Calcitonin Gene-related Peptide Receptor Antagonist Research Articles

Efficacy of Atogepant in Chronic Migraine With and Without Acute Medication Overuse in the Randomized, Double-Blind, Phase 3 PROGRESS Trial.

Atogepant is an oral, calcitonin gene-related peptide receptor antagonist approved for the preventive treatment of migraine. We evaluated the efficacy of atogepant for the preventive treatment of chronic migraine (CM) in participants with and without acute medication overuse. This subgroup analysis of the phase 3, 12-week, randomized, double-blind, placebo-controlled PROGRESS trial evaluated adults with a ≥1-year history of CM, ≥15 monthly headache days (MHDs), and ≥8 monthly migraine days (MMDs) during the 4-week baseline period. Participants were randomized (1:1:1) to placebo, atogepant 30 mg twice daily (BID), or atogepant 60 mg once daily (QD) for 12 weeks and were analyzed by acute medication overuse status (triptans/ergots for ≥10 days per month, simple analgesics for ≥15 days per month, or combinations of triptans/ergots/simple analgesics for ≥10 days per month). Outcomes included change from baseline in mean MMDs, MHDs, and monthly acute medication use days; ≥50% reduction in mean MMDs across 12 weeks; and patient-reported outcome (PRO) measures. Of 755 participants in the modified intent-to-treat population, 500 (66.2%) met baseline acute medication overuse criteria (placebo, n = 169 [68.7%]; atogepant 30 mg BID, n = 161 [63.6%]; atogepant 60 mg QD, n = 170 [66.4%]). The least squares mean difference (LSMD) (95% CI) from placebo in MMDs was -2.7 (-4.0 to -1.4) with atogepant 30 mg BID and -1.9 (-3.2 to -0.6) with atogepant 60 mg QD. Mean MHDs (LSMD [95% CI] -2.8 [-4.0 to -1.5] and -2.1 [-3.3 to -0.8]) and mean acute medication use days (LSMD [95% CI] -2.8 [-4.1 to -1.6] and -2.6 [-3.9 to -1.3]) were reduced and a higher proportion of participants achieved ≥50% reduction in MMDs (odds ratio [95% CI] 2.5 [1.5-4.0] and 2.3 [1.4-3.7]) with atogepant 30 mg BID and atogepant 60 mg QD. There was a 52.1%-61.9% reduction in the proportion of atogepant-treated participants meeting acute medication overuse criteria over 12 weeks. Atogepant improved PRO measures. Similar results were observed in the subgroup without acute medication overuse. Atogepant was effective in participants with CM, with and without acute medication overuse, as evidenced by reductions in mean MMDs, MHDs, and acute medication use days; reductions in the proportion of participants meeting acute medication overuse criteria; and improvements in PROs. ClinicalTrials.gov NCT03855137. Submitted: February 25, 2019; first patient enrolled: March 11, 2019. clinicaltrials.gov/ct2/show/NCT03855137. This study provides Class II evidence that atogepant reduces mean MMDs, MHDs, and monthly acute medication use days in adult patients with or without medication overuse.

Migraine inhibitor olcegepant reduces weight loss and IL-6 release in SARS-CoV-2-infected older mice with neurological signs.

COVID-19 can cause neurological symptoms such as fever, dizziness, and nausea. However, such neurological symptoms of SARS-CoV-2 infection have been hardly assessed in mouse models. In this study, we infected two commonly used wild-type mouse lines (C57BL/6J and 129/SvEv) and a 129S calcitonin gene-related peptide (αCGRP) null-line with mouse-adapted SARS-CoV-2 and demonstrated neurological signs including fever, dizziness, and nausea. We then evaluated whether a CGRP receptor antagonist, olcegepant, a "gepant" antagonist used in migraine treatment, could mitigate acute neuroinflammatory and neurological signs of SARS-COV-2 infection. First, we determined whether CGRP receptor antagonism provided protection from permanent weight loss in older (>18 m) C57BL/6J and 129/SvEv mice. We also observed acute fever, dizziness, and nausea in all older mice, regardless of treatment. In both wild-type mouse lines, CGRP antagonism reduced acute interleukin 6 (IL-6) levels with virtually no IL-6 release in mice lacking αCGRP. These findings suggest that migraine inhibitors such as those blocking CGRP receptor signaling protect against acute IL-6 release and subsequent inflammatory events after SARS-CoV-2 infection, which may have repercussions for related pandemic or endemic coronavirus outbreaks.IMPORTANCECoronavirus disease (COVID-19) can cause neurological symptoms such as fever, headache, dizziness, and nausea. However, such neurological symptoms of severe acute respiratory syndrome CoV-2 (SARS-CoV-2) infection have been hardly assessed in mouse models. In this study, we first infected two commonly used wild-type mouse lines (C57BL/6J and 129S) with mouse-adapted SARS-CoV-2 and demonstrated neurological symptoms including fever and nausea. Furthermore, we showed that the migraine treatment drug olcegepant could reduce long-term weight loss and IL-6 release associated with SARS-CoV-2 infection. These findings suggest that a migraine blocker can be protective for at least some acute SARS-CoV-2 infection signs and raise the possibility that it may also impact long-term outcomes.

