represented >80% of included patients (mean age 37.9–45.7 years). Odds of achieving both pain freedom and pain relief at 2 hours were higher with lasmiditan 100 and 200 mg versus rimegepant 75 mg and ubrogepant 25 and 50 mg. Results for pain relief at 1 hour were consistent with those at 2 hours, but fewer comparisons were available. There were no statistically significant differences between lasmiditan 50 mg and ubrogepant or rimegepant for any outcome. Sensitivity analyses were in the same direction as base case analyses. Most commonly reported ADRs (incidence ≥2%) were: dizziness, fatigue, paraesthesia, sedation, nausea/vomiting and muscle weakness with lasmiditan; nausea with rimegepant; and nausea, somnolence and dry mouth with ubrogepant.

Conclusions

The efficacy findings of this indirect comparison indicate that lasmiditan 100 mg or 200 mg might be an appropriate acute treatment option for patients with migraine seeking a fast onset of action. Differently from rimegepant and ubrogepant, lasmiditan use is associated with mainly neurological events, which are mostly mild or moderate in severity and self-limiting.

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Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01440-w.

A systematic review with expert opinion on the role of gepants for the preventive and abortive treatment of migraine

INTRODUCTION

Gepants are small molecules targeting the calcitonin gene-related peptide (CGRP) that have been recently introduced and are under additional clinical development as preventive and abortive treatment options for migraine.

AREAS COVERED

After providing a narrative overview of current preventive and acute treatment options for migraine and summarizing the pathophysiology of migraine attack and the role of CGRP, we performed a systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, on trials on gepants in preventive and acute treatment of migraine. Studies and results were reviewed and discussed, and expert opinion was presented. We also collected data on relevant ongoing trials.

EXPERT OPINION

Whether direct targeting CGRP pathways within the central nervous system or indirectly modulating them from the peripheral nervous system is more effective and safer in migraine remains still unclear. The available data on the efficacy and safety of gepants suggest they may represent an abortive, and to some extent, preventive treatment option for migraine, in patients who do not respond or have adverse effects to first/second line treatments or at high risk for medication overuse headache; thus opening new therapeutic horizons.

Cardiovascular Disease and Migraine: Are the New Treatments Safe?

PURPOSE OF REVIEW

The authors present data on cardiovascular safety for the new acute and preventive migraine treatments including ditans, gepants, and calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) alongside older medications like triptans and ergotamines.

RECENT FINDINGS

The authors conclude that there are no cardiovascular safety concerns for lasmiditan, and that it could be used in those with cardiovascular disease. In fact, the literature even suggests that triptans are safer in cardiovascular disease than their contraindications may suggest. At this time, there is insufficient evidence that gepants and CGRP mAbs should be contraindicated in those with cardiovascular disease including stroke or myocardial infarction, though erenumab has now been associated with hypertension. Vasodilation may be an important CGRP-mediated mechanism mid-ischemia especially in patients with small vessel disease; hence, CGRP antagonists should be use with caution in this context. Long-term data is still needed, and prescribers should ensure patients are aware of the limitations of our knowledge at this time, while still offering these effective and well-tolerated treatment options.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Targeting the adrenomedullin-2 receptor for the discovery and development of novel anti-cancer agents

INTRODUCTION

Adrenomedullin (AM) is a peptide responsible for many physiological processes including vascular health and hormone regulation. Dysregulation of AM signaling can stimulate cancers by promoting proliferation, angiogenesis and metastasis. Two AM receptors contribute to tumor progression in different ways. Adrenomedullin-1 receptor (AM₁R) regulates blood pressure and blocking AM signaling via AM₁R would be clinically unacceptable. Therefore, antagonizing adrenomedullin-2 receptor (AM₂R) presents as an avenue for anti-cancer drug development.

AREAS COVERED

We review the literature to highlight AM's role in cancer as well as delineating the specific roles AM₁R and AM₂R mediate in the development of a pro-tumoral microenvironment. We highlight the importance of exploring the residue differences between the receptors that led to the development of first-in-class selective AM₂R small molecule antagonists. We also summarize the current approaches targeting AM and its receptors, their anti-tumor effects and their limitations.

EXPERT OPINION

As tool compounds, AM₂R antagonists will allow the dissection of the functions of CGRPR (calcitonin gene-related peptide receptor), AM₁R and AM₂R, and has considerable potential as a first-in-class oncology therapy. Furthermore, the lack of detectable side effects and good drug-like pharmacokinetic properties of these AM₂R antagonists support the promise of this class of compounds as potential anti-cancer therapeutics.

