Calcitonin Gene-related Peptide Receptor Antagonist Research Articles

New perspectives on migraine treatment: a review of the mechanisms and effects of complementary and alternative therapies

Migraine is a prevalent and disabling neurovascular disorder, with women being more susceptible, characterized by unilateral throbbing headache, often accompanied by nausea and vomiting, and often associated with various comorbidities such as brain and cardiovascular diseases, which can have a serious impact on quality of life. Although nonsteroidal anti-inflammatory drugs (NSAIDs) are the main first-line medications for the treatment of pain, long-term use often leads to side effects and drug addiction, which emphasizes the need to investigate alternative pain management strategies with fewer adverse effects. Complementary and alternative medicine is a viable pain intervention often used in conjunction with traditional medications, including acupuncture, herbs, moxibustion, transcutaneous electrical stimulation, bio-supplements, and acupressure, which offer non-pharmacological alternatives that are now viable pain management options. This review focuses on the mechanistic doctrine of migraine generation and the role and potential mechanisms of Complementary and Alternative Therapies (CAT) in the treatment of migraine, summarizes the research evidences for CAT as an adjunct or alternative to conventional therapies for migraine, and focuses on the potential of novel migraine therapies (calcitonin gene-related peptide (CGRP) antagonists and pituitary adenylyl cyclase-activating peptide (PACAP) antagonists) with the aim of evaluating CAT therapies as adjunctive or alternative therapies to conventional migraine treatment, thereby providing a broader perspective on migraine management and the design of treatment programs for more effective pain management.

Anti-CGRP monoclonal antibodies improve cognitive function in patients affected by chronic migraine complicated with medication overuse-headache

Background: Migraine represents one of the most disabling neurological diseases in the world. This burden is primarily due to recurrent pain episodes, alongside cognitive function impairments that patients may experience. This paper aims to explore the effect of three anti-calcitonin Gene-Related Peptide (CGRP) monoclonal antibodies (mAbs) – erenumab, fremanezumab, and galcanezumab – on the cognitive performance of a sample of patients suffering from migraine using the Montreal Cognitive Assessment (MoCA) questionnaire.Methods: A total of 215 patients suffering from migraine who visited the Modena Headache Center were enrolled. The MoCA questionnaire was filled in by the patients at the baseline and subsequent assessments were conducted at 6 and 12 months thereafter. Additionally, patients were requested to complete the 6-item Headache Impact Test, Migraine Disability Assessment Score, and Hospital Anxiety and Depression Scale every three months.Results: The sample was composed of 82% of female participants and 87% of the enrolled patients were diagnosed with chronic migraine. Following one year of treatment, there was a significant enhancement observed in MoCA scores compared to baseline measurements. Moreover, higher consumption of analgesics, elevated body mass index (BMI), and prolonged chronic migraine history exhibited an inverse correlation with MoCA score improvements after 12 months.Conclusions: Erenumab, fremanezumab, and galcanezumab have proven to be effective in relieving the cognitive impairment associated with migraine after 1 year of treatment. These findings underscore the reversibility of cognitive impairment among migraine sufferers, even among those suffering from chronic migraine, as delineated by the majority of the patients under study. This study revealed that prolonged chronic migraine history, higher baseline analgesic intake, and elevated BMI were all predictive of diminished cognitive enhancements following treatment.

Prospective evaluation of aura during anti-calcitonin gene-related peptide monoclonal antibody therapy after 52 weeks of treatment

Background: Clinical studies have shown the efficacy and safety of monoclonal antibodies (mAbs) against calcitonin gene-related peptide (anti- CGRP) in migraine patients with and without aura. Early evidence from post hoc and small subgroup analyses suggests that anti-CGRP mAbs reduce the frequency and intensity of aura. Herein, we prospectively assessed the changes in aura after 12 months of anti-CGRP mAb treatment and performed a literature review.Methods: All outpatients treated with anti-CGRP mAbs for one year in two tertiary Headache Centers and who experienced ≥1 episode of aura/month were enrolled. The study reports data from one month before (baseline) and the last three months (months 10, 11, 12) of treatment.Results: Data from 13 patients with a diagnosis of migraine with and without aura were collected. The mean duration from aura onset was 17.8±7.9 years. At baseline nine patients (69.2%) reported visual aura, and four (30.8%) visual and sensory aura. Mean duration of aura episodes was of 34.2±15.7 minutes. At baseline, the mean number of monthly migraine days (MMDs) was 22.3±7.5, and the mean number of MMDs preceded by aura was 9.15±9.0. At month 12 of treatment, there was a significant reduction of MMDs (6.2±9.0, p=0.002) and MMDs with aura (2.6±2.7, p=0.015). Three patients reported episodes of aura without subsequent headache, a phenomenon that was absent prior to treatment. We identified 14 studies that reported changes in aura during anti-CGRP mAbs treatment.Conclusions: This prospective study shows that anti-CGRP mAbs reduce the number of migraine attacks with aura consistently with the reduction of MMDs. Randomized studies with anti-CGRP mAbs specifically assessing migraine aura are required.

