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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 rigorous than modern day treatment studies, of small sample size, and have not since been 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. [ABSTRACT FROM AUTHOR]

Background: One of the aims of migraine prevention is to improve response to acute migraine treatments. The aim of the present study was to assess whether monoclonal antibodies targeting the CGRP pathway (CGRP-mAbs) can improve the perceived efficacy of acute treatments. Methods: We included and followed up patients with chronic or episodic migraine from the Headache Centers of Avezzano-L'Aquila and Naples treated with CGRP-mAbs from March 2021 to December 2022. All patients filled out the Migraine Treatment Optimization Questionnaire (MTOQ), the Headache Impact Test (HIT-6), and the Migraine Impact and Disability Assessment Scale (MIDAS) at baseline and 3–6 months after the start of treatment with CGRP-mAbs. Results: Sixty-five patients (81.3%) completed the 6-month follow-up. Most patients were female (55, 84.6%), with a median age of 46 years (IQR 39–56). Median MTOQ score increased from 8 (interquartile range [IQR] 4–13) at baseline to 15 (IQR 11–17) at 3 months (p < 0.001) and 16 (IQR 13–17) at the 6-month follow-up (p < 0.001). Median migraine days over 90-day periods decreased from 40 (IQR 24–60) to 24 (IQR 15–30) at 3 months (p < 0.001) and to 20 (IQR 12–24) at 6 months (p < 0.001). Median monthly intake of acute medication decreased from 55 doses (IQR 29–80.5) to 24 doses (IQR 15–40) at 3 months and 18 doses (IQR 11–30) at 6 months (p < 0.001). Conclusions: We showed that 6 months of preventive treatment with CGRP-mAbs led to a significantly better effectiveness of acute treatments, paralleled by decreased monthly migraine days and acute treatment intake. [ABSTRACT FROM AUTHOR]

Cluster headache, characterised by attacks of severe, recurrent, unilateral headache and ipsilateral cranial autonomic symptoms, remains a primary headache with an elusive pathophysiology. Recent advances have introduced effective treatments and broadened understanding of the clinical features of cluster headache. These features are similar in patients globally, but regional differences in prevalence and burden exist. International collaborations have led to identification of eight genetic loci associated with cluster headache. The pathophysiological mechanisms are still not fully understood but recent studies show that targeting the trigeminal autonomic reflex by neurostimulation, or targeting the neuropeptide calcitonin gene-related peptide (CGRP), might lessen the attack burden. The US Food and Drug Administration has approved galcanezumab, a monoclonal antibody targeting CGRP, as the first specific preventive treatment for episodic cluster headache. However, a preventive effect was not replicated in chronic cluster headache, and the European Medicines Agency did not approve galcanezumab, restricting its availability in Europe. Owing to the low prevalence of cluster headache, continued collaboration through multicentre clinical trials and data sharing will be imperative for further breakthroughs in understanding and management. [ABSTRACT FROM AUTHOR]

Active artificial bone substitutes are crucial in bone repair and reconstruction. Calcium phosphate bone cement (CPC) is known for its biocompatibility, degradability, and ability to fill various shaped bone defects. However, its low osteoinductive capacity limits bone regeneration applications. Effectively integrating osteoinductive magnesium ions with CPC remains a challenge. Herein, we developed magnesium malate-modified CPC (MCPC). Incorporating 5% magnesium malate significantly enhances the compressive strength of CPC to (6.18 ± 0.49) MPa, reduces setting time and improves disintegration resistance. In vitro, MCPC steadily releases magnesium ions, promoting the proliferation of MC3T3-E1 cells without causing significant apoptosis, proving its biocompatibility. Molecularly, magnesium malate prompts macrophages to release prostaglandin E2 (PGE2) and synergistically stimulates dorsal root ganglion (DRG) neurons to synthesize and release calcitonin gene-related peptide (CGRP). The CGRP released by DRG neurons enhances the expression of the key osteogenic transcription factor Runt-related transcription factor-2 (RUNX2) in MC3T3-E1 cells, promoting osteogenesis. In vivo experiments using minipig vertebral bone defect model showed MCPC significantly increases the bone volume fraction, bone density, new bone formation, and proportion of mature bone in the defect area compared to CPC. Additionally, MCPC group exhibited significantly higher levels of osteogenesis and angiogenesis markers compared to CPC group, with no inflammation or necrosis observed in the hearts, livers, or kidneys, indicating its good biocompatibility. In conclusion, MCPC participates in the repair of bone defects in the complex post-fracture microenvironment through interactions among macrophages, DRG neurons, and osteoblasts. This demonstrates its significant potential for clinical application in bone defect repair. [ABSTRACT FROM AUTHOR]

Background: Chronic migraine (CM) is the most severe and burdensome subtype of migraine. Fremanezumab is a monoclonal antibody that targets the calcitonin gene-related peptide pathway as a migraine preventive therapy. This study aimed to conduct a cost-effectiveness analysis of fremanezumab from a societal perspective in the Netherlands, using a Markov cohort simulation model. Methods: The base-case cost-effectiveness analysis adhered to the Netherlands Authority guidelines. Fremanezumab was compared with best supportive care (BSC; acute migraine treatment only) in patients with CM and an inadequate response to topiramate or valproate and onabotulinumtoxinA (Dutch patient group [DPG]). A supportive analysis was conducted in the broader group of CM patients with prior inadequate response to 2–4 different classes of migraine preventive treatments. One-way sensitivity, probabilistic sensitivity, and scenario analyses were conducted. Results: Over a lifetime horizon, fremanezumab is cost saving compared with BSC in the DPG (saving of €2514 per patient) and led to an increase of 1.45 quality-adjusted life-years (QALYs). In the broader supportive analysis, fremanezumab was cost effective compared with BSC, with an incremental cost-effectiveness ratio of €2547/QALY gained. Fremanezumab remained cost effective in all sensitivity and scenario analyses. Conclusion: In comparison to BSC, fremanezumab is cost saving in the DPG and cost effective in the broader population. [ABSTRACT FROM AUTHOR]

Objective Background Methods Results Conclusion 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. [ABSTRACT FROM AUTHOR]

Objective Background Methods Results Conclusion To analyze the specificity of calcitonin gene–related peptide (CGRP) levels, we measured alpha‐CGRP circulating levels in a large series of patients with a recent diagnosis of inflammatory bowel disease (IBD) who were interviewed regarding comorbid headache.Several studies have found an association between migraine and IBD.In this cross‐sectional study performed in an IBD clinic, morning serum alpha‐CGRP levels were measured by enzyme‐linked immunosorbent assay in 96 patients who were recently diagnosed with IBD and compared to those from 50 similar patients with chronic migraine (CM) and 50 healthy controls (HC).Alpha‐CGRP levels were higher in patients with IBD (median [interquartile range] 56.9 [35.6–73.9] pg/mL) and patients with CM (53.0 [36.7–73.9] pg/mL) compared to HC (37.2 [30.0–51.8] pg/mL; p = 0.003; p = 0.019, respectively). Regarding IBD diagnostic subtypes, alpha‐CGRP levels for ulcerative colitis (67.2 ± 49.3 pg/mL; 57.0 [35.6–73.4] pg/mL) and Crohn's disease (54.9 ± 27.5 pg/mL; 57.7 [29.1–76.1] pg/mL) were significantly higher than those of HC (p = 0.013, p = 0.040, respectively). Alpha‐CGRP levels were further different in patients with IBD with migraine (70.9 [51.8–88.7] pg/mL) compared to HC (p < 0.001), patients with IBD without headache (57.5 [33.3–73.8] pg/mL; p = 0.049), and patients with IBD with tension‐type headache but without migraine (41.7 [28.5–66.9] pg/mL; p = 0.004), though alpha‐CGRP levels in patients with IBD without migraine (53.7 [32.9–73.5] pg/mL) remained different over HC (p = 0.028).Together with CM, circulating alpha‐CGRP levels are different in patients with IBD, perhaps reflecting a chronic inflammatory state. IBD is an example of how alpha‐CGRP levels are not a totally specific migraine biomarker. However, alpha‐CGRP levels were further increased in patients with IBD who have a history of migraine, which reinforces its role as a biomarker in migraine patients, always bearing in mind their comorbidities. [ABSTRACT FROM AUTHOR]

Stimulation of the calcium‐sensing receptor (CaSR) regulates vascular contractility, but cellular mechanisms involved remain unclear. This study investigated the role of perivascular sensory nerves in CaSR‐induced relaxations of male rat mesenteric arteries. In fluorescence studies, colocalisation between synaptophysin, a synaptic vesicle marker, and the CaSR was present in the adventitial layer of arterial segments. Using wire myography, increasing external Ca2+ concentration ([Ca2+]o) from 1 to 10 mM induced vasorelaxations, previously shown to involve the CaSR, which were inhibited by pretreatment with capsaicin. [Ca2+]o‐induced vasorelaxations were partially reduced by the calcitonin gene‐related peptide (CGRP) receptor blockers, CGRP 8–37 and BIBN 4096, and the neurokinin 1 (NK1) receptor blocker L733,060. The inhibitory effect of CGRP 8–37 required a functional endothelium whereas the inhibitory action of L733,060 did not. Complete inhibition of [Ca2+]o‐induced vasorelaxations occurred when CGRP 8–37 and L733,060 were applied together. [Ca2+]o‐induced vasorelaxations in the presence of capsaicin were abolished by the ATP‐dependent K+ channel (KATP) blocker PNU 37883, but unaffected by the endothelium nitric oxide synthase (eNOS) inhibitor L‐NAME. We suggest that the CaSR on perivascular sensory nerves mediate relaxations in rat mesenteric arteries via endothelium‐dependent and ‐independent mechanisms involving CGRP and NK1 receptor‐activated NO production and KATP channels, respectively. [ABSTRACT FROM AUTHOR]