The neurotransmitter calcitonin gene-related peptide shapes an immunosuppressive microenvironment in medullary thyroid cancer

Neurotransmitters are key modulators in neuro-immune circuits and have been linked to tumor progression. Medullary thyroid cancer (MTC), an aggressive neuroendocrine tumor, expresses neurotransmitter calcitonin gene-related peptide (CGRP), is insensitive to chemo- and radiotherapies, and the effectiveness of immunotherapies remains unknown. Thus, a comprehensive analysis of the tumor microenvironment would facilitate effective therapies and provide evidence on CGRP’s function outside the nervous system. Here, we compare the single-cell landscape of MTC and papillary thyroid cancer (PTC) and find that expression of CGRP in MTC is associated with dendritic cell (DC) abnormal development characterized by activation of cAMP related pathways and high levels of Kruppel Like Factor 2 (KLF2), correlated with an impaired activity of tumor infiltrating T cells. A CGRP receptor antagonist could offset CGRP detrimental impact on DC development in vitro. Our study provides insights of the MTC immunosuppressive microenvironment, and proposes CGRP receptor as a potential therapeutic target.

Efficacy and safety of atogepant, a small molecule CGRP receptor antagonist, for the preventive treatment of migraine: a systematic review and meta-analysis

BackgroundMigraine is one of the most common diseases worldwide while current treatment options are not ideal. New therapeutic classes of migraine, the calcitonin gene-related peptide (CGRP) antagonists, have been developed and shown considerable effectiveness and safety. The present study aimed to systematically evaluate the efficacy and safety of atogepant, a CGRP antagonist, for migraine prophylaxis from the results of randomized controlled trials (RCTs).MethodsThe Cochrane Library, Embase, PubMed and https://www.clinicaltrials.gov/ were searched for RCTs that compared atogepant with placebo for migraine prophylaxis from inception of the databases to Feb 1, 2024. Outcome data involving efficacy and safety were combined and analyzed using Review Manager Software version 5.3 (RevMan 5.3). For each outcome, risk ratios (RRs) or standardized mean difference (SMD) were calculated.Results4 RCTs with a total of 2813 subjects met our inclusion criteria. The overall effect estimate showed that atogepant was significantly superior to placebo in terms of the reduction of monthly migraine (SMD − 0.40, 95% CI -0.46 to -0.34) or headache (SMD − 0.39, 95% CI -0.46 to -0.33) days, the reduction of acute medication use days (SMD − 0.45, 95% CI -0.51 to -0.39) and 50% responder rate (RR 1.66, 95% CI 1.46 to 1.89), while no dose-related improvements were found between different dosage groups. For the safety, significant number of patients experienced treatment-emergent adverse events (TEAEs) with atogepant than with placebo (RR 1.10, 95% CI 1.02–1.21) while there was no obvious difference between the five dosage groups. Most TEAEs involved constipation (RR 2.55, 95% CI 1.91–3.41), nausea (RR 2.19, 95% CI 1.67–2.87) and urinary tract infection (RR 1.49, 95% CI 1.05–2.11). In addition, a high dosage of atogepant may also increase the risk of treatment-related TEAEs (RR 1.64, 95% CI 1.02–2.63) and fatigue (RR 3.07, 95% CI 1.13–8.35).ConclusionsThis meta-analysis suggests that atogepant is effective and tolerable for migraine prophylaxis including episodic or chronic migraine compared with placebo. It is critical to weigh the benefits of different doses against the risk of adverse events in clinical application of atogepant. Longer and multi-dose trials with larger sample sizes are required to verify the current findings.

