CGRP Antagonists for the Treatment of Chronic Migraines: a Comprehensive Review

Calcitonin gene-related peptide (CGRP) exerts membrane, cellular and synaptic actions on serotonergic dorsal raphe neurons ex vivo: Functional implications for a role in dorsal raphe-controlled functions

Serotonin (5-HT) plays a role in limbic-controlled behaviors and is implicated in migraine, which is often co-morbid with cognitive-based affective disorders. The neuropeptide calcitonin gene-related peptide (CGRP) regulates vascular tone. Serotonin-acting drugs and CGRP receptor antagonists have proved therapeutic in management of migraine. Clinical interactions between the two systems have been shown, however, whether CGRP exerts direct actions on serotonergic Dorsal Raphe (DR) neurons is unknown. To fully understand the role of CGRP in control of behavior and to predict how CGRP targeted therapies (i.e. CGRP receptor antagonists) could alter DR neuronal activity, investigation of whether CGRP can directly affect 5-HT DR activity was conducted. Patch clamp electrophysiology and single photon calcium imaging in DR brain slices revealed that CGRP (10-6 M) elicited postsynaptically mediated, potassium-involved outward currents in the majority of 5-HT DR cells. Miniature excitatory synaptic events were reduced in frequency. Further, intracellular calcium was reduced in the majority of neurons, which did not involve actions on the L-type calcium channel. The CGRP agonist SAX replicated effects on the membrane and intracellular calcium. In contrast, the CGRP receptor antagonist MK-3207 blocked the effects on outward current and attenuated the action of CGRP on reducing intracellular calcium. Despite inhibitory membrane and synaptic effects, no change was noted in firing rate. Our findings raise the intriguing possibility that the CGRP system plays a role in mediating limbic-controlled behaviors, at least in part, through direct actions on serotonergic DR neurons, however the effect of CGRP on DR 5-HT output remains to be investigated.

Identifying signals of disproportionate reporting for calcitonin gene-related peptide inhibitors: real-world evidence from the FDA adverse event reporting system

BACKGROUND

Calcitonin gene-related peptide (CGRP) inhibitors have been FDA-approved for migraine prophylaxis and relief. However, their safety profile remains uncertain. This study analyzes adverse events (AEs) and signals of disproportionate reporting (SDRs) using the FDA Adverse Event Reporting System (FAERS).

RESEARCH DESIGN AND METHODS

We analyzed FAERS reports from approval through Q2 2023, standardizing terms using preferred terminology and system organ class (SOCs) classifications. Disproportionality analyses (ROR, PRR, IC) identified SDRs and inclusion in FDA prescribing information was reviewed. Additional analyses included comparisons with other migraine drugs, indication-based sensitivity analyses and causality assessment using the Bradford Hill framework.

RESULTS

Galcanezumab showed strong signals for underdose (ROR 47.4; 95% CI 43.79-51.3), alopecia (5.72; 5.09-6.43), and constipation (6.01; 5.35-6.75), while fremanezumab exhibited notable associations with alopecia (6.9; 5.72-8.33) and weight increased (6.34; 5.18-7.76). Among gepants, rimegepant was linked to somnolence (4.52; 3.57-5.73) and dizziness (3.73; 3.15-4.42) and atogepant showed a strong signal for therapy interruption (16.58; 12.86-21.38).

CONCLUSIONS

This study highlights CGRP inhibitor-associated AEs, underscoring the need for clinical monitoring and risk identification. Early detection of AEs and SDRs can inform protective measures to enhance patient safety.

Disproportionality analysis of Raynaud's phenomenon associated with calcitonin gene-related peptide inhibitors using the Food and Drug Administration adverse event reporting system

Raynaud's phenomenon is a vascular condition characterized by episodic vasoconstriction, and recent reports suggest a potential link between calcitonin gene-related peptide (CGRP) inhibitors, used for migraine treatment, and the onset of this condition. This study evaluated the association between CGRP inhibitors and Raynaud's phenomenon using data from the FDA Adverse Event Reporting System (FAERS). A retrospective analysis of adverse events from the approval year of each drug through August 2023 was conducted. Disproportionality was assessed using Reporting Odds Ratios (ROR) and Information Components (IC), with significant signals of disproportionate reporting (SDR) identified by a lower 95% confidence interval (CI) for ROR > 1.0 and IC > 0. Intra-class and inter-class analyses were conducted to compare SDRs among CGRP inhibitors and other migraine therapies, including triptans, beta-blockers, and anticonvulsants. CGRP inhibitors demonstrated significant SDRs for Raynaud's phenomenon (ROR 19.12; 95% CI 15.44-23.69), with rimegepant, ubrogepant, and atogepant showing particularly strong signals. Intra-class analysis revealed a significant SDR only for galcanezumab (ROR 2.01; 95% CI 1.28-3.17). Inter-class analysis indicated significant SDRs for CGRP inhibitors compared to beta-blockers, anticonvulsants, and celecoxib, but not triptans. These findings underscore the importance of ongoing pharmacovigilance and further research to validate these associations and ensure patient safety.

Potential Predictors of Response to CGRP Monoclonal Antibodies in Chronic Migraine: Real-World Data

PURPOSE OF REVIEW

Real-world data (RWD) has identified potential predictors of response to anti-CGRP therapies in patients with chronic migraine (CM). This review aims to synthesize the most remarkable findings published to date regarding this topic.