Background and Purpose: Multiple drugs targeting the calcitonin gene‐related peptide (CGRP) receptor have been developed for migraine treatment. Here, the effect of the monoclonal antibody erenumab on CGRP‐induced vasorelaxation was investigated in human isolated blood vessels, as well as the effect of combining erenumab with the small molecule drugs, namely rimegepant, olcegepant, or sumatriptan. Experimental Approach: Concentration–response curves to CGRP, adrenomedullin or pramlintide were constructed in human coronary artery (HCA) and human middle meningeal artery (HMMA) segments, incubated with or without erenumab and/or olcegepant. pA2 or pKb values were calculated to determine the potency of erenumab in both tissues. To study whether acutely acting antimigraine drugs exerted additional CGRP‐blocking effects on top of erenumab, HCA segments were incubated with a maximally effective concentration of erenumab (3 μM), precontracted with KCl and exposed to CGRP, followed by rimegepant, olcegepant, or sumatriptan in increasing concentrations. Key Results: Erenumab shifted the concentration‐response curve to CGRP in both vascular tissues. However, in HCA, the Schild plot slope was significantly smaller than unity, whereas this was not the case in HMMA, indicating different CGRP receptor mechanisms in these tissues. In HCA, rimegepant, olcegepant and sumatriptan exerted additional effects on CGRP on top of a maximal effect of erenumab. Conclusions and Implications: Gepants have additional effects on top of erenumab for CGRP‐induced relaxation and could be effective in treating migraine attacks in patients already using erenumab as prophylaxis. [ABSTRACT FROM AUTHOR]

Punishment such as electric shock or physical discipline employs a mixture of physical pain and emotional distress to induce behavior modification. However, a neural circuit that produces behavior modification by selectively focusing the emotional component, while bypassing the pain typically induced by peripheral nociceptor activation, is not well studied. Here, we show that genetically silencing the activity of neurons expressing calcitonin gene-related peptide (CGRP) in the parabrachial nucleus blocks the suppression of addictive-like behavior induced by footshock. Furthermore, activating CGRP neurons suppresses not only addictive behavior induced by self-stimulating dopamine neurons but also behavior resulting from self-administering cocaine, without eliciting nocifensive reactions. Moreover, among multiple downstream targets of CGRP neurons, terminal activation of CGRP in the central amygdala is effective, mimicking the results of cell body stimulation. Our results indicate that unlike conventional electric footshock, stimulation of CGRP neurons does not activate peripheral nociceptors but effectively curb addictive behavior. [ABSTRACT FROM AUTHOR]

Aging impacts the vestibular system and contributes to imbalance. In fact, imbalance precedes changes in cognition in the elderly. However, research is limited in assessing aging mouse models that are deficient in crucial neuromodulators like Calcitonin Gene-Related Peptide (CGRP). We studied the loss of CGRP and its effects in the aging mouse, namely its effect on both static and dynamic imbalances. Postural sway and rotarod testing were performed before and after a vestibular challenge (VC) in the 129S wild type and the αCGRP (-/-) null mice. Four age groups were tested that correspond to young adulthood, late adulthood, middle age, and senescence in humans. Our results suggest wild type mice experience a decline in rotarod ability due to aging after they reach their prime performance at 6–10 months of age, while the αCGRP (-/-) null mice perform poorly on rotarod early in life but improve with age as they get older, potentially due to vestibular compensation. Our postural sway study suggests that a vestibular challenge can lead to significantly reduced CoP ellipse areas (freezing behaviors) in older mice, and this change occurs earlier in the αCGRP (-/-) null but requires future studies to evaluate anxiety effects. These results indicate that αCGRP is an important component of proper balance and that the loss of αCGRP can contribute to balance complications that may compound with aging. [ABSTRACT FROM AUTHOR]

Background: Idiopathic intracranial hypertension (IIH) is a debilitating condition characterized by increased intracranial pressure often presenting with chronic migraine-like headache. Calcitonin gene-related peptide (CGRP) plays an important pathophysiological role in primary headaches such as migraine, whilst its role in IIH has not yet been established. Methods: This longitudinal exploratory study included patients with IIH, episodic migraine (EM) in a headache-free interval and healthy controls (HC). Blood samples were collected from a cubital vein and plasma CGRP (pCGRP) levels were measured by standardized ELISA. Results: A total of 26 patients with IIH (mean age 33.2 years [SD 9.2], 88.5% female, median BMI 34.8 kg/m2 [IQR 30.0–41.4]), 30 patients with EM (mean age 27.6 years [7.5], 66.7% female) and 57 HC (mean age 25.3 years [5.2], 56.1% female) were included. pCGRP levels displayed a wide variation in IIH as well as in EM and HC on a group-level. Within IIH, those with migraine-like headache had significantly higher pCGRP levels than those with non-migraine-like headache (F(2,524) = 84.79; p < 0.001) and headache absence (F(2,524) = 84.79; p < 0.001) throughout the observation period, explaining 14.7% of the variance in pCGRP levels. CGRP measurements showed strong intraindividual agreement in IIH (ICC 0.993, 95% CI 0.987–0.996, p < 0.001). No association was found between pCGRP levels and ophthalmological parameters. Conclusions: Although interindividual heterogeneity of pCGRP levels is generally high, migraine-like headache seems to be associated with higher pCGRP levels. CGRP may play a role in the headache pathophysiology at least in a subgroup of IIH. [ABSTRACT FROM AUTHOR]

Prurigo nodularis (PN) is an inflammatory skin condition characterized by intensely pruritic nodules on the skin. Patients with PN suffer from an intractable itch–scratch cycle leading to impaired sleep, psychosocial distress and a significant disruption in quality of life. The pathogenesis of PN is associated with immune and neural dysregulation, mediated by inflammatory cytokines [such as interleukin (IL)-4, -13, -17, -22 and -31] and neuropeptides (such as substance P and calcitonin gene-related peptide). There is a role for type 2 inflammation in PN in addition to T-helper (Th)17 and Th22-mediated inflammation. The neuroimmune feedback loop in PN involves neuropeptides released from nerve fibres that cause vasodilation and further recruitment of inflammatory cells. Inflammatory cells, particularly mast cells and eosinophils, degranulate and release neurotoxins, as well as nerve growth factor, which may contribute to the neuronal hyperplasia seen in the dermis of patients with PN and neural sensitization. Recent studies have also indicated underlying genetic susceptibility to PN in addition to environmental factors, the existence of various disease endotypes centred around degrees of type 2 inflammation or underlying myelopathy or spinal disc disease, and significant race and ethnicity-based differences, with African Americans having densely fibrotic skin lesions. Dupilumab became the first US Food and Drug Administration-approved therapeutic for PN, and there are several other agents currently in development. The anti-IL-31 receptor A inhibitor nemolizumab is in late-stage development with positive phase III data reported. In addition, the oral Janus kinase (JAK) 1 inhibitors, abrocitinib and povorcitinib, are in phase II trials while a topical JAK1/2 inhibitor, ruxolitinib, is in phase III studies. [ABSTRACT FROM AUTHOR]

Neuropathic corneal pain (NCP) is a new and ill-defined disease characterized by pain, discomfort, aching, burning sensation, irritation, dryness, and grittiness. However, the mechanism underlying NCP remain unclear. Here, we reported a novel rat model of primary NCP induced by long ciliary nerve (LCN) ligation. After sustained LCN ligation, the rats developed increased corneal mechanical and chemical sensitivity, spontaneous blinking, and photophobia, which were ameliorated by intraperitoneal injection of morphine or gabapentin. However, neither tear reduction nor corneal injury was observed in LCN-ligated rats. Furthermore, after LCN ligation, the rats displayed a significant reduction in corneal nerve density, as well as increased tortuosity and beading nerve ending. Long ciliary nerve ligation also notably elevated corneal responsiveness under resting or menthol-stimulated conditions. At a cellular level, we observed that LCN ligation increased calcitonin gene-related peptide (neuropeptide)-positive cells in the trigeminal ganglion (TG). At a molecular level, upregulated mRNA levels of ion channels Piezo2, TRPM8, and TRPV1, as well as inflammatory factors TNF-α, IL-1 β, and IL-6, were also detected in the TG after LCN ligation. Meanwhile, consecutive oral gabapentin attenuated LCN ligation-induced corneal hyperalgesia and increased levels of ion channels and inflammation factors in TG. This study provides a reliable primary NCP model induced by LCN ligation in rats using a simple, minimally invasive surgery technique, which may help shed light on the underlying cellular and molecular bases of NCP and aid in developing a new treatment for the disease. [ABSTRACT FROM AUTHOR]

Introduction: The efficacy of galcanezumab has been demonstrated in randomized controlled trials, but evidence about its use under clinical practice conditions is still limited. This study aimed to describe the characteristics of the patients treated with galcanezumab in routine clinical practice in Spain as well as treatment patterns, persistence, and effectiveness. Methods: A retrospective chart review study was carried out in six hospitals. Information of adults with migraine, who started treatment with galcanezumab between November 2019 and September 2021, was analyzed until end or loss of follow-up. Continuous variables were described as mean (standard deviation, SD) and median (interquartile range, IQR), and categorical variables as frequency and percentages. Persistence to treatment was estimated using Kaplan–Meier analysis. Results: A total of 314 patients were analyzed over median follow-up period of 17.5 months (13.8–20.7), with a mean age of 46.3 (12.6), 85% women, 80.6% chronic migraine, and reporting a mean of monthly migraine days of 16.7 (7.8). Overall, 72.9% had comorbid conditions, with anxiety and depression disorders being the most frequent. More than 60% had received ≥ 6 previous preventive drugs, the most common being antiepileptics, antidepressants, and botulinum toxin (95.2%, 89.8% and 84.1%, respectively). Overall, 60.3% of the patients with other preventive treatments maintained them after galcanezumab initiation. The median time on galcanezumab was 14.6 months (9.4–22.8); 95.7%, 82.0%, 76.2% and 59.8% of patients were persistent to treatment at 3, 6, 9 and 12 months, respectively. Of the patients who discontinued (151: 48.1%), 57.6% were due to lack of effectiveness and 31.1% were due to improvement in migraine. The average reduction of monthly migraine days at 3, 6, 9 and 12 months was 7.9 (7.2), 9.1 (7.5), 8.8 (6.6) and 9.0 (6.9) days, respectively. Conclusions: In real clinical practice, galcanezumab is an effective treatment and has a high persistence in patients with migraine, mostly chronic and with multiple use of previous preventive treatments. [ABSTRACT FROM AUTHOR]

