The effect and safety of monoclonal antibodies to calcitonin gene-related peptide and its receptor on migraine: a systematic review and meta-analysis

Efficacy and safety of atogepant, a small molecule CGRP receptor antagonist, for the preventive treatment of migraine: a systematic review and meta-analysis

BACKGROUND

Migraine is one of the most common diseases worldwide while current treatment options are not ideal. New therapeutic classes of migraine, the calcitonin gene-related peptide (CGRP) antagonists, have been developed and shown considerable effectiveness and safety. The present study aimed to systematically evaluate the efficacy and safety of atogepant, a CGRP antagonist, for migraine prophylaxis from the results of randomized controlled trials (RCTs).

METHODS

The Cochrane Library, Embase, PubMed and https://www.

CLINICALTRIALS

gov/ were searched for RCTs that compared atogepant with placebo for migraine prophylaxis from inception of the databases to Feb 1, 2024. Outcome data involving efficacy and safety were combined and analyzed using Review Manager Software version 5.3 (RevMan 5.3). For each outcome, risk ratios (RRs) or standardized mean difference (SMD) were calculated.

RESULTS

4 RCTs with a total of 2813 subjects met our inclusion criteria. The overall effect estimate showed that atogepant was significantly superior to placebo in terms of the reduction of monthly migraine (SMD - 0.40, 95% CI -0.46 to -0.34) or headache (SMD - 0.39, 95% CI -0.46 to -0.33) days, the reduction of acute medication use days (SMD - 0.45, 95% CI -0.51 to -0.39) and 50% responder rate (RR 1.66, 95% CI 1.46 to 1.89), while no dose-related improvements were found between different dosage groups. For the safety, significant number of patients experienced treatment-emergent adverse events (TEAEs) with atogepant than with placebo (RR 1.10, 95% CI 1.02-1.21) while there was no obvious difference between the five dosage groups. Most TEAEs involved constipation (RR 2.55, 95% CI 1.91-3.41), nausea (RR 2.19, 95% CI 1.67-2.87) and urinary tract infection (RR 1.49, 95% CI 1.05-2.11). In addition, a high dosage of atogepant may also increase the risk of treatment-related TEAEs (RR 1.64, 95% CI 1.02-2.63) and fatigue (RR 3.07, 95% CI 1.13-8.35).

CONCLUSIONS

This meta-analysis suggests that atogepant is effective and tolerable for migraine prophylaxis including episodic or chronic migraine compared with placebo. It is critical to weigh the benefits of different doses against the risk of adverse events in clinical application of atogepant. Longer and multi-dose trials with larger sample sizes are required to verify the current findings.

Adverse and serious adverse events incidence of pharmacological interventions for managing chronic and episodic migraine in adults: a systematic review

Background

Migraine is the second most common prevalent disorder worldwide and is a top cause of disability with a substantial economic burden. Many preventive migraine medications have notable side effects that affect different body organs.

Method

We systematically searched for published randomised controlled trials (RCTs) using terms for migraine/headache and preventive medications. Using eligibility criteria, two reviewers independently assessed the articles. Cochrane risk-of-bias tool was applied to assess the quality of the studies. Data were classified by system organ class (SOC).

Results

Thirty-two RCTs with 21 780 participants met the eligibility criteria for the incidence of adverse events (AEs). Additionally, 33 RCTs with 22 615 participants were included to synthesise the incidence of serious AEs (SAEs). The percentage of attributed AEs and SAEs to each SOC for 10 preventive drugs with different dosing regimens was calculated. Amitriptyline and topiramate had a higher incidence of nervous system disorders; Topiramate was also associated with a higher incidence of psychiatric disorders. All drugs showed a certain incidence of infections and infestations, with Onabotulinumtoxin A (BTA) having the lowest rate. BTA had a higher incidence of musculoskeletal disorders than the other drugs. Calcitonin gene-related peptide (CGRP) monoclonal antibodies (MAbs) such as fremanezumab and galcanezumab were linked to more general disorders and administration site conditions than other drugs.

Conclusion

Notably, the observed harm to SOCs varies among these preventive drugs. We suggest conducting head-to-head RCTs to evaluate the safety profile of oral medications, BTA, and CGRP MAbs in episodic and/or chronic migraine populations.

PROSPERO registration number

CRD42021265993.

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.

Adverse event profile of CGRP monoclonal antibodies: findings from the FDA adverse event reporting database

BACKGROUND

Four CGRP Monoclonal Antibodies (mAbs) have been approved for migraine prophylaxis by the Food and Drug Administration (FDA) since 2018. However, there are concerns about the safety of these four drugs for real-world use.

OBJECTIVE

To compare the adverse event profiles of four CGRP-mAbs with FAERS data.

METHODS

The study was based on records from the FAERS database. Only reports containing one of the active ingredients with CGRP-mAbs were included in this study. Disproportionality analyses including but not limited to reporting odds ratio (ROR) and information components (IC) were conducted to identify drug-AE associations.

RESULTS

In total, 58110 reports were identified for CGRP-mAbs. 80 overlapping signals were disproportionately reported. They affected a range of organs and systems, including the gastrointestinal and cardiovascular systems, skin, and hair. Additionally, the rare cardiovascular adverse events were significantly different among the four CGRP-mAbs.