Pharmacokinetics and Safety of Atogepant Co-administered with Quinidine Gluconate in Healthy Participants: A Phase 1, Open-Label, Drug-Drug Interaction Study.

Atogepant, an oral calcitonin gene-related peptide receptor antagonist, is approved for the preventive treatment of migraine. Atogepant is a substrate of P-glycoprotein (P-gp), breast cancer resistance protein, organic anion transporting polypeptide transporters, and cytochrome P450 (CYP)3A4 and 2D6. Quinidine is a strong P-gp and CYP2D6 inhibitor. A phase 1 open-label study evaluated the effect of P-gp and CYP2D6 inhibition by quinidine on the pharmacokinetics of atogepant, and the safety and tolerability of atogepant and quinidine gluconate (QG) when co-administered and when given alone in 33 healthy adults. There was no significant change in the atogepant maximum plasma concentration with QG co-administration. The overall systemic exposure, the area under the plasma concentration-time curve (from time 0 to time t or to infinity), of atogepant increased by 25% when co-administered with QG. However, such an increase was not considered clinically relevant. Atogepant did not alter the mean plasma concentration of quinidine at steady state. The incidence of treatment-emergent adverse events (TEAEs) was highest when QG was administered alone (42.4%), which was primarily due to QT prolongation. Most TEAEs reported were mild in severity and resolved within 1-2 days. Co-administration of atogepant with QG did not result in any unexpected tolerability findings in this phase 1 study in healthy participants. The increase in atogepant exposure during QG co-administration could be due to inhibition of CYP2D6 (a minor contributor to atogepant clearance) as well as inhibition of P-gp.

Nitrergic inhibition of sympathetic arteriolar constrictions in the female rodent urethra.

During the urine storage phase, tonically contracting urethral musculature would have a higher energy consumption than bladder muscle that develops phasic contractions. However, ischaemic dysfunction is less prevalent in the urethra than in the bladder, suggesting that urethral vasculature has intrinsic properties ensuring an adequate blood supply. Diameter changes in rat or mouse urethral arterioles were measured using a video-tracking system. Intercellular Ca2+ dynamics in arteriolar smooth muscle (SMCs) and endothelial cells were visualised using NG2- and parvalbumin-GCaMP6 mice, respectively. Fluorescence immunohistochemistry was used to visualise the perivascular innervation. In rat urethral arterioles, sympathetic vasoconstrictions were predominantly suppressed by α,β-methylene ATP (10μM) but not prazosin (1μM). Tadalafil (100nM), a PDE5 inhibitor, diminished the vasoconstrictions in a manner reversed by N-ω-propyl-l-arginine hydrochloride (l-NPA, 1μM), a neuronal NO synthesis (nNOS) inhibitor. Vesicular acetylcholine transporter immunoreactive perivascular nerve fibres co-expressing nNOS were intertwined with tyrosine hydroxylase immunoreactive sympathetic nerve fibres. In phenylephrine (1μM) pre-constricted rat or mouse urethral arterioles, nerve-evoked vasodilatations or transient SMC Ca2+ reductions were largely diminished by l-nitroarginine (l-NA, 10μM), a broad-spectrum NOS inhibitor, but not by l-NPA. The CGRP receptor antagonist BIBN-4096 (1μM) shortened the vasodilatory responses, while atropine (1μM) abolished the l-NA-resistant transient vasodilatory responses. Nerve-evoked endothelial Ca2+ transients were abolished by atropine plus guanethidine (10μM), indicating its neurotransmitter origin and absence of non-adrenergic non-cholinergic endothelial NO release. In urethral arterioles, NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions pre- and post-synaptically to restrict arteriolar contractility. KEY POINTS: Despite a higher energy consumption of the urethral musculature than the bladder detrusor muscle, ischaemic dysfunction of the urethra is less prevalent than that of the bladder. In the urethral arterioles, sympathetic vasoconstrictions are predominately mediated by ATP, not noradrenaline. NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions by its pre-synaptic inhibition of sympathetic transmission as well as post-synaptic arteriolar smooth muscle relaxation. Acetylcholine released from parasympathetic nerves contributes to endothelium-dependent, transient vasodilatations, while CGRP released from sensory nerves prolongs NO-mediated vasodilatations. PDE5 inhibitors could be beneficial to maintain and/or improve urethral blood supply and in turn the volume and contractility of urethral musculature.

