Characterization of binding, functional activity, and contractile responses of the selective 5-HT1F receptor agonist lasmiditan

Is calcitonin gene-related peptide (CGRP) the missing link in food histamine-induced migraine? A review of functional gut-to-trigeminovascular system connections

Calcitonin gene-related peptide (CGRP) and histamine plasma concentrations increase during migraine attacks. Both mediators are potent vasodilators, and they have been shown to reciprocally contribute to the release of each other in the trigeminovascular system, possibly driving migraine development. A high-histamine-content diet triggers migraine in patients who have histamine degradation deficiency owing to diaminooxidase (DAO) gene mutations. Therefore, studying functional links between exogenous histamine and CGRP seems promising for the understanding of diet-induced migraine generation. Notably, there is a lack of knowledge about the interplay of the enteric nervous system and the spinal/trigeminal somatosensory system with regard to CGRP and histamine. Based on background evidence, we propose that a functional interconnection between exogenous histamine and CGRP contributes to migraine development.

Comparison of Lasmiditan 200 mg Versus 100 mg for Migraine Patients: A Meta-analysis of Randomized Controlled Studies

INTRODUCTION

The ideal dose of lasmiditan for migraine is not clear. This meta-analysis aims to compare the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients.

METHODS

We have searched several databases including PubMed, Embase, Web of Science, EBSCO, and Cochrane Library Databases and selected the randomized controlled trials comparing the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients. This meta-analysis was conducted using the random-effect model.

RESULTS

Five randomized controlled trials were included in this meta-analysis. Compared with lasmiditan 100-mg group in migraine patients, lasmiditan 200-mg group was associated with substantially increased pain free at 2 hours (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.12-1.44; P = 0.0002) and pain free at 24 hours (OR, 1.31; 95% CI, 1.08-1.60; P = 0.007) but demonstrated no obvious impact on pain relief at 2 hours (OR, 1.02; 95% CI, 0.91-1.16; P = 0.72) or MBS free at 2 hours (OR, 0.94; 95% CI, 0.77-1.14; P = 0.52). In addition, the incidence of adverse events was higher in lasmiditan 200-mg group than that in lasmiditan 100-mg group (OR, 1.29; 95% CI, 1.15-1.45; P < 0.0001).

CONCLUSIONS

Lasmiditan 200 mg is better for the treatment of migraine patients than lasmiditan 100 mg.

Health equity, care access and quality in headache - part 2

BACKGROUND

Headache disorders are a global public health concern affecting diverse populations. This review examines headache service organizations in low-, middle-, and high-income countries. It addresses global challenges in pharmacological headache treatment, with a focus on safety, tolerability, reproductive and child health, and outlines disparities in accessing innovative treatments worldwide.

MAIN BODY

Organized headache services are essential due to the wide prevalence and varying severity of headache disorders. The tiered headache service model is globally recognized, although its implementation varies based on financial and workforce considerations. Headache burden affects well-being, causing disability, economic challenges, and work limitations, irrespective of location or income. All nations still require improved diagnosis and treatment, and the majority of countries face obstacles including limited access, awareness, economic barriers, and inadequate health policies. Provided adequate internet availability, telemedicine could help improve health equity by expanding access to headache care, since it can offer patients access to services without lengthy waiting times or extensive travel and can provide healthcare unavailable in underserved areas due to staff shortages. Numerous health disparities restrict global access to many headache medications, especially impacting individuals historically excluded from randomized controlled trials, such as those with cardiovascular and cerebrovascular conditions, as well as pregnant women. Furthermore, despite advancements in researching migraine treatments for young patients, the options for treatment remain limited. Access to headache treatment relies on factors like medication availability, approval, financial coverage, and healthcare provider expertise. Inadequate public awareness leads to neglect by policymakers and undertreatment by patients and healthcare providers. Global access discrepancies are exacerbated by the introduction of novel disease-specific medications, particularly impacting Asian, African, and Latin American nations excluded from clinical trials. While North America and Europe experience broad availability of migraine treatments, the majority of countries worldwide lack access to these therapies.

CONCLUSIONS

Healthcare disparities, treatment access, and medication availability are concerning issues in headache medicine. Variations in national healthcare systems impact headache management, and costly innovative drugs are widening these gaps. Healthcare practitioners and experts should acknowledge these challenges and work towards minimizing access barriers for equitable global headache care in the future.

Mode and site of action of therapies targeting CGRP signaling

Targeting CGRP has proved to be efficacious, tolerable, and safe to treat migraine; however, many patients with migraine do not benefit from drugs that antagonize the CGRPergic system. Therefore, this review focuses on summarizing the general pharmacology of the different types of treatments currently available, which target directly or indirectly the CGRP receptor or its ligand. Moreover, the latest evidence regarding the selectivity and site of action of CGRP small molecule antagonists (gepants) and monoclonal antibodies is critically discussed. Finally, the reasons behind non-responders to anti-CGRP drugs and rationale for combining and/or switching between these therapies are addressed.

The Neuropsychiatric Safety Profile of Lasmiditan: A Comparative Disproportionality Analysis with Triptans

Migraine constitutes the world's second-leading cause of disability. Triptans, as serotonin 5-HT1B/1D receptor agonists, remain the first-line treatment, despite discouraged use in individuals at high cardiovascular risk. Lasmiditan, a selective lipophilic 5-HT1F agonist without vasoconstrictive effects, is an emerging option. We aimed to investigate the safety profile of lasmiditan in the WHO pharmacovigilance database (VigiBase®) using a comparative disproportionality analysis with triptans. VigiBase® was queried for all reports involving lasmiditan and triptans. Disproportionality analyses relied on the calculation of the information component (IC), for which 95% confidence interval (CI) lower bound positivity was required for signal detection. We obtained 826 reports involving lasmiditan. Overall, 10 adverse drug reaction classes were disproportionately reported with triptans, while only neurological (IC 1.6; 95% CI 1.5-1.7) and psychiatric (IC 1.5; 95% CI 1.3-1.7) disorders were disproportionately reported with lasmiditan. Sedation, serotonin syndrome, euphoric mood, and autoscopy had the strongest signals. When compared with triptans, 19 out of 22 neuropsychiatric signals persisted. The results of our analysis provide a more precise semiology of the neuropsychiatric effects of lasmiditan, with symptoms such as autoscopy and panic attacks. The cardiovascular adverse drug reaction risk with triptans was confirmed. In contrast, caution is warranted with lasmiditan use in patients with neurological or psychiatric comorbidities or serotonin syndrome risk. Our study was hindered by pharmacovigilance flaws, and further studies should help in validating these results. Our findings suggest that lasmiditan is a safe alternative for migraine treatment, especially when the neuropsychiatric risk is outweighed by the cardiovascular burden.

Migraine and cardiovascular disease: what cardiologists should know

Migraine is a chronic neurovascular disease with a complex, not fully understood pathophysiology with multiple causes. People with migraine suffer from recurrent moderate to severe headache attacks varying from 4 to 72 h. The prevalence of migraine is two to three times higher in women compared with men. Importantly, it is the most disabling disease in women <50 years of age due to a high number of years lived with disability, resulting in a very high global socioeconomic burden. Robust evidence exists on the association between migraine with aura and increased incidence of cardiovascular disease (CVD), in particular ischaemic stroke. People with migraine with aura have an increased risk of atrial fibrillation, myocardial infarction, and cardiovascular death compared with those without migraine. Ongoing studies investigate the relation between migraine and angina with non-obstructive coronary arteries and migraine patients with patent foramen ovale. Medication for the treatment of migraine can be preventative medication, such as beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, antiepileptics, antidepressants, some of the long-acting calcitonin gene-related peptide receptor antagonists, or monoclonal antibodies against calcitonin gene-related peptide or its receptor, or acute medication, such as triptans and calcitonin gene-related peptide receptor antagonists. However, these medications might raise concerns when migraine patients also have CVD due to possible (coronary) side effects. Specifically, knowledge gaps remain for the contraindication to newer treatments for migraine. All cardiologists will encounter patients with CVD and migraine. This state-of-the-art review will outline the basic pathophysiology of migraine and the associations between migraine and CVD, discuss current therapies, and propose future directions for research.

