Phase I, Randomized, Double-blind, Placebo-controlled, Single-dose, and Multiple-dose Studies of Erenumab in Healthy Subjects and Patients With Migraine

Long-Term Outcome After Discontinuation of CGRP-Targeting Therapy for Migraine

PURPOSE OF REVIEW

Calcitonin gene-related peptide (CGRP)-targeting agents are potential candidates for disease-modifying migraine drugs. However, most studies on CGRP-targeting agents have assessed efficacy outcomes rather than long-term effects after discontinuation. This review aimed to synthesize and scrutinize the latest clinical data on the outcomes after the discontinuation of CGRP-targeting therapy in patients with episodic and chronic migraine, with a particular focus on chronic migraine.

RECENT FINDINGS

Real-world studies involving patients with migraine have reported consistent findings of worsened headache frequency and quality of life after the discontinuation of CGRP monoclonal antibodies (CGRP mAbs). Although many patients maintain improvements for up to 4 months after discontinuation compared to baseline (before starting CGRP mAbs), no studies have evaluated the effects of stopping treatment for > 5 months, which is the five-half-life of CGRP mAbs. Several studies have suggested that patients treated with CGRP receptor mAbs experience more rapid deterioration than those treated with CGRP ligand mAbs after discontinuing CGRP mAbs. The results of real-world studies suggest that for many patients with migraine, the benefits of CGRP mAbs diminish months after discontinuation. Therefore, anti-CGRP therapies may not be considered disease-modifying. However, the comprehensive assessment of the disease-modifying potential of these drugs requires studies with extended treatment and cessation durations.

Induction of cGMP-mediated migraine attacks is independent of CGRP receptor activation

BACKGROUND

The cAMP and cGMP pathways are implicated in the initiation of migraine attacks, but their interactions remain unclear. Calcitonin gene-related peptide (CGRP) triggers migraine attacks via cAMP, whereas the phosphodiesterase-5 inhibitor sildenafil induces migraine attacks via cGMP. Our objective was to investigate whether sildenafil could induce migraine attacks in individuals with migraine pre-treated with the CGRP-receptor antibody erenumab.

METHODS

In this randomized, double-blind, placebo-controlled, cross-over study, adults with migraine without aura received a single subcutaneous injection of 140 mg erenumab on day 1. They were then randomized to receive sildenafil 100 mg or placebo on two experimental days, each separated by at least one week, between days 8 and 21. The primary endpoint was the difference in the incidence of migraine attacks between sildenafil and placebo during the 12-h observation period after administration.

RESULTS

In total, 16 participants completed the study. Ten participants (63%) experienced a migraine attack within 12 h after sildenafil administration compared to three (19%) after placebo (p = 0.016). The median headache intensity was higher after sildenafil than after placebo (area under the curve (AUC) for the 12-h observation period, p = 0.026). Furthermore, sildenafil induced a significant decrease in mean arterial blood pressure (AUC, p = 0.026) and a simultaneous increase in heart rate (AUC, p < 0.001) during the first hour after administration compared to placebo.

CONCLUSION

These findings provide evidence that migraine induction via the cGMP pathway can occur even under CGRP receptor blockade.

TRIAL REGISTRATION

ClinicalTrials.gov: Identifier NCT05889455.

Anti-calcitonin Gene-Related Peptide Monoclonal Antibodies in Migraine: Focus on Clinical Pharmacokinetics

The calcitonin gene-related peptide transmission was the target for recent development of drugs that effectively prevent attacks of both episodic and chronic migraine. The aim of this narrative review was to offer deeper insight into pharmacokinetics of monoclonal antibodies approved for prevention of migraine attacks. For this narrative review, relevant literature was searched for in MEDLINE and Google Scholar databases, covering periods 1966-2023 and 2006-2023, respectively. The ClinicalTrials.gov database was also searched for relevant clinical studies whose results had not been published previously in medical journals, covering the period 2000-2023. The monoclonal antibodies from this group are distributed mainly in the plasma and part of the extracellular space; they are neither metabolized in the liver nor excreted via the kidneys. The elimination of galcanezumab, eptinezumab and fremanezumab takes place only by a non-specific linear process via the reticuloendothelial system in the liver, while erenumab is eliminated by a non-specific process and by a specific, saturable process because of binding to receptors located on the cell membrane. Since the elimination processes do not have a large capacity, the half-life is about 2 weeks for erenumab and about 4 weeks for other monoclonal antibodies. Variability in the pharmacokinetics of these monoclonal antibodies is small in different subpopulations, and body weight is the only parameter to consider when choosing the dose of these drugs.

Switching CGRP(r) MoAbs in migraine: what evidence?

INTRODUCTION

Approximately 50% of patients that receive a CGRP(r) MoAb for the preventative treatment of migraine are expected to discontinue therapy. For patients that discontinue CGRP(r) MoAb therapy, few clinical options are available. One potential option is to switch CGRP(r) MoAbs, however, data concerning the efficacy of this intervention is scarce.

AREAS COVERED

This manuscript aims to summarize all available data concerning the potential efficacy of switching CGRP(r) MoAbs following previous medication discontinuation. Data was sourced by completing a database search for the terms: 'CGRP monoclonal antibody switch OR CGRP monoclonal antibody switching.'

EXPERT OPINION

While data considering the potential efficacy of CGRP(r) switching continues to grow, our expert opinion supports the most recent European Headache Federation statement regarding CGRP(r) MoAb prescribing practices, concluding that there remains insufficient data to determine the efficacy of this intervention. As this topic is of significant clinical importance, we recommend a call-to-action to expand on current data considering the therapeutic options for patients that discontinue CGRP(r) MoAb therapy.

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

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

Pharmacokinetics and safety of erenumab in pediatric patients with migraine: A phase I, randomized, open-label, multiple-dose study

Erenumab, a fully human monoclonal antibody targeting the calcitonin gene-related peptide receptor, is efficacious and safe for prevention of attacks of migraine in adults. This phase I, randomized, open-label, multiple-dose study evaluated the safety, tolerability, and pharmacokinetics (PK) of erenumab in children and adolescents with migraine. The initial treatment phase lasted 12 weeks, followed by an optional 40-week extension phase for adolescents. Primary end points were PK of erenumab, incidence of treatment-emergent adverse events (TEAEs), and changes in clinical and laboratory assessments. Participants received erenumab 35 mg (n = 4), 70 mg (n = 17), or 140 mg (n = 32) q4w. The mean age was 14.1 years. Of the 53 participants, 48 (90.6%) completed the initial treatment phase and 36 (67.9%) received erenumab during the extension phase. Mean exposures to erenumab based on the maximum observed concentration and the area under the drug concentration-time curve during the dosing interval increased approximately dose-proportionally. A total of 42 participants (79.2%) reported TEAEs (307.2 per 100 participant-years); and four (7.5%) reported serious TEAEs not considered treatment-related. The most common TEAEs were upper respiratory tract infection, headache, and vomiting. No clinically significant changes were reported in vital signs, electrocardiograms, and laboratory and neurological assessments. Overall, the observed PK profile of erenumab in children and adolescents with migraine is consistent with that in adults when body weight differences are taken into consideration. The safety profile of erenumab in children and adolescents is consistent with that in adults.

IUPHAR review: Navigating the role of preclinical models in pain research

Chronic pain is a complex and challenging medical condition that affects millions of people worldwide. Understanding the underlying mechanisms of chronic pain is a key goal of preclinical pain research so that more effective treatment strategies can be developed. In this review, we explore nociception, pain, and the multifaceted factors that lead to chronic pain by focusing on preclinical models. We provide a detailed look into inflammatory and neuropathic pain models and discuss the most used animal models for studying the mechanisms behind these conditions. Additionally, we emphasize the vital role of these preclinical models in developing new pain-relief drugs, focusing on biologics and the therapeutic potential of NMDA and cannabinoid receptor antagonists. We also discuss the challenges of TRPV1 modulation for pain treatment, the clinical failures of neurokinin (NK)- 1 receptor antagonists, and the partial success story of Ziconotide to provide valuable lessons for preclinical pain models. Finally, we highlight the overall success and limitations of current treatments for chronic pain while providing critical insights into the development of more effective therapies to alleviate the burden of chronic pain.