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.

Calcitonin gene-related peptide antagonist therapy and migraines

ABSTRACT

Calcitonin gene-related peptide antagonists are a novel new class of medications that have been shown to reduce migraine headache pain and bothersome symptoms in patients who have had an insufficient response to triptans or for whom triptans are contraindicated. This article describes the new medications.

Efficacy and safety of calcitonin gene-related peptide antagonists in migraine treatment: A meta-analysis

INTRODUCTION

We systematically reviewed the efficacy and safety of Calcitonin Gene-Related Peptide (CGRP) antagonists for migraine treatment.

METHODS

Various databases including PubMed, Embase, The Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), WanFang Data were electronically searched for randomized controlled trials (RCTs) on CGRP antagonists for migraine treatment since inception to March 2021. The trials were screened for inclusion, after which the methodological quality of the included trials was assessed. Then meta-analysis was performed using the Revman 5.3 software.

RESULTS

A total of 26 RCTs involving 21,736 patients were included. The CGRP antagonists group included 13,635 patients while the control group included 8101 patients. Meta-analysis showed that compared to the control group, CGRP antagonists were associated with various significant effects, including the following outcome indicators: (1) number of patients with ≥50% reduction from baseline in mean monthly migraine days (RR = 1.50, 95% CI [1.39,1.62], p < .00001); (2) number of patients with pain free at 2 h postdose (RR = 1.98, 95% CI [1.77, 2.20], p < .00001), and (3) number of patients with 2-24 h sustained pain free postdose (RR = 2.18, 95% CI [1.93, 2.46], p < .00001). However, the number of patients with any adverse events was significantly high in the antagonists group, relative to the control group (RR = 1.08, 95% CI [1.04, 1.12], p < .0001).

CONCLUSIONS

CGRP antagonists are significantly effective for migraine treatment; however, they are associated with various adverse events. Due to limitations with regards to quantity and quality of the included studies, the above conclusions should be verified by more high quality studies.

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

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

Lipidated Calcitonin Gene-Related Peptide (CGRP) Peptide Antagonists Retain CGRP Receptor Activity and Attenuate CGRP Action In Vivo

Signaling through calcitonin gene-related peptide (CGRP) receptors is associated with pain, migraine, and energy expenditure. Small molecule and monoclonal antibody CGRP receptor antagonists that block endogenous CGRP action are in clinical use as anti-migraine therapies. By comparison, the potential utility of peptide antagonists has received less attention due to suboptimal pharmacokinetic properties. Lipidation is an established strategy to increase peptide half-life in vivo. This study aimed to explore the feasibility of developing lipidated CGRP peptide antagonists that retain receptor antagonist activity in vitro and attenuate endogenous CGRP action in vivo. CGRP peptide analogues based on the archetypal CGRP receptor antagonist, CGRP_8-37, were palmitoylated at the N-terminus, position 24, and near the C-terminus at position 35. The antagonist activities of the lipidated peptide analogues were tested in vitro using transfected Cos-7 cells expressing either the human or mouse CGRP receptor, amylin subtype 1 (AMY₁) receptor, adrenomedullin (AM) receptors, or calcitonin receptor. Antagonist activities were also evaluated in SK-N-MC cells that endogenously express the human CGRP receptor. Lipidated peptides were then tested for their ability to antagonize endogenous CGRP action in vivo using a capsaicin-induced dermal vasodilation (CIDV) model in C57/BL6J mice. All lipidated peptides except for the C-terminally modified analogue retained potent antagonist activity compared to CGRP_8-37 towards the CGRP receptor. The lipidated peptides also retained, and sometimes gained, antagonist activities at AMY₁, AM₁ and AM₂ receptors. Several lipidated peptides produced robust inhibition of CIDV in mice. This study demonstrates that selected lipidated peptide antagonists based on αCGRP_8-37 retain potent antagonist activity at the CGRP receptor and are capable of inhibition of endogenous CGRP action in vivo. These findings suggest that lipidation can be applied to peptide antagonists, such as αCGRP_8-37 and are a potential strategy for antagonizing CGRP action.

Atogepant - an orally-administered CGRP antagonist - attenuates activation of meningeal nociceptors by CSD

BACKGROUND

This study investigated the mechanism of action of atogepant, a small-molecule CGRP receptor antagonist recently approved for the preventive treatment of episodic migraine, by assessing its effect on activation of mechanosensitive C- and Aδ-meningeal nociceptors following cortical spreading depression.