RECENT FINDINGS

Migraine features such as unilateral pain and positive triptan response and chronic features such as daily headache or medication overuse (MO) emerge as predictors of positive outcomes, potentially linked to elevated baseline serum anti-calcitonin gene-related peptide (anti-CGRP) levels. Demographic and baseline characteristics, encompassing obesity, psychiatric comorbidities, and prior refractoriness to prophylactic treatments, are associated with poor responses in both treatment-naïve patients and after-switch scenarios. Nevertheless, the consistency of these predictors across diverse populations requires further investigation. Recent RWD literature highlights emerging predictors of response of different sources among patients with CM receiving anti-CGRP therapies. Comprehending these predictors and identifying novel biomarkers of response hold the potential to refine treatment strategies for CM patients, enhancing their management and therapeutic outcomes.

Cyclic vomiting syndrome: From pathophysiology to treatment

Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent and unpredictable episodes of intense vomiting, interspersed with periods of apparent wellbeing. This disorder, which primarily affects children and adolescents but can persist into adulthood, has recently been the subject of extensive study and analysis in the medical literature. The aim of the present review is to examine the most important aspects of the epidemiology, pathophysiology, subtypes, diagnostic criteria, and current management of CVS. Even though the exact etiology remains unknown, genetic factors (polymorphisms), nervous system alterations and autonomic dysregulation, and environmental factors (use and abuse of cannabinoids) are postulated as possible triggers. CVS has significant diagnostic challenges, given that there is no specific test for confirming its presence. Thorough evaluation of symptoms and the ruling out of other possible causes of recurrent vomiting are required. Management of CVS typically involves a multidisciplinary approach. Pharmacologic options are explored, such as antiemetics and preventive medications, as well as behavioral and psychologic support therapies. Treatment personalization is essential, adapting it to the individual needs of each patient. Despite advances in the understanding of CVS, it remains a significant clinical challenge. This disorder impacts the quality of life of those affected and their families, underscoring the ongoing need for research and the development of more effective treatment strategies.

Utility of Repetitive Transcranial Magnetic Stimulation for Chronic Daily Headache Prophylaxis: A Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

Management of chronic daily headaches (CDH) remains challenging due to the limited efficacy of standard prophylactic pharmacological measures. Several studies have reported that repetitive transcranial magnetic stimulation (rTMS) can effectively treat chronic headaches. The objective was to determine the utility of rTMS for immediate post-treatment and sustained CDH prophylaxis.

RECENT FINDINGS

All procedures were conducted per PRISMA guidelines. PubMed, Scopus, Web of Science, and ProQuest databases were searched for controlled clinical trials that have tested the efficacy of rTMS on populations with CDH. DerSimonian-Laird random-effects meta-analyses were performed using the 'meta' package in R to examine the post- vs. pre-rTMS changes in standardized headache intensity and frequency compared to sham-control conditions. Thirteen trials were included with a combined study population of N = 538 patients with CDH (rTMS, N = 284; Sham, N = 254). Patients exposed to rTMS had significantly reduced standardized CDH intensity and frequency in the immediate post-treatment period (Hedges' g = -1.16 [-1.89, -0.43], p = 0.002 and Δ = -5.07 [-10.05, -0.11], p = 0.045 respectively). However, these effects were sustained marginally in the follow-up period (Hedges' g = -0.43 [-0.76, -0.09], p = 0.012 and Δ = -3.33 [-5.52, -1.14], p = 0.003). Significant between-study heterogeneity was observed, at least partially driven by variations in rTMS protocols. Despite the observed clinically meaningful and statistically significant benefits in the immediate post-treatment period, the prophylactic effects of rTMS on CDH do not seem to sustain with discontinuation. Thus, the cost-effectiveness of the routine use of rTMS for CDH prophylaxis remains questionable.

REGISTRATION

Protocol preregistered in PROSPERO International Prospective Register of Systematic Reviews (CRD42021250100).

Identification of novel signal of Raynaud's phenomenon with Calcitonin Gene-Related Peptide(CGRP) antagonists using data mining algorithms and network pharmacological approaches

BACKGROUND

Calcitonin gene-related peptide (CGRP) antagonists are recently approved for the treatment of migraine.

AIM

The main aim of the current study was to find out the association of CGRP antagonists with RP using data mining algorithms integrated with network pharmacological approaches.

RESEARCH DESIGN AND METHODS

The individual case safety reports were extracted using OpenVigil2.1-MedDRA-V17 (2004Q1-2022Q3), the United States Adverse Event Reporting System (US FAERS). The data mining algorithms i.e. reporting odds ratio (ROR) with 95% confidence and proportionality reporting ratio (PRR) with associated chi-square value were calculated along with a minimum of three ICSRs to identify the signal. Further, the network was constructed using Cytoscape 3.7.2. Finally, molecular docking was performed using Glide, Schrodinger Inc.

RESULTS

The PRR ≥2 with a linked chi-square value ≥4, add up of co-occurrence ≥3, and a lower limit of 95% confidence interval of ROR exceeding 2 indicates a positive signal of RP. Further, the network pharmacological and molecular docking results have shown the involvement of insulin-like growth factor 1-receptor (IGF1R) pathways.