The 5-HT1F receptor as the target of ditans in migraine - from bench to bedside

Migraine is a leading cause of disability in more than one billion people worldwide, yet it remains universally underappreciated, even by individuals with the condition. Among other shortcomings, current treatments (often repurposed agents) have limited efficacy and potential adverse effects, leading to low treatment adherence. After the introduction of agents that target the calcitonin gene-related peptide pathway, another new drug class, the ditans - a group of selective serotonin 5-HT_1F receptor agonists - has just reached the international market. Here, we review preclinical studies from the late 1990s and more recent clinical research that contributed to the development of the ditans and led to their approval for acute migraine treatment by the US Food and Drug Administration and the European Medicines Agency.

Neurological and psychiatric comorbidities of migraine: Concepts and future perspectives

BACKGROUND

This narrative review aims to discuss several common neurological and psychiatric disorders that show comorbidity with migraine. Not only can we gain pathophysiological insights by studying these disorders, comorbidities also have important implications for treating migraine patients in clinical practice.

METHODS

A literature search on PubMed and Embase was conducted with the keywords "comorbidity", "migraine disorders", "migraine with aura", "migraine without aura", "depression", "depressive disorders", "epilepsy", "stroke", "patent foramen ovale", "sleep wake disorders", "restless legs syndrome", "genetics", "therapeutics".

RESULTS

Several common neurological and psychiatric disorders show comorbidity with migraine. Major depression and migraine show bidirectional causality and have shared genetic factors. Dysregulation of both hypothalamic and thalamic pathways have been implicated as a possibly cause. The increased risk of ischaemic stroke in migraine likely involves spreading depolarizations. Epilepsy is not only bidirectionally related to migraine, but is also co-occurring in monogenic migraine syndromes. Neuronal hyperexcitability is an important overlapping mechanism between these conditions. Hypothalamic dysfunction is suggested as the underlying mechanism for comorbidity between sleep disorders and migraine and might explain altered circadian timing in migraine.

CONCLUSION

These comorbid conditions in migraine with distinct pathophysiological mechanisms have important implications for best treatment choices and may provide clues for future approaches.

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

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

Trigeminovascular effects of propranolol in men and women, role for sex steroids

Objective

Assess whether propranolol modulates the trigeminovascular system in both men and women.

Methods

We investigated the effect of propranolol (80 mg, 90 min after oral administration, corresponding to T_max) on the increase in dermal blood flow of the forehead skin (innervated by the trigeminal nerve) by capsaicin application (0.6 mg/mL) and electrical stimulation (0.2–1.0 mA) before and after placebo (grapefruit juice) or propranolol (oral solution diluted in grapefruit juice) in a randomized, double‐blind, placebo‐controlled cross‐over study, including healthy males (n = 10) and females on contraceptives (n = 11). Additionally, we compared our results with data from the Dutch IADB.nl prescription database by analyzing the change in triptan use after propranolol prescription in a population similar to our dermal blood flow study subjects (males and females, 20–39 years old).

Results

Dermal blood flow responses to capsaicin were significantly attenuated after propranolol, but not after placebo. When stratifying by sex, no significant changes in the capsaicin‐induced dermal blood flow were observed in females after propranolol, whereas they remained significant in males. Dermal blood flow responses to electrical stimulation were not modified in any case. In our prescription database study, after propranolol, a more pronounced decrease in triptan use was observed in male patients than in female patients.

Interpretation

Propranolol (80 mg) inhibits capsaicin‐induced increases in dermal blood flow in a sex‐dependent manner. In patients, a more pronounced decrease in triptan use is observed in males when compared with females, suggesting an interaction between propranolol and sex steroids in the modulation of the trigeminovascular system.

Cardiovascular Disease and Migraine: Are the New Treatments Safe?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Lasmiditan for Patients with Migraine and Contraindications to Triptans: A Post Hoc Analysis

INTRODUCTION

As 5-HT1B receptor agonists, triptans produce vasoconstriction and have cardiovascular contraindications and precautions. Lasmiditan, a selective 5-HT1F receptor agonist, has a low affinity for 5-HT1B receptors, does not cause vasoconstriction, and is free of cardiovascular contraindications and precautions. The objective of this post hoc analysis was to evaluate the efficacy and safety of lasmiditan in patients with and without at least one triptan contraindication.

METHODS

Patient subgroups, with and without triptan contraindications, were analyzed from pooled patient data from four randomized, double-blind, placebo-controlled clinical trials (SAMURAI, SPARTAN, CENTURION, and MONONOFU). Patients experiencing a single migraine attack of moderate or severe intensity were treated with lasmiditan 50 mg (SPARTAN and MONONOFU only), 100 mg, 200 mg, or placebo, and efficacy data were recorded in an electronic diary.

RESULTS

Of 5704 patients, 207 (3.6%) patients had at least one contraindication to triptans. Overall subgroup analysis revealed that the effects of lasmiditan on pain freedom, pain relief, freedom from most bothersome symptom, disability freedom, and Patient Global Impression of Change at 2 h post-dose did not differ in patient groups with and without triptan contraindications. These outcomes generally showed a similar benefit pattern for lasmiditan in both subgroups, with all results being statistically significant in patients without contraindications, and pain relief being statistically significant in patients with contraindications. The safety and tolerability profiles of patients with triptan versus without triptan contraindications were similar, including dizziness in 18.3 to 22.8% and somnolence in 7.9 to 9.9% of patients at the highest dose of lasmiditan.

CONCLUSIONS

In pooled analyses from four trials, patients with and without triptan contraindications did not differ in their patterns of lasmiditan efficacy. Lasmiditan may be a treatment option in patients with contraindications to triptans.

TRIAL REGISTRATION NUMBERS

SAMURAI, NCT:02439320; SPARTAN, NCT:02605174; CENTURION, NCT:03670810; and MONONOFU, NCT:03962738.

The Role of Serotonin Neurotransmission in Gastrointestinal Tract and Pharmacotherapy

5-Hydroxytryptamine (5-HT, serotonin) is a neurotransmitter in both the central nervous system and peripheral structures, acting also as a hormone in platelets. Although its concentration in the gut covers >90% of all organism resources, serotonin is mainly known as a neurotransmitter that takes part in the pathology of mental diseases. Serotonin modulates not only CNS neurons, but also pain transmission and platelet aggregation. In the periphery, 5-HT influences muscle motility in the gut, bronchi, uterus, and vessels directly and through neurons. Serotonin synthesis starts from hydroxylation of orally delivered tryptophan, followed by decarboxylation. Serotonin acts via numerous types of receptors and clinically plays a role in several neural, mental, and other chronic disorders, such as migraine, carcinoid syndrome, and some dysfunctions of the alimentary system. 5-HT acts as a paracrine hormone and growth factor. 5-HT receptors in both the brain and gut are targets for drugs modifying serotonin neurotransmission. The aim of the present article is to review the 5-HT receptors in the gastrointestinal (GI) tract to determine the role of serotonin in GI physiology and pathology, including known GI diseases and the role of serotonin in GI pharmacotherapy.

Dual action of the cannabinoid receptor 1 ligand arachidonyl-2′-chloroethylamide on calcitonin gene-related peptide release

Background

Based on the current understanding of the role of neuropeptide signalling in migraine, we explored the therapeutic potential of a specific cannabinoid agonist. The aim of the present study was to examine the effect of the synthetic endocannabinoid (eCB) analogue, arachidonyl-2′-chloroethylamide (ACEA), on calcitonin gene-related peptide (CGRP) release in the dura and trigeminal ganglion (TG), as cannabinoids are known to activate G_i/o-coupled cannabinoid receptors type 1 (CB1), resulting in neuronal inhibition.

Methods

The experiments were performed using the hemi-skull model and dissected TGs from male Sprague-Dawley rats. CGRP release was induced by either 60 mM K⁺ (for depolarization-induced stimulation) or 100 nM capsaicin (for transient receptor potential vanilloid 1 (TRPV1) -induced stimulation) and measured using an enzyme-linked immunosorbent assay. The analysis of CGRP release data was combined with immunohistochemistry in order to study the cellular localization of CB1, cannabinoid receptor type 2 (CB2), CGRP and receptor activity modifying protein 1 (RAMP1), a subunit of the functional CGRP receptor, in the TG.