METHODS

Single-unit recordings of trigeminal ganglion neurons (32 Aδ and 20 C-fibers) innervating the dura was used to document effects of orally administered atogepant (5 mg/kg) or vehicle on cortical spreading depression-induced activation in anesthetized male rats.

RESULTS

Bayesian analysis of time effects found that atogepant did not completely prevent the activation of nociceptors at the tested dose, but it significantly reduced response amplitude and probability of response in both the C- and the Aδ-fibers at different time intervals following cortical spreading depression induction. For C-fibers, the reduction in responses was significant in the early phase (first hour), but not delayed phase of activation, whereas in Aδ-fibers, significant reduction in activation was apparent in the delayed phase (second and third hours) but not early phase of activation.

CONCLUSIONS

These findings identify differences between the actions of atogepant, a small molecule CGRP antagonist (partially inhibiting both Aδ and C-fibers) and those found previously for fremanezumab, a CGRP-targeted antibody (inhibiting Aδ fibers only) and onabotulinumtoxinA (inhibiting C-fibers only)- suggesting that these agents differ in their mechanisms for the preventive treatment of migraine.

Phase 3 randomized, double-blind, sham-controlled Trial of e-TNS for the Acute treatment of Migraine (TEAM)

Migraine is one of the most common and debilitating neurological disorders worldwide. External Trigeminal Nerve Stimulation (e-TNS) is a non-pharmacological, non-invasive therapeutic alternative for patients with migraine. The TEAM study was a prospective, multicenter, randomized, double-blind, sham-controlled, Phase 3 trial for 2-h, continuous, e-TNS treatment of a single moderate or severe migraine attack at home. A total of 538 adults meeting the International Classification of Headache Disorders 3rd edition criteria for 2–8 migraine headache days per month were recruited and randomized in a 1:1 ratio to 2-h active or sham stimulation. Migraine pain levels and most bothersome migraine-associated symptoms (MBS) were recorded at baseline, 2 h, and 24 h using a paper diary. The primary endpoints for the study were pain freedom at 2 h and freedom from the MBS at 2 h. The secondary endpoints were pain relief at 2 h, absence of most bothersome migraine-associated symptoms (MBSs) at 2 h, acute medication use within 24 h after treatment, sustained pain freedom at 24 h, and sustained pain relief at 24 h. Adverse event data was also collected and compared between groups. Five hundred thirty-eight patients were randomized to either the verum (n = 259) or sham (n = 279) group and were included in an intention-to-treat analysis. The percentage of patients with pain freedom at 2 h was 7.2% higher in verum (25.5%) compared to sham (18.3%; p = 0.043). Resolution of most bothersome migraine-associated symptom was 14.1% higher in verum (56.4%) compared to sham (42.3%; p = 0.001). With regards to secondary outcomes, pain relief at 2 h was 14.3% higher in verum (69.5%) than sham (55.2%; p = 0.001), absence of all migraine-associated symptoms at 2 h was 8.4% higher in verum (42.5%) than sham (34.1%; p = 0.044), sustained pain freedom and pain relief at 24 h was 7.0% and 11.5% higher in verum (22.8 and 45.9%) than sham (15.8 and 34.4%; p = 0.039 and .006, respectively). No serious adverse events were reported. Treatment with 2-h e-TNS is a safe and effective, non-invasive, and non-pharmacological alternative for the acute treatment of migraine attacks in an at-home setting.

Trial registration Clinicaltrials.gov Identifier: NCT03465904. Registered 14/03/2018. https://www.clinicaltrials.gov/ct2/show/record/NCT03465904.

P-Glycoprotein and Breast Cancer Resistance Protein Transporter Inhibition by Cyclosporine and Quinidine on the Pharmacokinetics of Oral Rimegepant in Healthy Subjects