Activation of ATP-sensitive potassium channels triggers migraine attacks independent of calcitonin gene-related peptide receptors: a randomized placebo-controlled trial

BACKGROUND

The present study aimed to investigate whether levcromakalim, a KATP channel opener, induces migraine attacks in people with migraine pre-treated with erenumab, a monoclonal CGRP receptor antibody.

METHODS

In this double-blind, placebo-controlled, two-way cross-over study, adults with migraine without aura received a subcutaneous injection of 140 mg of erenumab on day 1. Subsequently, they were randomized to receive a 20-minute infusion of 0.05 mg/ml levcromakalim or placebo on two experimental days separated by at least one week (between days 8 and 21). The primary endpoint was the difference in the incidence of migraine attacks between levcromakalim and placebo during the 12-hour post-infusion period.

RESULTS

In total, 16 participants completed the study. During the 12-hour observation period, 14 (88%) of 16 participants experienced migraine attacks after levcromakalim, compared to two (12%) after placebo (p < 0.001). The area under the curve for median headache intensity was greater after levcromakalim than placebo (p < 0.001). Levcromakalim elicited dilation of the superficial temporal artery during the first hour after infusion, a response absent following placebo (p < 0.001).

CONCLUSIONS

The induction of migraine attacks via opening of KATP channels appears independent of CGRP receptor activation.Trial Registration: ClinicalTrials.gov, Identifier NCT05889442.

Pharmacological characterisation of erenumab, Aimovig, at two calcitonin gene-related peptide responsive receptors

BACKGROUND AND PURPOSE

Calcitonin gene-related peptide (CGRP) is involved in migraine pathophysiology. CGRP can signal through two receptors. The canonical CGRP receptor comprises the calcitonin receptor-like receptor and receptor activity-modifying protein 1 (RAMP1); the AMY1 receptor comprises the calcitonin receptor with RAMP1. Drugs that reduce CGRP activity, such as receptor antagonists, are approved for the treatment and prevention of migraine. Despite being designed to target the canonical CGRP receptor, emerging evidence suggests that these antagonists, including erenumab (a monoclonal antibody antagonist) can also antagonise the AMY1 receptor. However, it is difficult to estimate its selectivity because direct comparisons between receptors under matched conditions have not been made. We therefore characterised erenumab at both CGRP-responsive receptors with multiple ligands, including αCGRP and βCGRP.

EXPERIMENTAL APPROACH

Erenumab antagonism was quantified through IC50 and pKB experiments, measuring cAMP production. We used SK-N-MC cells which endogenously express the human CGRP receptor, and HEK293S and Cos7 cells transiently transfected to express either human CGRP or AMY1 receptors.

KEY RESULTS

Erenumab antagonised both the CGRP and AMY1 receptors with an ~20-120-fold preference for the CGRP receptor, depending on the cells, agonist, analytical approach and/or assay format. Erenumab antagonised both forms of CGRP equally, and appeared to act as a competitive reversible antagonist at both receptors.

CONCLUSION AND IMPLICATIONS

Despite being designed to target the CGRP receptor, erenumab can antagonise the AMY1 receptor. Its ability to antagonise CGRP activity at both receptors may be useful in better understanding the clinical profile of erenumab.

Second messenger signalling bypasses CGRP receptor blockade to provoke migraine attacks in humans

There are several endogenous molecules that can trigger migraine attacks when administered to humans. Notably, calcitonin gene-related peptide (CGRP) has been identified as a key player in a signalling cascade involved in migraine attacks, acting through the second messenger cyclic adenosine monophosphate (cAMP) in various cells, including intracranial vascular smooth muscle cells. However, it remains unclear whether intracellular cAMP signalling requires CGRP receptor activation during a migraine attack in humans. To address this question, we conducted a randomized, double-blind, placebo-controlled, parallel trial using a human provocation model involving the administration of CGRP and cilostazol in individuals with migraine pretreated with erenumab or placebo. Our study revealed that migraine attacks can be provoked in patients by cAMP-mediated mechanisms using cilostazol, even when the CGRP receptor is blocked by erenumab. Furthermore, the dilation of cranial arteries induced by cilostazol was not influenced by the CGRP receptor blockade. These findings provide clinical evidence that cAMP-evoked migraine attacks do not require CGRP receptor activation. This discovery opens up new possibilities for the development of mechanism-based drugs for the treatment of migraine.

Retreating migraine patients in the second year with monoclonal antibodies anti-CGRP pathway: the multicenter prospective cohort RE-DO study

BACKGROUND

The outcome of migraine patients retreated with monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (anti-CGRP) or its receptor (anti-CGRPr) is not completely known.

METHODS

This multicentric prospective observational cohort study assessed monthly migraine days (MMDs), migraine acute medication intake (MAMI), and HIT-6 at baseline, after 90-112 days (Rev-1), after 84-90 days since Rev-1 (Rev-2) and 30 days after the last injection of anti-CGRP/CGRPr mAbs (Year-end), in the first and the second year after a discontinuation period.

RESULTS

We enrolled 226 patients (79.6% with chronic migraine; 55.3% on erenumab and 44.7% on galcanezumab or fremanezumab). MMDs, MAMI, and HIT-6-did not differ at the respective first and second-year evaluations in the entire cohort, and comparing anti-CGRP with anti-CGRPr Abs. MMDs (18.1 ± 7.8 vs. 3.4 ± 7.8), MAMI (26.7 ± 28.3 vs.17.7 ± 17.2), and HIT-6 scores (63.1 ± 5.9 vs. 67.1 ± 10.3) were lower in the second year than in the pre-treatment baseline (consistently, p < 0.0001). Second-year baseline MMDs were lower in patients on anti-CGRP mAbs (p = 0.001) and with lower pre-treatment baseline MMDs (p ≤ 0.001).

CONCLUSION

Anti-CGRP/CGRPr mAbs are effective in the second as in the first year. The use of anti-CGRP or CGRPr mAbs influenced the second-year baseline MMDs, but their effectiveness did not differ during the two treatment years.

The vascular role of CGRP: a systematic review of human studies

Intravenous infusion of human alpha calcitonin gene-related peptide (h-α-CGRP) has been applied to explore migraine pathogenesis and cerebral hemodynamics during the past three decades. Cumulative data implicate h-α-CGRP in regulating the vascular tone. In this systematic review, we searched PubMed and EMBASE for clinical studies investigating the vascular changes upon intravenous infusion of h-α-CGRP in humans. A total of 386 studies were screened by title and abstract. Of these, 11 studies with 61 healthy participants and 177 participants diagnosed with migraine were included. Several studies reported hemodynamic effects including flushing, palpitation, warm sensation, heart rate (HR), mean arterial blood pressure (MABP), mean blood flow velocity of middle cerebral artery (mean V_MCA), and diameter of superficial temporal artery (STA). Upon the start of h-α-CGRP infusion, 163 of 165 (99%) participants had flushing, 98 of 155 (63%) participants reported palpitation, and 160 of 165 (97%) participants reported warm sensation. HR increased with 14%-58% and MABP decreased with 7%-12%. The mean V_MCA was decreased with 9.5%-21%, and the diameter of the STA was dilated with 41%-43%. The vascular changes lasted from 20 to >120 min. Intravenous infusion of h-α-CGRP caused a universal vasodilation without any serious adverse events. The involvement of CGRP in the systemic hemodynamic raises concerns regarding long-term blockade of CGRP in migraine patients with and without cardiovascular complications.