Introduction: Fremanezumab, a humanized monoclonal antibody targeting calcitonin gene-related peptide, is indicated for preventive treatment of migraine in adults. Real-world evidence assessing the effect of fremanezumab on migraine-related medication use, health care resource utilization (HCRU), and costs in patient populations with comorbidities, acute medication overuse (AMO), and/or unsatisfactory prior migraine preventive response (UPMPR) is needed. Methods: Data for this US, retrospective claims analysis were obtained from the Merative® MarketScan® Commercial and supplemental databases. Eligible adults with migraine initiated fremanezumab between 1 September 2018 and 30 June 2019 (date of earliest fremanezumab claim is the index date), had ≥ 12 months of continuous enrollment prior to initiation (preindex period) and ≥ 6 months of data following initiation (postindex period; variable follow-up after 6 months), and had certain preindex migraine comorbidities (depression, anxiety, and cardiovascular disease), potential AMO, or UPMPR. Changes in migraine-related concomitant acute and preventive medication use, HCRU, and costs were assessed pre- versus postindex. Results: In total, 3193 patients met the eligibility criteria. From pre- to postindex, mean (SD) per patient per month (PPPM) number of migraine-related acute medication and preventive medication claims (excluding fremanezumab), respectively, decreased from 0.97 (0.90) to 0.86 (0.87) (P < 0.001) and 0.94 (0.74) to 0.81 (0.75) (P < 0.001). Migraine-related outpatient and neurologist office visits, emergency department visits, and other outpatient services PPPM decreased pre- versus postindex (P < 0.001 for all), resulting in a reduction in mean (SD) total health care costs PPPM from US$541 (US$858) to US$490 (US$974) (P = 0.003). Patients showed high adherence and persistence rates, with mean (SD) proportion of days covered of 0.71 (0.29), medication possession ratio of 0.74 (0.31), and persistence duration of 160.3 (33.2) days 6 months postindex. Conclusions: Patients with certain migraine comorbidities, potential AMO, and/or UPMPR in a real-world setting had reduced migraine-related medication use, HCRU, and costs following initiation of fremanezumab. Graphical abstract available for this article. [ABSTRACT FROM AUTHOR]

Objective: Migraine, a prevalent and debilitating disease, involves complex pathophysiology possibly including inflammation and heightened pain sensitivity. The current study utilized the complete Freund's adjuvant (CFA) model of inflammation, with onabotulinumtoxinA (BoNT/A) as a treatment of interest due to its use in clinical migraine management. Using an animal model, the study sought to investigate the role of BoNT/A in modulating CFA‐induced inflammation, alterations in pain sensitivity, and the regulation of calcitonin gene–related peptide (CGRP) release. Further, we aimed to assess the changes in SNAP‐25 through western blot analysis to gain insights into the mechanistic action of BoNT/A. Methods: BoNT/A or control was administered subcutaneously at the periorbital region of rats 3 days before the induction of inflammation using CFA. Periorbital mechanical sensitivity was assessed post‐inflammation, and alterations in CGRP release were evaluated. Changes in SNAP‐25 levels were determined using western blot analysis. Results: Upon CFA‐induced inflammation, there was a marked increase in periorbital mechanical sensitivity, with the inflammation side showing increased sensitivity compared to other periorbital areas. BoNT/A did decrease the withdrawal thresholds in the electronic von Frey test. Despite not being able to observe differences in pain thresholds or CGRP release, BoNT/A reduced baseline release under CFA inflamed conditions. Analysis of SNAP‐25 levels in the trigeminal ganglion revealed both intact and cleaved forms that were notably elevated in BoNT/A‐treated animals. These findings, derived from western blot analysis, suggest an effect on neurotransmitter release. Conclusion: Our investigation highlights the role of BoNT/A in reducing baseline CGRP in the context of inflammation and its involvement in SNAP‐25 cleavage. In contrast, BoNT/A did not appear to alter facial pain sensitivity induced by inflammation, suggesting that mechanisms other than baseline CGRP could be implicated in the elevated thresholds in the CFA model. Plain Language Summary: Migraine is often linked to increased pain sensitivity and potential inflammation, and treatments targeting these symptoms are crucial for improving the quality of life for those with migraine. Our research investigated the impact of onabotulinumtoxinA (BoNT/A) on migraine‐related conditions in a laboratory animal model, focusing on its effect on pain sensitivity and calcitonin gene‐related peptide (CGRP), a peptide associated with migraine, and we discovered that while BoNT/A does not significantly alter pain sensitivity, it reduced the baseline release of CGRP when inflammation was present, shedding light on its potential role in treating migraine. The reduction in CGRP release in inflamed conditions suggests that BoNT/A might be beneficial in managing migraine by targeting specific aspects of the condition, such as inflammation‐related peptide release. [ABSTRACT FROM AUTHOR]

Ubrogepant is a calcitonin gene‐related peptide receptor antagonist indicated for the acute treatment of migraine with or without aura in adults. The objectives of this study were to evaluate (1) single‐dose pharmacokinetics (PK) and dose proportionality of ubrogepant in Japanese participants, (2) the safety and tolerability of ubrogepant in healthy Japanese and White participants, and (3) to compare the PK of ubrogepant in Japanese versus White participants. A total of 48 participants were enrolled into 4 cohorts (N = 12 [9 active + 3 placebo] per cohort). A single dose was administered on Day 1 following an overnight fast to assess the PK of ubrogepant at 3 dose levels and test dose proportionality between 25 and 100 mg in Japanese participants. White participants were randomly assigned to ubrogepant (100 mg) or placebo. Dose proportionality was observed in the dose range of 25‐100 mg in Japanese participants. Systemic exposure was 20% lower in Japanese participants as compared with White participants, but this difference is unlikely to be clinically relevant. Single doses of ubrogepant (25‐100 mg) had a safety profile similar to placebo, and no differences in the safety profile of ubrogepant 100 mg were observed between Japanese versus White participants. [ABSTRACT FROM AUTHOR]

Background: The outcomes of traumatic brain injury (TBI) exhibit variance contingent upon biological sex. Although female sex hormones exert neuroprotective effects, the administration of estrogen and progesterone has not yielded conclusive results. Hence, it is conceivable that additional mediators, distinct from female sex hormones, merit consideration due to their potential differential impact on TBI outcomes. Calcitonin gene-related peptide (CGRP) exhibits sexually dimorphic expression and demonstrates neuroprotective effects in acute brain injuries. In this study, we aimed to examine sex-based variations in TBI structural and functional outcomes with respect to CGRP expression. Methods: Male and female Sprague Dawley rats were exposed to controlled cortical impact to induce severe TBI, followed by interventions with and without CGRP inhibition. In the acute phase of TBI, the study centered on elucidating the influence of CGRP on oxidative stress, nuclear factor erythroid 2-related factor 2 (Nrf2) and endothelial nitric oxide synthase (eNOS) signaling in the peri-impact tissue. Subsequently, during the chronic phase of TBI, the investigation expanded to evaluate CGRP expression in relation to lesion volume, microvascular dysfunction, and white matter injury, as well as working and spatial memory, anxiety-like, and depression-like behaviors in subjects of both sexes. Results: Female rats exhibited elevated levels of CGRP in the peri-impact brain tissue during both baseline conditions and in the acute and chronic phases of TBI, in comparison to age-matched male counterparts. Enhanced CGRP levels in specific brain sub-regions among female rats correlated with superior structural and functional outcomes following TBI compared to their male counterparts. CGRP inhibition induced heightened oxidative stress and a reduction in the expression of Nrf2 and eNOS in both male and female rats, with the observed alteration being more pronounced in females than in males. Conclusions: This study marks the inaugural identification of CGRP as a downstream mediator contributing to the sexually dimorphic response observed in TBI outcomes. Highlights: Sexual dimorphism is evident in the levels of CGRP in peri-impact cerebral tissue both prior to and following TBI. Female rats demonstrate elevated and more pronounced sensitivity to CGRP expression in the context of TBI when contrasted with their male counterparts. Increased levels of CGRP in female rats initiated Nrf2 and eNOS signaling during the acute stage of TBI, resulting in a reduction of lesion volume by alleviating microvascular, white matter, and hippocampal injury in the chronic phase of TBI, as compared to male rats. Elevated CGRP levels within specific brain sub-regions were associated with enhanced working and spatial memory function, as well as reduced anxiety- and depression-like behaviors in female rats compared to their male counterparts following TBI. The roles of CGRP levels vary across different degrees of tissue injury severity, ranging from deleterious to potentially beneficial, necessitating further exploration and investigation. Plain language summary: Investigating sex disparities in traumatic brain injury (TBI) is crucial for the advancement of precision therapeutics. Despite the neuroprotective effects demonstrated by female sex hormones, the administration of estrogen and progesterone has not produced conclusive results. Therefore, it is conceivable that additional mediators, separate from female sex hormones, warrant consideration due to their potential differential influence on TBI outcomes. In this study, we examined sex-related variations in calcitonin gene-related peptide (CGRP) expression in peri-impact brain tissue and investigated its potential implications on associated TBI outcomes. CGRP exhibits sexually dimorphic expression and exerts a multifaceted influence on diverse physiological processes that contribute to the pathophysiology of TBI. Our findings reveal that female rats exhibit heightened CGRP levels at both baseline and post-TBI within specific brain sub-regions, thereby contributing to superior structural and functional outcomes compared to their age-matched male counterparts. Additionally, we identified substantial sex-based variations in mechanisms modulated by CGRP pertaining to oxidative stress and microvascular dysfunction. The disparities in CGRP levels may be crucial for comprehending the advantageous outcomes noted in female TBI. Therefore, elucidating the sex-related distinctions in CGRP within TBI brains could pave the way for improved management and treatment strategies for TBI in both male and female individuals. [ABSTRACT FROM AUTHOR]