CONCLUSION

We identified numerous shared underlying signals (overlapping signals) for CGRP-mAbs as suspected drugs in multiple systems and organs. The unlabeled common signals may indicate potential safety issues. In addition, the underlying safety signals varied among the four CGRP-mAbs, particularly in the cardiovascular system, and further studies are needed to confirm these associations and the potential clinical implications.

Preventive CGRP-targeted therapies for chronic migraine with and without medication-overuse headache

Background:

Calcitonin gene-related peptide (CGRP) targeted therapies are an important breakthrough in migraine prevention. Randomized clinical trials, post-hoc analyses, and phase IV studies have demonstrated their efficacy and safety in chronic migraine patients, including those with concomitant medication-overuse and medication-overuse headache. Real world evidence studies support these findings and provide realistic endpoints for estimation of effect.

Methods and results

We have performed a narrative review including results from double-blind placebo-controlled randomized clinical trials and real-world evidence studies regarding efficacy of the CGRP(-receptor) monoclonal antibodies and CGRP-receptor antagonists (gepants) in patients with chronic migraine with concomitant medication overuse (headache). We have included patient profiles and main efficacy endpoints (monthly migraine days, monthly headache days, monthly acute medication days and percentage responder rates).

Conclusion

The results of this review show that CGRP monoclonal antibodies are effective in chronic migraine patients, also in those with medication overuse (headache). At the time of this review, atogepant clinical trials in chronic migraine have not been communicated. Direct comparative studies are needed for comparison with other treatment options.

Therapeutic monoclonal antibodies with a focus on hereditary angioedema

Monoclonal antibodies (mAbs) have been shown to be effective and generally safe across a continually expanding list of therapeutic areas. We describe the advantages and limitations of mAbs as a therapeutic option compared with small molecules. Specifically, we discuss a novel mAb in the treatment of hereditary angioedema (HAE), a rare and potentially life-threatening condition characterized by recurrent unpredictable swelling attacks. HAE is mediated by dysregulation of plasma kallikrein activity leading to overproduction of bradykinin. Current prophylactic treatment for HAE includes androgens or replacement of the endogenous plasma kallikrein inhibitor, C1 inhibitor. However, there remains an unmet need for an effective, less burdensome treatment option. Lanadelumab is a fully human mAb targeting plasma kallikrein. Results from clinical trials, including a pivotal Phase 3 study and its ensuing open-label extension study, demonstrated that lanadelumab is associated with few treatment-related adverse events and reduced the rate of HAE attacks. This novel treatment option has the potential to significantly improve the lives of patients with HAE.

Advances in CGRP Monoclonal Antibodies as Migraine Therapy: A Narrative Review

Migraine is a potentially disabling disorder, yet it remains underdiagnosed and undertreated. The release of the neuropeptide calcitonin gene-related peptide (CGRP) in the trigemino-cerebrovascular system plays a vital role in the evolution of migraine. It enhances peripheral sensitization by mediating neurogenic inflammation and also influences central sensitization. The majority of the drug classes available for migraine prophylaxis are nonspecific and associated with numerous side effects and drug interactions. Anti-CGRP monoclonal antibodies (mAb) are an innovative therapeutic class that fulfills the need for more efficacious and tolerable preventive therapy. While erenumab is a mAb to the CGRP receptor, eptinezumab, fremanezumab, and galcanezumab bind to the CGRP molecule. They decrease the number of headache days and improve disability. Upper respiratory tract infection, nausea, constipation, pain at the site of injection, and fatigue are the associated side effects. CGRP mAbs are an excellent advancement in translational research and are a promising addition in migraine therapy. This article discusses the recent advances in the development of the CGRP mAbs.

Migraine Pathophysiology in Children and Adolescents: A Review of the Literature

Although migraine in adult and pediatric patients are overall very similar to each other, differences in prevalence, presentation, and treatment efficacy may reflect slight differences in the pathophysiological processes underlying migraine in these patient groups, perhaps because of ongoing development of the nervous system during childhood and adolescence. Although major gains have been made in understanding the pathophysiology of migraine in adults in recent years, equivalent research on migraine in pediatric patients continues to lag behind. In this review, we will describe the current state of migraine research in pediatric patients with regard to presentation and frequency of prodromal and postdromal symptoms, ictal and interictal calcitonin gene-related peptide elevation, and evidence for cortical spreading depression, thus covering all phases of migraine, and discuss how the findings seen here may relate to possible underlying pathophysiological mechanisms of migraine. We aim to elucidate possible differences between migraine in children and adults, and the need for further research specific to pediatric patients with migraine in order to improve treatment in this patient group.

Quality of Life Related to Functional Disability in Migraine Patients: A Systematic Review and Network Meta-analysis

OBJECTIVE

The aim of this study was to conduct a systematic review and network meta-analysis of all randomized trials investigating effect of anti-calcitonin gene-related peptide monoclonal antibodies on disability related to migraine in adult patients.

MATERIALS AND METHODS

Medline, Embase, and Cochrane Central Register of Controlled Trials searched from inception to July 2020 with an additional review of clinical trial registries. Disability evaluated using change in patient reported Migraine Disability Assessment scores from baseline were considered for the final analysis. The network meta-analysis was conducted in Bayesian framework using OpenBUGS and R, with the random effects model selected to allow for apparent heterogeneity between studies in the treatment comparison effects.