Revisiting dose-finding of monoclonal antibodies in migraine

Migraine is a debilitating disorder, and while the introduction of monoclonal antibodies (mAbs) has led to efficacious and tolerable responses, a substantial number of patients are so-called "non-responders". We introduce reasons for this insufficient response, including insufficient blockade of Calcitonin Gene-Related Peptide (CGRP) or its receptor. We present a clinical case, i.e. a female migraine patient who mistakenly administered supratherapeutic (three-fold higher) doses of erenumab leading to more efficacious clinical responses without any side-effects. This example illustrates that the initial dosages might have been too low, resulting in a remaining undesired increased effect of CGRP. While a capsaicin forearm model has repeatedly been used to evaluate the pharmacokinetic-pharmacodynamic relationship of mAbs, we provide directions to revisit or reconsider dose-finding and dose-ranging of these drugs. These directions include (i) refinement and application of a capsaicin forehead model (instead of a forearm model) to study trigeminovascular activity and improve dosing, and (ii) reconsideration of trial populations. Indeed, the dose-finding studies were mainly performed in relatively young and normal-weight males, while most phase III/IV trials are marked by a high female-to-male ratio, mainly consisting of overweight to obese females. Considering these aspects in future trials could optimize healthcare for a larger proportion of migraine patients.

Pharmacokinetics and Safety of Erenumab after a Single Subcutaneous Injection Dose in Healthy Chinese Subjects

BACKGROUND AND OBJECTIVE

Erenumab is the first-in-class, selective, and competitive human monoclonal antibody antagonist of the calcitonin gene-related peptide (CGRP) receptor that has been shown to be effective and well-tolerated in the preventive therapy of episodic and chronic migraine. The pharmacokinetics of erenumab may be affected by differences in race and ethnicity, which can lead to suboptimal outcomes. The present study was conducted to assess the single-dose pharmacokinetics and safety of erenumab in healthy Chinese subjects.

METHODS

This was an open-label, randomized, parallel group, non-confirmatory, single-dose study in healthy Chinese subjects. A total of 24 healthy Chinese subjects of both sexes aged between 14 and 45 years were administered a single subcutaneous injection of erenumab 70 mg or 140 mg. The serum concentration of erenumab was quantified using a validated enzyme-linked immunosorbent assay method and pharmacokinetic parameters were determined using non-compartmental models. Safety was also assessed.

RESULTS

A total of 55 subjects were screened for eligibility and 25 subjects were randomized to receive study treatments (12 subjects to the 70-mg erenumab group and 13 subjects to the 140-mg erenumab group). Erenumab was absorbed slowly with maximum serum concentration (Cmax) occurring 3-11 days after administration. The mean Cmax and area under the serum concentration versus time curve from time 0 to infinity with extrapolation of the terminal phase (AUC0-∞) were 9.20 µg/mL and 296 day·µg/mL for the 70 mg dose group, and 15.6 µg/mL and 569 day·µg/mL for the 140 mg dose group, respectively. Serum concentrations of erenumab exhibited low to high variability, with variable coefficients ranging from 17.1 to 72.2% for the 70-mg dose and 32.5 to 88.5% for the 140-mg dose. All adverse events were mild or moderate in intensity, and all resolved without intervention.

CONCLUSIONS

Erenumab was safe and well tolerated after a single subcutaneous injection in healthy Chinese subjects. The systemic exposure in Chinese subjects in terms of AUC0-∞ was 70% higher than that in White subjects as previously reported.

CHINESE CLINICAL TRIAL REGISTRY NO

ChiCTR2000032435.

First-in-human development of a pharmacodynamic biomarker for PAC1 receptor antagonists using intradermal injections of maxadilan

Maxadilan, a potent vasodilator peptide, selectively activates the PAC₁ receptor, a promising target for migraine therapy. Therefore, maxadilan has been suggested as a tool to study the pharmacodynamics (PDs) of PAC₁ receptor antagonists. The objectives of this first-in-human study were to: (1) determine the safety, tolerability, dose response, and time course of the dermal blood flow (DBF) changes after intradermal (i.d.) injections of maxadilan in the human forearm, and (2) assess the inter-arm and inter-period reproducibility of this response. This was a single-center, open-label study in healthy subjects, comprising three parts: (1) dose-response (n = 25), (2) response duration (n = 10), and (3) reproducibility (n = 15). DBF measurements were performed using laser Doppler imaging (LDI) up to 60 min postinjection, or up to 5 days for the response duration assessments. To assess reproducibility, the intraclass correlation coefficient (ICC) and sample sizes were calculated. The i.d. maxadilan (0.001, 0.01, 0.1, 0.9, 3, and 10 ng) produced a well-tolerated, dose-dependent increase in DBF, with a half-maximal effective concentration fitted at 0.0098 ng. The DBF response to 0.9 ng maxadilan was quantifiable with LDI up to 72 h postinjection. The inter-period reproducibility of the DBF response was better upon 0.9 ng (ICC > 0.6) compared to 0.01 ng (ICC < 0.4) maxadilan. However, irrespective of the study design or maxadilan dose, a sample size of 11 subjects is sufficient to detect a 30% difference in DBF response with 80% power. In conclusion, intradermal maxadilan provides a safe, well-tolerated, and reproducible PD biomarker for PAC₁ receptor antagonists in vivo in humans.

Erenumab for episodic migraine

In this review, the authors provide an overview of erenumab, a monoclonal antibody used for the preventative treatment of episodic migraine by targeting the CGRP pathway. Randomized controlled trials have shown that erenumab is associated with a statistically significant decrease in monthly migraine days in patients with episodic migraine at monthly doses of 70 or 140 mg when given for a period of 9-12 weeks. Post hoc analyses have also shown long-term maintenance of efficacy. Clinical trials have found erenumab at doses of both 70 and 140 mg to have a favorable safety profile. Erenumab faces significant limitations because of its high financial cost. Additional long-term real-world data are needed to understand the role of erenumab in the treatment of migraine.

Post-marketing safety surveillance of erenumab: new insight from Eudravigilance

BACKGROUND

We aimed at evaluating adverse drug reactions during the post-marketing phase with erenumab as the suspected/interacting drug in Eudravigilance, with the final goal of investigating the consistency of the disproportionality signals (DS) for erenumab in Eudravigilance and the American Food and Drug Administration Adverse Event Reporting System (FDA FAERS) and undetected disproportionality signals from Eudravigilance.

RESEARCH DESIGN AND METHODS

Eudravigilance was screened in the period from October 2019 to October 2020. Disproportionality measure was performed using the Reporting Odds Ratio (ROR) according to the guidelines by the European Medicine Agency and using sumatriptan as the control group.

RESULTS

3381 cases were reported in the study period. Forty DS were identified both in Eudravigilance and FAERS. Sixteen DS were not identified in FAERS, 10 DS were found to have a biological probability and six DS were considered false-positive and potentially related to confounding by indication. The three system organ classes with the highest proportion of adverse events were general disorders and administration site conditions (16.12%), nervous system disorders (15.95%), and gastrointestinal disorders (13.59%).

CONCLUSIONS

Adverse events reports were mostly reported as non-serious. The co-analysis of multiple spontaneous reported databases unveiled undetected disproportionality signals for erenumab in individual databases. Future studies should be conducted to confirm the associations and potential clinical implications.

Deterioration of headache impact and health-related quality of life in migraine patients after cessation of preventive treatment with CGRP(-receptor) antibodies

Background

Migraine preventive treatment with CGRP(−receptor) monoclonal antibodies (mAbs) has a positive effect on patients’ health-related quality of life (HRQoL). The German treatment guidelines recommend discontinuing successful treatment with CGRP(−receptor) mAbs after 6–12 months. We aimed to evaluate headache-specific and generic HRQoL for three months after discontinuation of CGRP(−receptor) mAb treatment.