Background Objective Methods Results Conclusions Erenumab is a fully human monoclonal antibody that selectively targets the calcitonin gene–related peptide receptor. It has been proven to be safe and efficacious in patients with episodic migraine (EM) and chronic migraine (CM) as demonstrated in phase 2 and 3 clinical trials including patients from Europe, Japan, and the United States. Reversion from CM to EM, as indicated by a reduction in the frequency of headache days, is an important indicator for efficacy outcome, though it has not been analyzed widely in patients with CM to date.Primary results of the DRAGON study demonstrated the efficacy and safety of erenumab in patients with CM from China and other Asian countries. This post hoc analysis evaluated the rate of reversion from CM to EM in the overall population and in subgroups of patients defined by baseline demographic and clinical characteristics (age, body mass index, gender, prior preventive treatment failure, medication overuse status, and disease duration).Reversion from CM to EM was defined as a reduction in headache frequency to < 45 headache days over the 12 weeks of the double‐blind treatment period. In addition, migraine‐related disability and disease impact on functional impairment were assessed within each treatment group in reverters and non‐reverters using the Headache Impact Test‐6 (HIT‐6), Migraine Physical Function Impact Diary (MPFID), and modified Migraine Disability Assessment (mMIDAS).Overall, 557 patients with CM were randomized to monthly erenumab 70 mg (n = 279) or placebo (n = 278), of whom 52.3% (146 of 279) treated with erenumab reverted from CM to EM compared to 41.0% (114 of 278) in the placebo group (odds ratio [OR] 1.59, 95% confidence interval: 1.1–2.2; p = 0.007). Treatment with erenumab resulted in a greater mean change (standard error) from baseline in the HIT‐6 total score for reverters versus non‐reverters compared to placebo (erenumab: −9.5 [0.6] vs. −5.1 [0.5]; placebo: −8.9 [0.7] vs. −4.9 [0.5]). A similar pattern was observed for mMIDAS score in erenumab treatment groups versus placebo (erenumab: −22.1 [1.2] vs. −6.3 [1.8]; placebo: −19.9 [1.3] vs. −7.9 [1.6]). Substantial improvements were reported in MPFID‐Physical Impairment (PI) and Everyday Activities (EA) scores in reverters versus non‐reverters in erenumab treatment groups (MPFID‐PI: −5.9 [0.3] vs. −1.9 [0.6]; MPFID‐EA: −7.9 [0.4] vs. −3.4 [0.6]) and in placebo (MPFID‐PI: −5.4 [0.4] vs. −1.0 [0.5]; MPFID‐EA: −7.1 [0.5] vs. −3.2 [0.5]).This analysis demonstrated that a greater proportion of patients treated with erenumab reverted from CM to EM compared to patients treated with placebo. The reversion from CM to EM was reflected by the greater improvements in patient‐reported outcomes in the erenumab group. [ABSTRACT FROM AUTHOR]

The inhibition of endocannabinoid hydrolysis by enzymatic inhibitors may interfere with mechanisms underlying migraine-related pain. The dual FAAH/MAGL inhibitor AKU-005 shows potent inhibitory activity in vitro. Here, we assessed the effect of AKU-005 in a migraine animal model based on nitroglycerin (NTG) administration. Male rats were treated with AKU-005 (0.5 mg/kg, i.p.) or vehicle 3 h after receiving NTG (10 mg/kg, i.p.) or NTG vehicle. One hour later, rats were subjected to the open field test followed by the orofacial formalin test. At the end of the test, we collected serum samples for assessing calcitonin gene-related peptide (CGRP) levels as well as meninges, trigeminal ganglia, and brain areas to assess mRNA levels of CGRP and pro-inflammatory cytokines, and endocannabinoid and related lipid levels. AKU-005 reduced NTG-induced hyperalgesia during the orofacial formalin test but did not influence NTG-induced changes in the open field test. It significantly reduced serum levels of CGRP, CGRP, and pro-inflammatory cytokine mRNA levels in the meninges, trigeminal ganglia, and central areas. Surprisingly, AKU-005 caused no change in endocannabinoids and related lipids in the regions evaluated. The present findings suggest that AKU-005 may have anti-migraine effects by reducing CGRP synthesis and release and the associated inflammatory events. This effect, however, does not seem mediated via an interference with the endocannabinoid pathway. [ABSTRACT FROM AUTHOR]

Introduction: In 2020, the Italian Medicines Agency (AIFA) approved the reimbursement of calcitonin gene-related peptide (CGRP) pathway monoclonal antibodies (mAbs), including fremanezumab, in patients with a Migraine Disability Assessment Scale (MIDAS) score ≥ 11, with prescription renewals for up to 12 months in patients with ≥ 50% reduction in MIDAS score at Months 3 and 6. In this sub-analysis of the Pan-European Real Life (PEARL) study, we provide real-world data on fremanezumab use in Italian routine clinical practice (EUPAS35111). Methods: This first interim analysis for Italy was conducted when 300 enrolled adult patients with episodic or chronic migraine (EM, CM) completed 6 months of treatment with fremanezumab. The primary endpoint is the proportion of patients achieving ≥ 50% reduction in monthly migraine days (MMD) across the 6 months post-fremanezumab initiation. Secondary endpoints include: proportion of patients achieving ≥ 50% reduction in MIDAS score at Months 3 and 6, and mean change from baseline across Months 1–6 in MMD and headache-related disability. Safety was assessed through adverse events (AEs) reported. Results: Of 354 patients enrolled at Italian centers, 318 (EM, 35.5%, CM, 64.5%) were included in the effectiveness analysis. Of patients with available data, 109 (61.2%) achieved the primary endpoint. 61.0% and 65.1% achieved ≥ 50% reduction in MMDs at Months 3 and 6, respectively; 79.9% and 81.0% experienced ≥ 50% reduction in MIDAS at the same timepoints. Conclusion: Fremanezumab was effective and well-tolerated over the first 6 months of treatment, with approximately 80% of patients meeting Italian criteria for treatment continuation at Months 3 and 6. [ABSTRACT FROM AUTHOR]

Calcitonin gene-related peptide (CGRP) has long been implicated in both the physiology and pathophysiology of the respiratory tract. The objective of our study was to determine the serum concentration of alpha CGRP (αCGRP) in cystic fibrosis (CF) that arises from mutations in the gene responsible for encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Currently, there are not many data in the literature about the role of CGRP in CF. The serum level of αCGRP was estimated using the enzyme-linked immunosorbent assay among 64 patients with CF and 31 healthy controls. The αCGRP concentration in the CF group was 62.51 ± 15.45 pg/mL, while in the control group it was 47.43 ± 8.06 pg/mL (p < 0.001). We also compared the level of αCGRP in CF patients according to the type of CFTR mutation. Homozygotes for ΔF508 had higher αCGRP levels than heterozygotes (67.9 ± 10.2 vs. 54.5 ± 18.3 pg/mL, p < 0.01). The level of this neuropeptide was statistically higher in patients with severe disease than in those with mild CF (p = 0.003) when patients were divided into three groups by spirometry results. αCGRP concentration was not correlated with age, sex, clinical parameters, and pulmonary function test results in the study participants. The results of our study suggest a significant increase in the concentration of αCGRP in the serum of patients with CF compared to the control group. This observation opens interesting possibilities for understanding the role of αCGRP in the context of CF pathophysiology. [ABSTRACT FROM AUTHOR]

Background: The development and approval of antibodies targeting calcitonin gene-related peptide or its receptor mark a revolutionary era for preventive migraine treatment. Real-world evidence sheds light on rare, stigmatized or overlooked side effects of these drugs. One of these potential side effects is sexual dysfunction. Case reports: We present two cases of one 42-year-old and one 45-year-old female patient with chronic migraine who both reported sexual dysfunction as a possible side effect of treatment with galcanezumab, a monoclonal antibody targeting calcitonin gene-related peptide. Discussion: As calcitonin gene-related peptide is involved in vaginal lubrication as well as genital sensation and swelling, inhibiting the calcitonin gene-related peptide pathway may lead to sexual dysfunction as a potential side effect. Conclusion: Sexual dysfunction in female migraine patients might be a rare and overlooked side effect of monoclonal antibodies targeting the calcitonin gene-related peptide pathway. Considering the discomfort and stigma surrounding both migraine and sexual dysfunction, we advocate for an open attitude and awareness among clinicians toward such side effects. [ABSTRACT FROM AUTHOR]