CONCLUSION

The RP is recognized as a novel signal with all CGRP antagonists.

Associations between Cerebrovascular Function and the Expression of Genes Related to Endothelial Function in Hormonal Migraine

There is evidence to suggest that hormonal migraine is associated with altered cerebrovascular function. We aimed to investigate whether the expression of genes related to endothelial function in venous blood (1) might influence cerebrovascular function, (2) differs between hormonal migraineur and non-migraineur women, and (3) changes following resveratrol supplementation. This study utilised data obtained from 87 women (59 hormonal migraineurs and 28 controls) where RNA from venous blood was used to quantify gene expression and transcranial Doppler ultrasound was used to evaluate cerebrovascular function. Spearman's correlation analyses were performed between gene expression, cerebrovascular function, and migraine-related disability. We compared the expression of genes associated with endothelial function between migraineurs and non-migraineurs, and between resveratrol and placebo. The expression of several genes related to endothelial function was associated with alterations in cerebrovascular function. Notably, the expression of CALCA was associated with increased neurovascular coupling capacity (p = 0.013), and both CALCA (p = 0.035) and VEGF (p = 0.014) expression were associated with increased cerebral blood flow velocity in the overall study population. Additionally, VCAM1 expression correlated with decreased pulsatility index (a measure of cerebral arterial stiffness) (p = 0.009) and headache impact test-6 scores (p = 0.007) in the migraineurs. No significant differences in gene expression were observed between migraineurs and controls, or between placebo and resveratrol treatments in migraineurs. Thus, altering the expression of genes related to endothelial function may improve cerebrovascular function and decrease migraine-related disability.

A Comprehensive Review of the Mechanism, Efficacy, Safety, and Tolerability of Ubrogepant in the Treatment of Migraine

Ubrogepant is an innovative medication designed for the acute treatment of migraine, a debilitating neurological condition that profoundly impairs quality of life, productivity, and social interactions. This comprehensive review assesses the efficacy, safety, tolerability, and mechanism of action of ubrogepant through a rigorous methodology, including an in-depth literature review from reputable databases like PubMed, Web of Science, Embase, Scopus, and Cochrane. Classified as a calcitonin gene-related peptide (CGRP) receptor antagonist, ubrogepant has emerged as a potential revolutionary medication for migraine treatment. CGRP is a peptide integral to migraine pathophysiology, and its blockade has demonstrated great therapeutic potential. Unlike triptans, known for their cardiovascular risks, ubrogepant lacks vasoconstrictive properties, making it a safer alternative for a broader patient population. Ubrogepant offers significant potential for pain relief, symptom reduction, and restoration of normal function during a migraine attack, and it outperforms placebo in terms of efficacy. It also presents favorable safety, with generally mild adverse drug events (ADEs), such as nausea, dizziness, and somnolence, similar to placebo effects. Consistent results from clinical trials confirm its tolerability, with minor ADEs and no safety alerts for the tested doses, indicating that ubrogepant is a safe and well-tolerated option for migraine treatment. As an effective oral medication, ubrogepant could be an alternative to traditional acute migraine treatments. Its benefits include a unique mechanism of action, rapid onset, and favorable safety profile. However, specific contraindications, such as hypersensitivity, severe hepatic impairment, concurrent use of CYP3A4 inhibitors, pregnancy or breastfeeding, and uncontrolled hypertension, require caution or avoidance of ubrogepant. Despite these limitations, ubrogepant signals a promising new direction in migraine therapeutics.

Abnormal heart rate variability and its application in predicting treatment efficacy in patients with chronic migraine: An exploratory study

AIM

This study aimed to investigate the extent of autonomic nervous system dysfunction in patients with chronic migraine using heart rate variability analysis. In addition, we explored the potential association between heart rate variability and treatment outcomes in patients receiving preventive treatment.

METHODS

In this cross-sectional and prospective study, we compared heart rate variability profiles in 81 preventive-naïve chronic migraine patients and 58 healthy controls. In addition, treatment responses of patients, who received a 12-week treatment with flunarizine, were assessed in relation to baseline heart rate variability.

RESULTS

We observed that chronic migraine patients had a reduced heart rate variability, signifying autonomic dysfunction in comparison to healthy controls. Furthermore, patients presenting normal heart rate variability, characterized by a standard deviation exceeding 30 milliseconds in normal-to-normal RR intervals, experienced a superior response to flunarizine treatment. This improvement was exemplified by a significantly larger reduction in monthly headache days for patients with higher heart rate variability compared to those with lower heart rate variability: -9.7 (5.9) vs. -6.2 (6.0) days (p = .026).

CONCLUSIONS

Autonomic dysfunction occurs in chronic migraine as evaluated by heart rate variability. A preserved function is associated with a better treatment outcome to flunarizine.Trial registration: Neurologic Signatures of Chronic Pain Disorders, NCT02747940. Registered 22 April 2016, https://clinicaltrials.gov/ct2/show/NCT02747940.