RESULTS

Overall 41 studies (7095 migraineurs in 9 randomized trials) were included with treatment course of at least 12 weeks. Subcutaneous injections of fremanezumab 675+225+225 mg QM and 225+225+225 mg QM were more effective in reducing disability in chronic and episodic migraine patients, respectively, with higher median difference in Migraine Disability Assessment score from baseline compared with other treatments including erenumab (70 mg QM; 140 mg QM), galcanezumab (120 mg QM; 240 mg QM), and low doses of fremanezumab (225 mg single dose; 675 mg single dose).

DISCUSSION

For short-term prevention of migraine, fremanezumab demonstrated slightly better improvement in disability compared with other anti-calcitonin gene-related peptide monoclonal antibodies in adult patients with migraine.

The impact of CGRPergic monoclonal antibodies on prophylactic antimigraine therapy and potential adverse events

Migraine is a prevalent medical condition and the second most disabling neurological disorder. Regarding its pathophysiology, calcitonin gene-related peptide (CGRP) plays a key role, and, consequently, specific antimigraine pharmacotherapy has been designed to target this system. Hence, apart from the gepants, the recently developed monoclonal antibodies (mAbs) are a novel approach to treat this disorder. In this review we consider the current knowledge on the mechanisms of action, specificity, safety, and efficacy of the above mAbs as prophylactic antimigraine agents, and examine the possible adverse events that these agents may trigger. Antimigraine mAbs act as direct scavengers of CGRP (galcanezumab, fremanezumab, and eptinezumab) or against the CGRP receptor (erenumab). Due to their long half-lives, these molecules have revolutionized the prophylactic treatment of this neurovascular disorder. Moreover, because of their physicochemical properties, these agents are hepato-friendly and do not cross the blood-brain barrier (highlighting the relevance of peripheral mechanisms in migraine). Nevertheless, apart from potential cardiovascular side effects, the interaction with AMY₁ receptors and immunogenicity induced by autoantibodies against mAbs could be a concern for the safety of long-term treatment with these molecules.

Efficacy and safety of anti-calcitonin gene-related peptide monoclonal antibodies for treatment of chronic migraine: A systematic review and network meta-analysis

BACKGROUND & OBJECTIVE

To conduct a systematic review and network meta-analysis of all randomized trials investigating effects of anti-calcitonin gene related peptide monoclonal antibodies (anti-CGRP mAbs) on adult patients with chronic migraine.

METHODS

MEDLINE, Embase and Cochrane Central Register of Controlled Trials searched from inception to July 2020; and clinical trial registries. The network meta-analysis was conducted in Bayesian framework using OpenBUGS and R, with the random effects model selected to allow for apparent heterogeneity between studies in the treatment comparison effects.

RESULTS

Overall 38 studies (5164 chronic migraineurs in seven randomized trials) were included with treatment course of at least 12 weeks. Fremanezumab 675 + 225 + 225 mg QM (SC) injections were numerically more effective in lowering migraine days with lower MDs compared to eptinezumab 10 mg (IV) (MD: -1.52, 95% CrIs: -4.24, 0.99), eptinezumab 30 mg (IV) (MD: -0.33, 95% CrIs: -3.02, 2.16), eptinezumab 100 mg (IV) (MD: -0.59, 95% CrIs: -2.80, 1.42), eptinezumab 300 mg (IV) (MD: -0.02, 95% CrIs: -2.29, 1.98), erenumab 70 mg QM (SC) (MD: -0.17, 95% CrIs: -2.84, 2.25), erenumab 140 mg QM (SC) (MD: -0.18, 95% CrIs: -2.87, 2.26), fremanezumab 675 mg (SC) (MD: -0.30, 95% CrIs: -1.81, 1.14), galcanezumab 120 mg QM (SC) (MD: -0.71, 95% CrIs: -3.44, 1.55) and galcanezumab 240 mg QM (SC) (MD: -0.58, 95% CrIs: -3.09, 1.89), however the results were non-significant. Similarly, the anti-CGRP mAbs were also observed to have comparable safety and immunogenicity with no significant differences.

CONCLUSIONS

Although all doses of anti-CGRP mAbs have comparable efficacy, safety and tolerability based on uncertainties in indirect comparisons for all outcomes, the calculated effect estimates numerically favored high doses of subcutaneous fremanezumab and intravenous eptinezumab as the effective therapy with acceptable safety and tolerability for short term prevention of chronic migraine.

MAB-MIG: registry of the spanish neurological society of erenumab for migraine prevention

BACKGROUND

Erenumab was approved in Europe for migraine prevention in patients with ≥ 4 monthly migraine days (MMDs). In Spain, Novartis started a personalized managed access program, which allowed free access to erenumab before official reimbursement. The Spanish Neurological Society started a prospective registry to evaluate real-world effectiveness and tolerability, and all Spanish headache experts were invited to participate. We present their first results.

METHODS

Patients fulfilled the ICHD-3 criteria for migraine and had ≥ 4 MMDs. Sociodemographic and clinical data were registered as well as MMDs, monthly headache days, MHDs, prior and concomitant preventive treatment, medication overuse headache (MOH), migraine evolution, adverse events, and patient-reported outcomes (PROs): headache impact test (HIT-6), migraine disability assessment questionnaire (MIDAS), and patient global improvement change (PGIC). A > 50% reduction of MMDs after 12 weeks was considered as a response.