Update on Cluster Headaches: From Genetic to Novel Therapeutic Approaches

Cluster headaches affect 0.1% of the population and are four times more common in males than in females. Patients with this condition present with severe unilateral head pain localized in the frontotemporal lobe, accompanied by ipsilateral lacrimation, conjunctival injection, nasal congestion, diaphoresis, miosis, and eyelid edema. Recently, the first genome-wide association study of cluster headaches was conducted with the goal of aggregating data for meta-analyses, identifying genetic risk variants, and gaining biological insights. Although little is known about the pathophysiology of cluster headaches, the trigeminovascular and trigeminal autonomic reflexes and hypothalamic pathways are involved. Among anti-calcitonin gene-related peptide monoclonal antibodies, galcanezumab has been reported to be effective in preventing episodic cluster headaches.

Nonspecific oral medications versus anti-calcitonin gene-related peptide monoclonal antibodies for migraine: Asystematic review and meta-analysis of randomized controlled trials.

To compare calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) versus nonspecific oral migraine preventives (NOEPs). Insurers mandate step therapy with NOEPs before approving CGRP mAbs. Databases were searched for class I or II randomized controlled trials (RCTs) comparing CGRP mAbs or NOEPs versus placebo for migraine prevention in adults. The primary outcome measure was monthly migraine days (MMD) or moderate to severe headache days. Twelve RCTs for CGRP mAbs, 5 RCTs for topiramate, and 3 RCTs for divalproex were included in the meta-analysis. There was high certainty that CGRP mAbs are more effective than placebo, with weighted mean difference (WMD; 95% confidence interval) of -1.64 (-1.99 to -1.28) MMD, which is compatible with small effect size (Cohen's d -0.25 [-0.34 to -0.16]). Certainty of evidence that topiramate or divalproex is more effective than placebo was very low and low, respectively (WMD -1.45 [-1.52 to -1.38] and -1.65 [-2.30 to -1.00], respectively; Cohen's d -1.25 [-2.47 to -0.03] and -0.48 [-0.67 to -0.29], respectively). Trial sequential analysis showed that information size was adequate and that CGRP mAbs had clear benefit versus placebo. Network meta-analysis showed no statistically significant difference between CGRP mAbs and topiramate (WMD -0.19 [-0.56 to 0.17]) or divalproex (0.01 [-0.73 to 0.75]). No significant difference was seen between topiramate or divalproex (0.21 [-0.45 to 0.86]). There is high certainty that CGRP mAbs are more effective than placebo, but the effect size is small. When feasible, CGRP mAbs may be prescribed as first-line preventives; topiramate or divalproex could be as effective but are less well tolerated. The findings of this study support the recently published 2024 position of the American Headache Society on the use of CGRP mAbs as the first-line treatment.

Rimegepant orally disintegrating tablet 75 mg for acute treatment of migraine in adults from China: a subgroup analysis of a double-blind, randomized, placebo-controlled, phase 3 clinical trial