Results

CB1 was predominantly expressed in neuronal somas in which colocalization with CGRP was observed. Furthermore, CB1 exhibited colocalization with RAMP1 in neuronal Aδ-fibres but was not clearly expressed in the CGRP-immunoreactive C-fibres. CB2 was mainly expressed in satellite glial cells and did not show substantial colocalization with either CGRP or RAMP1. Without stimulation, 140 nM ACEA per se caused a significant increase in CGRP release in the dura but not TG, compared to vehicle. Furthermore, 140 nM ACEA did not significantly modify neither K⁺- nor capsaicin-induced CGRP release. However, when the TRPV1 blocker AMG9810 (1 mM) was coapplied with ACEA, K⁺-induced CGRP release was significantly attenuated in the TG and dura.

Conclusions

Results from the present study indicate that ACEA per se does not exhibit antimigraine potential due to its dual agonistic properties, resulting in activation of both CB1 and TRPV1, and thereby inhibition and stimulation of CGRP release, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01399-8.

Lasmiditan and 5-Hydroxytryptamine in the rat trigeminal system; expression, release and interactions with 5-HT1 receptors

Background

5-Hydroxytryptamine (5-HT) receptors 1B, 1D and 1F have key roles in migraine pharmacotherapy. Selective agonists targeting these receptors, such as triptans and ditans, are effective in aborting acute migraine attacks and inhibit the in vivo release of calcitonin gene-related peptide (CGRP) in human and animal models. The study aimed to examine the localization, genetic expression and functional aspects of 5- HT_1B/1D/1F receptors in the trigeminal system in order to further understand the molecular sites of action of triptans (5-HT_1B/1D) and ditans (5-HT_1F).

Methods

Utilizing immunohistochemistry, the localization of 5-HT and of 5-HT_1B/1D/1F receptors was examined in rat trigeminal ganglion (TG) and combined with quantitative polymerase chain reaction to quantify the level of expression for 5-HT_1B/1D/1F receptors in the TG. The functional role of these receptors was examined ex vivo with a capsaicin/potassium induced 5-HT and CGRP release.

Results

5-HT immunoreactivity (ir) was observed in a minority of CGRP negative C-fibres, most neuron somas and faintly in A-fibres and Schwann cell neurolemma. 5-HT_1B/1D receptors were expressed in the TG, while the 5-HT_1F receptor displayed a weak ir. The 5-HT_1D receptor co-localized with receptor activity-modifying protein 1 (RAMP1) in Aδ-fibres in the TG, while 5-HT_1B-ir was weakly expressed and 5-HT_1F-ir was not detected in these fibres. None of the 5-HT₁ receptors co-localized with CGRP-ir in C-fibres.

5-HT_1D receptor mRNA was the most prominently expressed, followed by the 5-HT_1B receptor and lastly the 5-HT_1F receptor. The 5-HT_1B and 5-HT_1D receptor antagonist, GR127935, could reverse the inhibitory effect of Lasmiditan (a selective 5-HT_1F receptor agonist) on CGRP release in the soma-rich TG but not in soma-poor TG or dura mater. 5-HT release in the soma-rich TG, and 5-HT content in the baseline samples, negatively correlated with CGRP levels, showing for the first time a physiological role for 5-HT induced inhibition.

Conclusion

This study reveals the presence of a subgroup of C-fibres that store 5-HT. The data shows high expression of 5-HT_1B/1D receptors and suggests that the 5-HT_1F receptor is a relatively unlikely target in the rat TG. Furthermore, Lasmiditan works as a partial agonist on 5-HT_1B/1D receptors in clinically relevant dose regiments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01394-z.

The selective 5-HT1F receptor agonist lasmiditan inhibits trigeminal nociceptive processing: Implications for migraine and cluster headache

BACKGROUND AND PURPOSE

Lasmiditan is a novel selective 5-HT1F receptor agonist, recently approved for acute treatment of migraine. 5-HT1F receptors are widely expressed in the CNS and trigeminovascular system. Here, we have explored the therapeutic effects of 5-HT1F receptor activation in preclinical models of migraine and cluster headache.

EXPERIMENTAL APPROACH

Electrical stimulation of the dura mater or the superior salivatory nucleus in anaesthetised rats evoked trigeminovascular or trigeminal-autonomic reflex activation at the level of the trigeminocervical complex. Additionally, cranial autonomic manifestations in response to trigeminal-autonomic reflex activation were measured, via anterior choroidal blood flow alterations. These responses were then challenged with lasmiditan. We explored the tissue distribution of mRNA for 5-HT1F receptors in human post-mortem tissue and of several 5-HT1 receptor subtypes in specific tissue beds.

KEY RESULTS

Lasmiditan dose-dependently reduced trigeminovascular activation in a preclinical model of migraine. Lasmiditan also reduced superior salivatory nucleus-evoked activation of the trigeminal-autonomic reflex, but had no effect on cranial autonomic activation. mRNA profiling in human tissue showed expression of the 5-HT1F receptor in several structures relevant for migraine and cluster headache.

CONCLUSION AND IMPLICATIONS

Our data suggest that lasmiditan acts, at least in part, as an anti-migraine agent by reducing trigeminovascular activation. Furthermore, our results highlight a clear action for lasmiditan in a preclinical model of cluster headache. Given the proven translational efficacy of this model, our data support the potential utility of lasmiditan as a therapeutic option for the acute treatment of cluster headache attacks.

LINKED ARTICLES

This article is part of a themed issue on Advances in Migraine and Headache Therapy (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.3/issuetoc.

Lasmiditan: Acute Migraine Treatment Without Vasoconstriction. A Review

Objective: To review the efficacy and safety of the newly Food and Drug Administration approved drug lasmiditan, and its place in therapy in the treatment of acute migraine attacks. Data Sources: A literature search of Web of Science, PubMed, and Google Scholar was preformed (September 1999 to May 2021) using the following search terms: acute migraine treatment, triptans, lasmiditan, Reyvow, Rimegepant, Nurtec, Ubrogepant, Ubrelvy, migraine, vasoconstriction, and cardiovascular risk. Product labeling, https://www.clinicaltriasl.gov, and product monographs were also reviewed. Study Selection and Data Extraction: Relevant English-language studies were considered. Data Synthesis: Lasmiditan is the first in its class approved for acute migraine treatment. Lasmiditan exerts its therapeutic effect through agonism at the 5-HT_1F receptor, which has been shown to produce no vasoconstriction in preclinical models. Relevance to Patient Care and Clinical Practice: It is both scientifically and clinically relevant to review lasmiditan and determine the value of an acute migraine drug that does not induce vasoconstriction. Patients with preexisting cardiovascular conditions for which current migraine therapy is contraindicated may benefit from therapeutic use of lasmiditan. However, the potential cardiovascular benefit needs to be weighed against the increased central nervous system risks observed with lasmiditan. Conclusions: Lasmiditan is an oral tablet drug that is used for acute migraine abortive treatment and data suggest that it does not induce vasoconstriction, a common side effect often observed with the current first-line abortive migraine treatment drug class, triptans. This is especially important in acute migraine patients with cardiovascular risk factors in which triptan use is contraindicated.

5-hydroxytryptamine in migraine: The puzzling role of ionotropic 5-HT3 receptor in the context of established therapeutic effect of metabotropic 5-HT1 subtypes

5-hydroxytryptamine (5-HT; serotonin) is traditionally considered as a key mediator implicated in migraine. Multiple 5-HT receptor subtypes contribute to a variety of region-specific functional effects. The raphé nuclei control nociceptive inputs by releasing 5-HT in the brainstem, whereas dural mast cells provide the humoral source of 5-HT in the meninges. Triptans (5-HT_1B/D agonists) and ditans (5-HT_1F agonists) are the best established 5-HT anti-migraine agents. However, activation of meningeal afferents via ionotropic 5-HT₃ receptors results in long-lasting excitatory drive suggesting a pro-nociceptive role for these receptors in migraine. Nevertheless, clinical data do not clearly support the applicability of currently available 5-HT₃ antagonists to migraine treatment. The reasons for this might be the presence of 5-HT₃ receptors on inhibitory interneurons dampening the excitatory drive, a lack of 5-HT₃ A-E subunit-selective antagonists and gender/age-dependent effects. This review is focusing on the controversial role of 5-HT₃ receptors in migraine pathology and related pharmacological perspectives of 5-HT ligands.