Sustained Efficacy, Safety and High Adherence Rate of Onabotulinum Toxin Type A in Chronic Migraine Patients: A Multicentric Prospective Real-Life Study

Guidelines regarding long-term use with onabotulinumtoxinA (onaBT-A) in chronic migraine (CM) prophylaxis are lacking. This multicentric prospective real-life study aimed to assess the efficacy and safety of a long-term treatment. A total of 195 chronic migraine patients were treated with onaBT-A, every 3 months for 5 cycles (Phase 1). In the Phase 2 of the study, depending on response rate, patients were divided into "responders" (R), "partially responders" (PR) and "non-responders" (NR). Then, we proposed to R and PR patients to continue with an additional 12 months of treatment (additional 4 sessions). Response to treatment and adverse events were collected for the entire duration of the study. Of the 195 patients included (females 82.1%, mean age 47.4 ± 12.4), at the end of Phase 1 there were 52.3% of R patients, 17.9% of PR patients, 15.4% of NR patients and 14.4% drop-outs. During Phase 2 of treatment, R patients presented a maintenance of the improvement achieved during the first year of treatment, as well as PR patients. Except for three serious adverse events not related to treatment, all other adverse events were mild or moderate in severity and resolved without sequelae. In the literature, adherence to oral migraine-preventive medications among patients with CM was found to be less than 25%. The results of this prospective real-life multicenter study show efficacy, safety and adherence to a long-term treatment with onaBT-A.

Eptinezumab-jjmr, a humanized monoclonal specific to Calcitonin Gene Related Peptide, for the preventive treatment of migraine in adults

PURPOSE OF REVIEW

Migraines are prevalent and cause significant morbidity, decline in quality of life and healthcare costs universally. Treatment options are varied, but efficacy is limited. This review centers on Eptinezumab-jjmr, a humanized monoclonal specific to CGRP for the prevention of migraines in adults. Herein presented are the science and mechanism of action, indication and clinical evidence for use.

RECENT FINDINGS

Migraines are severe, recurrent headaches, which are either episodic or chronic in nature. The pain is severe, often accompanied by co-morbid symptoms, such as photophobia, phonophobia, nausea and emesis, and is limiting in nature. It is a prevalent disorder that causes significant, worldwide disability, morbidity, suffering, and costs.The pathophysiology of migraines is actively studied, though recent research points to an initiating event causing migraine generation, that is then propagated by other brain regions, a significant one being the trigeminocervical complex. This is driven by biochemical transmitters, chiefly CGRP. This discovery led to the development of CGRP-targeting drugs, including gepants (small molecular antagonists) and anti-CGRP antibodies, such as Eptinezumab-jjmr.Traditional therapy includes preventative and abortive treatment; however, adherence with preventative treatment has been historically poor, and certain types of abortive therapy carry risks and side effects that preclude them from a large patient population. Moreover, traditional therapy often falls short in migraine therapy. CGRP antagonist, including Eptinezumab, aims to cover the gaps in migraine therapy. We present here evidence to support the safe and effective use of Eptinezumab for the prevention of migraines.

SUMMARY

Migraines are a prevalent primary headache disorder causing significant morbidity worldwide. Traditional abortive and preventative treatments fall short for many patients. Eptinezumab is part of new generation of CGRP-targeting medications and has shown significant evidence to support its use for the prevention of migraines. Further research is required to properly compare eptinezumab with existing pharmacotherapy and update guidelines on the appropriate combinations of therapies that are not available and the correct patient selection for each.

Current understanding of the etiology of cyclic vomiting syndrome and therapeutic strategies in its management

INTRODUCTION

Cyclic vomiting syndrome is a chronic debilitating disorder of the gut-brain interaction and is characterized by recurrent episodes of nausea and vomiting.Recent studies indicate that it is common and affects 2% of the US population. Unfortunately, there is significant heterogeneity in the management of these patients in the medical community. This review article aims to bridge this gap and will review the epidemiology and etiology with a focus on management of CVS.

AREAS COVERED

This article reviews the epidemiology, and pathophysiology of CVS and impact on patients. It also discusses management based on recent guidelines based on which is intended for the busy clinician. A literature search was done using PubMed and key words "cyclic vomiting", "management", "etiology", and pathophysiology were used to identify articles of importance.

EXPERT OPINION

CVS is a complex, poorly understood disorder of gut-brain interaction (DGBI) and has a significant negative impact on patients, families and the healthcare system. Recent guidelines recommend a multidisciplinary approach to management using prophylactic therapy in moderate-severe CVS and abortive medication for acute flares. However more research is needed to better understand the pathophysiology and develop targeted therapies for CVS.

Rimegepant for the treatment of migraine

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

Management of chronic migraine

Chronic migraine is a neurologic disorder associated with considerable disability, lost productivity, and a profound economic burden worldwide. The past five years have seen a dramatic expansion in new treatments for this often challenging condition, among them calcitonin gene related peptide antagonists and neuromodulatory devices. This review outlines the epidemiology of and diagnostic criteria and risk factors for chronic migraine. It discusses evidence based drug and non-drug treatments, their advantages and disadvantages, and the principles of patient centered care for adults with chronic migraine, with attention to differential diagnosis and comorbidities, clinical reasoning, initiation and monitoring, cost, and availability. It discusses the international guidelines on drug treatment for chronic migraine and evaluates non-drug treatments including behavioral and complementary therapies and lifestyle modifications. Finally, it discusses the management of chronic migraine in special populations, including pediatrics, pregnancy, and older people, and considers future questions and emerging research in the field.