Background Rimegepant orally disintegrating tablet (ODT), an oral small-molecule calcitonin gene-related peptide receptor antagonist, is indicated for acute and preventive treatment of migraine in the United States and other countries. Previously, a large clinical trial assessed the efficacy and safety of rimegepant ODT 75 mg for the acute treatment of migraine in adults living in China or South Korea. A post hoc subgroup analysis of this trial was performed to evaluate the efficacy and safety of rimegepant for acute treatment of migraine in adults living in China.Methods Eligible participants were ≥ 18 years of age and had a ≥ 1-year history of migraine, with 2 to 8 attacks of moderate or severe pain intensity per month and < 15 headache days per month during the 3 months before screening. Participants self-administered rimegepant ODT 75 mg or matching placebo to treat a single migraine attack of moderate or severe pain intensity. The co-primary endpoints were pain freedom and freedom from the most bothersome symptom (MBS) at 2 h post-dose. Key secondary endpoints included pain relief at 2 h post-dose, ability to function normally at 2 h post-dose, use of rescue medication within 24 h post-dose, and sustained pain freedom from 2 to 24 h and 2 to 48 h post-dose. All p values were nominal. Safety was assessed via treatment-emergent adverse events (TEAEs), electrocardiograms, vital signs, and routine laboratory tests.ResultsOverall, 1075 participants (rimegepant, n = 538; placebo, n = 537) were included in the subgroup analysis. Rimegepant was more effective than placebo for the co-primary endpoints of pain freedom (18.2% vs. 10.6%, p = 0.0004) and freedom from the MBS (48.0% vs. 31.8%, p < 0.0001), as well as all key secondary endpoints. The incidence of TEAEs was comparable between the rimegepant (15.2%) and placebo (16.4%) groups. No signal of drug-induced liver injury was observed, and no study drug-related serious TEAEs were reported in the rimegepant group.ConclusionsA single dose of rimegepant 75 mg rimegepant was effective for the acute treatment of migraine in adults living in China, with safety and tolerability similar to placebo.Trial registration Clinicaltrials.gov NCT04574362 Date registered: 2020-10-05.Graphical

Analysis of Calcitonin Gene-Related Peptide Receptor Monoclonal Antibody and Antagonist Usage and Medication Switch Profile from a Tertiary Care Facility (P5-12.009)

Analysis of Calcitonin Gene-Related Peptide Receptor Monoclonal Antibody and Antagonist Usage and Medication Switch Profile from a Tertiary Care Facility (P5-12.009)

Cost-effectiveness of rimegepant oral lyophilisate compared to best supportive care for the acute treatment of migraine in the UK

Aims Migraine is the most common disabling headache disorder and is characterized by recurrent throbbing head pain and symptoms of photophobia, phonophobia, nausea, and vomiting. Rimegepant 75 mg, an oral lyophilisate calcitonin gene-related peptide antagonist, is the first treatment approved for both the acute and preventative treatment of migraine, and the first acute therapy approved in over 20-years. The objective was to assess the cost-utility of rimegepant compared with best supportive care (BSC) in the UK, for the acute treatment of migraine in the adults with inadequate symptom relief after taking at least 2 triptans, or for whom triptans are contraindicated or not tolerated. Materials and methods A de novo model was developed to estimate incremental costs and quality-adjusted life years (QALYs), structured as a decision tree followed by Markov model. Patients received rimegepant or BSC for a migraine attack and were assessed for response (pain relief at 2-h). Responders and non-responders followed different pain trajectories over 48-h cycles. Non-responders discontinued treatment while responders continued treatment for subsequent attacks, with a proportion discontinuing over time. Data sources included a post-hoc pooled analysis of the phase 3 acute rimegepant trials (NCT03235479, NCT03237845, NCT03461757), and a long-term safety study (NCT03266588). The analysis was conducted from the perspective of the UK National Health Service and Personal Social Services over a 20-year time horizon. Results Rimegepant resulted in an incremental cost-utility ratio (ICUR) of £10,309 per QALY gained vs BSC, which is cost-effectiveness at a willingness to pay threshold of £30,000/QALY. Rimegepant generated +0.44 incremental QALYs and higher incremental lifetime costs (£4,492). Improved QALYs for rimegepant were a result of less time spent with severe and moderate headache pain. Conclusion This study highlights the economic value of rimegepant which was found to be cost-effective for the acute treatment of migraine in adults unsuitable for triptans.

Synergism of Anti-CGRP Monoclonal Antibodies and OnabotulinumtoxinA in the Treatment of Chronic Migraine: A Real-World Retrospective Chart Review.