RESULTS

We included 210 patients (female 86.7%, mean age 46.4 years old) from 22 Spanish hospitals from February 2019 to June 2020. Most patients (89.5%) suffered from chronic migraine with a mean evolution of 8.6 years. MOH was present in 70% of patients, and 17.1% had migraine with aura. Patients had failed a mean of 7.8 preventive treatments at baseline (botulinum toxin type A-BoNT/A-had been used by 95.2% of patients). Most patients (67.6%) started with erenumab 70 mg. Sixty-one percent of patients were also simultaneously taking oral preventive drugs and 27.6% were getting simultaneous BoNT/A. Responder rate was 37.1% and the mean reduction of MMDs and MHDs was -6.28 and -8.6, respectively. Changes in PROs were: MIDAS: -35 points, HIT-6: -11.6 points, PIGC: 4.7 points. Predictors of good response were prior HIT-6 score < 80 points (p = 0.01), ≤ 5 prior preventive treatment failures (p = 0.026), absence of MOH (p = 0.039), and simultaneous BoNT/A treatment (p < 0.001). Twenty percent of patients had an adverse event, but only two of them were severe (0.9%), which led to treatment discontinuation. Mild constipation was the most frequent adverse event (8.1%).

CONCLUSIONS

In real-life, in a personalized managed access program, erenumab shows a good effectiveness profile and an excellent tolerability in migraine prevention in our cohort of refractory patients.

Efficacy and safety of galcanezumab for preventive treatment of migraine: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis aimed to systematically evaluate the effectiveness and safety of galcanezumab in the prophylactic treatment of adult migraine.

METHODS

A systematic literature search was performed to identity randomized-controlled trials (RCTs). The primary outcome was the decline in the number of monthly migraine days (MMDs). Secondary outcomes included the reduction of monthly acute migraine‑specific medication days (MSMDs), the number of participants showing a reduction in MMDs from baseline of ≥ 50%, ≥ 75%, and 100%, the incidence of adverse events (AEs), and the number of participants developing anti-drug antibodies (ADAs) to galcanezumab. We calculated the mean difference (MD), relative risk (RR), and 95% confidence intervals (CIs) for these outcomes.

RESULTS

Among the five included trials, galcanezumab given at doses of 120, 150, 240, and 300 mg was superior to placebo for both MMDs and secondary outcomes. The degree of AEs in all group was mild. Notably, no significant differences were found in the occurrence of AEs and ADAs between the galcanezumab and placebo groups.

CONCLUSION

Galcanezumab is a safe and effective treatment for adult patients with episodic and chronic migraine.

Efficacy and Safety of Monoclonal Antibody Against Calcitonin Gene-Related Peptide or Its Receptor for Migraine: A Systematic Review and Network Meta-analysis

Background: The optimal monoclonal antibody against calcitonin gene-related peptide (CGRP) for adult patients with migraine has yet to be determined. Therefore, we aimed to compare the effectiveness of different monoclonal antibodies against CGRP or its receptor for adult patients with migraine through a network meta-analysis of randomized controlled trials. Methods: We systematically searched the MEDILNE, Embase, ClinicalTrials.gov, and Cochrane Library databases for relevant publications from inception until October 30, 2020. Only randomized clinical trials of adults with migraine that assessed any calcitonin gene-related peptide monoclonal antibody and reported clinical outcomes were included. The primary outcomes were changes in monthly migraine days and treatment-emergent adverse events Results: We initially retrieved 2,070 publications, and ultimately, 18 randomized clinical trials totaling 8,926 patients were included. In terms of efficacy, eptinezumab (MD -1.43, 95% CrI -2.59 to -0.36), erenumab (MD -1.61, 95% CrI -2.40 to -0.84), fremanezumab (MD -2.19, 95% CrI -3.15 to -1.25), and galcanezumab (MD -2.10, 95% CrI -2.76 to -1.45) significantly reduced MMDs compared with placebo. In terms of safety, only galcanezumab increased the incidences of TEAEs (RR 1.11, 95% CrI 1.01-1.22) and serious adverse events (RR 2.95, 95% CrI 1.41-6.87) compared with placebo. Conclusion: Most drugs performed similarly and were superior to placebo in most of our analyses. Further head-to-head research on different types of CGRP monoclonal antibodies is necessary to validate the present findings.

New Insight on the Safety of Erenumab: An Analysis of Spontaneous Reports of Adverse Events Recorded in the US Food and Drug Administration Adverse Event Reporting System Database

AIM

The aim of this article was to provide an overview of adverse events reported for erenumab in post-marketing through the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) and perform a disproportionality analysis with other drugs used for acute or preventative treatment of migraine as controls.

METHODS

FAERS was screened from the first quarter of 2018 to the second quarter of 2020 (latest data update 30 June 2020). Clinical and demographic characteristics of cases were described along with the seriousness and outcome of adverse events. Disproportionality analyses were performed using the reporting odds ratio (ROR).

RESULTS

In total, 23,312 cases were reported during the study period, 67.0% by consumers. Cases in the age range 18-64 years (10,922 cases; 45.8%), in female sex (15,099 cases; 64.8%), and with adverse events that were classified as non-serious (19,626 cases; 84.2%) were the most prevalent in the database. After the exclusion of duplicates, 146 fatal cases were identified. A total of 1303 unlabeled adverse events were reported, of which 49 had statistically significant disproportionality of reporting in comparison with other drugs used for acute or preventative treatment of migraine. Identified disproportionality signals included alopecia, depression, anxiety, myocardial infarction, increased heart rate, pulmonary embolism, weight alteration, insomnia, tinnitus, and influenza-like symptoms. Injection-site reactions (labeled events) were co-reported with errors in administration procedures.

