Is selective 5-HT1F receptor agonism an entity apart from that of the triptans in antimigraine therapy?

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.

Recent Advances in the Management of Cluster Headache

Purpose of review

Among the spectrum of pain conditions, cluster headache represents one of the most severe. Targeted therapies for cluster headache are evolving thus improving the available therapeutic armamentarium. A better understanding of the currently available therapies, as well as new and emerging options, may aide physicians to manage affected sufferers better by evolving treatment guidance.

Recent findings

While classic first-line medications are useful in some patients with cluster headache, they are often accompanied by significant side effects that limit their use. Recently, novel treatments with better tolerability and decreased medication interactions have proven to be effective. A remarkable example of this is the blockage of the calcitonin gene-related peptide pathway with monoclonal antibodies, which may be a key element in the future treatment of cluster headache. The sphenopalatine ganglion and vagus nerve perform a critical role in the regulation of pain and the trigeminal autonomic reflex. Neuromodulation therapies targeting these structures have shown excellent tolerability and few significant adverse events, constituting a promising form of treatment. Finally, several potential therapeutic targets are examined in this review, such as small molecule CGRP receptor antagonists, known as gepants, and serotonin receptor 5-HT1F receptor agonists: ditans.

Summary

In summary, a deepening of the understanding of cluster headache mechanisms in recent years has driven the evolution of sophisticated therapeutic approaches that could allow a new era in the treatment of this difficult condition.

Sex Differences in Response to Triptans: A Systematic Review and Meta-analysis

OBJECTIVE

To examine the effect of sex on clinical response to triptans in migraine and to determine whether these differences are related to pharmacokinetics of triptans in men and women, we performed a systematic review and meta-analysis.

METHODS

We searched clinical trials distinguishing clinical response to or pharmacokinetic parameters of triptans between sexes in PubMed, MEDLINE, Cochrane Library, Embase, and Web of Science up to Dec 12, 2019. Analysis was based on data extracted from published reports. Male-to-female pooled risk ratios (RR) were calculated for clinical outcomes and pooled ratio of means (RoM) for pharmacokinetic outcomes using random-effects models.

RESULTS

Of 1,188 publications on clinical trials with triptans, 244 were identified with sex-related search terms. Only 19 publications presented sex-specific results, comprising n = 2,280 men and n = 13,899 women. No sex differences were revealed for 2-hour headache and pain-free responses, but men had a lower risk for headache recurrence (male-to-female RR 0.64, 95% confidence interval [CI]: 0.55-0.76, Q = 0.81) and adverse events (RR 0.82, 95% CI: 0.72-0.93, Q = 4.93). Men had lower drug exposure with lower area under the curve (RoM 0.69, 95% CI: 0.60-0.81, Q = 18.06) and peak drug concentration (RoM 0.72, 95% CI: 0.64-0.82, Q = 8.24) than women.

CONCLUSIONS

Remarkably few publications about sex differences in triptan response are available. The limited number of eligible studies show sex differences in adverse event frequency, which may be partly because of drug exposure differences. This higher drug exposure in women is not reflected in different response rates. Despite higher exposure, women have higher headache recurrence rates possibly because of longer attack duration related to sex hormonal changes.

Triptanophobia in migraine: A case-control study on the causes and consequences of the nonuse of triptans in chronic migraine patients