The Role of Neuro-Immune Interactions in Chronic Pain: Implications for Clinical Practice

Chronic pain remains a public health problem and contributes to the ongoing opioid epidemic. Current pain management therapies still leave many patients with poorly controlled pain, thus new or improved treatments are desperately needed. One major challenge in pain research is the translation of preclinical findings into effective clinical practice. The local neuroimmune interface plays an important role in the initiation and maintenance of chronic pain and is therefore a promising target for novel therapeutic development. Neurons interface with immune and immunocompetent cells in many distinct microenvironments along the nociceptive circuitry. The local neuroimmune interface can modulate the activity and property of the neurons to affect peripheral and central sensitization. In this review, we highlight a specific subset of many neuroimmune interfaces. In the central nervous system, we examine the interface between neurons and microglia, astrocytes, and T lymphocytes. In the periphery, we profile the interface between neurons in the dorsal root ganglion with T lymphocytes, satellite glial cells, and macrophages. To bridge the gap between preclinical research and clinical practice, we review the preclinical studies of each neuroimmune interface, discuss current clinical treatments in pain medicine that may exert its action at the neuroimmune interface, and highlight opportunities for future clinical research efforts.

A Comprehensive Review of Zavegepant as Abortive Treatment for Migraine

Migraine headache is a widespread and complex neurobiological disorder that is characterized by unilateral headaches that are often accompanied by photophobia and phonophobia. Migraine is one of the leading chief complaints in the emergency department with negative impacts on quality of life and activities of daily living. The high number of emergency presentations also results in a significant economic burden. Its risk factors include family history, genetics, sex, race, socioeconomics, the existence of comorbid conditions, and level of education. Triggers include stress, light, noise, menstruation, weather, changes in sleep pattern, hunger, dehydration, dietary factors, odors, and alcohol. The International Headache Society has defined criteria for the diagnosis of migraine with and without aura. The pathophysiology of migraine headaches is multifactorial so there are a variety of treatment approaches. The current treatment approach includes abortive medications and prophylactic medications. Abortive medications include the first-line treatment of triptans, followed by ergot alkaloids, and calcitonin gene-related peptide (CGRP) receptor antagonists along with supplemental caffeine and antiemetics. Trigeminal afferents from the trigeminal ganglion innervate most cranial tissues and many areas of the head and face. These trigeminal afferents express certain biomarkers such as calcitonin gene-related peptide (CGRP), substance P, neurokinin A, and pituitary adenylate cyclase-activating polypeptide that are important to the pain and sensory aspect of migraines. In this comprehensive review, we discuss Zavegepant, a calcitonin gene-related peptide receptor antagonist, as a new abortive medication for migraine headaches.

Calcitonin gene-related peptide-targeting drugs and Raynaud's phenomenon: a real-world potential safety signal from the WHO pharmacovigilance database

BACKGROUND

Migraine is responsible for significant disability and societal burden. Recently, drugs targeting the calcitonin gene-related peptide (CGRP) pathway raised new hopes. CGRP, a potent vasodilator, plays a key role in the pathogenesis of migraine attacks. The deficiency of CGRP is involved in Raynaud's phenomenon, which consists of abnormal vasoconstriction of the digits. We aimed to assess the potential association of Raynaud's phenomenon with CGRP-targeting drugs, analyzing real-world data from the World Health Organization (VigiBase®).

METHODS

We queried all reports of Raynaud's phenomenon involving a CGRP-targeting drug. We sought disproportionate reporting of Raynaud's phenomenon with these drugs. For this purpose, we relied on the calculation of the Information Component (IC). A positive lower end of the 95% confidence interval (CI) of the IC defines a statistically significant association. As migraine patients are prone to Raynaud's phenomenon, we also calculated the IC of Raynaud's phenomenon with CGRP-targeting drugs compared to 5HT1B/D agonists (triptans), and beta-blockers used in the treatment of migraine.

RESULTS

Overall, 99 reports of Raynaud's phenomenon involving CGRP-targeting drugs have been yielded in VigiBase®. The most reported CGRP-targeting drug was erenumab, with 56 reports (56.6%). The median time to onset was 84 days. No fatality was notified, but one patient suffered from gangrene and extremity necrosis. As a whole, CGRP-targeting drugs were significantly associated with Raynaud's phenomenon, with an IC of 3.3 (95%CI: 3.0-3.5). There was a disproportionate reporting of Raynaud's phenomenon with CGRP-targeting drugs compared to triptans (IC 0.4; 95%CI: 0.1-0.6) and to beta-blockers (IC 0.5; 95%CI: 0.2-0.7) as well.

CONCLUSIONS

There is a significant disproportionality signal of Raynaud's phenomenon with CGRP-targeting. This signal stands out when CGRP-targeting drugs are compared to other drugs used in patients with migraine. This study is limited by missing data in pharmacovigilance reports. CGRP-targeting drugs may be subject to Weber effect and reporting bias. Nonetheless, CGRP blockade might be the last straw that disrupts the physiological balance of vascular response in patients at-risk of Raynaud's phenomenon. Pending further data regarding vascular safety of CGRP-targeting drugs, caution is warranted in these patients.