CONCLUSION

Adverse events reported during the first 2 years of post-marketing surveillance were mostly non-serious and with a favorable prognosis. However, new safety aspects emerged for which further studies are needed to confirm the associations, prioritizing unlabeled events with consistent disproportionality signals (e.g., emerging in at least 4 out of 6 analyses).

Indirect Comparison of Topiramate and Monoclonal Antibodies Against CGRP or Its Receptor for the Prophylaxis of Episodic Migraine: A Systematic Review with Meta-Analysis

BACKGROUND

Head-to-head comparator trials between first-line oral migraine preventatives and the new monoclonal antibodies (mAbs) blocking the calcitonin gene-related peptide (CGRP) pathway have not been published to date.

OBJECTIVES

This study aimed to indirectly compare the clinical efficacy and safety of mAbs against CGRP or its receptor (CGRPR) and topiramate in episodic migraine prophylaxis using meta-analysis.

METHODS

We included controlled trials testing efficacy and safety of erenumab, galcanezumab, fremanezumab, eptinezumab, and topiramate in adults diagnosed with episodic migraine. We searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov from January 2000 to November 2020. We used the Risk of Bias 2 (RoB2) tool to assess the risk of bias and report pooled mean effects (mean difference and risk ratio) as estimated in a random effect model. For efficacy analysis, we determined the reduction of monthly migraine days (MMDs), reduction of days with acute medication (AMDs), and 50% responder rates (50% RR). For safety, we determined adverse events (AEs) occurring in ≥ 2% of study participants and the number of patients who discontinue treatment due to AEs (DAEs). The number needed to treat (NNT) and to harm (NNH) were estimated as well as the likelihood to help or harm (LLH).

RESULTS

We included 13 trials involving 7557 patients: three trials with erenumab, two trials with galcanezumab, two trials with fremanezumab, one trial with eptinezumab, and five trials with topiramate, for the prophylaxis of episodic migraine in adults. The placebo-subtracted reduction (pooled mean difference) of MMDs were - 1.55 (95% CI - 1.86 to - 1.24; active drug n = 3326 vs placebo n = 2219, 8 studies) for the CGRP(R) mAb and - 1.11 (95% CI - 1.62 to - 0.59; active drug n = 1032 vs placebo n = 543, 4 studies) for topiramate (p for subgroup difference = 0.15). 'Cognitive' and 'sensory & pain'-related adverse events occurred more often in patients treated with topiramate compared with those treated with a CGRP(R) mAb (p for subgroup difference 0.03 and < 0.001, respectively). Based on the 50% RR and DAE, the NNT, NNH, and LHH for the CGRP(R) mAbs were 6, 130, and 24.3:1, respectively. For topiramate, these values were 7, 9, and 1.8:1, respectively.

CONCLUSION

The efficacy of CGRP(R) mAbs to reduce migraine days does not differ from topiramate. However, the safety profile is in favor of the CGRP(R) mAbs, with a higher likelihood to help than to harm compared with topiramate. The diversity of endpoint determination and the heterogeneity between studies for some endpoints cause some limitations for this study.

Optimal treatment strategy of fremanezumab in migraine prevention: a systematic review with network meta-analysis of randomized clinical trials

Identifying the optimal fremanezumab treatment strategy is crucial in treating patients with migraines. The optimal strategy was investigated by assessing the cumulative 50% reduction rate (50%CRR), cumulative 75% reduction rate (75%CRR), reduction in the number of migraine days, treatment-related adverse events, and serious adverse events in patients treated with fremanezumab 225 mg monthly (225 mg), 675 mg monthly (675 mg), 900 mg monthly (900 mg), a single high dose of 675 mg (S675mg), 675 mg at baseline with 225 mg monthly (675/225 mg), and placebo. Biomedical databases were searched for randomized controlled trials on this topic, and data were individually extracted. Risk ratios and mean differences were used to present the pooled results. The surface under the cumulative ranking curve (SUCRA) was used to determine the effects of the medication strategies of fremanezumab. Five trials (n = 3404) were used to form a six-node network meta-analysis. All fremanezumab medication strategies displayed significantly higher cumulative 50% reduction rates than the placebo. The SUCRA revealed that treatment with 675 mg yielded the highest 50%CRR value (mean rank = 2.5). S675 mg was the only treatment with significantly higher 75%CRR reduction rate than placebo, whereas the SUCRA for 225 mg displayed the highest mean rank (2.2). Moreover, 225 mg (mean rank = 2.2) and S675 mg (mean rank = 2.2) presented lower probabilities of serious adverse events. Collectively, S675mg and 225 mg exhibited the optimal balance between efficacy and safety within three months. Long-term efficacy and safety remain unclear, and future studies should further evaluate the long-term outcomes.