Stress-induced impairment of parasympathetic NO-mediated inhibition of sympathetic vasoconstriction in submucosal arteriole of rat rectum.

In the gastrointestinal tract, nitrergic inhibition of the arteriolar contractility has not been demonstrated. Here, we explored whether neurally-released nitric oxide (NO) inhibits sympathetic vasoconstrictions in the rat rectal arterioles. Changes in sympathetic vasoconstrictions and their nitrergic modulation in rats exposed to water avoidance stress (WAS, 10days, 1h per day) were also examined. In rectal submucosal preparations, changes in arteriolar diameter were monitored using video microscopy. In control or sham-treated rats, electrical field stimulation (EFS)-induced sympathetic vasoconstrictions were increased by the neuronal nitric oxide synthase (nNOS) inhibitor L-NPA (1μM) and diminished by the cyclic guanosine monophosphate-specific phosphodiesterase 5 (PDE5) inhibitor tadalafil (10nM). In phenylephrine-constricted, guanethidine-treated arterioles, EFS-induced vasodilatations were inhibited by the calcitonin gene-related peptide (CGRP) receptor antagonist BIBN-4096 (1μM) but not L-NPA. Perivascular nNOS-immunoreactive nitrergic fibres co-expressing the parasympathetic marker vesicular acetylcholine transporter (VAChT) were intermingled with tyrosine hydroxylase (TH)-immunoreactive sympathetic fibres expressing soluble guanylate cyclase (sGC), a receptor for NO. In WAS rats in which augmented sympathetic vasoconstrictions were developed, L-NPA failed to further increase the vasoconstrictions, while tadalafil-induced inhibition of the vasoconstrictions was attenuated. Phenylephrine- or α,β-methylene ATP-induced vasoconstrictions and acetylcholine-induced vasodilatations were unaltered by WAS. Thus, in arterioles of the rat rectal submucosa, NO released from parasympathetic nerves appears to inhibit sympathetic vasoconstrictions presumably by reducing sympathetic transmitter release. In WAS rats, sympathetic vasoconstrictions are augmented at least partly due to the diminished pre-junctional nitrergic inhibition of transmitter release without changing α-adrenoceptor or P2X-purinoctor mediated vasoconstriction and endothelium-dependent vasodilatation.

Effect of a High-Fat Meal on the Pharmacokinetics of an Immediate Release Atogepant Tablet.

Atogepant, an oral calcitonin gene-related peptide receptor antagonist, is approved for the preventive treatment of migraine. A phase 1, open-label, single-dose, 2-period crossover study evaluated the effect of a high-fat meal on the pharmacokinetics and safety of atogepant in 20 healthy adults. Administration of atogepant 60mg immediate-release (IR) tablets under fed conditions reduced the area under the plasma concentration-time curve (AUC) from 0 to time t and from 0 to time infinity by approximately 18% and reduced the maximum plasma concentration (Cmax) by 22%. The 90% confidence intervals for the geometric mean ratios of Cmax and AUC were not contained within the bioequivalence limits of 80%-125%. There was no change in the median time to maximum plasma concentration in the fed versus fasted state. The incidence of treatment-emergent adverse events (TEAEs) was similar between fed and fasted conditions. Four TEAEs were considered related to study intervention and were reported after participants received atogepant under fasted conditions (3 participants). A single-dose atogepant 60mg IR tablet was safe and tolerated under both fed and fasted states. Due to the wide effective dose range of 10-60mg/day for atogepant for the preventive treatment of migraine, the food effect on its pharmacokinetics is not considered clinically relevant.

Safety of Rimegepant in Adults with Migraine and Cardiovascular Risk Factors: Analysis of a Multicenter, Long-Term, Open-Label Study.