Many patients with chronic migraine do not achieve clinically meaningful improvement in their headache frequency with monotherapy. The burden associated with chronic migraine calls for a multifaceted treatment approach targeting multiple aspects of migraine pathophysiology. The aim of this study was to evaluate the effect of concurrent anti-calcitonin gene-related peptide (CGRP) monoclonal antibody (mAb) and onabotulinumtoxinA (onabot) treatment on median monthly migraine days (MMD) in patients with chronic migraine, through a retrospective study. The electronic medical records of Cleveland Clinic patients either concurrently (dual therapy) or consecutively (monotherapy) treated with anti-CGRP mAbs and onabot between June 2018 and November 2021 were extracted. Only adult patients (≥ 18years of age) were included in this study. MMDs for 194 concurrently treated (86.6% female and a median [interquartile range] age of 51 [41-61] years) and 229 consecutively treated (88.2% female and median age of 47 [IQR 39-57] years) patients were examined at baseline, after first therapy of either anti-CGRP mAb or onabot, and following dual therapy for 3 consecutive months. The reduction of MMDs for each treatment group were compared. The same approach was utilized to compare consecutive monotherapy at separate times (n = 229) and dual-therapy groups. The initial treatment of the dual-therapy group reduced the median (IQR) MMDs from 30 (30-30) to 15 (12-30) [p < 0.0001]. After initiation of dual therapy, the median MMDs was further decreased from 15 (12-30) to 8 (3-22) [p < 0.0001]. A majority [132/194 (68.0%)] of the dual-therapy patients reported a ≥ 50% reduction in MMD and 90/194 (46.4%) reported a ≥ 75% reduction. For the consecutive monotherapy group, median MMDs changed from a baseline of 30 (25-30) to 15 (8-25) from onabot monotherapy and decreased from 25 (15-30) to 12 (4-25) after anti-CGRP mAb monotherapy. Almost half (113/229 [49.3%] from onabot, and 104/229 [45.4%] from anti-CGRP mAb) of these patients achieved a ≥ 50% reduction in MMDs and a minority (38/229 [16.6%] from onabot, and 45/229 [19.7%] from anti-CGRP mAb) achieved a reduction of ≥ 75%. Additionally, dual therapy showed significant improvement in MMDs compared with monotherapy of either treatment (p < 0.0001). Dual therapy of anti-CGRP mAbs and onabot may be more efficacious than monotherapy, possibly due to their synergistic mechanisms of action.

A multicenter, open-label long-term safety study of rimegepant for the acute treatment of migraine.

The present study evaluated the long-term safety and tolerability of rimegepant, an orally administered small molecule calcitonin gene-related peptide receptor antagonist, in people with migraine. This multicenter, long-term, open-label safety study included adults (≥18 years) with ≥1 year history of migraine who were sequentially enrolled into three groups: participants in the first two groups had either 2-8 or 9-14 moderate to severe migraine attacks per month by history and treated as needed (pro re nata [PRN]) with one rimegepant 75 mg oral tablet up to once per calendar day for 52 weeks (PRN 2-8 and PRN 9-14); a third group, included to collect safety data during higher-frequency dosing, had 4-14 moderate to severe migraine attacks per month by history and who took one rimegepant tablet every other day as scheduled dosing plus PRN dosing of one rimegepant tablet for migraine attacks of any severity on nonscheduled dosing days for 12 weeks (every other day (EOD) + PRN). Overall, 1800 participants self-administered rimegepant (PRN 2-8: n = 1033; PRN 9-14: n = 481; EOD + PRN: n = 286). The most common on-treatment adverse events (AEs) were upper respiratory tract infection (8.8%), nasopharyngitis (6.8%) and sinusitis (5.1%). Most AEs were mild or moderate and considered unrelated to rimegepant. Serious AEs considered possibly (n = 1) or unlikely (n = 9) related to rimegepant were reported in ten (0.6%) participants. No signal of drug-induced liver injury because of rimegepant was identified. Rimegepant 75 mg up to once per day as EOD + PRN for 12 weeks or PRN for up to 52 weeks was safe and well tolerated. No signal of hepatotoxicity, potential drug abuse, or medication-overuse headache was identified.Trial registration: Clinicaltrials.gov: NCT03266588.

Medication "underuse" headache.