Tolerability and Safety of Lasmiditan Treatment in Elderly Patients With Migraine: Post Hoc Analyses From Randomized Studies

PURPOSE

Limited information is available on acute treatments for migraine in elderly patients. Our objective was to evaluate the tolerability and safety of lasmiditan, a serotonin 1F agonist, for the acute treatment of migraine in elderly compared with nonelderly patients, with special emphasis on cardiovascular-related issues because cardiovascular comorbidities are more common in the elderly population.

METHODS

These post hoc analyses evaluated the incidence of treatment-emergent adverse events (TEAEs) in elderly (≥65 years of age) versus nonelderly (<65 years of age) lasmiditan-treated patients. Two clinical trials entitled A Study of Two Doses of LAsMiditan (100 mg and 200 mg) Compared to Placebo in the AcUte Treatment of MigRAIne (SAMURAI) and A Study of Three Doses of Lasmiditan (50 mg, 100 mg and 200 mg) Compared to Placebo in the Acute TReaTment of MigrAiNe (SPARTAN) were randomized, double-blind, placebo-controlled, Phase III studies in adults (no upper age limit) who took placebo or lasmiditan 50 (SPARTAN only), 100, or 200 mg for a single migraine attack within 4 hours of the onset of moderate or severe pain. Patients who completed SAMURAI or SPARTAN were eligible to enroll in An Open-label, LonG-term, Safety Study of LAsmiDItan (100 mg and 200 mg) in the Acute Treatment Of MigRaine (GLADIATOR), a Phase III, randomized, open-label, multiattack study of lasmiditan 100 or 200 mg. For pooled SAMURAI+SPARTAN data, treatment × age subgroup interactions were examined using logistic regression analyses. In addition, common cardiovascular event rates were assessed from GLADIATOR during 3 periods: treatment-emergent (<48 hours after dosing), intermediate (48 hours to 1 week after dosing), and remote (>1 week after dosing).

FINDINGS

Of 3177 lasmiditan-treated patients in SAMURAI or SPARTAN, 132 (4.2%) were elderly, and of 1262 placebo-treated patients, 54 (4.3%) were elderly. Of 2030 lasmiditan-treated patients in GLADIATOR, 85 (4.2%) were elderly. The incidences of at least 1 TEAE with lasmiditan in nonelderly and elderly patients with migraine were 36% and 35% in pooled SAMURAI+SPARTAN, respectively, and 49% and 38% in GLADIATOR, respectively. No significant treatment × age subgroup interactions were observed in patients with ≥1 TEAE overall or for any individual TEAE in pooled SPARTAN+SAMURAI; however, numerical differences in the incidence of some specific TEAEs were seen. No treatment × age subgroup interactions and no tolerability concerns for individual TEAEs were detected. Cardiovascular TEAEs were much more frequent in the nonelderly population than the elderly population. Cardiovascular events were not reported in the elderly population during the treatment-emergent period or intermediate period. There were 2 cases of increased blood pressure in elderly patients during the remote period.

IMPLICATIONS

The incidence of TEAEs was similar for elderly and nonelderly patients, and cardiovascular safety of lasmiditan was generally consistent with that in single-attack studies. No safety signals were observed with the limited number of patients in the elderly population. ClinicalTrials.gov identifiers: NCT02565186 (GLADIATOR), NCT02439320 (SAMURAI), and NCT02605174 (SPARTAN).

Emerging Targets for Migraine Treatment

Background

While understanding the pathophysiology of migraine has led to CGRP-based treatments, other potential targets have also been implicated in migraine.

Objectives

To catalog new promising targets for the treatment of migraine.

Methods

We completed a literature review focusing on 5HT_1F, PACAP, melatonin, and orexins.

Results

The 5HT_1F receptor agonist lasmiditan, following two positive randomized placebo-controlled trials, was FDA-approved for the acute treatment of migraine. PACAP-38 has shown analogous evidence to what was obtained for CGRP with its localization in key structures, provocation tests, and positive studies when antagonizing its receptor in animal models, although a PAC-1 receptor monoclonal antibody study was negative. Melatonin has undergone several randomized controlled trials showing a positive trend. Filorexant is the only dual orexin receptor antagonist, which was tested in humans with negative results.

Conclusions

Further and ongoing studies will determine the utility of these new therapies with lasmiditan and melatonin having demonstrated efficacy for the treatment of migraine.

Phase 2 randomized placebo-controlled study of lasmiditan for the acute treatment of migraine in Japanese patients

Objective

To evaluate the efficacy and safety of lasmiditan in Japanese adults with migraine.

Background

Global clinical studies have demonstrated the efficacy and safety of lasmiditan in the acute treatment of migraine.

Methods

This was a multicenter, randomized, double‐blind, placebo‐controlled, phase 2 study in Japan (NCT03962738), which enrolled adults with migraine with or without aura. Participants were randomized 7:3:7:6 to placebo, lasmiditan 50 mg, 100 mg, or 200 mg to be self‐administered orally within 4 h of onset of a single moderate‐to‐severe migraine attack. Participants recorded their response to treatment prior to dosing and for 48 h postdose. The primary endpoint was headache pain freedom at 2 h postdose.

Results

Participants (N = 846) were randomized and treated (N = 691, safety; N = 682, modified intent‐to‐treat). At 2 h postdose, a significantly higher proportion of participants were headache pain‐free in the lasmiditan 200 mg (40.8%, 73/179; odds ratio 3.46 [95% confidence interval 2.17 to 5.54]; p < 0.001; primary objective) and 100 mg groups (32.4%, 67/207; odds ratio 2.41 [1.51 to 3.83]; p < 0.001) compared with the placebo group (16.6%, 35/211), whereas the lasmiditan 50 mg group had a numerically higher proportion of participants headache pain‐free (23.5%, 20/85; odds ratio 1.55 [0.83 to 2.87]; p = 0.167) compared with placebo. A statistically significant linear dose–response relationship for pain freedom was achieved at 2 h by a Cochran–Armitage trend test (p < 0.001). Lasmiditan treatment was also associated with headache pain relief, most bothersome symptom freedom, and improvement on disability and Patient Global Impression of Change outcomes. The majority of treatment‐emergent adverse events were mild and of short duration, the most common of which were dizziness (39.4%; 188/477), somnolence (19.3%; 92/477), and malaise (10.5%; 50/477) in all lasmiditan groups, with no serious adverse events reported.

Conclusions

Lasmiditan was well tolerated and effective for the acute treatment of Japanese patients with migraine, consistent with global phase 3 studies.

Lasmiditan inhibits calcitonin gene-related peptide release in the rodent trigeminovascular system

Lasmiditan, an antimigraine drug with selective 5-HT_1F receptor affinity, prejunctionally inhibits calcitonin gene-related peptide release in peripheral and central trigeminal nerve terminals of rodents.

Migraine headache pathophysiology involves trigeminovascular system activation, calcitonin gene-related peptide (CGRP) release, and dysfunctional nociceptive transmission. Triptans are 5-HT_1B/1D/(1F) receptor agonists that prejunctionally inhibit trigeminal CGRP release, but their vasoconstrictor properties limit their use in migraine patients with cardiovascular disease. By contrast, lasmiditan is a novel antimigraine and selective 5-HT_1F receptor agonist devoid of vasoconstrictor properties. On this basis, this study has investigated the modulation of trigeminal CGRP release by lasmiditan. For this purpose, we have comparatively analysed the inhibition of several components of the trigeminovascular system induced by lasmiditan and sumatriptan through: ex vivo KCl-induced CGRP release from isolated dura mater, trigeminal ganglion, and trigeminal nucleus caudalis of mice; and in vivo dural vasodilation in the rat closed-cranial window model induced by endogenous (electrical stimulation and capsaicin) and exogenous CGRP. The ex vivo release of CGRP was similarly inhibited by sumatriptan and lasmiditan in all trigeminovascular system components. In vivo, intravenous (i.v.) lasmiditan or higher doses of sumatriptan significantly attenuated the vasodilatory responses to endogenous CGRP release, but not exogenous CGRP effects. These data suggest that lasmiditan prejunctionally inhibits CGRP release in peripheral and central trigeminal nerve terminals. Because lasmiditan is a lipophilic drug that crosses the blood–brain barrier, additional central sites of action remain to be determined.