Cardiovascular (CV) risk factors can limit treatment options for migraine. Rimegepant is an orally administered small-molecule calcitonin gene-related peptide receptor antagonist that does not induce vasoconstriction. The aim of these post hoc subgroup analyses was to assess the safety of rimegepant according to CV risk. In a multicenter, long-term, open-label, phase II/III safety study, participants with a history of 2-14 migraine attacks per month of moderate or severe pain intensity self-administered rimegepant 75 mg, orally, to treat migraine up to once daily for up to 52 weeks. Uncontrolled, unstable, or recently diagnosed CV disease was part of the exclusion criteria. Safety was assessed across subgroups according to number of CV risk factors (0, 1, or ≥ 2) and Framingham Risk Score (< 10% or ≥ 10%). Of 1800 treated participants, 28.8% had one CV risk factor and 12.1% had ≥ 2 CV risk factors; 7.0% had Framingham Risk Score ≥ 10%. Across the subgroups with 0, 1, and ≥ 2 CV risk factors and Framingham Risk Score < 10% and ≥ 10%, respectively, proportions of participants reporting adverse events (AEs; 59.6%, 61.4%, 62.2%, 59.9%, 67.5%) and serious AEs (2.7%, 2.5%, 2.3%, 2.6%, 2.4%) were consistent, and AEs leading to study drug discontinuation were low (1.9%, 3.1%, 5.5%, 2.5%, 4.8%). Rimegepant showed favorable safety and tolerability in adults with migraine and CV risk factors, including those with moderate to high CV risk. ClinicalTrials.gov NCT03266588.

Role of calcitonin gene-related peptide (CGRP) receptor antagonist in acute and preventive treatment of migraine.

Migraine is the most common neurological disease in the world. It is characterized by recurrent attacks of severe headaches of a one-sided, throbbing nature, often accompanied by sensory and motor disturbances and generally associated with nausea and increased sensitivity to light and sound. Migraine treatment can be divided into emergency treatment and preventive treatment, which aims to reduce the overall frequency and severity of attacks. In the first case, nonsteroidal anti-inflammatory drugs (NSAIDs) can be used, but in some patients they do not have the desired effect. The gold standard in the fight against migraine pain are triptans (selective serotonin 5-HT1 receptor agonists), although they too are not effective in all patients. Current understanding suggests that CGRP plays a significant role in the pathophysiology of migraines. Evidence supporting this includes increased CGRP levels during migraine attacks, causing inflammation and activation of other pathophysiological processes responsible for pain. The hope for patients are CGRP receptor antagonists, which greatly expand therapeutic options.

A real-world pharmacovigilance study of FDA adverse event reporting system events for atogepant

ABSTRACT Background Atogepant, an orally administered, small-molecule, calcitonin gene-related peptide (CGRP) receptor antagonist, is being investigated for the treatment of migraine. Methods We collected data from the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. Four algorithms (ROR, PRR, BCPNN, and EBGM) were used as measures to detect signals of atogepant-associated adverse events (AEs) in real-world data. Result Of the 3,552,072 reports, 2876 expressly stated the use of atogepant. Women accounted for the majority of adverse events (AEs), with a notable age concentration of 45–65 years. The percentage of reported adverse events was the highest in the United States. Significant system organ categories (SOC) included nervous system disorders, gastrointestinal disorders, nervous system disorders, surgical and medical procedures, ear and labyrinth disorders. Notably, preferred terms (PTs) related to atogepant include migraine, constipation, nausea, vertigo, somnolence, decreased appetite, dizziness and fatigue. Unexpected adverse events such as abnormal dreams, self-injurious ideation, brain fog, tension headache, nightmare, brain neoplasm, feeling abnormal, euphoric mood, hyperacusis and post concussion syndrome were also identified. Conclusions The present investigation has detected new and unexpected signals of atogepant-related adverse drug reactions (ADRs). In order to confirm these solve safety issues that were previously overlooked, more research is necessary.

Situational prevention: Pharmacotherapy during periods of increased risk for migraine attacks.

The small molecule calcitonin gene-related peptide receptor antagonists (gepants) are the only drug class with medicines indicated for both the acute and preventive treatment of migraine. Given this dual capacity to both treat and prevent, along with their favorable tolerability profiles and lack of an association with medication-overuse headache, headache specialists have begun to use gepants in ways that transcend the traditional categories of acute and preventive treatment. One approach, called situational prevention, directs patients to treat during the interictal phase, before symptoms develop, insituations of increased risk for migraine attacks. Herein, we present three patients to illustrate scenarios of gepant use for situational prevention. In each case, a gepant was started in anticipation of a period of increased headache probability (vulnerability) and continued for a duration of 1 day to 5 consecutive days. Although this approach may expose patients to medication when headache may not have developed, the tolerability and safety profile and preventive effect of gepants may represent a feasible approach for some patients. Situational prevention is an emerging strategy for managing migraine before symptoms develop in individuals who can identify periods when the probability of headache is high. This paper is intended to increase awareness of this strategy and stimulate future randomized, placebo-controlled trials to rigorously assess this strategy.