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

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

Beyond the Raskin Protocol: Ketamine, Lidocaine, and Other Therapies for Refractory Chronic Migraine

PURPOSE OF REVIEW

The purpose of this review is to discuss the available evidence and therapeutic considerations for intravenous drug therapy for refractory chronic migraine.

RECENT FINDINGS

In carefully monitored settings, the inpatient administration of intravenous lidocaine and ketamine can be successful in treating refractory chronic migraine. Many patients with refractory chronic migraine have experienced treatment failure with the Raskin protocol. The use of aggressive inpatient infusion therapy consisting of intravenous lidocaine or ketamine, along with other adjunctive medications, has become increasingly common for these patients when all other treatments have failed. There is a clear need for prospective studies in this population comprised of patients who have largely been excluded from other studies.

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

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

Real-life assessment of erenumab in refractory chronic migraine with medication overuse headache

OBJECTIVE

To determine whether erenumab is effective and safe in refractory chronic migraine with medication overuse headache.

METHODS

In this prospective, multicentric, real-life study, chronic migraine with medication overuse headache patients who received erenumab were recruited. Study inclusion was limited to patients who previously failed onabotulinumtoxinA in addition to at least three other pharmacological commonly used migraine preventive medication classes.

RESULTS

Of 396 patients who received erenumab, 38% (n = 149) met inclusion criteria. After 3 months, 51% (n = 76) and 20% (n = 30) patients achieved ≥ 50% and ≥ 75% reduction in monthly headache days, respectively. Monthly pain medications intake decreased from 46.1 ± 35.3 to 16.8 ± 13.9 (p < 0.001), while monthly headache days decreased from 25.4 ± 5.4 to 14.1 ± 8.6 (p < 0.001). Increasing efficacy of erenumab over the study period was observed. Allodynia was a negative predictive factor of erenumab response (odds ratio = 0.47; p = 0.03). Clinical conversion to episodic migraine with no medication overuse was observed in 64% (n = 96) patients. No serious adverse events were observed.

CONCLUSIONS

Erenumab reduced significantly migraine frequency and pain medication intake in refractory chronic migraine with MOH patients.

Preoperative Management of Opioid and Nonopioid Analgesics: Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

There is a lack of guidelines for preoperative dosing of opioid and nonopioid pain medications for surgical patients, which can lead to suboptimal preoperative pain control. The Society for Perioperative Assessment and Quality Improvement identified preoperative dosing of opioid and nonopioid analgesics as an area in which consensus could improve patient care. The aim of this guideline is to provide consensus that will allow perioperative physicians to make optimal recommendations regarding preoperative pain medication dosing. Six categories of pain medications were identified: opioid agonists, opioid antagonists, opioid agonist-antagonists, acetaminophen, muscle relaxants, and triptans/headache medications. We then used a Delphi survey technique to develop consensus recommendations for preoperative dosing of individual medications in each of these groups.

Exploring the Link Between Dry Eye and Migraine: From Eye to Brain

Dry eye and migraine are common diseases with large societal and economic burdens that have recently been associated in the literature. This review outlines the link between dry eye and migraine, which may have implications for reducing their respective burdens. We highlight possible shared pathophysiology, including peripheral and central sensitization, as the potential link between dry eye and migraine. Finally, therapies targeting similar pathophysiological mechanisms between dry eye and migraine are discussed.

Current and Future Challenges in Modern Drug Discovery

Drug discovery is an expensive, time-consuming, and risky business. To avoid late-stage failure, learnings from past projects and the development of new approaches are crucial. New modalities and emerging new target spaces allow the exploration of unprecedented indications or to address so far undrugable targets. Late-stage attrition is usually attributed to the lack of efficacy or to compound-related safety issues. Efficacy has been shown to be related to a strong genetic link to human disease, a better understanding of the target biology, and the availability of biomarkers to bridge from animals to humans. Compound safety can be improved by ligand optimization, which is becoming increasingly demanding for difficult targets. Therefore, new strategies include the design of allosteric ligands, covalent binders, and other modalities. Design methods currently heavily rely on artificial intelligence and advanced computational methods such as free energy calculations and quantum chemistry. Especially for quantum chemical methods, a more detailed overview is given in this chapter.

Pharmacological Characterization of Orofacial Nociception in Female Rats Following Nitroglycerin Administration

Rodent models of human disease can be valuable for understanding the mechanisms of a disease and for identifying novel therapies. However, it is critical that these models be vetted prior to committing resources to developing novel therapeutics. Failure to confirm the model can lead to significant losses in time and resources. One model used for migraine headache is to administer nitroglycerin to rodents. Nitroglycerin is known to produce migraine-like pain in humans and is presumed to do the same in rodents. It is not known, however, if the mechanism for nitroglycerin headaches involves the same pathological processes as migraine. In the absence of known mechanisms, it becomes imperative that the model not only translates into successful clinical trials but also successfully reverse translates by demonstrating efficacy of current therapeutics. In this study female rats were given nitroglycerin and nociception was evaluated in OPADs. Estrous was not monitored. Based on the ED₅₀ of nitroglycerin a dose of 10 mg/kg was used for experiments. Sumatriptan, caffeine, buprenorphine and morphine were administered to evaluate the reverse translatability of the model. We found that nitroglycerin did not produce mechanical allodynia in the face of the rats, which is reported to be a consequence of migraine in humans. Nitroglycerin reduced the animals’ participation in the assay. The reduced activity was verified using an assay to measure exploratory behavior. Furthermore, the effects of nitroglycerin were not reversed or prevented by agents that are effective acute therapies for migraine. Two interesting findings from this study, however, were that morphine and nitroglycerin interact to increase the rats’ tolerance of mechanical stimuli on their faces, and they work in concert to slow down the central motor pattern generator for licking on the reward bottle. These interactions suggest that nitroglycerin generated nitric oxide and mu opioid receptors interact with the same neuronal circuits in an additive manner. The interaction of nitroglycerin and morphine on sensory and motor circuits deserves additional examination. In conclusion, based on the results of this study the use of nitroglycerin at these doses in naïve female rats is not recommended as a model for migraine headaches.