Lasmiditan: an additional therapeutic option for the acute treatment of migraine

Introduction: Migraine is currently listed as the second cause of 'years lived with disability' and the sixth cause of global disability. Despite the burden associated to the disease, availability of specific drugs is still limited.Areas covered: The authors have evaluated lasmiditan, the first 'ditan' approved by the Food and Drugs Administration in 2019, from a global perspective: basic chemistry, pharmacodynamic and pharmacokinetic profiles, efficacy in migraine as a 5-HT_1F receptor selective agonist, tolerability and clinical safety, and impact on migraine-related disability. Our evaluation considered original papers and review articles published from 2010 to 2020.Expert opinion: Available data point to the efficacy of lasmiditan in reducing migraine pain and the most bothersome symptoms within 2 hours from oral administration. Moreover, lasmiditan has a positive effect on migraine-related disability. Its side effects mostly reflect an involvement of the central nervous system or the vestibular system, while cardiovascular side effects are rare and mild.Lasmiditan can be safely prescribed in patients who have failed non-steroid anti-inflammatory drugs or triptans or with cardiovascular risk factors. Caution is advised in frequent users, due to lack of reliable data on its abuse potential. Further data are necessary to determine the usability of lasmiditan in particular populations, e.g. children and adolescents, pregnancy.

Drug interactions and risks associated with the use of triptans, ditans and monoclonal antibodies in migraine

PURPOSE OF REVIEW

The aim of this study was to review current evidence concerning potential risks and interactions associated with concomitant use of drugs indicated for the abortive treatment of migraine, namely triptans and ditans, and more recently developed drugs used for the preventive treatment. The latter drug class encompasses monoclonal antibodies (mAbs), which target either calcitonin gene-related peptide (CGRP) or its receptor.

RECENT FINDINGS

To date, no pharmacokinetic interactions between these drug classes have been reported. However, patients who suffer from triptan- (or ditan-) induced medication overuse headache or those who are nonresponders to triptans might respond less effectively to mAbs. Caution is warranted when coadministrating these drugs in migraine patients with comorbid cardiovascular disease or with an increased cardiovascular risk profile.

SUMMARY

In this review, the main mechanisms of action of triptans, ditans and mAbs targeting CGRP or its receptor are summarized as well as the current evidence on their individual risks. Studies on risks and interactions in case of concomitant use of triptans, ditans and mAbs in migraine patients are relatively scarce. Therefore, these aspects have been considered from a theoretical and hypothetical point of view by taking both their overlapping target, CGRP, and contraindications into account.

Lasmiditan for the acute treatment of migraine

Migraine is a leading cause of morbidity and disability worldwide. Triptans were the first migraine-specific drug class developed and have proven efficacy in treatment of this neurological disease. They are however contraindicated in patients with cardiovascular disease and possibly others, owning to their vasoconstrictive properties. This review will focus on lasmiditan, which has been called the first 'ditan' and 'neurally acting anti-migraine agent', designed to selectively agonize the serotonin 5-HT_1F receptor subtype, providing anti-migraine effects without concomitant vasoconstriction. To date, lasmiditan has proven safe and effective for the acute treatment of migraine in two Phase II and four Phase III trials. Post hoc analysis revealed that the majority of treatment-emergent adverse events were CNS-related, mild-to-moderate in severity and self-limiting. The US FDA label recommends that patients not drive or operate machinery until at least 8 h after taking each dose of lasmiditan.

Targets for migraine treatment: beyond calcitonin gene-related peptide

PURPOSE OF REVIEW

Despite the development of several medications for the acute and preventive treatment of migraine, there are still many patients in whom lack of efficacy, tolerability, interactions or contraindications make other options necessary. CGRP-based drugs have opened the door to a new era of migraine-targeted treatments. Beyond CGRP, there are other promising targets covered here.

RECENT FINDINGS

For the acute treatment of migraine, 5-HT1F receptor agonists, ditans, are now available. Unlike triptans, 5-HT1B/1D receptor agonists, cardiovascular disease is not a contraindication for the use of ditans. The first study on a monoclonal antibody targeting PAC1 receptor was negative, although this may not be the end for the pituitary adenylate cyclase-activating polypeptide (PACAP) pathway as a target.

SUMMARY

Following positive phase-III clinical trials, lasmiditan is the first ditan to be FDA-approved. PACAP has experimental evidence suggesting a role in migraine pathophysiology. As for CGRP, the presence of PACAP in key migraine structures along with positive provocative tests for both PACAP-38 and PACAP-27 indicate this pathway may still be a pharmacological target. Glutamate-based targets have long been considered in migraine. Two clinical trials with memantine, an NMDA-R antagonist, for the preventive treatment of migraine have now been published. The hypothalamus has also been implicated in migraine pathophysiology: the potential role of orexins in migraine is discussed. Acid-sensing ion channels, as well as amylin-blocking drugs, may also become migraine treatments in the future: more research is warranted.

Effect of a change in lasmiditan dose on efficacy and safety in patients with migraine

Background: Lasmiditan is a selective serotonin (1F) receptor agonist approved for acute treatment of migraine with 3 doses: 50, 100, and 200 mg.Objective: To help provide dosing insights, we assessed the efficacy and safety of lasmiditan in patients who treated two migraine attacks with the same or different lasmiditan doses.Methods: Integrated analyses used data from the migraine attack treated in either of two controlled, Phase 3, single attack studies (SAMURAI/SPARTAN), and after the first attack treated in the open-label GLADIATOR extension study. Eight patient groups were created based on the initial dose received in SAMURAI or SPARTAN and the subsequent dose in GLADIATOR: placebo-100, placebo-200, 50-100, 50-200, 100-100, 100-200, 200-100, 200-200. Migraine pain freedom, migraine-related functional disability freedom, most bothersome symptom (MBS) freedom, and pain relief were evaluated at 2-h post-dose. The occurrence of most common treatment-emergent adverse events (MC-TEAE) was evaluated. Shift analyses were performed for pain freedom and ≥1 MC-TEAE. The incidence of patients with a specific outcome from the first and subsequent doses were compared within each dose change group using McNemar's test.Results: Small, but consistent, increases in incidences of pain freedom, migraine-related functional disability freedom, MBS freedom, and pain relief occurred when the second lasmiditan dose was higher than the initial dose. For patients starting on 50 mg, increasing to 100 or 200 mg provided a positive efficacy-TEAE balance, despite an increase in incidence of ≥1 MC-TEAE. For patients starting on 100 mg, increasing to 200 mg provided a positive efficacy-TEAE balance. If the initial dose was 100 or 200 mg, the incidence of patients experiencing ≥1 MC-TEAE decreased or stayed the same with their subsequent dose, regardless of dose. Decreasing from 200 to 100 mg led to a decrease in patients with pain freedom and ≥1 MC-TEAE, resulting in a neutral efficacy-TEAE balance. Shift analyses supported these findings.Conclusion: A positive efficacy-TEAE balance exists for patients increasing their lasmiditan dose for treatment of a subsequent migraine attack. These results could be important for optimizing dosing for individual patients.Clinicaltrials.gov: SAMURAI (NCT02439320); SPARTAN (NCT02605174); GLADIATOR (NCT02565186).

Rational Use of Lasmiditan for Acute Migraine Treatment in Adults: A Narrative Review

PURPOSE

This narrative review provides an update on the research that led to the development of ditans and lasmiditan for the acute treatment of migraine in adults and discusses the potential advantages and disadvantages of lasmiditan in clinical use.

METHODS

The electronic databases PubMed, Scopus, and ClinicalTrials.gov were searched from database inception through January 9, 2021, to identify relevant studies. Search results were assessed for their overall relevance to this review.

FINDINGS

Because part of the effect of the triptans is mediated by the serotonin 1F receptors, which are not present in the smooth muscle, a pure agonist of these receptors, lasmiditan, was developed. Lasmiditan is hypothesized to act on antinociceptive pathways and inhibit the calcitonin gene-related peptide release. Lasmiditan was approved by the US Food and Drug Administration in 2019 based on the results of 2 pivotal trials that found a significant difference from placebo in the percentage of patients who achieved freedom from pain and most bothersome symptom at 2 h. The main concern of lasmiditan derives from its central nervous system-related adverse effects, mainly dizziness and paraesthesia, probably attributable to its high blood brain barrier penetration. These central nervous system adverse effects impair driving performance for hours and might be suboptimal for individuals with migraine who want to quickly stop the migraine attack to resume their activities as soon as possible.

IMPLICATIONS

Despite the advantage of being beneficial in the acute treatment of migraine without vasocostrictive action, lasmiditan also presents limitations, in particular the central nervous system adverse effects. Moreover, head-to-head trials against triptans and gepants are indispensable to determine the better option for patients.