Background: Triptanophobia is the excessive and inadequately justified concern about potential risks of triptans. We evaluated causes and consequences of nonuse of triptans in chronic migraine (CM) Methods: Case-control study. We included CM patients firstly referred to aheadache unit. Patients were cases or controls depending on whether they were triptan naïve, or not. We analyzed if nonuse of triptans was justified by formal contraindications or adverse events. We assessed if triptan naïve patients had higher frequency of vascular risk factors (VRF), contraceptive drugs or older age. Results: We included 941 patients, 247 (26.2%) triptan users. Triptans had been discontinued due to tolerability in 116 patients (12.3%), being 578 patients (61.4%) triptan naïve. Formal contraindications were found in 23 patients (2.4%). Frequency of VRF, contraceptive drugs or age did not differ between the groups (p > 0.1). Triptan users consumed symptomatic medications fewer days/month (13.9 vs 17.1, p < 0.001), were under prophylactic treatment more frequently (79.4% vs 34.8%, p < 0.001) and had medication overuse headache less frequently (55.1% vs. 63.0%, p = 0.03). Conclusion: Triptans were not used by three-quartersof CM patients. Nonuse of triptans was not justified by tolerability, frequency of contraindications, or frequency of VRF. Expert opinion: In the present study, we evaluated causes and consequences of the nonuse of triptans in CM sufferers. We analyzed frequency of triptan use in CM patients. We compared, between triptan users and triptan naïve patients, the presence of contraindications, frequency of vascular risk factors, and differences in management prior to the referral to a headache unit.

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 Therapeutic Prospects of Naturally Occurring and Synthetic Indole Alkaloids for Depression and Anxiety Disorders

Depression and anxiety are the most common disorders among all age groups. Several antidepressant drugs including benzodiazepine, antidepressant tricyclics, azapirone, noradrenaline reuptake inhibitors, serotonin selective reuptake inhibitors, serotonin, noradrenaline reuptake inhibitors, and monoamine oxidase inhibitors have been used to treat these psychiatric disorders. However, these antidepressants are generally synthetic agents and can cause a wide range of side effects. The potential efficacy of plant-derived alkaloids has been reviewed against various neurodegenerative diseases including Alzheimer's disease, Huntington disease, Parkinson's disease, schizophrenia, and epilepsy. However, data correlating the indole alkaloids and antidepressant activity are limited. Natural products, especially plants and the marine environment, are rich sources of potential new drugs. Plants possess a variety of indole alkaloids, and compounds that have an indole moiety are related to serotonin, which is a neurotransmitter that regulates brain function and cognition, which in turn alleviates anxiety, and ensures a good mood and happiness. The present review is a summary of the bioactive compounds from plants and marine sources that contain the indole moiety, which can serve as potent antidepressants. The prospects of naturally occurring as well as synthetic indole alkaloids for the amelioration of anxiety and depression-related disorders, structure-activity relationship, and their therapeutic prospects have been discussed.

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.

Long-term safety and efficacy of lasmiditan for acute treatment of migraine: Final results of the GLADIATOR study

GLADIATOR was a prospective, randomized, open-label, phase 3 study of lasmiditan 100 mg or 200 mg dosed intermittently for up to 1 year in patients with episodic migraine. Most patients had completed one of two single-attack studies before participation. A total of 2030 patients received ≥1 lasmiditan dose and 19,879 migraine attacks were treated. Safety results were similar to the previously reported interim analysis. The most frequently reported treatment-emergent adverse events (TEAEs) included dizziness (18.5%), somnolence (8.5%), and paresthesia (6.8%), with frequency of adverse events appearing to decrease with subsequently treated attacks. At 2 h post-dose, 26.7% and 32.2% of all attacks treated with lasmiditan 100 mg and 200 mg, respectively, were pain free. This pattern was generally consistent across study quarters and treated attacks. In conclusion, during a 1-year treatment period, intermittent lasmiditan for episodic migraine treatment was associated with generally decreasing TEAEs and consistent efficacy.

Access to Migraine Treatments in Ontario, Canada: A Review of the Ontario Drug Benefit Program

BACKGROUND

This paper provides a critical review of the decision-making process of the Ontario Ministry of Health and Long-Term Care (MOHLTC) regarding which migraine treatment drugs will be covered under the Ontario Drug Benefit Formulary (ODB).