Methods

We conducted a prospective, longitudinal cohort study, including patients with migraine after 8–12 months of therapy with a CGRP(−R) mAb and before a planned discontinuation attempt. HRQoL was assessed at the time of the last mAbs injection (V1), eight weeks later (V2), and sixteen weeks later (V3). For headache-specific HRQoL, we used the Headache Impact Test-6 (HIT-6). Generic HRQoL was determined with the EuroQol-5-Dimension-5-Level (ED-5D-5L) form, and the Short-Form 12 (SF-12), which comprises a Physical Component Summary (PCS-12) and a Mental Component Summary (MCS-12).

Questionnaires’ total scores were compared across the three observation points using nonparametric procedures.

Results

The study cohort consisted of n = 61 patients (n = 29 treated with the CGRP-receptor mAb erenumab and n = 32 with the CGRP mAbs galcanezumab or fremanezumab). The HIT-6 sum score was 59.69 ± 6.90 at V1 and increased by 3.69 ± 6.21 at V3 (p < 0.001), indicating a greater headache impact on patients’ lives. The mean total EQ-D5-L5 score declined from 0.85 ± 0.17 at V1 by − 0.07 ± 0.18 at V3 (p = 0.013). Both Mental and Physical Component Scores of the SF-12 worsened significantly during treatment discontinuation: The PCS-12 total score decreased by − 4.04 ± 7.90 from V1 to V3 (p = 0.013) and the MCS-12 score by − 2.73 ± 9.04 (p = 0.003). Changes in all questionnaires’ scores but the MCS-12 were already significant in the first month of the drug holiday (V2).

Conclusions

Our results show a significant decline in headache impact and generic HRQoL of migraine patients after treatment discontinuation of a CGRP(−R) mAb. The observed deterioration is above the established minimally clinically important differences for each of the questionnaires and can therefore be considered clinically meaningful. Monitoring HRQoL during a discontinuation attempt could facilitate the decision whether or not to resume preventive treatment with CGRP(−R) mAbs.

Risk of hypertension in erenumab-treated patients with migraine: Analyses of clinical trial and postmarketing data

Objective

To assess the risk of hypertension in patients with migraine who received erenumab in clinical trials and in the postmarketing setting.

Background

Erenumab is a monoclonal antibody for migraine prevention that targets the calcitonin gene‐related peptide (CGRP) receptor. Hypertension is a theoretical risk for inhibitors of the CGRP pathway. Although no evidence of an association between erenumab treatment and hypertension was observed during the clinical development program, adverse events (AEs) of hypertension have been identified in the postmarketing setting.

Methods

Safety data from four phase 2 and phase 3 clinical trials were used to perform a pooled analysis of hypertension AEs in patients with migraine receiving erenumab. Postmarketing AEs of hypertension were identified from the Amgen Global Safety database from May 17, 2018, through January 31, 2020.

Results

In the pooled analysis of clinical trials, hypertension AEs (placebo, 9/1043 [0.9%]; erenumab 70 mg, 7/893 [0.8%]; erenumab 140 mg, 1/507 [0.2%]) and percentage of patients initiating medication to treat hypertension (12/1043 [1.2%], 7/893 [0.8%], 1/507 [0.2%], respectively) were similar across treatment groups. A total of 362 AEs of hypertension were identified from the postmarketing setting, 26.2% (95/362) of which were serious, >245,000 patient‐years of exposure. The exposure‐adjusted incidence of hypertension was 0.144 per 100 patient‐years.

Conclusions

Clinical trials did not demonstrate an increased risk of hypertension with erenumab compared with placebo, and AE rates of hypertension reported with erenumab in the postmarketing setting were generally low. Additional data are needed to fully characterize the extent to which hypertension is a risk associated with erenumab.

Migraine evolution after the cessation of CGRP(-receptor) antibody prophylaxis: a prospective, longitudinal cohort study

BACKGROUND

National and international guidelines recommend stopping migraine prophylaxis with CGRP(-receptor) monoclonal antibodies after 6-12 months of successful therapy. In this study, we aimed to analyze the course of migraine for four months after the cessation of CGRP(-receptor) antibodies use.

METHODS

This longitudinal cohort study included patients with migraine who received a CGRP-(receptor) antibody for ≥8 months before treatment cessation. We analyzed headache data in the four-week period prior to mAb treatment initiation (baseline), in the month before the last mAb injection, in weeks 5-8 and 13-16 after last treatment. Primary endpoint of the study was the change of monthly migraine days from the month before last treatment to weeks 13-16. Secondary endpoints were changes in monthly headache days and monthly days with acute medication use.

RESULTS

A total of 62 patients equally distributed between prophylaxis with the CGRP-receptor antibody erenumab and the CGRP antibodies galcanezumab or fremanezumab participated in the study. Patients reported 8.2 ± 6.6 monthly migraine days in the month before last treatment. Monthly migraine days gradually increased to 10.3 ± 6.8 in weeks 5-8 (p = 0.001) and to 12.5 ± 6.6 in weeks 13-16 (p < 0.001) after drug cessation. Monthly migraine days in weeks 13-16 were not different from baseline values (-0.8 ± 5.4; p > 0.999). Monthly headache days and monthly days with acute medication use showed a similar pattern.

CONCLUSIONS

The cessation of CGRP(-receptor) antibodies migraine prophylaxis was associated with a significant increase of migraine frequency and acute medication intake over time.

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.

Reversible cerebral vasoconstriction syndrome developing after an erenumab injection for migraine prevention

BACKGROUND

Reversible cerebral vasoconstriction syndrome is normally triggered by vasoactive compounds or illicit drugs. A new type of migraine preventive medication blocks calcitonin gene-related peptide utilizing monoclonal antibodies. Calcitonin gene-related peptide is a potent vasodilator for the cerebrovascular system. Could blocking calcitonin gene-related peptide be a trigger for cerebral artery vasospasm in patients susceptible to developing reversible cerebral vasoconstriction syndrome (migraine patients) or in individuals using vasoactive compounds? We present a case of reversible cerebral vasoconstriction syndrome occurring after calcitonin gene-related peptide monoclonal antibody treatment.

CASE REPORT

A 43-year -old woman with a history of episodic migraine developed an acute headache with orgasm two days after taking her second injection of erenumab. Ten days after erenumab injection she developed a thunderclap headache while completing a high intensity workout. These new headaches were only left sided. Computed tomography angiography demonstrated mild to moderate areas of narrowing involving the left middle and anterior cerebral arteries, concerning for reversible cerebral vasoconstriction syndrome. She denied exposure to any known reversible cerebral vasoconstriction syndrome precipitant medication or illicit drugs. She did endorse recent exposure to high altitude prior to erenumab therapy. She was started on verapamil 40 mg three times per day and her headache ceased within 24 h of initiating treatment. A repeat CT angiogram completed 4 weeks after the initial study noted resolution of the areas of vessel stenosis.

CONCLUSION

A case of reversible cerebral vasoconstriction syndrome developing after treatment with a calcitonin gene-related peptide monoclonal antibody is presented. The timing of the new type of headache occurring 2 days post erenumab injection suggests a possible cause and effect relationship. Reversible cerebral vasoconstriction syndrome as a possible treatment-related complication to the usage of calcitonin gene-related peptide monoclonal antibodies needs to be studied further.