Many risk factors have been associated with migraine progression, including insufficient and ineffective utilization of migraine medications; however, they have been inadequately explored. This has resulted in suboptimal usage of medications without effective altering of prescribing recommendations for patients, posing a risk for migraine chronification. Our aim is to conduct a comprehensive review of the available evidence regarding the underuse of migraine medications, both acute and preventive. The term "underuse" includes, but is not limited to: (1) ineffective use of appropriate and inappropriate medication; (2) underutilization; (3) inappropriate timing of usage; and (4) patient dissatisfaction with medication. The underuse of both acute and preventive medications has been shown to contribute to the progression of migraine. In terms of acute medication, chronification occurs as a result of insufficient drug use, including failure of the prescriber to select the appropriate type based on pain intensity and disability, patients taking medication too late (more than 60 minutes after the onset or after central sensitization has occurred as evidenced by allodynia), and discontinuation because of lack of effect or intolerable side effects. The underlying cause of inadequate effectiveness of acute medication lies in its inability to halt the propagation of peripheral activation to central sensitization in a timely manner. For oral and injectable preventive migraine medications, insufficient efficacy and intolerable side effects have led to poor adherence and discontinuation with subsequent progression of migraine. The underlying pathophysiology here is rooted in the repetitive stimulation of afferent sensory pain fibers, followed by ascending brainstem pain pathways plus dysfunction of the endogenous descending brainstem pain inhibitory pathway. Although anti-calcitonin gene-related peptide (CGRP) medications partially address pain caused by the above factors, including decreased efficacy and tolerability from conventional therapy, some patients do not respond well to this treatment. Research suggests that initiating preventive anti-CGRP treatment at an early stage (during low frequency episodic migraine attacks) is more beneficial than commencing it during high frequency episodic attacks or when chronic migraine has begun. The term "medication underuse" is underrecognized, but it holds significant importance. Optimal usage of acute care and preventive migraine medications could potentially prevent migraine chronification and improve the treatment of migraine attacks.

Preventive Treatment of Migraine.

This article describes strategies for the preventive treatment of migraine including the emerging role of calcitonin gene-related peptide (CGRP)-targeted therapies and introduces novel paradigms for the preventive treatment of migraine. Multiple migraine medications targeting CGRP have been introduced since 2018, including injectable monoclonal antibodies (ie, eptinezumab, erenumab, fremanezumab, and galcanezumab) and oral small-molecule CGRP receptor antagonists (ie, ubrogepant, rimegepant, atogepant, and zavegepant). With the exceptions of ubrogepant and zavegepant, which are approved only as acute treatments, all of these agents have demonstrated efficacy in the preventive treatment of migraine; the monoclonal antibodies and atogepant have evidence of effectiveness in adults with either episodic or chronic migraine. The safety and tolerability profiles of CGRP-targeted therapies in migraine are favorable. The goals of preventive migraine therapy include reducing the frequency, severity, duration, and disability associated with attacks, reducing the need for acute treatment and the risk of medication overuse, enhancing self-efficacy and health-related quality of life, and reducing headache-related distress and interictal burden. Six drugs targeting CGRP (four monoclonal antibodies and two gepants) are now available for the preventive treatment of episodic migraine in adults. The efficacy of CGRP-targeted medications in the acute and preventive treatment of migraine, together with good safety and tolerability, has led to the emergence of new approaches to preventive treatment.

CGRP Released by Corneal Sensory Nerve Maintains Tear Secretion of the Lacrimal Gland.

This study aims to elucidate the calcitonin gene-related peptide (CGRP) mediation and primary mechanism of corneal sensory nerves on tear production of the lacrimal gland. Mouse corneal denervation models were constructed through surgical axotomy, pharmacologic treatment with capsaicin or resiniferatoxin, and Trpv1-Cre/DTR mice with diphtheria toxin injection. The capsaicin-treated mice received subconjunctival injection of CGRP or substance P, while the normal C57BL/6J mice were administered with CGRP receptor antagonist BIBN-4096. Furthermore, double immunostaining of c-FOS+ and choline acetyltransferase was used to evaluate the activation of the superior salivatory nucleus (SSN). Mouse lacrimal glands were collected for transcriptomic sequencing and subsequent RNA and protein expression analysis. The corneal denervated mice exhibited a significant reduction in corneal sensitivity and tear secretion. In capsaicin-treated mice, tear secretion decreased to 2.5 ± 0.5mm compared to 6.3 ± 0.9mm in control mice (P < 0.0001). However, exogenous administration of CGRP in capsaicin-treated mice increased tear secretion from 2.6 ± 0.5mm to 4.5 ± 0.5mm (P = 0.0009), while BIBN-4096 treatment reduced tear secretion to 3.4 ± 0.5mm when compared to 7.3 ± 0.7mm in control mice (P = 0.0022). Furthermore, c-FOS+ cell number in the SSN increased by twofold (P = 0.0168) after CGRP administration compared with capsaicin-treated mice. In addition, the expressions of CCNA2, Ki67, PCNA, and CDK1 in acinar cells of the lacrimal gland were impaired by corneal denervation and alleviated by CGRP administration. CGRP released by corneal sensory nerves mediates tear secretion of the lacrimal gland, providing a new strategy for improving tear secretion in patients with neurotrophic keratitis.