MAIN TEXT

Under MOHLTC policy, triptans and OnabotulinumtoxinA are available to patients only through the Exceptional Access Program (EAP). This policy, and justifications for it, are examined with reference to clinical guidelines, patient experiences, and health policy literature. The contexts and consequences of compromised access are outlined. Improvements in access to these treatments are suggested by highlighting how a country with similar healthcare infrastructure - Australia - employs policies that more adequately meet the needs of migraine patients as they secure treatments.

CONCLUSIONS

Despite clinically significant gains in the discovery of safe and effective migraine-specific treatments the ODB thus far has failed to align its practice with current clinical recommendations. This forces patients to rely heavily on medication that, while still effective for some, is potentially suboptimal. This review concludes it is prudent, at minimum, to follow clinical recommendations that advocate for the removal of triptans from EAP and recategorize them as Limited Use drugs. Ideally, moving them to a general benefit would further remove the barriers experienced by patients attempting to access this treatment.

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.

The fifth cranial nerve in headaches

The fifth cranial nerve is the common denominator for many headaches and facial pain pathologies currently known. Projecting from the trigeminal ganglion, in a bipolar manner, it connects to the brainstem and supplies various parts of the head and face with sensory innervation. In this review, we describe the neuroanatomical structures and pathways implicated in the sensation of the trigeminal system. Furthermore, we present the current understanding of several primary headaches, painful neuropathies and their pharmacological treatments. We hope that this overview can elucidate the complex field of headache pathologies, and their link to the trigeminal nerve, to a broader field of young scientists.

The current state of acute treatment for migraine in adults in the United States

Migraine is a common and disabling disorder with substantial personal, social, and economic burden that affects 37 million people in the United States. Risk factors for migraine include age, sex, and genetics. The goal of acute treatment of migraine attacks is to stop the pain and associated symptoms of the migraine attack and return the patient to normal function. The acute treatment landscape for migraine has recently expanded beyond the standard nonsteroidal anti-inflammatory drugs, analgesics, triptans, ergotamines, and combination therapies, to include neuromodulation devices, and recently approved calcitonin gene-related peptide receptor antagonists and a serotonin (5-HT_1F) receptor agonist. Unmet acute treatment needs still exist due to lack of efficacy, unwanted side effects, or contraindication to treatment. Effective treatment of migraine requires the clinician to assess the patient, make an accurate diagnosis, and then offer appropriate therapy based on the patient's medical history, comorbidities, and preferences, as well as published clinical evidence. The objective of this narrative review is to familiarize primary care clinicians with the variety of acute treatment options available in the United States today based on clinical trial findings, meta-analyses, evidence-based guidelines, and professional society consensus statements.

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.

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).

Interim results of a prospective, randomized, open-label, Phase 3 study of the long-term safety and efficacy of lasmiditan for acute treatment of migraine (the GLADIATOR study)

OBJECTIVES

To address the need for long-term lasmiditan data, the GLADIATOR study evaluated the safety (primary) and efficacy (secondary) of lasmiditan for the intermittent, acute treatment of migraine attacks for up to 1 year.

METHODS

In this prospective, randomized, open-label, Phase 3 study, patients who had completed either of two single-attack studies were offered the opportunity to be randomized 1:1 to lasmiditan 100 mg or 200 mg. Patients were asked to use lasmiditan as the first treatment for each new migraine attack of at least moderate severity. Assessments occurred at baseline and at prespecified time increments up to 48 hours after each dose of study drug using an electronic diary, and safety was assessed throughout the study. Migraine Disability Assessment (MIDAS) was assessed at each visit.

RESULTS

As of the cut-off date for this interim analysis (6 March 2018), 1978 patients had received ≥ 1 lasmiditan dose and treated 19,058 migraine attacks. Overall, treatment-emergent adverse events (TEAEs) were similar to those in the single-attack studies and included dizziness (18.6%), somnolence (8.5%), and paresthesia (6.8%). The frequency of TEAEs generally decreased with subsequent attacks. No treatment-related serious adverse events and no cardiovascular TEAEs potentially due to vasoconstriction were observed. For both lasmiditan doses, efficacy measures were generally consistent over study quarters and treated attacks. Overall, across all treated attacks at 2 hours post-dose, pain freedom was observed in 26.9% of the attacks treated with lasmiditan 100 mg and 32.4% of the attacks treated with lasmiditan 200 mg. MIDAS total scores decreased over time.