Identifying novel therapeutic approaches to promote recovery of neurological functions following spinal cord injury (SCI) remains a great unmet need. Nociceptive signaling in the acute phase of SCI has been shown to inhibit recovery of locomotor function and promote the development of chronic neuropathic pain. We therefore hypothesized that inhibition of nociceptive signaling in the acute phase of SCI might improve long-term functional outcomes in the chronic phase of injury. To test this hypothesis, we took advantage of a selective strategy utilizing AAV6 to deliver inhibitory (hM4Di) Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to nociceptors of the L4-L6 dorsal root ganglia to evaluate the effects of transient nociceptor silencing on long-term sensory and motor functional outcomes in a rat thoracic contusion SCI model. Following hM4Di-mediated nociceptor inhibition from 0-14 days post-SCI, we conducted behavioral assessments until 70 days post-SCI, then performed histological assessments of lesion severity and axon plasticity. Our results show highly selective expression of hM4Di within small diameter nociceptors including calcitonin gene-related peptide (CGRP)+ and IB4-binding neurons. Expression of hM4Di in less than 25% of nociceptors was sufficient to increase hindlimb thermal withdrawal latency in naïve rats. Compared with subjects who received AAV-yellow fluorescent protein (YFP; control), subjects who received AAV-hM4Di exhibited attenuated thermal hyperalgesia, greater coordination, and improved hindlimb locomotor function. However, treatment did not impact the development of cold allodynia or mechanical hyperalgesia. Histological assessments of spinal cord tissue suggested trends toward reduced lesion volume, increased neuronal sparing and increased CGRP+ axon sprouting in hM4Di-treated animals. Together, these findings suggest that nociceptor silencing early after SCI may promote beneficial plasticity in the acute phase of injury that can impact long-term functional outcomes, and support previous work highlighting primary nociceptors as possible therapeutic targets for pain management after SCI. [ABSTRACT FROM AUTHOR]

Growing evidence indicates that the parasympathetic system is implicated in migraine headache. However, the cholinergic mechanisms in the pathophysiology of migraine remain unclear. We investigated the effects and mechanisms of cholinergic modulation and a mast cell stabilizer cromolyn in the nitroglycerin‐induced in vivo migraine model and in vitro hemiskull preparations in rats. Effects of cholinergic agents (acetylcholinesterase inhibitor neostigmine, or acetylcholine, and muscarinic antagonist atropine) and mast cell stabilizer cromolyn or their combinations were tested in the in vivo and in vitro experiments. The mechanical hyperalgesia was assessed by von Frey hairs. Calcitonin gene‐related peptide (CGRP) and C‐fos levels were measured by enzyme‐linked immunosorbent assay. Degranulation and count of meningeal mast cells were determined by toluidine‐blue staining. Neostigmine augmented the nitroglycerin‐induced mechanical hyperalgesia, trigeminal ganglion CGRP levels, brainstem CGRP, and C‐fos levels, as well as degranulation of mast cells in vivo. Atropine inhibited neostigmine‐induced additional increases in CGRP levels in trigeminal ganglion and brainstem while it failed to do this in the mechanical hyperalgesia, C‐fos levels, and the mast cell degranulation. However, all systemic effects of neostigmine were abolished by cromolyn. The cholinergic agents or cromolyn did not alter basal release of CGRP, in vitro, but cromolyn alleviated the CGRP‐inducing effect of capsaicin while atropine failed to do it. These results ensure for a first time direct evidence that endogenous acetylcholine contributes to migraine pathology mainly by activating meningeal mast cells while muscarinic receptors are involved in CGRP release from trigeminal ganglion and brainstem, without excluding the possible role of nicotinic cholinergic receptors. [ABSTRACT FROM AUTHOR]

Aim: The purpose of this study was to quantify the effect of five different root canal preparation instruments on Substance P (SP), Calcitonin gene‐related peptide (CGRP) and their receptors expression in healthy human periodontal ligament. Methodology: STROBE guidelines were used to design a study using 60 periodontal ligament samples obtained from healthy lower premolars where extraction was indicated for orthodontic reasons. Prior to extraction 40 of these premolars were equally divided into four groups and root canals were prepared using different systems: Mtwo, Reciproc Blue, HyFlex EDM and Plex‐V. Ten premolars were prepared with hand files and served as a positive control group. The remaining 10 premolars where extracted without treatment and served as a negative control group. All periodontal ligament samples were processed to measure the expression of SP, CGRP and their receptors by radioimmunoassay. Kruskal–Wallis and Duncan tests were performed to determine statistically significant differences between the groups for each variable. Results: Greater expression of all the peptides measured were found in the hand‐file preparation group, followed by the Reciproc Blue, Mtwo, HyFlex EDM and Plex‐V groups. The lower SP, CGRP and their receptors values were for the intact teeth control group. Kruskal–Wallis test showed statistically significant differences amongst groups (p <.001). Dunn post‐hoc tests showed statistically significant differences in SP, CGRP and their receptors expression between the intact teeth and the hand‐file and Reciproc Blue groups. Hand‐file group showed significant differences with the other groups, except with Reciproc Blue, where no differences were observed in any of the peptides measured. Finally, no differences were observed between Plex‐V and HyFlex in any of the peptides measured. Conclusions: Root canal preparation with hand files and Reciproc Blue generates the highest expression of SP, CGRP, NK1 and CGRP1R in human periodontal ligament, whilst Plex‐V and HyFlex maintain the basal expression of neuropeptides and their receptors. Mtwo showed intermediate results between Reciproc Blue and HyFlex. [ABSTRACT FROM AUTHOR]

Purpose: The retina contains a number of vasoactive neuropeptides and corresponding receptors, but the role of these neuropeptides for tone regulation of retinal arterioles has not been studied in detail. Methods: Porcine arterioles with preserved perivascular retinal tissue were mounted in a wire myograph, and the tone was measured after the addition of increasing concentrations of bradykinin, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), substance P (SP), calcitonin gene‐related peptide (CGRP) and brain natriuretic peptide (BNP). The experiments were performed during inhibition of the synthesis of nitric oxide (NO), prostaglandins and dopamine and were repeated after removal of the perivascular retinal tissue. Results: Bradykinin, VIP and CGRP induced significant concentration‐dependent dilatation and NPY significant concentration‐dependent contraction of the arterioles in the presence of perivascular retinal tissue (p < 0.03 for all comparisons) but not on isolated arterioles. BNP and SP had no effect on vascular tone. The NOS inhibitor L‐NAME reduced bradykinin‐ and VIP‐induced relaxation (p < 0.001 for both comparisons), whereas none of the other inhibitors influenced the vasoactive effects of the studied neuropeptides. Conclusion: The effects of neuropeptides on the tone of retinal arterioles depend on the perivascular retinal tissue and may involve effects other than those mediated by nitric oxide, prostaglandins and adrenergic compounds. Investigation of the mechanisms underlying the vasoactive effect of neuropeptides may be important for understanding and treating retinal diseases where disturbances in retinal flow regulation are involved in the disease pathogenesis. [ABSTRACT FROM AUTHOR]

Background: Itch is the most common symptom of atopic dermatitis (AD) and significantly decreases the quality of life. Skin microbiome is involved in AD pathogenesis, whereas its role in the regulation of itch remains elusive. In this study, we aimed to investigate the effects of skin microbial metabolite propionate on acute and chronic pruritus and to explore the mechanism. Methods: Using various mouse models of itch, the roles of propionate were explored by behavioral tests and histopathology/immunofluorescent analysis. Primary‐cultured dorsal root ganglion neurons and HEK293 cells expressing recombinant human TRP channels were utilized for in vitro calcium imaging/in vivo miniature two‐photon imaging in combination with electrophysiology and molecular docking approaches for investigation of the mechanism. Results: Propionate significantly alleviated itch and alloknesis in various mouse models of pruritus and AD and decreased the density of intraepidermal nerve fibers. Propionate reduced the responsiveness of dorsal root ganglion neurons to pruritogens in vitro, attenuated the hyper‐excitability in sensory neurons in MC903‐induced AD model, and inhibited capsaicin‐evoked hTRPV1 currents (IC50 = 20.08 ± 1.11 μM) via interacting with the vanilloid binding site. Propionate also decreased the secretion of calcitonin gene‐related peptide by nerves in MC903‐induced AD mouse model, which further attenuated itch and skin inflammation. Conclusion: Our study revealed a protective effect of propionate against persistent itch through direct modulation of sensory TRP channels and neuropeptide production in neurons. Regulation of itch via the skin microbiome might be a novel strategy for the treatment of AD. [ABSTRACT FROM AUTHOR]

Background: Calcitonin gene-related peptide (CGRP) plays an important role in migraine pathophysiology, and post-traumatic headache (PTH) frequently presents with migraine-like features. Despite several clinical similarities, few studies have explored CGRP in PTH and concussion. This study investigates serum CGRP levels in patients with persistent post-concussion symptoms (PPCS), including PTH. Methods: This cohort study was based on serum samples from individuals aged 18–30 years with PPCS who participated in a previously published randomized controlled trial of a non-pharmacological intervention. The primary outcome was serum CGRP concentrations, determined at baseline before randomization and at follow-up 7 months later, using an enzyme-linked immunosorbent assay (ELISA). CGRP levels at baseline were compared with healthy anonymous blood donors in the same age group. Results: Baseline serum samples were collected from 86 participants with PPCS. The participants were most often female (78%) and migraine-like headache was the most frequent headache phenotype (74%). Serum CGRP levels were higher in participants with PPCS than in 120 healthy individuals (median: 158.5 pg/mL vs. 76.3 pg/mL, p = 0.050). A stratified analysis revealed that females with PPCS had a fivefold higher median than healthy females (166.3 pg/mL vs. 32.1 pg/mL, p = 0.0006), while no differences were observed in males (p = 0.83). At follow-up, CGRP levels decreased with a median change of – 1.3 pg/mL (95% confidence interval: – 17.6–0, p = 0.024). Discussion: Elevated serum levels of CGRP in patients with PPCS and a decrease over time suggest an involvement of CGRP in PTH/PPCS. If confirmed in other studies, it could pave the way for CGRP-targeted therapies, which could have clinical significance. [ABSTRACT FROM AUTHOR]