A Vestibular Challenge Combined with Calcitonin Gene-Related Peptide (CGRP) Promotes Anxiety-Like Behaviors.

Motion-induced anxiety and agoraphobia are more frequent symptoms in patients with vestibular migraine (VM) than migraine without vertigo. The neuropeptide calcitonin gene-related peptide (CGRP) is a therapeutic target for migraine and VM, but the link between motion hypersensitivity, anxiety, and CGRP is relatively unexplored, especially in preclinical mouse models. To further examine this link, we tested the effects of systemic CGRP and off-vertical axis rotation (OVAR) on elevated plus maze (EPM) and rotarod performance in male and female C57BL/6J mice. Rotarod ability was assessed using two different dowel diameters: mouse dowel (r = 1.5 cm) versus rat dowel (r = 3.5 cm). EPM results indicate that CGRP alone or OVAR alone did not increase anxiety indices. However, the combination of CGRP and OVAR did elicit anxiety-like behavior. On the rotarod, CGRP reduced performance in both sexes on a mouse dowel but had no effect on a rat dowel, whereas OVAR had a significant effect on the rat dowel. These results suggest that only the combination of CGRP with vestibular stimulation induces anxiety-like behavior and that CGRP affects the dynamic balance function in mice depending on the type of challenge presented. These findings suggest that anxiety-like behaviors can be teased out from imbalance behaviors in a mouse model of "migraine." Future studies are aimed to determine if CGRP receptor antagonists that have been effective treating migraineurs and mouse "migraine" models may also reduce the anxiety observed in migraine.

CGRP: from neuropeptide to the therapeutic target (background and pathophysiology)

Calcitonin gene-related peptide (CGRP) plays a pivotal role in migraine pathophysiology. The importance of CGRP in migraine became evident from numerous clinical studies investigating CGRP levels both interictally and ictally and reports on the efficacy of CGRP-based migraine therapies. In this paper, the above mentioned studies will be presented and the reader will be introduced to the development of CGRP-based medication. Finally, current study results on CGRP receptor antagonists, the so-called gepants, will be presented.

Reduced hepatic impairment study to evaluate pharmacokinetics and safety of zavegepant and to inform dosing recommendation for hepatic impairment.

Zavegepant, a high-affinity, selective, small-molecule calcitonin gene-related peptide (CGRP) receptor antagonist, is approved in the United States for acute treatment of migraine in adults. The effects of moderate hepatic impairment (8 participants with Child-Pugh score 7-9 points) on the pharmacokinetics of a single 10-mg intranasal dose of zavegepant versus eight matched participants with normal hepatic function were evaluated in a phase I study. Pharmacokinetic sampling determined total and unbound plasma zavegepant concentrations. Moderate hepatic impairment increased the exposure of total zavegepant (~2-fold increase in AUC0-inf and 16% increase in Cmax) versus normal hepatic function, which is not considered clinically meaningful. The geometric least squares mean ratios (moderate impairment/normal) of plasma zavegepant AUC0-inf and Cmax were 193% (90% confidence interval [CI]: 112, 333; p = 0.051) and 116% (90% CI: 69, 195; p = 0.630), respectively. The geometric mean fraction unbound of zavegepant was similar for participants with moderate hepatic impairment (0.13; coefficient of variation [CV] 13.71%) versus those with normal hepatic function (0.11; CV 21.43%). Similar exposure findings were observed with unbound zavegepant versus normal hepatic function (~2.3-fold increase in AUC0-inf and 39% increase in Cmax). One treatment-emergent adverse event (mild, treatment-related headache) was reported in a participant with normal hepatic function. No dosage adjustment of intranasal zavegepant is required in adults with mild or moderate hepatic impairment.

Intervening in the Premonitory Phase to Prevent Migraine: Prospects for Pharmacotherapy.