Identifying New Antimigraine Targets: Lessons from Molecular Biology

Primary headaches are one of the most common conditions; migraine being most prevalent. Recent work on the pathophysiology of migraine suggests a mismatch in the communication or tuning of the trigeminovascular system, leading to sensitization and the release of calcitonin gene-related peptide (CGRP). In the current Opinion, we use the up-to-date molecular understanding of mechanisms behind migraine pain, to provide novel aspects on how to modify the system and for the development of future treatments; acute as well as prophylactic. We explore the distribution and the expression of neuropeptides themselves, as well as certain ion channels, and most importantly how they may act in concert as modulators of excitability of both the trigeminal C neurons and the Aδ neurons.

Novel synthetic treatment options for migraine

Introduction: Migraine is one of the most common neurological disorders. Nowadays, the 5-HT_1B/1D receptor agonists, namely triptans, are considered as the standard of care for migraine acute treatment. However, triptans have limitations in some patients, such as incomplete pain relief, headache recurrence, and cardiovascular contraindications. New 5-HT_1F receptor agonists, namely ditans, and calcitonin gene-related peptide receptor antagonists, namely gepants, have been developed as migraine-specific treatments.Areas covered: This paper reviews the available data from RCTs to assess the clinical efficacy, safety, and tolerability profile of lasmiditan, rimegepant, and ubrogepant for the acute treatment of migraine and atogepant for the prevention of migraine.Expert opinion: Available data suggest that lasmiditan, rimegepant, and ubrogepant might not have a clinical efficacy similar to triptans. Lasmiditan did not cause the typical triptan side effects but was associated with central nervous system side effects, causing temporary driving impairment. On the contrary, the new generation of gepants showed a placebo-like tolerability profile and the absence of a specific pattern of side effects. Future studies on lasmiditan and gepants with respect to established effective comparators are mandatory to support phase III results and to help clinicians to balance the benefit/risk profiles of the various acute and preventive medications.

Lasmiditan in patients with common migraine comorbidities: a post hoc efficacy and safety analysis of two phase 3 randomized clinical trials

OBJECTIVE

Determine whether common migraine comorbidities affect the efficacy and safety of lasmiditan, a 5-HT_1F receptor agonist approved in the United States for the acute treatment of migraine.

METHODS

In SPARTAN and SAMURAI (double-blind Phase 3 clinical trials), patients with migraine were randomized to oral lasmiditan 50 mg (SPARTAN only), 100mg, 200 mg, or placebo. Lasmiditan increased the proportion of pain-free and most bothersome symptom (MBS)-free patients at 2 h after dose compared with placebo. Most common treatment-emergent adverse events (TEAEs) were dizziness, paraesthesia, somnolence, fatigue, nausea, muscular weakness, and hypoesthesia. Based upon literature review of common migraine comorbidities, Anxiety, Allergy, Bronchial, Cardiac, Depression, Fatigue, Gastrointestinal, Hormonal, Musculoskeletal/Pain, Neurological, Obesity, Sleep, and Vascular Comorbidity Groups were created. Using pooled results, efficacy and TEAEs were assessed to compare patients with or without a given common migraine comorbidity. To compare treatment groups, p-values were calculated for treatment-by-subgroup interaction, based on logistic regression with treatment-by-comorbidity condition status (Yes/No) as the interaction term; study, treatment group, and comorbidity condition status (Yes/No) were covariates. Differential treatment effect based upon comorbidity status was also examined. Trial registration at clinicaltrials.gov: SAMURAI (NCT02439320) and SPARTAN (NCT02605174).

RESULTS

Across all the Comorbidity Groups, with the potential exception of fatigue, treatment-by-subgroup interaction analyses did not provide evidence of a lasmiditan-driven lasmiditan versus placebo differential treatment effect dependent on Yes versus No comorbidity subgroup for either efficacy or TEAE assessments.

CONCLUSIONS

The efficacy and safety of lasmiditan for treatment of individual migraine attacks appear to be independent of comorbid conditions.

The potential of lasmiditan in migraine

Lasmiditan, a highly selective 5-hydroxytryptamine receptor 1F (5-HT_1F) agonist, is the first drug in its class and is lacking triptan-like vasoactive properties. The US Food and Drug Administration (FDA) has recently approved lasmiditan for the acute treatment of migraine in adults based on positive results of two pivotal phase III trials, which showed a significant difference to placebo in the proportion of patients achieving total migraine freedom within 2 h. More patients with lasmiditan achieved headache freedom and, in addition, freedom from the most bothersome symptom, that is, photophobia, than with placebo. Treatment-related side effects seem to be related to the rapid penetration of the drug into the brain and include dizziness, paresthesia and drowsiness, mostly of mild to moderate intensity. Interim results from an ongoing long-term phase III trial suggest a decrease in the frequency of adverse events after multiple lasmiditan use. Lasmiditan is a promising acute anti-migraine therapy, in particular for patients with cardiovascular risk factors, contraindications, or unwanted side effects to triptans.

No additive effect of combining sumatriptan and olcegepant in the GTN mouse model of migraine

INTRODUCTION

Despite recent advances in migraine treatment there is a need for therapies with higher clinical efficacy and/or fewer side effects. Triptans (5-HT_1B/1D/1F agonists) are essential in the present treatment regime and gepants (CGRP-receptor antagonists) are recognized as effective in acute migraine treatment. Triptans and gepants have different mechanisms of action and here we tested the hypothesis that a combination of these drugs (sumatriptan and olcegepant) would result in an additive effect.

METHODS

Using the validated glyceryl trinitrate mouse model of migraine, we initially tested dose-response relationships of sumatriptan (0.1, 0.3, and 0.6 mg/kg IP) and olcegepant (0.25, 0.50, and 1.0 mg/kg IP) to find suitable high and low doses. Subsequently, we performed a combination study of the two drugs with a low and a high dose. All experiments were vehicle (placebo) controlled and blinded.

RESULTS

Sumatriptan significantly reduced glyceryl trinitrate-induced allodynia (F(4,54) = 13.51, p < 0.0001) at all doses. Olcegepant also reduced glyceryl trinitrate-induced allodynia (F(4,53) = 16.11, p < 0.0001) with the two higher doses being significantly effective. Combining 0.50 mg/kg olcegepant with 0.1 or 0.6 mg/kg sumatriptan did not have any improved effect compared to either drug alone (p > 0.50 on all days) in our mouse model.

CONCLUSION

Combining olcegepant and sumatriptan did not have an additive effect compared to single-drug treatment in this study. Triptan-gepant combinations will therefore most likely not improve migraine treatment. Nevertheless, further studies are necessary, and combinations should also be examined in patients with migraine.

Lasmiditan for Acute Treatment of Migraine in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

The US Food and Drug Administration has approved orally administered 100-mg and 200-mg doses of lasmiditan for the acute treatment of migraine, with or without aura. Having a unique mechanism of action, lasmiditan is the first and only Food and Drug Administration-approved serotonin 5-HT_1F receptor agonist.

OBJECTIVE

The objective of this study was to systematically evaluate the efficacy and safety of lasmiditan for the acute treatment of migraine in adult patients.

METHODS

We systematically searched PUBMED, EMBASE, and Cochrane Library databases. Any relevant articles published before 3 March, 2020 were collected. Inclusion criteria were: (1) randomized clinical trials; (2) enrolled adult participants diagnosed with migraine; (3) compared lasmiditan at 100 mg or 200 mg with placebo; (4) enrolled more than 100 participants; and (5) provided any available data for predefined primary or secondary outcomes.