Objective: Nearly 60% of migraine patients treated with monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway experience a ≥ 50% reduction in monthly migraine days (MMD) at 12 weeks compared to baseline (responders). However, approximately half of the patients not responding to anti-CGRP mAbs ≤ 12 weeks do respond ≤ 24 weeks (late responders). We assessed frequency and characteristics of patients responding to anti-CGRP mAbs only > 24 weeks (ultra-late responders). Methods: In this multicenter (n = 16), prospective, observational, real-life study, we enrolled all consecutive adults affected by high-frequency episodic migraine (HFEM: ≥ 8 days/month) or chronic migraine (CM), with ≥ 3 prior therapeutic failures, treated with any anti-CGRP mAbs for ≥ 48 weeks. We defined responders patients with a ≥ 50% response rate ≤ 12 weeks, late responders those with a ≥ 50% response rate ≤ 24 weeks, and ultra-late responders those achieving a ≥ 50% response only > 24 weeks. Results: A total of 572 migraine patients completed ≥ 48 weeks of anti-CGRP mAbs treatment. Responders accounted for 60.5% (346/572), late responders for 15% (86/572), and ultra-late responders for 15.7% (90/572). Among ultra-late responders, 7.3% (42/572) maintained the ≥ 50% response rate across all subsequent time intervals (weeks 28, 32, 36, 40, 44, and 48) and were considered persistent ultra-late responders, while 8.4% (48/572) missed the ≥ 50% response rate at ≥ 1 subsequent time interval and were classified as fluctuating ultra-late responders. Fifty patients (8.7%) did not respond at any time interval ≤ 48 weeks. Ultra-late responders differed from responders for higher BMI (p = 0.033), longer duration of medication overuse (p < 0.001), lower NRS (p = 0.017) and HIT-6 scores (p = 0.002), higher frequency of dopaminergic symptoms (p = 0.002), less common unilateral pain—either alone (p = 0.010) or in combination with UAS (p = 0.023), allodynia (p = 0.043), or UAS and allodynia (p = 0.012)—a higher number of comorbidities (p = 0.012), psychiatric comorbidities (p = 0.010) and a higher proportion of patients with ≥ 1 comorbidity (p = 0.020). Conclusion: Two-thirds of patients not responding to anti-CGRP mAbs ≤ 24 weeks do respond later, while non-responders ≤ 48 weeks are quite rare (8.7%). These findings suggest to rethink the duration of migraine prophylaxis and the definition of resistant and refractory migraine, currently based on the response after 2–3 months of treatment. [ABSTRACT FROM AUTHOR]

Background: Bone cancer pain (BCP) is a common primary or metastatic bone cancer complication. Netrin-1 plays an essential role in neurite elongation and pain sensitization. This study aimed to determine the role of netrin-1 from the metastatic bone microenvironment in BCP development and identify the associated signaling pathway for the strategy of BCP management. Methods: The rat BCP model was established by intratibial implantation of Walker 256 cells. Von Frey filaments measured the mechanical pain threshold. Movementinduced pain was assessed using limb use scores. Expressions of associated molecules in the affected tibias or dorsal root ganglia (DRG) were measured by immunofluorescence, immunohistochemistry, real-time quantitative polymerase chain reaction, or western blotting. Transduction of deleted in colorectal cancer (DCC) signaling was inhibited by intrathecal injection of DCC-siRNA. Results: In BCP rats, the presence of calcitonin gene-related peptide (CGRP)-positive nerve fibers increased in the metastatic bone lesions. The metastatic site showed enrichment of well-differentiated osteoclasts and expressions of netrin-1 and its attractive receptor DCC. Upregulation of DCC and increased phosphorylation levels of focal adhesion kinase (FAK) and Rac family small GTPase 1/Cell division cycle 42 (Rac1/Cdc42) were found in the DRG. Intrathecal administration of DCC-siRNA led to a significant reduction in FAK and Rac1/Cdc42 phosphorylation levels in the DRG, decreased nociceptive nerve innervation, and improved pain behaviors. Conclusions: Netrin-1 may contribute to the activation of the BCP by inducing nociceptive nerve innervation and improving pain behaviors. [ABSTRACT FROM AUTHOR]

Rimegepant is a calcitonin gene‐related peptide receptor antagonist approved for migraine treatment. This phase 1, open‐label, single‐center, fixed‐sequence study evaluated the effect of rimegepant on the pharmacokinetics (PK) of metformin. Twenty‐eight healthy participants received metformin 500 mg twice daily from Days 1 to 4 and Days 7 to 10, and once daily on Days 5 and 11. Rimegepant, 75 mg tablet, was administered once daily from Days 9 to 12. At pre‐specified time points, plasma metformin concentration, serum glucose levels, and safety and tolerability were evaluated. A 16% increase in the area under the plasma metformin concentration‐time curve (AUC) for 1 dosing interval (AUC0‐τ,ss), a statistically insignificant increase in maximum and minimum steady‐state metformin concentration (Cmax,ss and Cmin,ss), and a decrease in metformin renal clearance were observed on Day 11 following metformin‐rimegepant coadministration compared with metformin alone; however, the changes were not clinically relevant. Additionally, coadministration of rimegepant with metformin did not induce clinically meaningful change in the maximum observed glucose concentration (Gmax) or AUCgluc compared with metformin alone. Overall, rimegepant and metformin coadministration did not result in clinically relevant changes in metformin PK, renal clearance, or the antihyperglycemic effects of metformin. Rimegepant is considered safe for use with metformin. [ABSTRACT FROM AUTHOR]

Reflux hypersensitivity (RH) is a subtype of gastroesophageal reflux disease. The Rome IV criteria separated RH from the original nonerosive reflux disease subgroup and classified it as a new functional oesophageal disease. Recently, the pathogenesis of RH has become the focus of research. According to the latest research reports, upregulation of acid-sensitive receptors, distribution of calcitonin gene-related peptide-positive nerve fibres, and psychiatric comorbidity have key roles in the pathogenesis of RH. This work reviews the latest findings regarding RH mechanisms. [ABSTRACT FROM AUTHOR]

Background and objective: Endometriosis (EM) involves the peripheral nervous system and causes chronic pain. Sensory nerves innervating endometriotic lesions contribute to chronic pain and influence the growth phenotype by releasing neurotrophic factors and interacting with nearby immune cells. Calcitonin gene-related peptide (CGRP), a pain-signaling neurotransmitter, has a significant role. This study examines the effect of Dienogest (DNG), a hormone therapy used for managing EM -related pain, on serum CGRP levels in EM patients. Materials and methods: The Visual Analog Scale (VAS) assessed pain in diagnosed EM. individuals. Serum samples were obtained to measure CGRP concentration. Participants received a 2 mg/day oral dose of DNG for six months as prescribed treatment. Additional serum samples were collected after this period to measure CGRP levels. Results: In the EM group, 6.7%, 33.3%, and 20% had ovarian EM, ovarian plus uterosacral, and ovarian plus bladder, respectively. The EM group showed higher CGRP serum levels than the control group (80.53 ± 16.13 vs. 58.55 ± 6.93, P < 0.0001). Still, after drug administration, CGRP serum levels significantly decreased compared to pre-treatment levels (69.66 ± 11.53 vs. 80.53 ± 16.13, P < 0.05). The EM group showed higher pain compared to the control group (7.93 ± 1.58 vs. 0.13 ± 0.35, P < 0.0001), but after drug administration, pain significantly decreased compared to pre-treatment levels (1.00 ± 2.00 vs. 7.93 ± 1.58, P < 0.05). Conclusion: DNG administration reduces pain and serum CGRP levels in EM patients, offering the potential for innovative treatments and tailored options. Understanding neurotransmitter roles and drug effects can aid in discovering more effective modulators for these pathways. [ABSTRACT FROM AUTHOR]

Background: Serum CGRP has been found to increase during migraine attack. However, whether CGRP can identify MA with PFO subtypes in MA remains unknown. This study aimed to investigate the differential expression of calcitonin gene-related peptide (CGRP) between migraine (MA) patients with and without patent foramen ovale (PFO), and to evaluate the predictive value of CGRP for MA with PFO. Methods: A total of 153 patients with MA, 51 patients with PFO and 102 patients without. Venous blood was drawn and HIT-6 score was calculated during the onset of MA, and blood routine, inflammatory indexes and serum CGRP were detected. The differences in serum markers and HIT-6 scores were compared between the two groups, and the risk factors of MA with PFO were determined by univariate and multivariate logistics regression. Furthermore, the correlation between CGRP level with right-to-left shunt (RLS) grades and headache impact test-6 (HIT-6) score in MA patients with PFO were assessed. Independent risk factors were screened out by multivariate Logistic regression analysis. We used the receiver operating characteristic (ROC) curve to analyze the diagnostic value of these risk factors in MA complicated with PFO. Results: The serum CGRP level and HIT-6 scores in the MA with PFO group were significantly higher than those in the MA group (P < 0.001). Multivariate regression analysis showed that CGRP was an independent risk factor for MA with PFO (OR = 1.698, 95% CI = 1.325–2.179, P < 0.001). CGRP values ​​increased with the increase of RLS grade(Spearmen rho = 0.703, P < 0.001). Furthermore, a positive correlation between CGRP and HIT-6 scores was found (Spearmen rho = 0.227; P = 0.016). ROC curve showed that the optimal cut-off value for diagnosing MA with PFO was 79 pg/mL, the area under the curve (AUC) for predicting MA with PFO was 0.845, with 72.55% sensitivity and 78.43% specificity. Conclusions: MA patients with PFO have higher serum CGRP level. elevated CGRP concentration was associated with higher RLS grade and increased HIT-6 score. Higher serum CGRP level has certain clinical value in predicting PFO in MA patients. Trial registration: This study was approved by the Ethics Committee of Zhuhai Hospital of Integrated Traditional Chinese and Western Medicine (Ethics batch number: 20,201,215,005). [ABSTRACT FROM AUTHOR]