Multiscale pharmacokinetic modeling of systemic exposure of subcutaneously injected biotherapeutics

Subcutaneously injected formulations have been developed for many biological products including monoclonal antibodies (mAbs). A knowledge gap nonetheless remains regarding the absorption and catabolism mechanisms and kinetics of a large molecule at the administration site. A multiscale pharmacokinetic (PK) model was thus developed by coupling multiphysics simulations of subcutaneous (SC) absorption kinetics with whole-body pharmacokinetic (PK) modeling, bridged by consideration of the presystemic clearance by the initial lymph. Our local absorption simulation of SC-injected albumin enabled the estimation of its presystemic clearance and led to the whole-body PK modeling of systemic exposure. The local absorption rate of albumin was found to be influential on the PK profile. Additionally, nineteen mAbs were explored via this multiscale simulation and modeling framework. The computational results suggest that stability propensities of the mAbs are correlated with the presystemic clearance, and electrostatic charges in the complementarity-determining region influence the local absorption rate. Still, this study underscores a critical need to experimentally determine various biophysical characteristics of a large molecule and the biomechanical properties of human skin tissues.

Monoclonal Antibodies Targeting CGRP: From Clinical Studies to Real-World Evidence-What Do We Know So Far?

Now more than ever is the time of monoclonal antibody use in neurology. In headaches, disease-specific and mechanism-based treatments existed only for symptomatic management of migraines (i.e., triptans), while the standard prophylactic anti-migraine treatments consist of non-specific and repurposed drugs that share limited safety profiles and high risk for interactions with other medications, resulting in rundown adherence rates. Recent advances in headache science have increased our understanding of the role of calcitonin gene relate peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) pathways in cephalic pain neurotransmission and peripheral or central sensitization, leading to the development of monoclonal antibodies (mAbs) or small molecules targeting these neuropeptides or their receptors. Large scale randomized clinical trials confirmed that inhibition of the CGRP system attenuates migraine, while the PACAP mediated nociception is still under scientific and clinical investigation. In this review, we provide the latest clinical evidence for the use of anti-CGRP in migraine prevention with emphasis on efficacy and safety outcomes from Phase III and real-world studies.

Comprehensive management of adults with chronic migraine: Clinical practice guidelines in Mexico

Introduction:

Migraine is a polygenic multifactorial disorder with a neuronal initiation of a cascade of neurochemical processes leading to incapacitating headaches. Headaches are generally unilateral, throbbing, 4–72 h in duration, and associated with nausea, vomiting, photophobia, and sonophobia. Chronic migraine (CM) is the presence of a headache at least 15 days per month for ≥3 months and has a high global impact on health and economy, and therapeutic guidelines are lacking.

Methods:

Using the Grading of Recommendations, Assessment, Development, and Evaluations system, we conducted a search in MEDLINE and Cochrane to investigate the current evidence and generate recommendations of clinical practice on the identification of risk factors and treatment of CM in adults.

Results:

We recommend avoiding overmedication of non-steroidal anti-inflammatory drugs (NSAIDs); ergotamine; caffeine; opioids; barbiturates; and initiating individualized prophylactic treatment with topiramate eptinezumab, galcanezumab, erenumab, fremanezumab, or botulinum toxin. We highlight the necessity of managing comorbidities initially. In the acute management, we recommend NSAIDs, triptans, lasmiditan, and gepants alone or with metoclopramide if nausea or vomiting. Non-pharmacological measures include neurostimulation.

Conclusions:

We have identified the risk factors and treatments available for the management of CM based on a grading system, which facilitates selection for individualized management.

Safety and tolerability evaluation of erenumab for the preventive treatment of migraine

Introduction: Erenumab, a monoclonal antibody targeting the receptor of calcitonin gene related peptide (CGRP), is the first disease-specific and mechanism-based treatment approved for the prevention of migraine. Although the safety and tolerability data from randomized trials are clear, the physiological effects of CGRP rise reasonable concerns. We aimed to evaluate the current evidence for safety and tolerability related to erenumab use in migraine. Areas covered: This review outlines the severe adverse events (AEs), common AEs, AEs leading to treatment discontinuation and AEs of special interest, reported in all phase 2, phase 3, open label, and observational studies with erenumab in migraine. Individual safety reports were also included in the systematic review of evidence. Expert opinion: No safety and tolerability flags were detected in this review. The most common AE are local skin reactions and constipation. No severe AEs, or frequent AEs leading to treatment discontinuation were detected. Treatment is well tolerated. The only AE of interest that may play a role in decision making and treatment monitoring is constipation. These findings are in line with previous safety reports, further highlighting the substantial tolerability and safety profile of the modern anti-CGRP monoclonal antibodies for the prevention of migraine.

CGRP receptor antagonists for migraine. Are they also AMY1 receptor antagonists?

The development of several drugs that target the calcitonin gene-related peptide (CGRP) system has been a major breakthrough in the pharmacological management of migraine. These are divided into two major classes, antibodies which bind to the CGRP peptide, preventing it from activating CGRP receptors and receptor antagonists. Within the receptor antagonist class, there are two mechanisms of action, small molecule receptor antagonists and an antibody antagonist. This mini-review considers the pharmacology of these receptor targeted antagonist drugs at the CGRP receptor and closely related AMY₁ receptor, at which CGRP may also act. The antagonists are most potent at the CGRP receptor but can also show antagonism of the AMY₁ receptor. However, important data are missing and selectivity parameters cannot be provided for all antagonists. The clinical implications of AMY₁ receptor antagonism are unknown, but we urge consideration of this receptor as a potential contributing factor to CGRP and antagonist drug actions.

Time course of efficacy of ubrogepant for the acute treatment of migraine: Clinical implications

BACKGROUND

The full utility of an acute treatment requires examination of the entire time course of effect during a migraine attack. Here the time course of effect of ubrogepant is evaluated.

METHODS

ACHIEVE-I and -II were double-blind, single-attack, Phase 3 trials. Adults with migraine were randomised 1:1:1 to placebo or ubrogepant (50mg or 100mg, ACHIEVE-I; 25 mg or 50 mg, ACHIEVE-II). Pain freedom, absence of most bothersome symptom, and pain relief were assessed at various timepoints. Samples were collected for pharmacokinetic analysis. Data were pooled for this post-hoc analysis.

RESULTS

Participants' (n = 912 placebo, n = 887 ubrogepant 50 mg, pooled analysis population) mean age was 41 years, with a majority female and white. Pain relief separated from placebo by 1 h (43% versus 37% [OR, 95% CI: 1.30, 1.0-1.59]), absence of most bothersome symptom by 1.5 h (28% versus 22% [1.42, 1.14-1.77]), and pain freedom by 2 h (20% vs. 13% [1.72, 1.33-2.22]). Efficacy was sustained from 2-24 h (pain relief: 1.71, 1.1-2.6; pain freedom: 1.71, 1.3-2.3) and remained separated at 48 h (pain relief: 1.7, 1.1-2.6; pain freedom: 1.31, 1.0-1.7). Pharmacokinetic analysis demonstrated maximum plasma concentrations were achieved at 1 h, with pharmacologically active concentrations reached within 11 min and remaining above the EC90 for nearly 12 h.

CONCLUSIONS

Evaluation of the time course of effect of ubrogepant showed pain relief as the most sensitive and earliest measure of clinical effect, followed by absence of most bothersome symptom, and pain freedom. Efficacy was demonstrated out to 48 h, providing evidence of the long-lasting effect of ubrogepant. This evaluation supports the role of examining the entire time course of effect to understand fully the utility of an acute treatment for migraine.Trial registration: ACHIEVE I (ClinicalTrials.gov, NCT02828020) and ACHIEVE II (ClinicalTrials.gov, NCT02867709).

Hypertension: A new safety risk for patients treated with erenumab

OBJECTIVE

To identify and analyze postmarketing case reports of elevated blood pressure (BP) associated with erenumab use.

METHODS

A retrospective analysis of postmarketing (spontaneous) case reports of erenumab-associated elevated BP submitted to the FDA Adverse Event Reporting System from May 17, 2018 through April 30, 2020. A case of elevated BP was defined as (a) an initiation of a pharmacological intervention or emergency department visit or hospitalization for emergent de novo or worsening of preexisting hypertension, or (b) BP measurement of ≥140 mm Hg systolic or ≥90 mm Hg diastolic with or without baseline BP measurement reported. Reports of elevated BP associated with erenumab use were analyzed for baseline and demographic information, latency, drug-event causal association, and clinical outcome.