Triptan efficacy does not predict onabotulinumtoxinA efficacy but improves with onabotulinumtoxinA response in chronic migraine patients

Chronic migraine (CM) is a highly disabling primary headache. Botulinum toxin (onabotulinumtoxinA) is effective for treatment of CM, with ~ 50% of patients responding after 24 weeks. A response predictor would prevent unnecessary treatments. Inhibiting calcitonin gene related peptide (CGRP) release from trigeminal nociceptive fibres is one of the modes of acting discussed for onabotulinumtoxinA in CM. Therefore, we hypothesized that the response to triptans might predict response to onabotulinumtoxinA. Contrariwise, onabotulinumtoxinA treatment might affect triptan efficacy. 49 CM patients scheduled for their first onabotulinumtoxinA treatment were included. Before (T0) and three months after (T1) onabotulinumtoxinA treatment, patients rated triptan efficacy and indicated number of headache days/month. At T1, patients additionally rated onabotulinumtoxinA efficacy. Headache days/month were on average reduced by 7.1 ± 7.0 days from T0 to T1 (p < 0.001). Triptan efficacy ratings at T0 did not predict onabotulinumtoxinA efficacy ratings at T1 (p = 0.19) or reduction of headache days (p = 0.37). However, triptan efficacy significantly improved from T0 to T1 in onabotulinumtoxinA responders (p < 0.001) but not in non-responders (p = 1.00). Triptan efficacy did not predict response to onabotulinumtoxinA in CM. However, triptan efficacy increased after successful onabotulinumtoxinA treatment. This supports the hypothesis that efficacy of acute migraine treatment with triptans improves with effective migraine prophylaxis.

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

Background

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

Methods

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

Results

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

Conclusions

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

Effects of Anti-Calcitonin Gene-Related Peptide for Migraines: A Systematic Review with Meta-Analysis of Randomized Clinical Trials

We aimed to evaluate the response rate of migraines by using anti-calcitonin gene-related peptide (anti-CGRP) for patients with migraines. We searched three main medical databases up to 29 March 2019. No restriction on language and publication time were applied. Eligible trials included randomized clinical trials investigating a 50%, 75%, and 100% response rate of migraine patients after anti-CGRP intervention. The collected data were dichotomous, and risk ratios (RRs) with a 95% confidence interval (CI) were used to present the quantitative synthesis results. The systematic review identified 16 eligible randomized clinical trials (RCTs) with 9439 patients. Eight of the 16 trials with 2516 patients reported a 50% response rate, and the pooled results showed a significant benefit from anti-CGRP. However, the effects seem to gradually reduce from the first month (RR 1.99, 95% CI 1.59 to 2.49) to the third month (RR 1.48, 95% CI 1.26 to 1.75) of treatment. The magnitude of effect was influenced by the type of anti-CGRP, according to the test for differences between subgroups (I-square = 53%). The funnel plots and Egger's tests did not show serious small study effects in the results. In conclusion, the current evidences confirmed that anti-CGRP treatment can reduce migraine pain in the short term (within three months), but the long-term effect should be investigated in the future. Moreover, its effects may be influenced by the type and dose of anti-CGRP. Therefore, future studies should make direct comparisons among anti-CGRP medications.

The association between headache and low back pain: a systematic review

Background

To systematically review studies quantifying the association between primary chronic headaches and persistent low back pain (LBP).

Main text

We searched five electronic databases. We included case-control, cross-sectional and cohort studies that included a headache and back pain free group, reporting on any association between persistent LBP and primary headache disorders. Methodological quality was assessed using Newcastle-Ottawa Scale. Our primary outcome was the association between primary headache disorders and persistent LBP. Our secondary outcomes were any associations between severity of LBP and severity of headache, and the relationship between specific headache sub-types classified as per International Classification of Headache Disorders (ICHD) criteria and persistent LBP.

We included 14 studies. The sizes of the studies ranged from 88 participants to a large international study with 404, 206 participants. Odds ratios for the association were between 1.55 (95% confidence interval (CI) 1.13–2.11) and 8.00 (95% CI 5.3–12.1). Study heterogeneity meant statistical pooling was not possible. Only two studies presented data investigating persistent LBP and chronic headache disorders in accordance with ICDH criteria.

Conclusions

We identified a positive association between persistent LBP and primary headache disorders. The quality of the review findings is limited by diversity of populations, study designs and uncertainly about headache and LBP definitions.

Trial registration

PROSPERO 2018 CRD42018086557.

Electronic supplementary material

The online version of this article (10.1186/s10194-019-1031-y) contains supplementary material, which is available to authorized users.

Are antimigraine drugs that influence CGRP levels justified?

Migraine is one of the most common disorders found in everyday clinical practice. Although migraines are not directly life-threatening or permanently disabling, the severity of the pain and symptoms that characterize a migraine attack often prevent normal work and cause difficulties in everyday life. Migraines also affect the patient's family, who often experience stress and depression in response to the patient's condition. Available therapy, used in both acute and chronic treatments, might not provide sufficient improvement. Due to problems like therapy inefficacy, side effects, and intolerance, patients often stop treatments. Recent studies have indicated that drugs that act through calcitonin gene-related peptide (CGRP) can significantly improve migraine therapy. Here, we review results from currently available clinical trials on CGRP receptor antagonists and anti-CGRP monoclonal antibodies.

Gepants for the treatment of migraine

INTRODUCTION

Migraine is the most common of all neurological disorders. A breakthrough in migraine treatment emerged in the early nineties with the introduction of 5-HT1B/D receptor agonists called triptans. Triptans are used as the standard of care for acute migraine; however, they have significant limitations such as incomplete and inconsistent pain relief, high rates of headache recurrence, class- specific side effects and cardiovascular contraindications. First- and second-generation calcitonin gene-related peptide (CGRP) receptor antagonists, namely gepants, is a class of drugs primarily developed for the acute treatment of migraine. CGRP is the most evaluated target for migraine treatments that are in development.