Colorectal cancer is one of the most widespread types of cancer that still causes many deaths worldwide. The development of new diagnostic and prognostic markers, as well as new therapeutic methods, is necessary. The calcitonin gene-related peptide (CGRP) neuropeptide alongside its receptor calcitonin receptor-like receptor (CRLR) could represent future biomarkers and a potential therapeutic target. Increased levels of CGRP have been demonstrated in thyroid, prostate, lung, and breast cancers and may also have a role in colorectal cancer. At the tumor level, it acts through different mechanisms, such as the angiogenesis, migration, and proliferation of tumor cells. The aim of this study was to measure the level of CGRP in colorectal cancer patients' serum by enzyme-linked immunosorbent assay (ELISA) and determine the level of CGRP and CRLR at the tumor level after histopathological (HP) and immunohistochemical (IHC) analysis, and then to correlate them with the TNM stage and with different tumoral characteristics. A total of 54 patients with newly diagnosed colorectal adenocarcinoma were evaluated. We showed that serum levels of CGRP, as well as CGRP and CRLR tumor level expression, correlate with the TNM stage, with local tumor extension, the presence of lymph node metastasis, and distant metastasis, and also with the tumor differentiation degree. CGRP is present in colorectal cancer from the incipient TNM stage, with levels increasing with the stage, and can be used as a diagnostic and prognostic marker and may also represent a potentially new therapeutic target. [ABSTRACT FROM AUTHOR]

Aim of the study: To evaluate the therapeutic effect of SYNC in diarrhea irritable bowel syndrome (IBS-D) and explore its underlying mechanism through transcriptomic sequencing (RNA-Seq). Materials and methods: A rat model of IBS-D was constructed to elucidate the effects of SYNC. Abdominal withdrawal reflex (AWR), fecal water content (FWC), and recording body weight were calculated to assess visceral sensitivity in rats. Histopathological changes in the colon and alterations in mast cell (MC) count were determined. Immunohistochemistry was employed to assess mast cell tryptase (MCT) expression in rat colons. Serum levels of corticotropin-releasing Hormone (CRH), interleukin-6 (IL-6), calcitonin gene-related peptide (CGRP), and 5-hydroxytryptamine (5-HT) were quantified using ELISA. RNA-Seq of colon tissue was performed, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Western blot analysis was conducted to quantify the expression levels of key proteins in the Nr4a3 pathway in the colon and hypothalamus tissues of rats. Results: SYNC alleviated visceral hypersensitivity and mood disorders in rats with IBS-D. Moreover, it was positively correlated with its dosage and the observed effects, such as the enhancement of the colon's mucosal lining condition and reduction in the number and activation of MCs within the model group. SYNC reduced the expression levels of factors related to the brain-gut axis and inflammatory markers in the bloodstream. RNA-Seq analysis indicated that SYNC down-regulated the expression of Nr4a3 and PI3K. These SYNC-targeted genes primarily played roles in immune regulation and inflammatory responses, correlating with the modulation of Nr4a3 and the PI3K/AKT pathway. Western blot analysis further confirmed SYNC's influence on inflammation-related MC activation by downregulating key proteins in the Nr4a3/PI3K pathway. Conclusions: SYNC inhibited mast cell activation and attenuated visceral hypersensitivity in the colon tissues of IBS-D rats. These effects were mediated by the Nr4a3/PI3K signaling pathway. [ABSTRACT FROM AUTHOR]

Subarachnoid hemorrhage (SAH) remains a major cause of cerebrovascular morbidity, eliciting severe headaches and vasospasms that have been shown to inversely correlate with vasodilator calcitonin gene-related peptide (CGRP) levels. Although dura mater trigeminal afferents are an important source of intracranial CGRP, little is known about the effects of SAH on these neurons in preclinical models. The present study evaluated changes in CGRP levels and expression in trigeminal primary afferents innervating the dura mater 72 h after experimentally induced SAH in adult rats. SAH, eliciting marked damage revealed by neurological examination, significantly reduced the density of CGRP-immunoreactive nerve fibers both in the dura mater and the trigeminal caudal nucleus in the medulla but did not affect the total dural nerve fiber density. SAH attenuated ex vivo dural CGRP release by ~40% and in the trigeminal ganglion, reduced both CGRP mRNA levels and the number of highly CGRP-immunoreactive cell bodies. In summary, we provide novel complementary evidence that SAH negatively affects the integrity of the CGRP-expressing rat trigeminal neurons. Reduced CGRP levels suggest likely impaired meningeal neurovascular functions contributing to SAH complications. Further studies are to be performed to reveal the importance of impaired CGRP synthesis and its consequences in central sensory processing. [ABSTRACT FROM AUTHOR]

• ERK activity plays a crucial role in regulating cortical spreading depolarization in male rodents. • CSD synergistically activates ERK1/2 and induces IL-1β production in the ipsilateral cerebral cortex of male rat. • Elevation of pERK and IL-1β production induced by CSD is predominantly TRPA1 channel-dependent. Extracellular signal-regulated kinase (ERK) are serine/threonine-selective proteins and ERK1/2 can be phosphorylated in peripheral and central brain regions after cortical spreading depolarization (CSD) and calcitonin gene-related peptide; However, it remains unclear about whether and how ERK activity modulates CSD that correlates to migraine aura. Here, we determined the role of ERK in regulating CSD and explored the underlying mechanism involving transient receptor potential ankyrin 1 (TRPA1), a stress-sensing cation channel. CSD was recorded using intrinsic optical imaging in mouse brain slices, and electrophysiology in rats. Phosphorylated ERK (pERK1/2) and interleukin-1β (IL-1β) protein levels were detected using Western blot or enzyme-linked immunosorbent assay, respectively. IL-1β mRNA level was detected using qPCR. The results showed that an ERK inhibitor, SCH77298, markedly prolonged CSD latency and reduced propagation rate in mouse brain slices. Corresponding to this, CSD induction increased levels of cytosolic pERK1/2 in ipsilateral cerebral cortices of rats, the elevation of which correlated to the level of IL-1β mRNA. Mechanistic analysis showed that pre-treatment of an anti-TRPA1 antibody reduced the cytosolic pERK2 level but not pERK1 following CSD in cerebral cortices of rats and this level of pERK2 correlated with that of cerebral cortical IL-1β protein. Furthermore, an ERK activator, AES16-2M, but not its scrambled control, reversed the prolonged CSD latency by a TRPA1 inhibitor, HC-030031, in mouse brain slices. These data revealed a crucial role of ERK activity in regulating CSD, and elevation of pERK and IL-1β production induced by CSD is predominantly TRPA1 channel-dependent, thereby contributing to migraine pathogenesis. [ABSTRACT FROM AUTHOR]

Background: Chrysin is a natural flavonoid with several demonstrated neuro-pharmacological effects in brain areas related to anxiety. However, the intra-hypothalamic molecular mechanisms underlying the anxiolytic effects of chrysin remain unclear. Objectives: The current study revealed the effects of chrysin on hypothalamic corticotrophin-releasing hormone (CRH) and calcitonin gene-related peptide (CGRP) gene expression levels in a rat model of stress. Methods: Thirty male Wistar rats weighing 200 ± 10 g were divided into six groups for this investigation. Acute restraint stress was induced in the animals for 2 hours. Intact or stress-induced rats received 20 or 40 µg of chrysin via the third cerebral ventricle, respectively. Open-field and forced swimming tests were performed to evaluate stress-related behaviors. Hypothalamic samples were then removed, and real-time polymerase chain reaction (PCR) was used to measure relative gene expression. Results: The results showed that in the rats receiving chrysin, CRH and CGRP gene expression levels were significantly decreased compared to the stress group. Additionally, chrysin injection reduced anxiogenic behaviors. Conclusions: Chrysin decreased the expression of hypothalamic CRH and CGRP genes in stressed rats. [ABSTRACT FROM AUTHOR]

Objective: Phase II/III randomized clinical trials (RCTs) are vulnerable to many types of bias beyond randomization. Insights into the reporting quality of RCTs involving migraine patients treated with monoclonal antibodies targeting the calcitonin gene-related peptide system (anti-CGRP MAbs) are currently lacking. Our aim was to analyze the reporting quality of phase II/III RCTs involving migraine patients treated with anti-CGRP MAbs. Methods: A systematic search was performed on the PubMed and EMBASE databases, according to PRISMA guidelines, for relevant RCTs in either episodic or chronic migraine prevention. Additionally, an adapted version of the 2010 CONSORT statement checklist was utilized. The ROBvis online tool was used to document the risk of bias. Results: From the initially identified 179 articles, we finally found 31 RCTs that were eligible for evaluation. The average CONSORT compliance was 88.7% (69.7–100%), while 93.5% (N = 29) of the articles had a compliance greater than 75%. Twenty-eight CONSORT items were reported in more than 75% of the articles. The average compliance of the analyzed RCTs was 93.9% for Galcanezumab, 91.3% for Fremanezumab, followed by 85.4% for Erenumab and Eptinezumab studies. Implementation of the ROB2 tool showed some concerning "missing information" arising from the inadequate reporting. Specifically, 50% of the studies (N = 16) were categorized as having inadequate information regarding the randomization process. Conclusions: Adequate reporting quality was disclosed in the evaluated RCTs with anti-CGRP MAbs in migraine prevention. However, some methodological issues need to be highlighted to be addressed in future studies assessing the efficacy of new molecules targeting CGRP or other candidate pathways implicated in migraine pathophysiology. [ABSTRACT FROM AUTHOR]