RESULTS

Sixty-one cases of elevated BP were identified, 86% (49/57) were women and the median age was 56 [range 24-88] years. Forty-one cases were associated with a serious outcome per regulatory criteria, including seven that specified hospitalization. No case reported an outcome of death. The median systolic BP increase was 39 (interquartile range (IQR) 32, 59) mm Hg and median diastolic BP increase was 28 (IQR 18, 41) mm Hg. A total of 27/61 (44%) cases reported treatment for elevated BP (i.e., pharmacologic intervention or emergency department visit/hospitalization). Elevated BP occurred most frequently (28/61, 46%) within a week of the first dose of erenumab. Nineteen cases (19/61, 31%) reported a history of preexisting hypertension.

CONCLUSIONS

This case series suggest an association between elevated BP and use of erenumab. In light of our findings, the erenumab (Aimovig) prescribing information was amended to include hypertension in the Warnings and Precautions section.

A systematic review, meta-analysis and meta-regression evaluating the adverse reactions to erenumab in the preventive treatment of migraine

Background: Erenumab has recently been approved as a pharmacological treatment for the prevention of migraine. However, the incidence estimates of adverse drug reactions (ADRs) were not consistent among studies. Consequently, pooled measures of the incidences of ADRs that accounts for inter-study heterogeneity are desirable. In addition, little is known on the factors leading to such heterogeneity.Research design and methods: Clinical trials evaluating the occurrence of ADRs related to erenumab in migraine patients were searched with Ovid MEDLINE until April 2020. Random intercept models were used to estimate the pooled incidence of the ADRs reported at least in 5 different study populations. To examine whether specific factors correlated with the pooled incidence, we performed random-effects meta-regression.Results: Of 138 retrieved references, 8 clinical trials were included in the meta-analysis. We observed a significant heterogeneity of the incidence estimates of back pain, influenza, nasopharyngitis, and upper respiratory tract infection (URTI). Most of the observed heterogeneity is ascribed to treatment duration for back pain (p = 0.045), influenza (p < 0.001) and URTI (p < 0.001), and significantly attributed to Body Mass Index (BMI) for nasopharyngitis (p < 0.001).Conclusions: Back pain, influenza, nasopharyngitis and URTI showed a significant heterogeneity of incidence estimates.

Real-World Patient Experience With Erenumab for the Preventive Treatment of Migraine

BACKGROUND

Erenumab, a calcitonin gene-related peptide (CGRP) receptor monoclonal antibody, has been well tolerated with good efficacy for the preventive treatment of episodic and chronic migraine in phase 2 and phase 3 clinical trials. Limited post-market observations are available to validate these findings in a real-world tertiary headache clinic population with complex comorbidities and refractory migraine.

OBJECTIVE

The goal of this study is to demonstrate the real-world performance of erenumab among patients in a tertiary care headache clinic by describing patient selection, experience, and clinical characteristics after 6 months of erenumab therapy.

METHODS

A retrospective, exploratory, observational study was conducted on patients receiving at least 1 erenumab injection (70 or 140 mg). Baseline data obtained by chart review and telephone calls were compared to 6-month follow-up telephone calls. The primary outcome was the reduction in self-reported headache days per month at baseline compared to 6 months for those with complete 6-month data. The significance level was set at P < .05. Secondary analyses explored the distribution of headache severity, responder rates, Migraine Disability Assessment scores, adverse effects, ineffective preventives, comorbidities, wearing-off, and discontinuation.

RESULTS

Of the 101 patients who consented to participate, 89.1% (90/101) were women, and the mean age of all patients was 49 years (range, 19-80 years). At baseline, 94.1% (95/101) of patients had chronic migraine, 5.0% (5/101) had episodic migraine, and 18.8% (19/101) had medication overuse headache. The mean (SD) number of baseline headache and migraine days per month for the entire cohort were 24.3 (8.2) and 18.2 (9.3) days, respectively. Participants had numerous comorbidities and had tried a mean of 11.2 unique oral medications and 4.8 unique medication categories before receiving erenumab, including 83.2% (84/101) who had also received onabotulinumtoxinA. Six-month post-erenumab follow-up data were available for 42.6% (43/101) of participants. For these 43 participants, the number of headache days per month decreased significantly by 6.5 days from a baseline mean (SD) of 24.8 (6.47) days to 18.3 (12) days at 6-month follow-up (P < .001); similarly, the monthly migraine days decreased significantly by 8.4 days from a baseline mean of 19.1 (9.3) days to 10.7 days at 6-month follow-up (P < .001). The 50% responder rate was 34.9% (15/43) for monthly headache days and 54.8% (23/43) for monthly migraine days. Of all 101 participants, 28 (27.7%) discontinued erenumab, primarily because it was ineffective (39.3%, 11/28) or because of adverse effects (42.9%, 12/28).

CONCLUSION

This post-market observational study of patient experience describes response to erenumab in a real-world tertiary headache clinic with a complex patient population. Overall, these complex patients had a significant positive clinical response to erenumab, but with high rates of discontinuation. This study also noted a 1-week wearing-off response and high rates of constipation. Further post-market studies are needed to better characterize patient selection and real-world response to erenumab.

The role of erenumab in the treatment of migraine

Calcitonin gene related peptide (CGRP) monoclonal antibodies (mAbs) have been the first class of specifically developed preventive treatments for migraine. Clinical trials data suggest superiority of the CGRP mAbs to placebo in terms of prevention of migraine symptoms, migraine-specific quality of life and headache related disability. Treatment-related side effects overall did not differ significantly from placebo and discontinuation rate due to side effects has been low across the clinical trials, perhaps in view of their peripheral mode of action. Along with their route and frequency of administration, these novel class of drugs may constitute an improvement compared with the established arsenal of migraine treatments. Erenumab is a fully human antibody and the only mAb acting on the CGRP pathway by blocking its receptor. It is the first of the CGRP mAb class approved by the US Food and Drug Administration (May 2018) and the European Medicines Agency (July 2018). Erenumab exists in two different doses (70 mg and 140 mg) and it is administered with monthly subcutaneous injections. This review summarises erenumab pharmacological characteristics, clinical trials data, focusing on the potential role of this treatment in clinical practice.

Population pharmacokinetic and exposure-response analysis of eptinezumab in the treatment of episodic and chronic migraine

Eptinezumab is a humanized mAb that targets calcitonin gene-related peptide and is under regulatory review for the prevention of episodic and chronic migraine (EM, CM). It is important to determine whether exposures achieved with intravenous (IV) administration of eptinezumab achieve desired pharmacologic effects. Population pharmacokinetics, including dose- and exposure-response analyses, were performed using patient-level data from the eptinezumab clinical trial program with IV doses ranging from 10 to 1000 mg in pharmacokinetic analyses or 10 to 300 mg in phase 2/3 clinical studies in patients with EM or CM. Exposure-response analysis explored the relationship between eptinezumab exposure metrics and efficacy parameters including monthly migraine days. The pharmacokinetic profile of eptinezumab was characterized by rapid attainment of maximum plasma concentration (ie, end of IV administration) and a terminal half-life of 27 days. Covariate analysis found that patient characteristics had no clinically significant effects on pharmacokinetic parameters and were insufficient to influence dosing. Dose- and exposure-response analyses found exposure with single doses ≥100 mg was associated with greater efficacy compared with doses ≤30 mg and a plateau of effect between 100 and 300 mg. A saturable inhibitory Emax model found the exposure over 12 weeks produced by single-dose eptinezumab 100 and 300 mg exceeded the exposure estimates required to achieve 90% of the maximal efficacy (EC90 ). This pharmacokinetic analysis of eptinezumab supports dosing every 12 weeks with no adjustment for patient characteristics, including exposures associated with 100- or 300-mg doses producing optimal efficacy effects. The similar efficacy profiles support 100 mg as the lowest effective dose of eptinezumab.