CONCLUSIONS

The interim results of this long-term study showed intermittent lasmiditan (100 mg and 200 mg) to be generally well tolerated and efficacious for the acute treatment of migraine over a 1-year period. Trial registration number: NCT02565186; https://clinicaltrials.gov/ct2/show/NCT02565186.

Lasmiditan for acute treatment of migraine in patients with cardiovascular risk factors: post-hoc analysis of pooled results from 2 randomized, double-blind, placebo-controlled, phase 3 trials

BACKGROUND

In addition to the increased risk for cardiovascular (CV) disease and CV events associated with migraine, patients with migraine can also present with a number of CV risk factors (CVRFs). Existing treatment options can be limited due to contraindications, increased burden associated with monitoring, or patient avoidance of side effects. Safe and effective migraine treatment options are needed for patients with migraine and a history of CV or cerebrovascular disease or with increased risk for CV events. This analysis was designed to evaluate the safety and efficacy of oral lasmiditan, a selective serotonin 5-hydroxytryptamine 1F receptor agonist, in acute treatment of migraine attacks in patients with CVRFs.

METHODS

SAMURAI and SPARTAN were similarly designed, Phase 3, randomized, double-blind, placebo-controlled trials in adults treating a single migraine attack with lasmiditan 50, 100, or 200 mg. Both studies included patients with CVRFs, and SPARTAN allowed patients with coronary artery disease, clinically significant arrhythmia, or uncontrolled hypertension. Efficacy and safety of lasmiditan in subgroups of patients with differing levels of CVRFs are reported. For efficacy analyses, logistic regression was used to assess treatment-by-subgroup interactions. For safety analyses, Cochran-Mantel-Haenszel test of general association evaluated treatment comparisons; Mantel-Haenszel odds ratio assessed significant treatment effects.

RESULTS

In this pooled analysis, a total of 4439 patients received ≥1 dose of study drug. A total of 3500 patients (78.8%) had ≥1 CVRF, and 1833 patients (41.3%) had ≥2 CVRFs at baseline. Both trials met the primary endpoints of headache pain freedom and most bothersome symptom freedom at 2 h. The presence of CVRFs did not affect efficacy results. There was a low frequency of likely CV treatment-emergent adverse events (TEAEs) overall (lasmiditan, 30 [0.9%]; placebo, 5 [0.4%]). There was no statistical difference in the frequency of likely CV TEAEs in either the absence or presence of any CVRFs. The only likely CV TEAE seen across patients with ≥1, ≥ 2, ≥ 3, or ≥ 4 CVRFs was palpitations.

CONCLUSIONS

When analyzed by the presence of CVRFs, there was no statistical difference in lasmiditan efficacy or the frequency of likely CV TEAEs. Despite the analysis being limited by a single-migraine-attack design, the lack of differences in efficacy and safety with increasing numbers of CVRFs indicates that lasmiditan might be considered in the treatment algorithm for patients with CVRFs. Future studies are needed to assess long-term efficacy and safety.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02439320 (SAMURAI), registered 18 March 2015 and ClinicalTrials.gov NCT02605174 (SPARTAN), registered 11 November 2015.