Migraine is a common brain condition characterised by disabling attacks of headache with sensory sensitivities. Despite increasing understanding of migraine neurobiology and the impacts of this on therapeutic developments, there remains a need for treatment options for patients underserved by currently available therapies. The first specific drugs developed to treat migraine acutely, the serotonin-5-hydroxytryptamine [5-HT1B/1D] receptor agonists (triptans), seem to require headache onset in order to have an effect, while early treatment during mild pain before headache escalation improves short-term and long-term outcomes. Some patients find treating in the early window once headache has started but not escalated difficult, and migraine can arise from sleep or in the early hours of the morning, making prompt treatment after pain onset challenging. Triptans may be deemed unsuitable for use in patients with vascular disease and in those of older age and may not be effective in a proportion of patients. Headache is also increasingly recognised as being just one of the many facets of the migraine attack, and for some patients it is not the most disabling symptom. In many patients, painless symptoms can start prior to headache onset and can reliably warn of impending headache. There is, therefore, a need to identify therapeutic targets and agents that may be used as early as possible in the course of the attack, to prevent headache onset before it starts, and to reduce both headache and non-headache related attack burden. Early small studies using domperidone, naratriptan and dihydroergotamine have suggested that this approach could be useful; these studies were methodologically less rigorousthan modern day treatment studies, of small sample size, and have not sincebeen replicated. The emergence of novel targeted migraine treatments more recently, specifically calcitonin gene-related peptide (CGRP) receptor antagonists (gepants), has reignited interest in this strategy, with encouraging results. This review summarises historical and emerging data in this area, supporting use of the premonitory phase as an opportunity to intervene as early as possible in migraine to prevent attack-related morbidity.

The evolving landscape and research trend of calcitonin gene-related peptide in migraine: A bibliometric analysis and visualization.

Migraine is a global public health concern, affecting both social and individual well-being. Calcitonin gene-related peptide (CGRP), a crucial neuropeptide, holds important research value in understanding migraine pathogenesis. CGRP receptor antagonists and monoclonal antibodies that target CGRP or its receptors have shown efficacy in reducing migraine frequency and severity, presenting a promising therapeutic approach. This study aimed to conduct a comprehensive bibliometric analysis to analyze the current state, research trends, and future directions of CGRP in migraine. Bibliometric tools including CiteSpace, VOSviewer, etc., were utilized to extract and summarize publications related to CGRP in migraine from the Web of Science Core Collection Database (WOSCC) between 2004 and 2023, as of December 31, 2023. The analysis focused on trends in annual publications, leading countries/regions and institutions, prominent journals and references, influential authors, and high-frequency keywords in the field. A total of 1,821 articles and reviews involving 5,180 authors from 1,315 organizations across 64 countries were included in the study. These publications were distributed across 362 journals and accumulated 56,999 citations by December 31, 2023. An increasing trend was observed in annual publications on CGRP in migraine. The United States emerged as the leading nation in both publications and citations, with academic Peter Goadsby contributing the highest number of publications. The University of Copenhagen stood out as the institution with the most publications, and Cephalalgia emerged as the most influential journal. The most cited paper identified was "Calcitonin gene-related peptide receptor antagonist BIBN4096BS for the acute treatment of migraine" by Jes Olesen, published in the New Engl Med. Keyword frequency analysis revealed prevalent terms such as "migraine," "CGRP," and "episodic migraine," along with emerging topics represented by keywords including "trial," "monoclonal antibodies," "preventive treatment," and "safety." CGRP is pivotal in migraine pathogenesis, and there is a robust research foundation exploring its role. The US leads in research output on CGRP in migraine. Investigating the mechanism of CGRP and its receptor in migraine remains a key area of interest, particularly focusing on signaling pathways. Future research should target identifying critical therapeutic targets in CGRP antagonist pathways for migraine treatment.

Long-term effectiveness of eptinezumab in the treatment of patients with chronic migraine and medication-overuse headache.