Erenumab: A novel calcitonin gene-related peptide receptor antagonist developed specifically for migraine prevention

Headaches and migraines continue to be a leading cause of suffering and disability. As per the Global Burden of Disease Survey conducted in 2010, the exact magnitude of the disease still is underestimated. Migraine alone continues to rank seventh as a cause of disability. Various therapeutic modalities exist and newer classes of medications are currently being trialed to provide effective treatment to this population of patients. Erenumab, a calcitonin gene-related peptide receptor inhibitor, is a recent addition to this armamentarium and has been approved by the FDA for use in 2018. It has shown modestly improved outcomes according to the current trials. However, long-term outcomes and adverse effects still are under research. The following article elaborates on the current literature and evidence on this novel drug.

Efficacy and safety of calcitonin-gene-related peptide binding monoclonal antibodies for the preventive treatment of episodic migraine - an updated systematic review and meta-analysis

BACKGROUND

Migraine is one of the most common neurological disorders that leads to disabilities. However, the conventional drug therapy for migraine might be unsatisfactory at times. Therefore, this meta-analysis aimed to evaluate the efficacy and safety of calcitonin-gene-related peptide binding monoclonal antibody (CGRP mAb) for the preventive treatment of episodic migraine, and provide high-quality clinical evidence for migraine therapy.

METHODS

A systematic electronic database search was conducted to identify the potentially relevant studies. Two independent authors performed data extraction and quality appraisal. Mean difference (MD) and risk ratio (RR) were pooled for continuous and dichotomous data, respectively. The significance levels, weighted effect sizes and homogeneity of variance were calculated.

RESULTS

Eleven high-quality randomized control trials that collectively included 4402 patients were included in this meta-analysis. Compared to placebo group, CGRP mAb therapy resulted in a reduction of monthly migraine days [weighted mean difference (WMD) = - 1.44, 95% CI = (- 1.68,- 1.19)] and acute migraine-specific medication days [WMD = - 1.28, 95% CI = (- 1.66,- 0.90)], with an improvement in 50% responder rate [RR = 1.51, 95% CI = (1.37,1.66)]. In addition, the adverse events (AEs) and treatment withdrawal rates due to AEs were not significantly different between CGRP mAb and placebo groups. Similar efficacy and safety results were obtained for erenumab, fremanezumab, and galcanezumab in subgroup analysis.

CONCLUSIONS

The current body of evidence reveals that CGRP mAb is an effective and safe preventive treatment for episodic migraine.

Calcitonin gene-related peptide (CGRP): role in migraine pathophysiology and therapeutic targeting

Introduction: The neuropeptide calcitonin gene-related peptide (CGRP) is recognized as a critical player in migraine pathophysiology. Excitement has grown regarding CGRP because of the development and clinical testing of drugs targeting CGRP or its receptor. While these drugs alleviate migraine symptoms in half of the patients, the remaining unresponsive half of this population creates an impetus to address unanswered questions that exist in this field.Areas covered: We describe the role of CGRP in migraine pathophysiology and CGRP-targeted therapeutics currently under development and in use. We also discuss how a second CGRP receptor may provide a new therapeutic target.Expert opinion: CGRP-targeting drugs have shown a remarkable safety profile. We speculate that this may reflect the redundancy of peptides within the CGRP family and a second CGRP receptor that may compensate for reduced CGRP activity. Furthermore, we propose that an inherent safety feature of peptide-blocking antibodies is attributed to the fundamental nature of peptide release, which occurs as a large bolus in short bursts of volume transmission. These facts support the development of more refined CGRP therapeutic drugs, as well as drugs that target other neuropeptides. We believe that the future of migraine research is bright with exciting advances on the horizon.

Vascular safety of erenumab for migraine prevention

Objective

To examine the cardiovascular, cerebrovascular, and peripheral vascular safety of erenumab across migraine prevention studies.

Methods

Vascular adverse events (AEs) and blood pressure data were integrated across 4 double-blind, placebo-controlled studies of erenumab and their open-label extensions in patients with chronic or episodic migraine. Subgroup analyses were conducted by acute migraine-specific medication use and number of vascular risk factors at baseline. Standardized search terms were used to identify vascular AEs (cardiovascular, cerebrovascular, or peripheral). An independent committee adjudicated whether targeted events were vascular in origin.

Results

In placebo-controlled studies, 2,443 patients received placebo (n = 1,043), erenumab 70 mg (n = 893), or erenumab 140 mg (n = 507) subcutaneously once monthly. Regardless of acute migraine-specific medication use or vascular risk factors at baseline, AE incidence was similar across the placebo and erenumab treatment groups. Hypertension AEs were reported for 0.9% (placebo), 0.8% (erenumab 70 mg), and 0.2% (erenumab 140 mg) of patients. Vascular AEs, which were similar across double-blind and open-label treatment, generally were confounded, with plausible alternative etiologies. In 18 patients with events reviewed by the independent committee, 4 events were positively adjudicated as cardiovascular in origin: 2 deaths and 2 vascular events. All 4 positively adjudicated cardiovascular events occurred during open-label erenumab treatment.

Conclusion

Selective blockade of the canonical calcitonin gene-related peptide receptor with erenumab for migraine prevention had a vascular safety profile comparable to that of placebo over 12 weeks, with no increased emergence of events over time. Further study of long-term safety of erenumab in patients with migraine is needed.

Clinicaltrials.gov identifiers

NCT02066415, NCT02456740, NCT01952574, NCT02483585, NCT02174861, and NCT01723514.

Classification of evidence

This analysis provides Class II evidence that for patients with migraine, erenumab does not increase the risk of vascular AEs.

Erenumab safety and efficacy in migraine: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Erenumab is a new medicine recently approved in the United States of America for the preventive treatment of migraine among adults. We aimed to conduct a meta-analysis and evaluation of the efficacy and safety of erenumab among patients with migraine.

METHODS

The electronic databases that were searched comprised PubMed, Embase and the Cochrane library, which were independently retrieved by 2 reviewers. Only randomized controlled trials (RCTs) that compared placebo with erenumab were selected. Mean differences (MDs), pooled risk ratios (RRs), and their corresponding 95% confidence intervals (CIs) were calculated for continuous and dichotomous data, respectively.

RESULTS

Five RCTs representing 2928 patients were included. Pooled analysis showed significant reductions in the 50% responder rate (RR 1.55; P < .00001; I = 49%). In addition, the mean monthly migraine days from baseline in the erenumab group compared with placebo (MD-1.32; P < .00001; I = 100%) and migraine-specific medication days) from baseline (MD-1.41; P < .00001; I = 100%) were significantly decreased for the erenumab group as compared with placebo. Furthermore, Migraine-specific medication days from baseline in the 140 mg erenumab group were significantly reduced as compared the 70 mg group (MD = 0.55; P < .00001; I = 90%). Finally, there was no significant difference between the erenumab group and placebo for any adverse event and serious adverse event.

CONCLUSION

Among patients with migraine, both 70 and 140 mg of erenumab were associated with reduced Migraine-specific medication days, Migraine-specific medication days from baseline, and an increased rate of a 50% reduction, in the absence of an increased risk of any serious adverse effect.