Phase 3 randomized, placebo-controlled, double-blind study of lasmiditan for acute treatment of migraine

Lasmiditan, a serotonin 5-HT1F receptor agonist, was effective for acute treatment of patients with migraine in a phase 3 double-blind randomized controlled study. The current study was designed to replicate these findings in a generalizable population of patients with migraine, including those with a cardiovascular medical history. This prospective, double-blind, phase 3 multicentre study randomly assigned patients with migraine with and without aura (1:1:1:1 ratio) to oral lasmiditan 200 mg, 100 mg, 50 mg, or placebo. Patients were instructed to dose at home within 4 h of onset of migraine attack of at least moderate intensity and not improving. The primary objective was to assess the proportion of patients' headache pain-free and most bothersome symptom-free at 2 h post-dose for each dose of lasmiditan versus placebo (NCT02605174). Patients (n = 3005) were assigned and treated (n = 2583, safety population): 1938 lasmiditan (200 mg n = 528, 100 mg n = 532, and 50 mg n = 556 included in primary analysis) and 645 placebo (540 included in primary analysis). Most patients (79.2%) had ≥1 cardiovascular risk factor at baseline, in addition to migraine. Lasmiditan was associated with significantly more pain freedom at 2 h (lasmiditan 200 mg: 38.8%, odds ratio 2.3, 95% confidence interval 1.8-3.1, P < 0.001; 100 mg: 31.4%, odds ratio 1.7, 1.3-2.2, P < 0.001; 50 mg: 28.6%, odds ratio 1.5, 1.1-1.9, P = 0.003 versus placebo 21.3%) and freedom from most bothersome symptom at 2 h (lasmiditan 200 mg: 48.7%, odds ratio 1.9, 95% confidence interval 1.4-2.4, P < 0.001; 100 mg: 44.2%, odds ratio 1.6, 1.2-2.0, P < 0.001; 50 mg: 40.8%, odds ratio 1.4, 1.1-1.8, P = 0.009 versus placebo 33.5%). Treatment-emergent adverse events were reported in 253 of 649 (39.0%), 229 of 635 (36.1%), and 166 of 654 (25.4%) of patients on lasmiditan 200, 100, and 50 mg, respectively, versus 75 of 645 (11.6%) on placebo. Most adverse events were CNS-related and included dizziness, somnolence and paraesthesia. Lasmiditan was effective at 2 h post-dose for acute treatment of migraine at all oral doses tested. Efficacy and safety were consistent with the previous phase 3 study.

Safety findings from Phase 3 lasmiditan studies for acute treatment of migraine: Results from SAMURAI and SPARTAN

BACKGROUND

We assessed the safety profile of lasmiditan, a selective 5-HT_1F receptor agonist without vasoconstrictive activity being developed as an acute therapy for migraine.

METHODS

SAMURAI and SPARTAN were Phase 3 double-blind studies of patients with migraine, randomized to oral lasmiditan 50 mg (SPARTAN only), 100 mg, 200 mg, or placebo to be taken within 4 hours of onset of migraine pain. Safety data from the studies were integrated. Treatment-emergent adverse events (occurring within 48 hours of first dose) were considered in the analyses.

RESULTS

The safety population comprised 1262 patients assigned placebo, and 654, 1265, and 1258 assigned lasmiditan 50 mg, 100 mg, and 200 mg, respectively. There were no deaths; serious adverse events were reported for seven patients (placebo, n = 2 [0.2%]; lasmiditan 50 mg, n = 1 [0.2%]; lasmiditan 100 mg, n = 1 [0.2%]; lasmiditan 200 mg, n = 3 [0.2%]). Patients reporting ≥ 1 treatment-emergent adverse events were: Placebo, n = 174 (13.5%); lasmiditan 50 mg, n = 166 (25.4%); lasmiditan 100 mg, n = 458 (36.2%); and lasmiditan 200 mg, n = 510 (40.6%). Treatment-emergent adverse events were generally mild or moderate in severity. The most common treatment-emergent adverse events with lasmiditan were dizziness, paresthesia, somnolence, fatigue, nausea, muscular weakness and hypoesthesia. There were no ischemic events.

CONCLUSIONS

As a centrally-penetrant drug, lasmiditan use was associated with neurologic treatment-emergent adverse events; most were mild or moderate in severity and self-limiting.