This post hoc analysis of the PREVAIL study explored the effectiveness of eptinezumab for up to 2 years of open-label treatment in the subgroup of patients with chronic migraine who had a confirmed diagnosis of medication-overuse headache (MOH) at screening. MOH is a disabling and costly secondary headache disorder characterized by increased headache frequency and/or severity with increased acute headache medication use. Eptinezumab, an anti-calcitonin gene-related peptide monoclonal antibody, reduces headache frequency, severity, and associated disability and improves functioning and health-related quality of life as a preventive migraine therapy; short-term benefits in patients with concurrent MOH have also been reported. Participants received up to eight quarterly intravenous infusions of eptinezumab 300 mg in the phase 3, single-arm, open-label PREVAIL study. Safety and patient-reported outcome measures (Migraine Disability Assessment [MIDAS], 6-item Headache Impact Test [HIT-6], patient-identified most bothersome symptom [PI-MBS], Patient Global Impression of Change [PGIC], and 36-item Short-Form Health Survey [SF-36]) were conducted at predefined intervals. Patients were observed up to 20 weeks after their last infusion (Week 104). A total of 49/128 (38.3%) patients enrolled in PREVAIL had an MOH diagnosis at screening. In the MOH subgroup, long-term eptinezumab treatment was associated with reductions in headache frequency (43/49 [87.8%] patients reported ≥50% reduction in MIDAS-derived headache days at ≥1 visit), severity (2.2-point reduction [on a 10-point scale]), disability (mean MIDAS total score reduction of 51.9 points), and impact (mean HIT-6 total score reduction of 9.7 points) at Week 104. Most patients described a "much improved" or "very much improved" status by Week 48 (PI-MBS, 31/46 [67.4%]) and Week 104 (PGIC, 31/36 [86.1%]). Health-related quality of life improvements in the SF-36 were also observed. Eptinezumab preventive therapy in patients with chronic migraine showed benefits that extended to the subset of patients with concomitant MOH.

Sensory ASIC3 channel exacerbates psoriatic inflammation via a neurogenic pathway in female mice

Psoriasis is an immune-mediated skin disease associated with neurogenic inflammation, but the underlying molecular mechanism remains unclear. We demonstrate here that acid-sensing ion channel 3 (ASIC3) exacerbates psoriatic inflammation through a sensory neurogenic pathway. Global or nociceptor-specific Asic3 knockout (KO) in female mice alleviates imiquimod-induced psoriatic acanthosis and type 17 inflammation to the same extent as nociceptor ablation. However, ASIC3 is dispensable for IL-23-induced psoriatic inflammation that bypasses the need for nociceptors. Mechanistically, ASIC3 activation induces the activity-dependent release of calcitonin gene-related peptide (CGRP) from sensory neurons to promote neurogenic inflammation. Botulinum neurotoxin A and CGRP antagonists prevent sensory neuron-mediated exacerbation of psoriatic inflammation to similar extents as Asic3 KO. In contrast, replenishing CGRP in the skin of Asic3 KO mice restores the inflammatory response. These findings establish sensory ASIC3 as a critical constituent in psoriatic inflammation, and a promising target for neurogenic inflammation management.

Aromatase inhibitors evoke periorbital allodynia in mice via calcitonin gene-related peptide and its receptors in Schwann cells