Rimegepant (Nurtec ODT)—an orally administered, small‐molecule calcitonin gene–related peptide receptor antagonist indicated for the acute and preventive treatment of migraine—is a substrate for both the P‐glycoprotein and breast cancer resistance protein transporters in vitro. We evaluated the effects of concomitant administration of strong inhibitors of these transporters on the pharmacokinetics of rimegepant in healthy subjects. This single‐center, open‐label, randomized study was conducted in 2 parts, both of which were 2‐period, 2‐sequence, crossover studies. Part 1 (n = 15) evaluated the effect of a single oral dose of 200‐mg cyclosporine, a strong inhibitor of the P‐glycoprotein and breast cancer resistance protein transporters, on the pharmacokinetics of rimegepant 75 mg. Part 2 (n = 12) evaluated the effect of a single oral dose of 600‐mg quinidine, a strong selective P‐glycoprotein transporter, on the pharmacokinetics of rimegepant 75 mg. Coadministration with cyclosporine showed an increase in rimegepant area under the plasma concentration–time curve from time 0 to infinity and maximum observed concentration based on geometric mean ratios (90% confidence intervals [CIs]) of 1.6 (1.49‐1.72) and 1.41 (1.27‐1.57), respectively, versus rimegepant alone. Coadministration with quinidine showed an increase in rimegepant area under the plasma concentration–time curve from time 0 to infinity and maximum observed concentration geometric mean ratios (90% CIs) of 1.55 (1.40‐1.72) and 1.67 (1.46‐1.91), respectively, versus rimegepant alone. Strong P‐glycoprotein inhibitors (cyclosporine, quinidine) increased rimegepant exposures (>50%, <2‐fold). In parts 1 and 2, rimegepant coadministration was well tolerated and safe. The similar effect of cyclosporine and quinidine coadministration on rimegepant exposure suggests that inhibition of breast cancer resistance protein inhibition may have less influence on rimegepant exposure.

New Generation Gepants: Migraine Acute and Preventive Medications

Migraine is a debilitating disease whose clinical and social impact is out of debate. Tolerability issues, interactions, contraindications, and inefficacy of the available medications make new options necessary. The calcitonin-gene-related peptide (CGRP) pathway has shown its importance in migraine pathophysiology and specific medications targeting this have become available. The first-generation CGRP receptor antagonists or gepants, have undergone clinical trials but their development was stopped because of hepatotoxicity. The new generation of gepants, however, are efficacious, safe, and well tolerated as per recent clinical trials. This led to the FDA-approval of rimegepant, ubrogepant, and atogepant. The clinical trials of the available gepants and some of the newer CGRP-antagonists are reviewed in this article.

Real world considerations for newly approved CGRP receptor antagonists in migraine care

INTRODUCTION

Migraine is the leading cause of years lived with disability in people under 50 . Electrophysiological phenomena at the basis of prodromal and headache attack phases and of chronification processes involve calcitonin-gene related peptide (CGRP) as a fundamental player become a game changer of migraine pharmacotherapy.Areas covered: The purpose of the present review is to retrace fundamental stages of CGRP from its discovery to the role in migraine pathogenesis and therapy to underscore the change of paradigm offered by the newly approved small molecules to antagonize CGRP receptor, the gepants. In particular, the development of this new class is gone over from the initial synthesis of C-terminus truncated CGRP antagonists to the development of the first generation of gepants ending with Zavegepant that can be considered the third generation.Expert opinion: The history of CGRP in migraine draws the successful road to follow for key signaling pathways of modulation of nociceptive facilitation by diencephalic and brainstem nuclei, including dopaminergic neurotransmission, orexin A and the large-conductance calcium-activated potassium (BK_Ca) and ATP-sensitive potassium (K_ATP) channels also investigating the potential of essential oils and the role of polymorphisms. Real-world post marketing long-term data are needed for gepants.

Human Milk and Plasma Pharmacokinetics of Single-Dose Rimegepant 75 mg in Healthy Lactating Women

Objective: Investigate whether rimegepant-an oral small molecule calcitonin gene-related peptide receptor antagonist for the treatment of migraine-is excreted in human milk after a single 75 mg dose and characterize its concentration-time profile in the plasma and milk of healthy lactating women to determine the relative infant dose (RID). Methods: This open-label, single-center study enrolled healthy lactating women aged 18-40 years with a gestation of 37-42 weeks and uncomplicated delivery of a single healthy child ≥2 weeks (14 days) and ≤6 months before study drug administration. Plasma samples were collected 0, 1, 2, 4, and 8 hours postdose; human milk samples were collected at 0, 1, 2, 4, 8, 12, 16, 24, 32, and 36 hours. The milk:plasma drug concentration ratio was estimated as the ratio of the human milk:plasma areas under the curve. The RID (%) was calculated as 100 times the quotient of the body weight-normalized infant and maternal doses. Results: Subjects (N = 12) were enrolled between 25 January and 15 September 2020. The mean (standard deviation [SD]) age was 29.8 (3.6) years; mean (SD) body mass index was 26.8 (4.9) kg/m². The mean (SD) RID of rimegepant was 0.51% (0.14). The mean (SD) body-weight normalized infant dose was 0.005 (0.001) mg/kg/day, the mean (SD) body-weight normalized maternal dose was 1.04 (0.18) mg/kg/day, and mean (SD) maternal body weight was 74.0 (13.3) kg. Conclusion: On a weight-adjusted basis, the mean RID of rimegepant was <1% of the maternal dose.