AREAS COVERED

This article reviews the available data for first- and second-generation CGRP receptor antagonists, the role of CGRPs in human physiology and migraine pathophysiology and the possible mechanism of action and safety of CGRP-targeted drugs.

EXPERT OPINION

Available data suggest that second generation of gepants has clinical efficacy similar to triptans and lasmiditan (5-HT1F receptor agonist) and has improved tolerability. Future studies will assess their safety, especially in specific populations such as patients with cardiovascular disease and pregnant women.

Calcitonin-gene-related peptide pathway mAbs and migraine prevention

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

The development of a mouse model of mTBI-induced post-traumatic migraine, and identification of the delta opioid receptor as a novel therapeutic target

BACKGROUND

Post-traumatic headache is the most common and long-lasting impairment observed following mild traumatic brain injury, and frequently has migraine-like characteristics. The mechanisms underlying progression from mild traumatic brain injury to post-traumatic headache are not fully understood. The aim of this study was to develop a mouse model of post-traumatic headache and identify mechanisms and novel targets associated with this disorder.

METHODS

We combined the closed head weight-drop method and the nitroglycerin chronic migraine model. To induce mild traumatic brain injury, a weight was dropped onto intact crania of mildly anesthetized mice, and mechanical responses to chronic-intermittent administration of nitroglycerin, a human migraine trigger, were determined at multiple time points post-injury.

RESULTS

Low dose nitroglycerin (0.1 mg/kg) evoked acute periorbital and hind paw allodynia in both mild traumatic brain injury and sham animals. However, only mild traumatic brain injury mice developed chronic hypersensitivity to low dose nitroglycerin. Migraine medications, sumatriptan and topiramate, inhibited post-traumatic headache-associated allodynia. In addition, the delta opioid receptor agonist, SNC80, also blocked post-traumatic headache-associated allodynia. Finally, we examined the expression of calcitonin gene-related peptide within this model and found that it was increased in trigeminal ganglia two weeks post-mild traumatic brain injury.

CONCLUSIONS

Overall, we have established a mouse model of post-traumatic headache and identified the delta opioid receptor as a novel therapeutic target for this disorder.

Refining the Benefit/Risk Profile of Anti-Epileptic Drugs in Headache Disorders

Anti-epileptic drugs are among the most effective drugs for migraine prophylaxis, and will likely continue to have a role even as new therapies emerge. Topiramate and valproate are effective for the preventive treatment of migraine, and other medications such as gabapentin or lamotrigine may have a role in the treatment of those with allodynia or frequent aura, respectively. Oxcarbazepine, carbamazepine, phenytoin, gabapentin, and others may alleviate pain in trigeminal neuralgia. While many anti-epileptic drugs can be effective in those with migraine or other headaches, most of these agents can potentially cause serious side effects. In particular, valproate, topiramate, carbamazepine, and phenytoin may lead to adverse outcomes for infants of exposed mothers. Valproate should not be given to women of childbearing potential for migraine prevention.

The Application of CGRP(r) Monoclonal Antibodies in Migraine Spectrum: Needs and Priorities

Migraine is among the highest impact illnesses in the global population. Its negative ramifications are personal, social, economic and work related. Research on the development of new preventative migraine therapies has been idle for decades. The introduction, shortly, of an innovative pharmacological class useful for migraine prevention, namely monoclonal antibodies towards calcitonin gene-related peptide or its receptor, opens a new, immense therapeutic scenario. The necessity to manage the chronic and refractory forms of migraine must not take our attention away from the target of the pre-chronic forms. This is the most important target in every study. Indeed, by reducing the evolution towards chronic and consequently refractory chronic migraine, we will reduce complications caused by pharmacological abuse, the serious disability of these devastating chronic states, and the healthcare expenses needed to manage chronicity, abuse and consequent pathologies. We will, lastly, be able to rehabilitate these patients to achieve a quality working and social life, and facilitate their reintegration into daily normality.

Side effects associated with current and prospective antimigraine pharmacotherapies

INTRODUCTION

Migraine is a neurovascular disorder. Current acute specific antimigraine pharmacotherapies target trigeminovascular 5-HT1B/1D, 5-HT1F and CGRP receptors but, unfortunately, they induce some cardiovascular and central side effects that lead to poor treatment adherence/compliance. Therefore, new antimigraine drugs are being explored. Areas covered: This review considers the adverse (or potential) side effects produced by current and prospective antimigraine drugs, including medication overuse headache (MOH) produced by ergots and triptans, the side effects observed in clinical trials for the new gepants and CGRP antibodies, and a section discussing the potential effects resulting from disruption of the cardiovascular CGRPergic neurotransmission. Expert opinion: The last decades have witnessed remarkable developments in antimigraine therapy, which includes acute (e.g. triptans) and prophylactic (e.g. β-adrenoceptor blockers) antimigraine drugs. Indeed, the triptans represent a considerable advance, but their side effects (including nausea, dizziness and coronary vasoconstriction) preclude some patients from using triptans. This has led to the development of the ditans (5-HT1F receptor agonists), the gepants (CGRP receptor antagonists) and the monoclonal antibodies against CGRP or its receptor. The latter drugs represent a new hope in the antimigraine armamentarium, but as CGRP plays a role in cardiovascular homeostasis, the potential for adverse cardiovascular side effects remains latent.