Anti-CGRP-based Migraine Medications: A Comprehensive Overview

In the early 1990s, the neuropeptide calcitonin gene-related peptide (CGRP) was identified as a key messenger in the pathophysiology of migraine and emerged as a treatment target, fundamentally transforming our approach to migraine therapy. While previous prophylactic drugs were non-specific and often caused intolerable side effects, the discovery of CGRP marked the advent of a new era in migraine treatment. The two main classes of CGRP-specific migraine treatments are monoclonal antibodies that bind to CGRP or the CGRP receptor, and CGRP receptor antagonists, the so-called gepants. Extensive clinical trials have conclusively demonstrated the safety, tolerability, and efficacy of monoclonal CGRP(-receptor) antibodies in the prophylactic treatment of both episodic and chronic migraine. The same positive results apply to the use of various gepants. They have proven to be not only an effective alternative to triptans in acute migraine therapy but also promising options for continuous use as prophylactic treatments. In this review, we aim to present the current state of research on CGRP-specific migraine therapy and insights in real-world data from the first years after their launch in clinical practice.

Evaluation of the effect of Exercise Trainings and CGRP receptor antagonist (BIBN 4096) on mitochondrial dynamic in the hippocampus of male Wistar rats

BackgroundExercise training showed beneficial effects on brain. The purpose of the present study is to evaluate the effect of six weeks of high-intensity interval training (HIIT) and Endurance training (ET) with calcitonin gene-related peptide (CGRP) receptor antagonist on the expression of genes involved in mitochondrial dynamics and apoptosis in hippocampal tissue of male Wistar rats. MethodsIn this study, forty-two healthymale Wistar rats (8-week) were randomly divided into 6 groups (n = 7) as follow; 1) Control; 2) HIIT which performed 6 weeks of HIIT; 3) ET which performed 6 weeks of endurance training; 4) CGRPi received 10 mg/kg CGRP receptor antagonist every day at the last 2 weeks; 5) CGRPi-HIIT performed HIIT and received CGRP receptor antagonist; 6) CGRPi-ET performed ET and received CGRP receptor antagonist. Real-time PCR (2-ΔΔCT) and western blotting were employedto measure the expression of genes and protein, respectively. ResultsHIIT and ET significantly increased Bcl-2, Pgc-1α, Sirt3, and Nrf-1 gene expression in the hippocampal tissue (p < 0.05, p < 0.01, p < 0.01, and p < 0.001, respectively). ET-CGRPi and HIIT-CGRPi significantly increased Sirt3, Pgc-1α, and Nrf-1 gene expression compared to the control group (p < 0.05, p < 0.01, and p < 0.05, respectively). ConclusionET and HIIT-induced physiological alterations in the hippocampus. In fact, this modulation showed protective properties in the hippocampusvia up regulation of Bcl-2, Pgc-1α, Nrf-1, and Sirt3 gene expression. CGRPi did not cause gene or protein changes harmful to mitochondrial dynamic balance and apoptosis in the hippocampus of rats.

LC-HRMS and NMR studies for the characterization of degradation impurities of ubrogepant along with the in silico approaches for the prediction of degradation and toxicity

Ubrogepant is the first oral calcitonin gene-related peptide (CGRP) receptor antagonist which is used for the acute treatment of migraine in adults. The present study employs liquid chromatography-high resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance spectroscopy (NMR) techniques for the identification and characterization of degradation impurities of ubrogepant. The forced degradation study of ubrogepant was performed as per the International Council for Harmonisation (ICH) Q1A and Q1B guidelines. The in silico degradation profile of ubrogepant was predicted by Zeneth. It was observed that ubrogepant was labile to acidic hydrolysis, basic hydrolysis, and oxidative degradation conditions (H2O2), although it was stable in neutral hydrolysis and photolytic (UV light and visible light) conditions. Eight degradation impurities were formed, which were separated on reversed-phase HPLC with a gradient program on an InertSustain C8 column (4.6 × 250 mm, 5 µm) using 10 mM ammonium formate (pH unadjusted) and acetonitrile as the mobile phase. The structures of all the degradation impurities were characterized using the exact masses obtained from the HRMS/MS. Further, NMR studies were conducted on two major degradation impurities (UB-4 and UB-7). A plausible mechanism was proposed to support the structures of all the degradation impurities of UBR. In silico toxicity and mutagenicity assessment were done by DEREK Nexus, SARAH Nexus, and ProTox-II.