An Innovative Pharmacometric Approach for the Simultaneous Analysis of Frequency, Duration and Severity of Migraine Events

PURPOSE

To explore the use of a multistate repeated, time-to-categorical event model describing the frequency, severity and duration of migraines.

METHODS

Subject level data from patients in placebo arms from two efficacy trials for migraine-preventive treatments were used. Models were developed using NONMEM 7.3. A survival model was combined with an ordered categorical model to form the repeated-time-to-start of categorical migraine event model, which simultaneously described the time-to-start of migraines and the severity of the starting migraine event. This was linked to a repeated-time-to-end of migraine event model with different hazard functions depending on the severity of the ongoing migraine event. Model performance was internally and externally qualified.

RESULTS

The successfully qualified model showed that patients responding to placebo had a reduction in migraine incidence rate, and a decreased proportion of severe migraines. There was an increase in moderate migraine duration, an increased proportion of mild migraines and a reduction in proportion of severe migraines. Age was related to migraine duration.

CONCLUSIONS

The model represents an innovative framework for clinical trial modeling and simulation, and successfully describes placebo effect in migraine prevention. This approach can be adapted to investigate exposure-response relationship of drugs and can also be implemented in other therapeutic areas where the rate, duration and severity of disease episodes are relevant to trial outcomes.

Pharmacological options for the treatment of chronic migraine pain

Migraine is a debilitating neurological condition with symptoms typically consisting of unilateral and pulsating headache, sensitivity to sensory stimuli, nausea, and vomiting. The World Health Organization (WHO) reports that migraine is the third most prevalent medical disorder and second most disabling neurological condition in the world. There are several options for preventive migraine treatments that include, but are not limited to, anticonvulsants, antidepressants, beta blockers, calcium channel blockers, botulinum toxins, NSAIDs, riboflavin, and magnesium. Patients may also benefit from adjunct nonpharmacological options in the comprehensive prevention of migraines, such as cognitive behavior therapy, relaxation therapies, biofeedback, lifestyle guidance, and education. Preventative therapies are an essential component of the overall approach to the pharmacological treatment of migraine. Comparative studies of newer therapies are needed to help patients receive the best treatment option for chronic migraine pain.

Addressing chronic persistent headaches after MTBI as a neuropathic pain state

An increasing number of patients with chronic persistent post-traumatic headache (PPTH) after mild traumatic brain injury (MTBI) are being referred to headache or pain specialists as conventional treatment options for primary headache disorders have not been able to adequately alleviate their debilitating headache symptoms. Evolving clinical and mechanistic evidences support the notation that chronic persistent MTBI related headaches (MTBI-HA) carry the hallmark characteristics of neuropathic pain. Thus, in addition to conventional treatment options applicable to non-traumatic primary headache disorders, other available treatment modalities for neuropathic pain should be considered. In this comprehensive review article, the author reveals the prevalence of MTBI-HA and its clinical manifestation, discusses existing clinical and mechanistic evidence supporting the classification of chronic persistent MTBI-HA as a neuropathic pain state, and explores current available treatment options and future directions of therapeutic research related to MTBI-HA.

Care Among Migraine Patients in a Commercially Insured Population

INTRODUCTION

Migraine management is characterized by the poor use of preventive therapy and the overuse of acute medications. An analysis of current treatment patterns in migraineurs is needed to improve care in this patient population. The aim of this study was to describe treatment patterns and healthcare utilization of newly diagnosed migraine patients.

METHODS

This was a retrospective observation study of newly diagnosed migraine patients (no indication of migraine in the past year) identified in the IBM MarketScan Commercial Claims and Encounters database from 1 January 2010 to 30 June 2014. The final study population comprised persons aged 18-64 years at index (new diagnosis of migraine) with 12 months of continuous enrollment in an insurance plan with medical and pharmacy benefits pre-index and post-index. Treatment patterns and healthcare resource utilization were assessed during the post-index period (at least 12-months).

RESULTS

Of the 1,588,666 migraine patients identified in the database as potentially eligible to participate in the study, 284,719 (17.9%) met the final inclusion criteria. Patients generally used acute and preventive therapies to manage migraine attacks, with most patients using preventive therapy (59.1%). However, 67.9% of those using preventive therapy discontinued the current therapy, with a median time to discontinuation of 5 months. Most of the patients who discontinued preventative therapy also used an acute treatment to manage migraine attacks after discontinuation (77.6%), generally in the year following discontinuation (68.4%). Patients on acute therapies were found to use triptans excessively (1.6%) and other non-migraine-specific acute medications for treatment (7.1%). Acute patients were also at risk of opioid dependence (12.0%) and commonly received opioids or barbiturates as first-line therapy (34.1%).

