Migraine Therapy: Current Approaches and New Horizons

N-Cyclo-hexyl-tryptamine: freebase, bromide and fumarate

The solid-state structures of N-cyclo-hexyl-tryptamine (I) {systematic name: N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-namine}, C16H22N2, and two of its salts, N-cyclo-hexyl-tryptammonium bromide (II) {systematic name: N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-naminium bromide}, C16H23N2 +·Br-, and N-cyclo-hexyl-tryptammonium fumarate (III) (systematic name: bis-{N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-naminium} (2E)-but-2-enedioate), 2C16H23N2 +·C4H2O4 2-, were determined by single-crystal X-ray diffraction. The freebase compound forms infinite chains along [010] through N-H⋯N hydrogen bonds. The bromide salt is held together by N-H⋯Br inter-actions in two-dimensional sheets along (001). The fumarate salt is held together in infinite three-dimensional frameworks by N-H⋯O hydrogen bonds.

[Cardiovascular safety of new drugs for the acute and preventive treatment of migraine: gepants and ditans]

INTRODUCTION

Migraine is a prevalent neurological condition characterised by disabling headache attacks. In recent decades, new drugs have been developed specifically for the acute and preventive treatment of migraine based on its pathophysiology. These include calcitonin gene-related peptide (CGRP) antagonists (CGRP) (gepants) and selective serotoninergic 5-HT1F receptor agonists (ditans). CGRP is a neuropeptide released by trigeminal terminals that acts as a vasodilator, causes neurogenic inflammation and thus generates pain and sensitisation in migraine. It also has a powerful vasodilatory action and is involved in cardiovascular regulation, which is why numerous studies are under way to assess the vascular safety of acting against CGRP. The high selectivity of ditans for the serotoninergic 5-HT1F receptor with a low affinity for other serotoninergic receptors seems to translate into little or no vasoconstrictor effect, which is mediated by the activation of 5-HT1B receptors.

DEVELOPMENT

The aim of our study is to review the cardiovascular safety demonstrated by these new drugs for the treatment of migraine by analysing the evidence published to date. We conducted a literature search in the PubMed database and a review of clinical trials published at clinicaltrial.gov. We included literature reviews, meta-analyses and clinical trials in English and Spanish. We analysed reported cardiovascular adverse effects.

CONCLUSIONS

Based on the results published to date, we can conclude that the cardiovascular safety profile of these new treatments is favourable. Longer-term safety studies are needed to confirm these results.

Gepants, calcitonin-gene-related peptide receptor antagonists: what could be their role in migraine treatment?

PURPOSE OF REVIEW

Migraine is the second leading cause of years lived with disability after back pain. Poor tolerability, contraindications, drug-drug interactions and efficacy limited to a subpopulation make new approaches necessary for the acute and preventive treatment of migraine. The study of the calcitonin-gene-related peptide (CGRP) pathway over the last decades is a good example of translational medicine leading to directed therapies for patients.

RECENT FINDINGS

After some of the first-generation CGRP receptor antagonists, gepants, were not fully developed because of hepatotoxicity, the second generation of gepants have shown efficacy, safety and tolerability in recent clinical trials.

SUMMARY

Both rimegepant and ubrogepant have published positive randomized placebo-controlled clinical trials data. Vazegepant is the first intranasal gepant for the acute treatment of migraine and has announced a positive phase II/III study. Daily rimegepant use has preliminary data to suggest efficacy. Atogepant has shown efficacy in migraine prevention in a phase II/III study. Most importantly, hepatotoxicity has not been reported in specifically designed phase I studies or long-term extension studies, with rimegepant or ubrogepant, or in a preventive study with atogepant. Given the preventive effect, it seems likely that gepants will not lead to medication overuse headache. They will likely have no cardiovascular warnings. Because of the particular benefit gepants may represent for these groups of patients, specific studies in patients with medication overuse headache, as well as those with comorbid cardiovascular diseases, would be of considerable interest.

Eptinezumab for the preventive treatment of migraine

Our knowledge of the pathophysiology of migraine and the molecules implicated in the disorder have evolved over time. Among these, calcitonin gene-related peptide has shown a crucial role that led to the development of therapies specifically targeting the molecule. Four monoclonal antibodies targeting the calcitonin gene-related peptide pathway are currently available after the US FDA approval of eptinezumab for the indication of migraine prevention. This is the only one of the class to be administered intravenously. The pharmacology of eptinezumab and the four studies that led to the approval, two Phase II and two Phase III clinical trials, are reviewed in this paper. Eptinezumab has demonstrated efficacy, tolerability and safety in patients with episodic and chronic migraine. Studies including migraineurs who have failed previous preventives, and comparison with other options administered quarterly, as well as real-world experience data will all be welcome.