Safety and tolerability of atogepant for the preventive treatment of migraine: a post hoc analysis of pooled data from four clinical trials

BackgroundConventional, non-specific preventive migraine treatments often demonstrate low rates of treatment persistence due to poor efficacy or tolerability. Effective, well-tolerated preventive treatments are needed to reduce migraine symptoms, improve function, and enhance quality of life. Atogepant is a migraine-specific oral calcitonin gene–related peptide receptor antagonist that is indicated for the preventive treatment of migraine in adults. This analysis evaluated the safety and tolerability profile of atogepant for the preventive treatment of migraine, including adverse events (AEs) of interest, such as constipation, nausea, hepatic safety, weight changes, and cardiac disorders.MethodsThis post hoc analysis was performed using data pooled from 2 (12-week) randomized, double-blind, placebo-controlled trials (RCTs) and 2 (40- and 52-week) open-label long-term safety (LTS) trials of oral atogepant for episodic migraine (EM).ResultsThe safety population included 1550 participants from the pooled RCTs (atogepant, n = 1142; placebo, n = 408) and 1424 participants from the pooled LTS trials (atogepant, n = 1228; standard care [SC], n = 196). In total, 643/1142 (56.3%) atogepant participants and 218/408 (53.4%) placebo participants experienced ≥ 1 treatment-emergent AEs (TEAEs) in the RCTs. In the LTS trials, 792/1228 (64.5%) of atogepant participants and 154/196 (78.6%) of SC participants experienced ≥ 1 TEAEs. The most commonly reported TEAEs (≥ 5%) in participants who received atogepant once daily were upper respiratory tract infection (5.3% in RCTs, 7.7% in LTS trials), constipation (6.1% in RCTs, 5.0% in LTS trials), nausea (6.6% in RCTs, 4.6% in LTS trials), and urinary tract infection (3.4% in RCTs, 5.2% in LTS trials). Additionally, weight loss appeared to be dose- and duration-dependent. Most TEAEs were considered unrelated to study drug and few led to discontinuation.ConclusionsOverall, atogepant is safe and well tolerated in pooled RCTs and LTS trials for the preventive treatment of EM in adults.Trial registrationClinicalTrials.gov identifiers: NCT02848326 (MD-01), NCT03777059 (ADVANCE), NCT03700320 (study 302), NCT03939312 (study 309).Graphical

Modification of Mesenchymal Stem/Stromal Cell-Derived Small Extracellular Vesicles by Calcitonin Gene Related Peptide (CGRP) Antagonist: Potential Implications for Inflammation and Pain Reversal.

During the progression of knee osteoarthritis (OA), the synovium and infrapatellar fat pad (IFP) can serve as source for Substance P (SP) and calcitonin gene-related peptide (CGRP), two important pain-transmitting, immune, and inflammation modulating neuropeptides. Our previous studies showed that infrapatellar fat pad-derived mesenchymal stem/stromal cells (MSC) acquire a potent immunomodulatory phenotype and actively degrade Substance P via CD10 both in vitro and in vivo. On this basis, our hypothesis is that CD10-bound IFP-MSC sEVs can be engineered to target CGRP while retaining their anti-inflammatory phenotype. Herein, human IFP-MSC cultures were transduced with an adeno-associated virus (AAV) vector carrying a GFP-labelled gene for a CGRP antagonist peptide (aCGRP). The GFP positive aCGRP IFP-MSC were isolated and their sEVs' miRNA and protein cargos were assessed using multiplex methods. Our results showed that purified aCGRP IFP-MSC cultures yielded sEVs with cargo of 147 distinct MSC-related miRNAs. Reactome analysis of miRNAs detected in these sEVs revealed strong involvement in the regulation of target genes involved in pathways that control pain, inflammation and cartilage homeostasis. Protein array of the sEVs cargo demonstrated high presence of key immunomodulatory and reparative proteins. Stimulated macrophages exposed to aCGRP IFP-MSC sEVs demonstrated a switch towards an alternate M2 status. Also, stimulated cortical neurons exposed to aCGRP IFP-MSC sEVs modulate their molecular pain signaling profile. Collectively, our data suggest that yielded sEVs can putatively target CGRP in vivo, while containing potent anti-inflammatory and analgesic cargo, suggesting the promise for novel sEVs-based therapeutic approaches to diseases such as OA.