RESULTS

Three high-quality, multi-centered randomized clinical trials with 4506 patients in total were included. We found that the use of lasmiditan was related to a significantly increased rate of pain freedom at 2 h post-dose with 31.60% patients achieving freedom of pain in the lasmiditan group compared with 17.55% patients in the placebo group (relative risk [RR] 1.80 [95% confidence interval (CI) 1.34-2.42]), with no significant heterogeneity. In addition, lasmiditan is reported to significantly increase the rate of absence of the most bothersome symptoms at 2 h compared with the placebo group with no significant heterogeneity (lasmiditan, 42.82%; placebo, 30.38%; RR 1.44 [95% CI 1.03-2.01], I² = 0%). With regard to the safety endpoints, compared with the placebo group, participants in the lasmiditan group had a higher rate of fatigue, paresthesia, and somnolence (fatigue: lasmiditan, 1.94%; placebo, 0.24%; RR 7.96 [95% CI 0.4-158.86]; paresthesia: lasmiditan, 6.91%; placebo, 1.56%; RR 4.46 [95% CI 1.54-12.93], somnolence: lasmiditan, 5.9%; placebo, 2.15%; RR 2.76 [95% CI, 1.49-5.11]) with low heterogeneity. A subgroup analysis demonstrated that without safety differences, participants who received the 200-mg dose had a higher percentage of freedom of pain at 2 h and sustained pain relief at 2-24 h compared with the 100-mg dose (freedom of pain at 2 h: lasmiditan, 34.53%; placebo, 28.67%; RR 1.2 [95% CI 1.04-1.38]; lasmiditan, 20.62%; placebo, 16.33%; RR 1.26 [95% CI 1.19-1.34]), with low heterogeneity for both outcomes (I² = 0%).

CONCLUSIONS

In this meta-analysis, the use of lasmiditan as an acute treatment for episodic migraine in adults led to a greater percentage of freedom of pain and the absence of the most bothersome symptoms at 2 h post-dose. Lasmiditan 200 mg had superior efficacy to 100-mg dose without a significantly increased risk for adverse events.

Pharmacological treatment of migraine: CGRP and 5-HT beyond the triptans

Migraine is a highly disabling neurovascular disorder characterized by a severe headache (associated with nausea, photophobia and/or phonophobia), and trigeminovascular system activation involving the release of calcitonin-gene related peptide (CGRP). Novel anti-migraine drugs target CGRP signaling through either stimulation of 5-HT1F receptors on trigeminovascular nerves (resulting in inhibition of CGRP release) or direct blockade of CGRP or its receptor. Lasmiditan is a highly selective 5-HT1F receptor agonist and, unlike the triptans, is devoid of vasoconstrictive properties, allowing its use in patients with cardiovascular risk. Since lasmiditan can actively penetrate the blood-brain barrier, central therapeutic as well as side effects mediated by 5-HT1F receptor activation should be further investigated. Other novel anti-migraine drugs target CGRP signaling directly. This neuropeptide can be targeted by the monoclonal antibodies eptinezumab, fremanezumab and galcanezumab, or by CGRP-neutralizing L-aptamers called Spiegelmers. The CGRP receptor can be targeted by the monoclonal antibody erenumab, or by small-molecule antagonists called gepants. Currently, rimegepant and ubrogepant have been developed for acute migraine treatment, while atogepant is studied for migraine prophylaxis. Of these drugs targeting CGRP signaling directly, eptinezumab, erenumab, fremanezumab, galcanezumab, rimegepant and ubrogepant have been approved for clinical use, while atogepant is in the last stage before approval. Although all of these drugs seem highly promising for migraine treatment, their safety should be investigated in the long-term. Moreover, the exact mechanism(s) of action of these drugs need to be elucidated further, to increase both safety and efficacy and to increase the number of responders to the different treatments, so that all migraine patients can satisfactorily be treated.

Evaluation of LY573144 (lasmiditan) in a preclinical model of medication overuse headache

BACKGROUND

Medication overuse is a significant issue that complicates the treatment of headache disorders. The most effective medications for the acute treatment of migraine all have the capacity to induce medication overuse headache (MOH). Novel acute migraine-specific treatments are being developed. However, because the mechanism(s) underlying medication overuse headache are not well understood, it is difficult to predict whether any particular acute medication will induce MOH in susceptible individuals. LY573144 (lasmiditan), a 5-HT_1F receptor agonist, has recently been shown to be effective in the acute treatment of migraine in phase 3 trials. The aim of this study is to determine whether frequent administration of lasmiditan induces behaviors consistent with MOH in a pre-clinical rat model.

METHODS

Sprague Dawley rats were administered six doses of lasmiditan (10 mg/kg), sumatriptan (10 mg/kg), or sterile water orally over 2 weeks and cutaneous allodynia was evaluated regularly in the periorbital and hindpaw regions using von Frey filaments. Testing continued until mechanosensitivity returned to baseline levels. Rats were then submitted to bright light stress (BLS) or nitric oxide (NO) donor administration and were again evaluated for cutaneous allodynia in the periorbital and hindpaw regions hourly for 5 hours.

RESULTS

Both lasmiditan and sumatriptan exhibited comparable levels of drug-induced cutaneous allodynia in both the periorbital and hindpaw regions, which resolved after cessation of drug administration. Both lasmiditan and sumatriptan pre-treatment resulted in cutaneous allodynia that was evoked by either BLS or NO donor.

CONCLUSIONS

In a pre-clinical rat model of MOH, oral lasmiditan, like sumatriptan, induced acute transient cutaneous allodynia in the periorbital and hindpaw regions that after resolution could be re-evoked by putative migraine triggers. These results suggest that lasmiditan has the capacity to induce MOH through persistent latent peripheral and central sensitization mechanisms.

Lasmiditan mechanism of action - review of a selective 5-HT1F agonist

Migraine is a leading cause of disability worldwide, but it is still underdiagnosed and undertreated. Research on the pathophysiology of this neurological disease led to the discovery that calcitonin gene-related peptide (CGRP) is a key neuropeptide involved in pain signaling during a migraine attack. CGRP-mediated neuronal sensitization and glutamate-based second- and third-order neuronal signaling may be an important component involved in migraine pain. The activation of several serotonergic receptor subtypes can block the release of CGRP, other neuropeptides, and neurotransmitters, and can relieve the symptoms of migraine. Triptans were the first therapeutics developed for the treatment of migraine, working through serotonin 5-HT1B/1D receptors. The discovery that the serotonin 1F (5-HT1F) receptor was expressed in the human trigeminal ganglion suggested that this receptor subtype may have a role in the treatment of migraine. The 5-HT1F receptor is found on terminals and cell bodies of trigeminal ganglion neurons and can modulate the release of CGRP from these nerves. Unlike 5-HT1B receptors, the activation of 5-HT1F receptors does not cause vasoconstriction.The potency of different serotonergic agonists towards 5-HT1F was correlated in an animal model of migraine (dural plasma protein extravasation model) leading to the development of lasmiditan. Lasmiditan is a newly approved acute treatment for migraine in the United States and is a lipophilic, highly selective 5-HT1F agonist that can cross the blood-brain barrier and act at peripheral nervous system (PNS) and central nervous system (CNS) sites.Lasmiditan activation of CNS-located 5-HT1F receptors (e.g., in the trigeminal nucleus caudalis) could potentially block the release of CGRP and the neurotransmitter glutamate, thus preventing and possibly reversing the development of central sensitization. Activation of 5-HT1F receptors in the thalamus can block secondary central sensitization of this region, which is associated with progression of migraine and extracephalic cutaneous allodynia. The 5-HT1F receptors are also elements of descending pain modulation, presenting another site where lasmiditan may alleviate migraine. There is emerging evidence that mitochondrial dysfunction might be implicated in the pathophysiology of migraine, and that 5-HT1F receptors can promote mitochondrial biogenesis. While the exact mechanism is unknown, evidence suggests that lasmiditan can alleviate migraine through 5-HT1F agonist activity that leads to inhibition of neuropeptide and neurotransmitter release and inhibition of PNS trigeminovascular and CNS pain signaling pathways.

Trajectory of migraine-related disability following long-term treatment with lasmiditan: results of the GLADIATOR study

BACKGROUND

Migraine is recognized as the second leading cause of disability globally. Lasmiditan is a novel, selective serotonin 5-HT1F receptor agonist developed for acute treatment of migraine. Here we analyzed effects of lasmiditan on migraine disability assessed with the Migraine Disability Assessment (MIDAS) scale for interim data from a long-term safety study.

METHODS

Completers of two single-attack parent studies were offered participation in the 1 year GLADIATOR study, that randomized participants to treatment with lasmiditan 100 mg or 200 mg taken as needed for migraine attacks of at least moderate severity. Changes in MIDAS were modeled using a mixed model repeated measures analysis.