Hejie Zhitong prescription promotes sleep and inhibits nociceptive transmission-associated neurotransmitter activity in a rodent migraine model

BACKGROUND

Migraine is painful disease in which neurotransmitters related to pain transmission play an important role. Hejie Zhitong prescription (HJZT) has been used in the clinic as an effective prescription for the treatment of migraine for many years. Our team aimed to further explore its antimigraine mechanism based on previous research results and to explore the inhibitory effect of HJZT on the transmission of pain related to nitroglycerine (NTG)-induced migraine as well as the synergistic effect of HJZT with pentobarbital sodium on promoting sleep.

METHODS

Sixty mice were randomly assigned to groups and received the corresponding interventions. Sleep latency and sleep time were recorded to calculate the incidence of sleep. Forty-eight Wistar rats were randomly assigned and administered an intervention corresponding to their group. Calcitonin gene-related peptide (CGRP), serotonin (5-HT), substance P (SP), and cholecystokinin (CCK) levels were measured using ELISAs. Levels of the cannabinoid receptor type 1 (CB1R) and cyclooxygenase-2 (COX-2) protein were assessed using immunohistochemistry. The expression of the CGRP and CCK mRNAs in the midbrain and trigeminal ganglion (TG) were measured using real-time quantitative PCR.

RESULTS

HJZT promoted the occurrence of sleep in mice. HJZT downregulated COX-2 expression in the midbrain and TG of rats but upregulated the expression of the CB1R, and decreased the plasma level of the CGRP protein and expression of its mRNA in the midbrain and TG. It also downregulated the expression of the CCK mRNA in the midbrain and TG. The high-dose HJZT treatment increased plasma 5-HT levels, but did not induce changes in the plasma levels of the SP or CCK protein.

CONCLUSIONS

HJZT exerts a synergistic effect with pentobarbital sodium on promoting sleep. As for anti-migraine, HJZT can inhibits the expression of nociceptive transmission-associated neurotransmitters, including 5-HT, CGRP and CCK, which may be related to its upregulation of CB1R and downregulation of COX-2.

The impact of fremanezumab on medication overuse in patients with chronic migraine: subgroup analysis of the HALO CM study

Background

We evaluated the efficacy of fremanezumab, a fully humanized monoclonal antibody that selectively targets calcitonin gene-related peptide, in patients with chronic migraine (CM) with and without medication overuse (MO).

Methods

In a 12-week, phase 3 trial, patients with CM were randomized to fremanezumab quarterly (675 mg/placebo/placebo), monthly (675 mg/225 mg/225 mg), or placebo. Post hoc analyses assessed the impact of fremanezumab in patients with and without MO (monthly use of acute headache medication ≥15 days, migraine-specific acute medication ≥10 days, or combination medication ≥10 days) on efficacy outcomes, including headache days of at least moderate severity (HDs), and six-item Headache Impact Test (HIT-6) and Migraine-Specific Quality of Life (MSQoL) questionnaire scores.

Results

Of 1130 patients enrolled, 587 (51.9%) had baseline MO. Fremanezumab reduced placebo-adjusted least-squares mean (95% confidence interval) monthly HDs (− 2.2 [− 3.1 to − 1.2] and − 2.7 [− 3.7 to − 1.8]; P < 0.0001) in patients with MO and without MO (quarterly − 1.4 [− 2.3 to − 0.5], P = 0.0026; monthly − 1.4 [− 2.3 to − 0.6], P = 0.0017). Significantly more fremanezumab-treated patients had ≥ 50% reduction in HDs versus placebo, regardless of baseline MO (with: quarterly 70/201 [34.8%], monthly 78/198 [39.4%] vs placebo 26/188 [13.8%]; without: quarterly 71/174 [40.8%], monthly 75/177 [42.4%] vs placebo 41/183 [22.4%]). Fremanezumab improved HIT-6 and MSQoL scores. Significantly more fremanezumab-treated patients reverted to no MO (quarterly 111/201 [55.2%], monthly 120/198 [60.6%]) versus placebo (87/188 [46.3%]).

Conclusions

Fremanezumab is effective for prevention of migraine in patients with CM, regardless of MO, and demonstrated a benefit over placebo in reducing MO.

Trial registration

ClinicalTrials.gov NCT02621931 (HALO CM), registered December 12, 2012.

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.