Post-traumatic Headache: Pharmacologic Management and Targeting CGRP Signaling

PURPOSE OF REVIEW

Post-traumatic headache is a common sequela of injury to the head and/or neck. Here, we review the current approach to pharmacologic management of post-traumatic headache and explore the therapeutic promise of targeting calcitonin gene-related peptide signaling to address unmet treatment needs.

RECENT FINDINGS

The scarcity of data from controlled trials has left clinicians to rely on mainly expert opinion for the pharmacologic management of post-traumatic headache. The current view is that a phenotype-guided approach should be used, in which patients are treated according to the primary headache phenotype that their clinical features resemble the most (e.g. migraine, tension-type headache). Moreover, incremental advances are being made in the field that aim to identify possible cellular and molecular drivers of headache persistence. Calcitonin gene-related peptide has emerged as a key drug target which, in turn, has prompted novel insights on the potential importance of early initiation of pharmacologic treatment following the onset of post-traumatic headache. This, in turn, might prevent subsequent persistence and chronification of headache.

Rimegepant 75 mg for acute treatment of migraine is associated with significant reduction in monthly migraine days: Results from a long-term, open-label study

Background:

Rimegepant, a small molecule oral calcitonin gene-related peptide (CGRP) receptor antagonist, is approved for the acute and preventive treatment of migraine. We hypothesized that intermittent CGRP receptor blockade with rimegepant 75 mg acute treatment as needed (PRN) might result in reductions in monthly migraine days (MMD) over time, and was evaluated as the study objective.

Methods:

This was a post-hoc analysis of adults with ≥6 MMD at baseline who self-administered rimegepant 75 mg orally PRN for acute treatment of migraine up to 52-weeks in an open-label safety study (BHV3000-201; NCT03266588). Outcome measures (defined as median time to) and response rates (defined as proportion of patients reporting) were captured for ≥30% and ≥50% reduction of baseline MMD.

Results:

1044 participants with ≥6 MMD at baseline were analyzed. Median time to ≥30% reduction in MMD was 12 weeks (IQR; 4–40 weeks); median time to ≥50% reduction was 32 weeks (IQR; 12-NR weeks). Reduction in MMD was observed over time regardless of baseline migraine frequency, however higher baseline MMD were associated with a longer time to achieving ≥30% or ≥50% MMD reduction.

Conclusion:

In participants presenting with ≥6 MMD, PRN acute treatment of migraine attacks over 52-weeks with oral rimegepant 75 mg was observed to confer reductions in migraine frequency.

Trial registration:

NCT03266588

Constipation Caused by Anti-calcitonin Gene-Related Peptide Migraine Therapeutics Explained by Antagonism of Calcitonin Gene-Related Peptide's Motor-Stimulating and Prosecretory Function in the Intestine

The development of small-molecule calcitonin gene-related peptide (CGRP) receptor antagonists (gepants) and of monoclonal antibodies targeting the CGRP system has been a major advance in the management of migraine. In the randomized controlled trials before regulatory approval, the safety of these anti-CGRP migraine therapeutics was considered favorable and to stay within the expected profile. Post-approval real-world surveys reveal, however, constipation to be a major adverse event which may affect more than 50% of patients treated with erenumab (an antibody targeting the CGRP receptor), fremanezumab or galcanezumab (antibodies targeting CGRP). In this review article we address the question whether constipation caused by inhibition of CGRP signaling can be mechanistically deduced from the known pharmacological actions and pathophysiological implications of CGRP in the digestive tract. CGRP in the gut is expressed by two distinct neuronal populations: extrinsic primary afferent nerve fibers and distinct neurons of the intrinsic enteric nervous system. In particular, CGRP is a major messenger of enteric sensory neurons which in response to mucosal stimulation activate both ascending excitatory and descending inhibitory neuronal pathways that enable propulsive (peristaltic) motor activity to take place. In addition, CGRP is able to stimulate ion and water secretion into the intestinal lumen. The motor-stimulating and prosecretory actions of CGRP combine in accelerating intestinal transit, an activity profile that has been confirmed by the ability of CGRP to induce diarrhea in mice, dogs and humans. We therefore conclude that the constipation elicited by antibodies targeting CGRP or its receptor results from interference with the physiological function of CGRP in the small and large intestine in which it contributes to the maintenance of peristaltic motor activity, ion and water secretion and intestinal transit.