CONCLUSION

Newly diagnosed migraine patients are not being properly treated, as indicated by their excessive use of acute therapies and short time on preventive treatment before discontinuation of that treatment. Further study of the reasons why patients discontinue preventive therapy (adverse events, no response, etc.) and continue to excessively use acute treatments once their treatment regimen has been established is needed.

Fluorescent Analogues of Human α-Calcitonin Gene-Related Peptide with Potent Vasodilator Activity

Human α-calcitonin gene-related peptide (h-α-CGRP) is a highly potent vasodilator peptide that belongs to the family of calcitonin peptides. There are two forms of CGRP receptors in humans and rodents: α-CGRP receptor predominately found in the cardiovascular system and β-CGRP receptor predominating in the gastrointestinal tract. The CGRP receptors are primarily localized to C and Aδ sensory fibers, where they are involved in nociceptive transmission and migraine pathophysiology. These fibers are found both peripherally and centrally, with extensive perivascular location. The CGRP receptors belong to the class B G-protein-coupled receptors, and they are primarily associated to signaling via Gα proteins. The objectives of the present work were: (i) synthesis of three single-labelled fluorescent analogues of h-α-CGRP by 9-fluorenylmethyloxycarbonyl (Fmoc)-based solid-phase peptide synthesis, and (ii) testing of their biological activity in isolated human, mouse, and rat arteries by using a small-vessel myograph setup. The three analogues were labelled with 5(6)-carboxyfluorescein via the spacer 6-aminohexanoic acid at the chain of Lys²⁴ or Lys³⁵. Circular dichroism (CD) experiments were performed to obtain information on the secondary structure of these fluorescently labelled peptides. The CD spectra indicated that the folding of all three analogues was similar to that of native α-CGRP. The three fluorescent analogues of α-CGRP were successfully prepared with a purity of >95%. In comparison to α-CGRP, the three analogues exhibited similar efficacy, but different potency in producing a vasodilator effect. The analogue labelled at the N-terminus proved to be the most readily synthesized, but it was found to possess the lowest vasodilator potency. The analogues labelled at Lys³⁵ or Lys²⁴ exhibited an acceptable reduction in potency (i.e., 3–5 times and 5–10 times less potent, respectively), and thus they have potential for use in further investigations of receptor internalization and neuronal reuptake.

Calcitonin gene-related peptide antagonists versus botulinum toxin A for the preventive treatment of chronic migraine protocol of a systematic review and network meta-analysis: A protocol for systematic review

BACKGROUND

Although calcitonin gene-related peptide antagonists and botulinum toxin A have been shown efficacy in preventing chronic migraine, there is no direct evidence for their comparative effectiveness. This review is to assess the comparative effectiveness and safety of calcitonin gene-related peptide antagonists and botulinum toxin A for chronic migraine using network meta-analysis.

METHODS

OVID MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials will be searched for relevant randomized controlled trials from their inception to December 2019 without language restriction. We will include trials testing the effectiveness of calcitonin gene-related peptide antagonists or botulinum toxin A in patients with chronic migraine. The outcomes are mean change from baseline in the number of headache days, the mean change from baseline in the number of migraine days, the mean change from baseline in headache hours, responder rate, and adverse events rate. The methodological quality of the included randomized controlled trials will be evaluated using Cochrane Collaboration's risk of bias tool. Standardized mean difference will be used to synthesize continuous variables and risk ratio will be used to synthesize categorical variables. Pairwise and network meta-analysis will be performed using a frequentist method in netmeta package (R 3.5.0, www.r-project.org).

RESULTS

Ethical approval and informed consent are not required for this systematic review. The results will be submitted to a peer-reviewed journal and conference abstracts for publication.

CONCLUSION

The result of the review will systematically provide suggestions for clinicians, patients, and policy makers in the treatment of chronic migraine.PROSPERO registration number: CRD42018089201.

Headache in the elderly

Headache is the most common neurologic symptom and affects nearly half the world's population at any given time. Although the prevalence declines with age, headache remains a common neurologic complaint among elderly populations. Headaches can be divided into primary and secondary causes. Primary headaches comprise about two-thirds of headaches among the elderly. They are defined by clinical criteria and are diagnosed based on symptom pattern and exclusion of secondary causes. Primary headaches include migraine, tension-type, trigeminal autonomic cephalalgias, and hypnic headache. Secondary headaches are defined by their suspected etiology. A higher index of suspicion for a secondary headache disorder is warranted in older patients with new-onset headache. They are roughly 12 times more likely to have serious underlying causes and, frequently, have different symptomatic presentations compared to younger adults. Various imaging and laboratory evaluations are indicated in the presence of any "red flag" signs or symptoms. Head CT is the procedure of choice for acute headache presentations, and brain MRI for those with chronic headache complaints. Management of headache in elderly populations can be challenging due to the presence of multiple medical comorbidities, polypharmacy, and differences in drug metabolism and clearance.

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.