RESULTS

The sample included 1978 patients who received ≥1 lasmiditan dose and were followed for a median of 288 days. Baseline mean MIDAS scores for the lasmiditan 100-mg and 200-mg groups were 29.4 and 28.9, respectively, indicating severe migraine-related disability. Relative to baseline, MIDAS total scores were significantly lower at 3, 6, 9, and 12 months for both dose groups. At 12 months, changes in MIDAS scores were - 12.5 and - 12.2 for lasmiditan 100 mg and 200 mg, respectively, with 49% and 53% of patients, respectively, achieving at least a 50% decrease in MIDAS total score. Statistically significant improvements were also seen for work and/or school absenteeism and presenteeism, monthly headache days, and mean headache pain intensity at all time points up to 1 year. Findings for patients who completed all visits versus those dropping out early were similar. Responses were generally similar for the lasmiditan 100 mg or 200 mg doses, between subgroups defined based on the number of baseline monthly migraine attacks (≤5 vs. >5), and also between subgroups defined by pain-free response (yes/no) during initial attacks.

CONCLUSIONS

Long-term treatment with lasmiditan was associated with significant reductions in migraine-related disability, including both work or school absenteeism and presenteeism. The similarity of responses in completers and those who dropped out suggests that selective attrition does not account for the improvements. Benefits were significant at 3 months and maintained through 12 months.

TRIAL REGISTRATION

clinicaltrials.govNCT02565186; first posted October 1, 2015.

The Risks or Lack Thereof of Migraine Treatments in Vascular Disease

PREMISES

Patients with migraine have a co-morbidity with vascular diseases such as hypertension, coronary heart disease, and stroke.

PROBLEM

This overview gives recommendations for the therapy of acute migraine attacks and for migraine  prevention in patients with vascular diseases. In particular, the use of triptans in patients with vascular diseases is discussed.

POTENTIAL SOLUTIONS

Currently, there is a contraindication for the use of the triptans in patients with vascular disease, although there is no evidence that triptans increase the risk of heart attacks or stroke.

Lasmiditan: First Approval

Lasmiditan (REYVOW™; Eli Lilly and Company) is an orally available serotonin (5-HT)1F receptor agonist. In October 2019, the US FDA approved lasmiditan 50 mg and 100 mg tablets for the acute treatment of migraine with or without aura in adults. Approval was based on positive results from two pivotal phase III trials, in which lasmiditan significantly improved the proportions of patients achieving freedom from headache pain and freedom from the most bothersome symptom (photophobia, phonophobia or nausea), relative to placebo, when used to treat a migraine with moderate to severe pain. Lasmiditan is not for use in the preventive treatment of migraine. This article summarizes the milestones in the development of lasmiditan leading to its first approval for the acute treatment of migraine in adults.

Characterization of binding, functional activity, and contractile responses of the selective 5-HT1F receptor agonist lasmiditan

BACKGROUND AND PURPOSE

Triptans are 5-HT1B/1D receptor agonists (that also display 5-HT1F receptor affinity) with antimigraine action, contraindicated in patients with coronary artery disease due to their vasoconstrictor properties. Conversely, lasmiditan was developed as an antimigraine 5-HT1F receptor agonist. To assess the selectivity and cardiovascular effects of lasmiditan, we investigated the binding, functional activity, and in vitro/in vivo vascular effects of lasmiditan and compared it to sumatriptan.

EXPERIMENTAL APPROACH

Binding and second messenger activity assays of lasmiditan and other serotoninergic agonists were performed for human 5-HT1A , 5-HT1B , 5-HT1D , 5-ht1E , 5-HT1F , 5-HT2A , 5-HT2B , and 5-HT7 receptors, and the results were correlated with their potency to constrict isolated human coronary arteries (HCAs). Furthermore, concentration-response curves to lasmiditan and sumatriptan were performed in proximal and distal HCA, internal mammary, and middle meningeal arteries. Finally, anaesthetized female beagle dogs received i.v. infusions of lasmiditan or sumatriptan in escalating cumulative doses, and carotid and coronary artery diameters were measured.

KEY RESULTS

Lasmiditan showed high selectivity for 5-HT1F receptors. Moreover, the functional potency of the analysed compounds to inhibit cAMP increase through 5-HT1B receptor activation positively correlated with their potency to contract HCA. In isolated human arteries, sumatriptan, but not lasmiditan, induced contractions. Likewise, in vivo, sumatriptan decreased coronary and carotid artery diameters at clinically relevant doses, while lasmiditan was devoid of vasoconstrictor activity at all doses tested.

CONCLUSIONS AND IMPLICATIONS

Lasmiditan is a selective 5-HT1F receptor agonist devoid of vasoconstrictor activity. This may represent a cardiovascular safety advantage when compared to the triptans.

Lasmiditan for the acute treatment of migraine: Subgroup analyses by prior response to triptans

Background

Lasmiditan demonstrated superiority to placebo in the acute treatment of migraine in adults with moderate/severe migraine disability in two similarly designed Phase 3 trials, SAMURAI and SPARTAN. Post-hoc integrated analyses evaluated the efficacy of lasmiditan in patients who reported a good or insufficient response to triptans and in those who were triptan naïve.

Methods

Subgroups of patients reporting an overall response of “good” or “poor/none” to the most recent use of a triptan at baseline (defined as good or insufficient responders, respectively) and a triptan-naïve subpopulation were derived from combined study participants randomized to receive lasmiditan 50 mg (SPARTAN only), 100 mg or 200 mg, or placebo, as the first dose. Outcomes including headache pain-freedom, most bothersome symptom-freedom, and headache pain relief 2 hours post-first dose of lasmiditan were compared with placebo. Treatment-by-subgroup analyses additionally investigated whether therapeutic benefit varied according to prior triptan response (good or insufficient).

Results

Regardless of triptan response, lasmiditan showed higher efficacy than placebo (most comparisons were statistically significant). Treatment-by-subgroup analyses found that the benefit over placebo of lasmiditan did not vary significantly between patients with a good response and those with an insufficient response to triptans. Lasmiditan also showed higher efficacy than placebo in triptan-naïve patients.

Conclusions

Lasmiditan demonstrated comparable efficacy in patients who reported a good or insufficient response to prior triptan use. Lasmiditan also showed efficacy in those who were triptan naïve. Lasmiditan may be a useful therapeutic option for patients with migraine.

Trial Registration

SAMURAI (NCT02439320); SPARTAN (NCT02605174).

C-fibers may modulate adjacent Aδ-fibers through axon-axon CGRP signaling at nodes of Ranvier in the trigeminal system

Background

Monoclonal antibodies (mAbs) towards CGRP or the CGRP receptor show good prophylactic antimigraine efficacy. However, their site of action is still elusive. Due to lack of passage of mAbs across the blood-brain barrier the trigeminal system has been suggested a possible site of action because it lacks blood-brain barrier and hence is available to circulating molecules. The trigeminal ganglion (TG) harbors two types of neurons; half of which store CGRP and the rest that express CGRP receptor elements (CLR/RAMP1).

Methods

With specific immunohistochemistry methods, we demonstrated the localization of CGRP, CLR, RAMP1, and their locations related to expression of the paranodal marker contactin-associated protein 1 (CASPR). Furthermore, we studied functional CGRP release separately from the neuron soma and the part with only nerve fibers of the trigeminal ganglion, using an enzyme-linked immunosorbent assay.

Results

Antibodies towards CGRP and CLR/RAMP1 bind to two different populations of neurons in the TG and are found in the C- and the myelinated Aδ-fibers, respectively, within the dura mater and in trigeminal ganglion (TG). CASPR staining revealed paranodal areas of the different myelinated fibers inhabiting the TG and dura mater. Double immunostaining with CASPR and RAMP1 or the functional CGRP receptor antibody (AA58) revealed co-localization of the two peptides in the paranodal region which suggests the presence of the CGRP-receptor. Double immunostaining with CGRP and CASPR revealed that thin C-fibers have CGRP-positive boutons which often localize in close proximity to the nodal areas of the CGRP-receptor positive Aδ-fibers. These boutons are pearl-like synaptic structures, and we show CGRP release from fibers dissociated from their neuronal bodies. In addition, we found that adjacent to the CGRP receptor localization in the node of Ranvier there was PKA immunoreactivity (kinase stimulated by cAMP), providing structural possibility to modify conduction activity within the Aδ-fibers.

Conclusion

We observed a close relationship between the CGRP containing C-fibers and the Aδ-fibers containing the CGRP-receptor elements, suggesting a point of axon-axon interaction for the released CGRP and a site of action for gepants and the novel mAbs to alleviate migraine.