Targeting calcitonin gene-related peptide: a new era in migraine therapy

Migraine is one of the most prevalent and disabling diseases worldwide, but until recently, few migraine-specific therapies had been developed. Extensive basic and clinical scientific investigation has provided strong evidence that the neuropeptide calcitonin gene-related peptide (CGRP) has a key role in migraine. This evidence led to the development of small molecule CGRP receptor antagonists and monoclonal antibodies targeting either CGRP or its receptor. Clinical trials investigating these therapies have consistently shown statistically significant efficacy for either the acute or preventive treatment of migraine. No serious safety or tolerability issues have been identified in the trials of the monoclonal antibody therapies. Although the appropriate place of these new migraine-specific therapies relative to other available acute and preventive treatments remains to be determined, a growing body of evidence shows that therapeutic approaches targeting CGRP have the potential to transform the clinical management of migraine.

Recent Advances in Pharmacotherapy for Episodic Migraine

In 2018, three calcitonin gene-related peptide (CGRP) pathway monoclonal antibodies, erenumab, fremanezumab and galcanezumab, were approved in various parts of the world, including Europe and the US, and another, eptinezumab, is pending, for the prevention of migraine. In this article, episodic migraine treatment is reviewed, although these medicines are approved and are just as effective for chronic migraine. These new medicines usher a new phase in the preventive management of migraine with migraine-specific treatments. Data from phase III trials of CGRP pathway monoclonal antibodies have shown they are efficacious, with adverse effect rates comparable to placebo. The combination of clear efficacy and excellent tolerability will be welcome in an area where poor adherence to current preventives is common. Rimegepant, ubrogepant and lasmiditan are migraine-specific acute therapies yet to be approved by regulators. Phase III data for the respective CGRP receptor antagonists, the gepants, and the serotonin 5-HT_1F receptor agonist, the ditan, have been positive and free of cardiovascular adverse effects. These medicines are not vasoconstrictors. When approved, they could meet the acute therapy demand of patients with cardiovascular risk factors where triptans are contraindicated. Beyond this, gepants will see the most disruptive development in migraine management in generations with medicines that can have both acute and preventive effects, the latter evidenced by data from the discontinued drug telcagepant and the early-phase drug atogepant. Moreover, one can expect no risk of medication overuse syndromes with gepants since the more patients take, the less migraines they have. During the next years, as experience with monoclonal antibodies grows in clinical practice, we can expect an evolution in migraine management to take shape. Clinicians will be able to offer treatment patients want rather than trying to fit migraineurs into therapeutic boxes for their management. Despite pessimistic susurrations of a largely addlepated form, many patients, and physicians, will welcome new options, and the challenges of new treatment paradigms, with optimism.

Monoclonal antibodies for the prevention of migraine

Introduction: Calcitonin Gene-Related Peptide (CGRP) plays a crucial role in migraine pathophysiology. A novel specific treatment strategy for the prevention of migraine incorporates monoclonal antibodies (mAbs) against CGRP and its canonical receptor. Eptinezumab, fremanezumab and galcanezumab block CGRP mediated effects by binding to the peptide, while erenumab blocks the CGRP receptor.Areas covered: Following a brief overview of pharmacological characteristics, we will review phase III trials for the use of CGRP mAbs in the prevention of episodic and chronic migraine.Expert opinion: All four CGRP mAbs demonstrated an excellent safety, tolerability and efficacy profile in migraine patients. Across all trials mAbs showed superior efficacy for the reduction of monthly migraine days compared to placebo with a net benefit of 2.8 days. Neither cardiovascular nor immunological safety concerns have emerged from clinical trials. Fremanezumab, galcanezumab, and erenumab are approved in the USA and Europe. Based on trial data there is no reason why these mAbs should not become first-line therapies in future. For now, we advocate for the use of mAbs in migraine prevention for patients who failed a minimum of two standard oral treatments based on the novelty and costs of this approach. mAbs are also effective in patients with medication overuse and with comorbid depression or anxiety disorders. Taken together, mAbs are likely to usher in a new era in migraine prevention and provide significant value to patients.

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.

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.

Erenumab: First Global Approval

Amgen and Novartis are developing erenumab (AIMOVIG™, erenumab-aooe)-a fully human monoclonal antibody calcitonin gene-related peptide (CGRP) receptor antagonist-for the prevention of migraine. CGRP is a vasodilatory neuropeptide implicated in the pathophysiology of migraine and treatment with erenumab was associated with significant reductions in migraine frequency in phase II and III clinical trials. Based on these positive results erenumab was recently approved in the US for the preventive treatment of migraine in adults and has received a positive opinion in the EU for the prophylaxis of migraines in adults who have at least 4 migraine days per month. This article summarizes the milestones in the development of erenumab leading to this first approval.

Nonclinical safety evaluation of erenumab, a CGRP receptor inhibitor for the prevention of migraine

Calcitonin gene-related peptide (CGRP) and its receptor have been implicated as a key mediator in the pathophysiology of migraine. Thus, erenumab, a monoclonal antibody antagonist of the CGRP receptor, administered as a once monthly dose of 70 or 140 mg has been approved for the preventive treatment of migraine in adults. Due to the species specificity of erenumab, the cynomolgus monkey was used in the pharmacology, pharmacokinetics, and toxicology studies to support the clinical program. There were no effects of erenumab on platelets in vitro (by binding, activation or phagocytosis assays). Specific staining of human tissues with erenumab did not indicated any off-target binding. There were no erenumab-related findings in a cardiovascular safety pharmacology study in cynomolgus monkeys or in vitro in human isolated coronary arteries. Repeat-dose toxicology studies conducted in cynomolgus monkeys at dose levels up to 225 mg/kg (1 month) or up to 150 mg/kg (up to 6 months) with twice weekly subcutaneous (SC) doses showed no evidence of erenumab-mediated adverse toxicity. There were no effects on pregnancy, embryo-fetal or postnatal growth and development in an enhanced pre-postnatal development study in the cynomolgus monkey. There was evidence of placental transfer of erenumab based on measurable serum concentrations in the infants up to 3 months post birth. The maternal and developmental no-observed-effect level (NOEL) was the highest dose tested (50 mg/kg SC Q2W). These nonclinical data in total indicate no safety signal of concern to date and provide adequate margins of exposure between the observed safe doses in animals and clinical dose levels.

Effects of monoclonal antagonist antibodies on calcitonin gene-related peptide receptor function and trafficking

Background

Monoclonal antibodies against calcitonin gene-related peptide (CGRP) or its receptor are efficacious for the prevention of migraine headaches. The downstream molecular mechanisms following ligand-receptor blockade by which these antibodies prevent CGRP signaling through CGRP receptors have not been demonstrated.

Methods

Here we produced tool monoclonal functional antagonist antibodies against CGRP and its canonical receptor and developed a novel cellular model using fluorogen-activated protein technology that allows detection of CGRP receptor internalization by flow cytometry and, for an extended time course, visualization by confocal microscopy.

Results

Using this cell model we showed that these antagonist antibodies block both CGRP-induced cAMP signaling and CGRP receptor internalization. At least 10-fold higher concentrations of either antibody are necessary to block CGRP receptor internalization compared with cAMP accumulation in our cell model.

Conclusion

These data reinforce our understanding of how monoclonal functional antagonist antibodies interfere with CGRP signaling.

Therapeutic novelties in migraine: new drugs, new hope?

Background

In the past decade, migraine research has identified novel drug targets. In this review, we discuss recent data on emerging anti-migraine therapies.

Main body

The development of ditans, gepants and anti-calcitonin gene-related peptide monoclonal antibodies for the treatment of migraine is one of the greatest advances in the migraine field. Lasmiditan, rimegepant and ubrogepant will extend our therapeutic armamentarium for managing acute migraine attacks when triptans are not effective or contraindicated due to cardiovascular disorders. The monoclonal antibodies are migraine specific prophylactic drugs with high responder rates and favorable adverse event profiles. Furthermore, they offer convenient treatment regimens of 4- or 12-week intervals.

Conclusion

Collectively, novel migraine therapies represent a major progress in migraine treatment and will undoubtedly transform headache medicine.