Background: Treatment with the currently recommended aromatase inhibitors (AIs) for adjuvant endocrine treatment of estrogen receptorpositive breast cancer is associated with debilitating musculoskeletal pain symptoms (AIMS) and headache. Recent evidence suggests that the proalgesic channel transient receptor potential ankyrin 1 (TRPA1) is implicated in AIMS. Here, we investigated the cellular and molecular mechanisms, including TRPA1, implicated in periorbital mechanical allodynia (PMA), a surrogate of headache-like pain, evoked by AIs in mice. Methods: C57BL6/J mice were treated with intragastric letrozole (0.05-0.5 mg/kg), exemestane (1-5 mg/kg) or anastrozole (0.02-0.2 mg/kg) and were evaluated by applying von Frey filaments to the periorbital region over the rostral portion of the eye. Some mice were pretreated (subcutaneous in the periorbital area) with receptor, channel, or enzyme inhibitors. PMA was also investigated in mice with selective silencing of Trpa1 and receptor activity modifying protein 1 [Ramp1, the component of calcitonin gene related peptide (CGRP) receptor required for its functioning] in Schwann cells (Plp-Cre+-Trpa1fl/fl and Plp-Cre+-Ramp1fl/fl mice, respectively) or trigeminal neurons (Adv-Cre+- Trpa1fl/fl and Adv- Cre+- Ramp1fl/fl mice, respectively). Results: Letrozole dose-dependently produced PMA that was attenuated by a TRPA1 antagonist (A967079) or a CGRP receptor antagonist (olcegepant), whereas indomethacin was ineffective. Selective silencing of Trpa1 in both Schwann cells and trigeminal neurons reduced letrozole- evoked PMA. Silencing of Ramp1 in Schwann cells, but not in trigeminal neurons, attenuated PMA. Inhibition of the intracellular pathway known to promote PMA by CGRP action in Schwann cells, including adenylyl cyclase (SQ-22536), nitric oxide synthase (L-NG-Nitro arginine methyl ester), and oxidative stress (N-tert-butyl-a-phenylnitrone) inhibitors reduced letrozole-evoked PMA. PMA evoked by exemestane (1, 5, 10 mg/kg i.g.) or anastrozole (0.02, 0.1, 0.2 mg/kg i.g.) Was also markedly reduced in mice with selective silencing of TRPA1 in Schwann cells and nociceptors. Conclusions: Data indicate that letrozole, targeting TRPA1 in peptidergic nerve terminals, releases CGRP that engages its receptor in adjacent Schwann cells to trigger a complex intracellular pathway that results in TRPA1 activation and the ensuing ROS release to sustain PMA. Should these mechanisms be present in patients, their inhibition may ameliorate cephalic mechanical allodynia associated with aromatase inhibitors-induced headaches.

Nociceptive adenosine A2A receptor on trigeminal nerves orchestrates CGRP release to regulate the progression of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) associated pain commonly predicts adverse events among patients. This clinical feature indicates the engagement of nociceptors on sensory neurons during the development of malignancy. However, it is yet to be determined if targeting oncometabolite-associated nociception processes can hinder OSCC progression. In this study, we reported that nociceptive endings infiltrating both clinical samples and mouse tumor xenografts were associated with poorer clinical outcomes and drove tumor progression in vivo, as evidenced by clinical tissue microarray analysis and murine lingual denervation. We observed that the OSCC microenvironment was characteristic of excessive adenosine due to CD73 upregulation which negatively predicted clinical outcomes in the TCGA-HNSC patient cohort. Notably, such adenosine concentrative OSCC niche was associated with the stimulation of adenosine A2A receptor (A2AR) on trigeminal ganglia. Antagonism of trigeminal A2AR with a selective A2AR inhibitor SCH58261 resulted in impeded OSCC growth in vivo. We showed that trigeminal A2AR overstimulation in OSCC xenograft did not entail any changes in the transcription level of CGRP in trigeminal ganglia but significantly triggered the release of CGRP, an effect counteracted by SCH58261. We further demonstrated the pro-tumor effect of CGRP by feeding mice with the clinically approved CGRP receptor antagonist rimegepant which inhibited the activation of ERK and YAP. Finally, we diminished the impact of CGRP on OSCC with istradefylline, a clinically available drug that targets neuronal A2AR. Therefore, we established trigeminal A2AR-mediated CGRP release as a promising druggable circuit in OSCC treatment.

The preclinical discovery and development of atogepant for migraine prophylaxis

ABSTRACT Introduction Atogepant is a selective calcitonin gene-related peptide (CGRP) receptor antagonist that is utilized in adults for the prevention of episodic and chronic migraine. Cumulative findings support the involvement of CGRP in migraine pathophysiology, and atogepant functions by competitively antagonizing CGRP receptors, which results in the inhibition of trigeminovascular nociception. The mechanism of action addresses the cause of migraine pain, providing an effective preventive treatment option. Areas covered The key milestones in its development, including preclinical achievements, phase I, II, and III clinical trials, and regulatory approvals are reviewed. Additionally, clinical efficacy, safety profile, and tolerability of atogepant are discussed. The literature review is based on a comprehensive search of English peer-reviewed articles from various electronic databases, including PubMed and ClinicalTrials.gov. Expert opinion The development of atogepant represents a significant breakthrough in migraine prevention, particularly due to its improved safety profile that reduces the risk of liver injury, which was a major limitation of first-generation gepants. Drug–drug interaction studies with atogepant highlight the necessity for more inclusive study populations. Given that migraine disproportionately affects females, future clinical development programs should include diverse patient demographics to ensure the findings are generalizable to all individuals suffering from migraine.