TRIAL REGISTRATION AT CLINICALTRIALS.GOV

SAMURAI (NCT02439320) and SPARTAN (NCT02605174).

Pathophysiological Mechanisms in Migraine and the Identification of New Therapeutic Targets

Migraine is a strongly disabling disease characterized by a unilateral throbbing headache lasting for up to 72 h for each individual attack. There have been many theories on the pathophysiology of migraine throughout the years. Currently, the neurovascular theory dominates, suggesting clear involvement of the trigeminovascular system. The most recent data show that a migraine attack most likely originates in the hypothalamus and activates the trigeminal nucleus caudalis (TNC). Although the mechanisms are unknown, activation of the TNC leads to peripheral release of calcitonin gene-related protein (CGRP), most likely from C-fibers. During the past year monoclonal antibodies against CGRP or the CGRP receptor have emerged as the most promising targets for migraine therapy, and at the same time established the strong involvement of CGRP in the pathophysiology of migraine. The viewpoint presented here focuses further on the activation of the CGRP receptor on the sensory Aδ-fiber, leading to the sensation of pain. The CGRP receptor activates adenylate cyclase, which leads to an increase in cyclic adenosine monophosphate (cAMP). We hypothesize that cAMP activates the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, triggering an action potential sensed as pain. The mechanisms behind migraine pain on a molecular level, particularly their importance to cAMP, provide clues to potential new anti-migraine targets. In this article we focus on the development of targets related to the CGRP system, and further include novel targets such as the pituitary adenylate cyclase-activating peptide (PACAP) system, the serotonin 5-HT_1F receptor, purinergic receptors, HCN channels, adenosine triphosphate-sensitive potassium channels (K_ATP), and the glutaminergic system.

Primary headache disorders: Five new things

Purpose of review

To review 5 new areas in primary headache disorders, especially migraine and cluster headache.

Recent findings

Calcitonin gene-related peptide (CGRP) receptor antagonists (gepants-rimegepant and ubrogepant) and serotonin 5-HT_1F receptor agonists (ditans-lasmiditan) have completed phase 3 clinical trials and will soon offer novel, effective, well-tolerated nonvasoconstrictor options to treat acute migraine. CGRP preventive treatment is being revolutionized after the licensing of 3 monoclonal antibodies (MABs), erenumab, fremanezumab, and galcanezumab, with eptinezumab to follow, especially designed for migraine; they are effective and well tolerated. For patients seeking a nondrug therapy, neuromodulation approaches, single-pulse transcranial magnetic stimulation, noninvasive vagus nerve stimulation (nVNS), and external trigeminal nerve stimulation, represent licensed, well-tolerated approaches to migraine treatment. For the acute treatment of episodic cluster headache, nVNS is effective, well tolerated, and licensed; nVNS is effective and well tolerated in preventive treatment of cluster headache. The CGRP MAB galcanezumab was effective and well tolerated in a placebo-controlled trial in the preventive treatment of episodic cluster headache. Sphenopalatine ganglion stimulation has been shown to be effective and well tolerated in 2 randomized sham-controlled studies on chronic cluster headache. Understanding the premonitory (prodromal) phase of migraine during which patients experience symptoms such as yawning, tiredness, cognitive dysfunction, and food cravings may help explain apparent migraine triggers in some patients, thus offering better self-management.

Summary

Headache medicine has made remarkable strides, particularly in understanding migraine and cluster headache in the past 5 years. For the most common reason to visit a neurologist, therapeutic advances offer patients reduced disability and neurologists a rewarding, key role in improving the lives of those with migraine and cluster headache.

The need for new acutely acting antimigraine drugs: moving safely outside acute medication overuse

Background

The treatment of migraine is impeded by several difficulties, among which insufficient headache relief, side effects, and risk for developing medication overuse headache (MOH). Thus, new acutely acting antimigraine drugs are currently being developed, among which the small molecule CGRP receptor antagonists, gepants, and the 5-HT_1F receptor agonist lasmiditan. Whether treatment with these drugs carries the same risk for developing MOH is currently unknown.