Calcitonin gene-related peptide receptor as a novel target for the management of people with episodic migraine: current evidence and safety profile of erenumab

Migraine is a highly disabling neurological condition, and preventative treatment still remains problematic, due to aspecificity of the majority of the currently available prophylactic drugs. Calcitonin-gene-related peptide (CGRP) plays a crucial role in migraine pathophysiology; agents aimed at blocking its activity have, therefore, been developed in recent years, among which are monoclonal antibodies (mAbs) against CGRP, to prevent migraine. Erenumab is the only mAb that targets the CGRP receptor instead of the ligand, with high specificity and affinity of binding. This review will report on the most recent data on erenumab characteristics and on the results of clinical trials on its employment in the prevention of episodic migraine (4–14 monthly migraine days): one Phase II and two Phase III trials (completed) and one Phase III trial (ongoing). Monthly subcutaneous administration (70 mg or 140 mg) of erenumab vs placebo for 3–6 months showed significantly higher efficacy in reducing the mean monthly number of migraine days and the use of migraine-specific medication, and in decreasing physical impairment and impact of migraine on everyday activities (P<0.001). A favorable safety profile was demonstrated by the lack of significant differences in the occurrence of adverse events in erenumab-treated vs placebo-treated patients. Global results so far obtained point to erenumab as a new promising candidate for the preventative treatment of episodic migraine. Licence applications for erenumab were recently submitted to the Food and Drug Administration in the USA and European Medicines Agency in Europe (May/June 2017).

Update on the pharmacology of calcitonin/CGRP family of peptides: IUPHAR Review 25

The calcitonin/CGRP family of peptides includes calcitonin, α and β CGRP, amylin, adrenomedullin (AM) and adrenomedullin 2/intermedin (AM2/IMD). Their receptors consist of one of two GPCRs, the calcitonin receptor (CTR) or the calcitonin receptor-like receptor (CLR). Further diversity arises from heterodimerization of these GPCRs with one of three receptor activity-modifying proteins (RAMPs). This gives the CGRP receptor (CLR/RAMP1), the AM₁ and AM₂ receptors (CLR/RAMP2 or RAMP3) and the AMY_1, AMY₂ and AMY₃ receptors (CTR/RAMPs1-3 complexes, respectively). Apart from the CGRP receptor, there are only peptide antagonists widely available for these receptors, and these have limited selectivity, thus defining the function of each receptor in vivo remains challenging. Further challenges arise from the probable co-expression of CTR with the CTR/RAMP complexes and species-dependent splice variants of the CTR (CT_(a) and CT_(b) ). Furthermore, the AMY_1(a) receptor is activated equally well by both amylin and CGRP, and the preferred receptor for AM2/IMD has been unclear. However, there are clear therapeutic rationales for developing agents against the various receptors for these peptides. For example, many agents targeting the CGRP system are in clinical trials, and pramlintide, an amylin analogue, is an approved therapy for insulin-requiring diabetes. This review provides an update on the pharmacology of the calcitonin family of peptides by members of the corresponding subcommittee of the International Union of Basic and Clinical Pharmacology and colleagues.

Pituitary adenylate cyclase-activating polypeptide receptors in the trigeminovascular system: implications for migraine

The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) has been implicated in a wide range of functions including vasodilatation, neuroprotection, nociception and neurogenic inflammation. PACAP activates three distinct receptors, the PAC₁ receptor, which responds to PACAP, and the VPAC₁ and VPAC₂ receptors, which respond to both PACAP and vasoactive intestinal polypeptide. The trigeminovascular system plays a key role in migraine and contains the trigeminal nerve, which is the major conduit of craniofacial pain. PACAP is expressed throughout the trigeminovascular system and in higher brain regions involved in processing pain. Evidence from human clinical studies suggests that PACAP may act outside the blood-brain barrier in the pathogenesis of migraine. However, the precise mechanisms involved remain unclear. PACAP potentially induces migraine attacks by activating different receptors in different cell types and tissues. This complexity prompted this review of PACAP receptor pharmacology, expression and function in the trigeminovascular system. Current evidence suggests that the PAC₁ receptor is the likely pathophysiological target of PACAP in migraine. However, multiple PACAP receptors are expressed in key parts of the trigeminovascular system and further work is required to determine their contribution to PACAP physiology and the pathology of migraine.

LINKED ARTICLES

This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc.

The KATP channel in migraine pathophysiology: a novel therapeutic target for migraine

BACKGROUND

To review the distribution and function of KATP channels, describe the use of KATP channels openers in clinical trials and make the case that these channels may play a role in headache and migraine.

DISCUSSION

KATP channels are widely present in the trigeminovascular system and play an important role in the regulation of tone in cerebral and meningeal arteries. Clinical trials using synthetic KATP channel openers report headache as a prevalent-side effect in non-migraine sufferers, indicating that KATP channel opening may cause headache, possibly due to vascular mechanisms. Whether KATP channel openers can provoke migraine in migraine sufferers is not known.

CONCLUSION

We suggest that KATP channels may play an important role in migraine pathogenesis and could be a potential novel therapeutic anti-migraine target.