Main body

Pathophysiological studies on MOH in animal models have suggested that decreased 5-hydroxytryptamine (5-HT, serotonin) levels, increased calcitonin-gene related peptide (CGRP) expression and changes in 5-HT receptor expression (lower 5-HT_1B/D and higher 5-HT_2A expression) may be involved in MOH. The decreased 5-HT may increase cortical spreading depression frequency and induce central sensitization in the cerebral cortex and caudal nucleus of the trigeminal tract. Additionally, low concentrations of 5-HT, a feature often observed in MOH patients, could increase CGRP expression. This provides a possible link between the pathways of 5-HT and CGRP, targets of lasmiditan and gepants, respectively. Since lasmiditan is a 5-HT_1F receptor agonist and gepants are CGRP receptor antagonists, they could have different risks for developing MOH because of the different (over) compensation mechanisms following prolonged agonist versus antagonist treatment.

Conclusion

The acute treatment of migraine will certainly improve with the advent of two novel classes of drugs, i.e., the 5-HT_1F receptor agonists (lasmiditan) and the small molecule CGRP receptor antagonists (gepants). Data on the effects of 5-HT_1F receptor agonism in relation to MOH, as well as the effects of chronic CGRP receptor blockade, are awaited with interest.

Effects of two isometheptene enantiomers in isolated human blood vessels and rat middle meningeal artery - potential antimigraine efficacy

Background

Racemic isometheptene [(RS)-isometheptene] is an antimigraine drug that due to its cardiovascular side-effects was separated into its enantiomers, (R)- and (S)-isometheptene. This study set out to characterize the contribution of each enantiomer to its vasoactive profile. Moreover, rat neurogenic dural vasodilatation was used to explore their antimigraine mechanism of action.

Methods

Human blood vessel segments (middle meningeal artery, proximal and distal coronary arteries, and saphenous vein) were mounted in organ baths and concentration response curves to isometheptene were constructed. Calcitonin gene-related peptide (CGRP)-induced neurogenic dural vasodilation was elicited in the presence of the enantiomers using a rat closed cranial window model.

Results

The isometheptene enantiomers did not induce any significant contraction in human blood vessels, except in the middle meningeal artery, when they were administered at the highest concentration (100 μM). Interestingly in rats, (S)-isometheptene induced more pronounced vasopressor responses than (R)-isometheptene. However, none of these compounds affected the CGRP-induced vasodilator responses.

Conclusion

The isometheptene enantiomers displayed a relatively safe peripheral vascular profile, as they failed to constrict the human coronary artery. These compounds do not appear to modulate neurogenic dural CGRP release, therefore, their antimigraine site of action remains to be determined.

Emerging Treatments in Episodic Migraine

PURPOSE OF REVIEW

The purpose of this review is to evaluate and describe recent and emerging treatment options for episodic migraine.

RECENT FINDINGS

Recent advances have been made in better understanding the pathophysiology of migraine, which has led to further investigation of potential new pharmacologic and non-pharmacologic treatment options. A number of new medications are emerging for the acute and preventive treatment of migraine, including CGRP monoclonal antibodies, CGRP receptor antagonists, serotonin 5-HT_1F agonists, and PACAP receptor monoclonal antibodies. Additionally, newer studies on existing non-invasive neuromodulation devices including transcranial magnetic stimulation, supraorbital transcutaneous nerve stimulation, and transcutaneous vagus nerve stimulation have recently received FDA approval for use in migraine. Neuromodulation devices including percutaneous mastoid electrical stimulation, non-painful remote electrical stimulation, and caloric vestibular stimulation are undergoing further investigation and have shown promising results thus far. These new developments are expected to contribute to better treatment and decreased disability in migraine.