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of cerebral small vessel disease, caused by a mutation in the NOTCH3 gene on chromosome 19. The main clinical features include migraine (often with aura), early onset, recurrent subcortical ischemic strokes, mood disturbances, and cognitive impairment, frequently leading to dementia and disability with a reduction in life expectancy. Cerebral chronic global hypoperfusion, due to impaired cerebrovascular reactivity, seems to play a primary role in CADASIL. Migraine is the most common early feature of the disease, and to date, there are no consensus guidelines for treatment. Given the vasomodulatory influence of many antimigraine drugs, there is concern about their use in this disease. In particular, the calcitonin gene-related peptide (CGRP) system serves as a vasodilatory protective mechanism during cerebral and cardiac ischemia. Blocking this system could exacerbate ischemic events. Herein, we describe two CADASIL patients who were treated with the calcitonin gene-related peptide (CGRP) receptor antagonist erenumab for chronic migraine, reporting a significant reduction in the frequency of attacks and intensity of pain, and an improvement in quality of life without adverse effects. [ABSTRACT FROM AUTHOR]

To describe long-term (24-month) treatment patterns of patients initiating galcanezumab versus standard of care (SOC) preventive migraine treatments including anticonvulsants, beta-blockers, antidepressants, and onabotulinumtoxinA using administrative claims data. This retrospective cohort study, which used Optum de-identified Market Clarity data, included adults with migraine with ≥1 claim for galcanezumab or SOC preventive migraine therapy (September 1, 2018 − March 31, 2020) and continuous database enrollment for 12 months before (baseline) and 24 months after (follow-up) the index date (date of first claim). Baseline patient demographics, clinical characteristics, and treatment patterns were analyzed after 24-month follow-up, including adherence (measured as the proportion of days covered [PDC]), persistence, discontinuation (≥60-day gap), restart, and treatment switch. Propensity score matching (1:1) was used to balance the galcanezumab and SOC cohorts. The study included 2307 matched patient pairs with 24-month follow-up. The mean age across cohorts was 44.5 years (females: ∼87%). Patients in the galcanezumab versus SOC cohort demonstrated greater treatment adherence (PDC: 48% vs. 38%), with more patients considered adherent (PDC ≥80%: 26.6% vs. 20.7%) and persistent (322.1 vs. 236.4 d) (all p <.001). After 24-month follow-up, fewer galcanezumab-treated patients had discontinued compared with SOC-treated patients (80.1% vs. 84.7%; p <.001), of which 41.3% and 39.6% switched to a non-index medication, respectively. The most prevalent medication patients switched to in both cohorts was erenumab. Significantly greater proportions of patients who initiated galcanezumab versus SOC medications switched to fremanezumab (p <.001) and onabotulinumtoxinA (p =.016). Patients who initiated galcanezumab for migraine prevention had higher treatment adherence and persistence compared with those who initiated SOC medications after 24-month follow-up. Only few patients (3 − 13%) with migraine, who qualify for preventive treatment, are using them. Conventional preventive treatments have not been developed specifically for migraine treatment, and more than half of the patients stop using them prematurely. Calcitonin gene-related peptide monoclonal antibodies such as galcanezumab, fremanezumab, and erenumab are newer treatments that provide migraine-specific preventive treatment. Prior studies have compared 6- to 12-month migraine medication use by patients starting galcanezumab versus those starting traditional standard of care (SOC) migraine preventive medications. We compared long-term (24-month) migraine medication use in patients starting galcanezumab versus those starting SOC migraine preventive medications to confirm if the results are sustained over a longer period. Over 24 months, patients who used galcanezumab followed the prescribed treatment regimen to a greater extent compared with those who used SOC medications (48% vs. 38%, respectively). Additionally, patients using galcanezumab continued treatment for a longer time compared with those using SOC. Over 24 months, about 85% of patients stopped taking SOC medications, while around 80% of patients stopped taking galcanezumab. Our findings indicate that patients with migraine are more likely to continue using galcanezumab as a preventive treatment for a longer period compared with SOC medications. This study helps identify gaps in the preventive treatment of migraine and provides insights on how they are not being used enough. [ABSTRACT FROM AUTHOR]

Objective: To explore the rate of hypertension incoming in patients treated with monoclonal antibodies against the calcitonin gene-related peptide. Background: The monoclonal antibodies blocking the calcitonin gene-related peptide are unquestionable effective in the prevention of migraine. Despite this, the development of hypertension has been detected in some patients. Methods: This was a retrospective study conducted at the University Hospital of Modena. Patients were visited quarterly up to 1 year. Results: Globally, no significant increase in the blood pressure was detected. The 5.7% of the patients developed a significant increase in their blood pressure. In particular, patients with a pre-existing hypertension were more likely to have a significant increase in the blood pressure. Conclusion: The risk of developing hypertension during a treatment with anti-calcitonin gene-related peptide monoclonal antibodies seems low. Anyway, patients with a pre-existing hypertension should be cautiously monitored because they are more likely to develop hypertension. [ABSTRACT FROM AUTHOR]

Multiple animal models of migraine have been used to develop new therapies. Understanding the transition from episodic (EM) to chronic migraine (CM) is crucial. We established models mimicking EM and CM pain and assessed neuropathological differences. EM and CM models were induced with single NTG or multiple injections over 9 days. Mechanical hypersensitivity was assessed. Immunofluorescence utilized c-Fos, NeuN, and Iba1. Proinflammatory and anti-inflammatory markers were analyzed. Neuropeptides (CGRP, VIP, PACAP, and substance P) were assessed. Mechanical thresholds were similar. Notable neuropathological distinctions were observed in Sp5C and ACC. ACC showed increased c-Fos and NeuN expression in CM (p < 0.001) and unchanged in EM. Sp5C had higher c-Fos and NeuN expression in EM (p < 0.001). Iba1 was upregulated in Sp5C of EM and ACC of CM (p < 0.001). Proinflammatory markers were strongly expressed in Sp5C of EM and ACC of CM. CGRP expression was elevated in both regions and was higher in CM. VIP exhibited higher levels in the Sp5C of EM and ACC of CM, whereas PACAP and substance P were expressed in the Sp5C in both models. Despite similar thresholds, distinctive neuropathological differences in Sp5C and ACC between EM and CM models suggest a role in the EM to CM transformation. [ABSTRACT FROM AUTHOR]

Calcitonin gene-related peptide (CGRP) and nitric oxide (NO) have been recognized as important mediators in migraine but their mechanisms of action and interaction have not been fully elucidated. Monoclonal anti-CGRP antibodies like fremanezumab are successful preventives of frequent migraine and can be used to study CGRP actions in preclinical experiments. Fremanezumab (30 mg/kg) or an isotype control monoclonal antibody was subcutaneously injected to Wistar rats of both sexes. One to several days later, glyceroltrinitrate (GTN, 5 mg/kg) mimicking nitric oxide (NO) was intraperitoneally injected, either once or for three consecutive days. The trigeminal ganglia were removed to determine the concentration of CGRP using an enzyme-linked immunosorbent assay (ELISA). In one series of experiments, the animals were trained to reach an attractive sugar solution, the access to which could be limited by mechanical or thermal barriers. Using a semi-automated registration system, the frequency of approaches to the source, the residence time at the source, and the consumed solution were registered. The results were compared with previous data of rats not treated with GTN. The CGRP concentration in the trigeminal ganglia was generally higher in male rats and tended to be increased in animals treated once with GTN, whereas the CGRP concentration decreased after repetitive GTN treatment. No significant difference in CGRP concentration was observed between animals having received fremanezumab or the control antibody. Animals treated with GTN generally spent less time at the source and consumed less sugar solution. Without barriers, there was no significant difference between animals having received fremanezumab or the control antibody. Under mechanical barrier conditions, all behavioral parameters tended to be reduced but animals that had received fremanezumab tended to be more active, partly compensating for the depressive effect of GTN. In conclusion, GTN treatment seems to increase the production of CGRP in the trigeminal ganglion independently of the antibodies applied, but repetitive GTN administration may deplete CGRP stores. GTN treatment generally tends to suppress the animals' activity and increase facial sensitivity, which is partly compensated by fremanezumab through reduced CGRP signaling. If CGRP and NO signaling share the same pathway in sensitizing trigeminal afferents, GTN and NO may act downstream of CGRP to increase facial sensitivity. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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). Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

Background and purpose: According to the latest European guidelines, discontinuation of monoclonal antibodies against calcitonin gene‐related peptide (anti‐CGRP MAb) may be considered after 12–18 months of treatment. However, some patients may worsen after discontinuation. In this study, we assessed the response following treatment resumption. Methods: This was a prospective study conducted in 14 Headache Units in Spain. We included patients with response to anti‐CGRP MAb with clinical worsening after withdrawal and resumption of treatment. Numbers of monthly migraine days (MMD) and monthly headache days (MHD) were obtained at four time points: before starting anti‐CGRP MAb (T‐baseline); last month of first treatment period (T‐suspension); month of restart due to worsening (T‐worsening); and 3 months after resumption (T‐reintroduction). The response rate to resumption was calculated. Possible differences among periods were analysed according to MMD and MHD. Results: A total of 360 patients, 82% women, with a median (interquartile range [IQR]) age at migraine onset of 18 (12) years. The median (IQR) MHD at T‐baseline was 20 (13) and MMD was 5 (6); at T‐suspension, the median (IQR) MHD was 5 (6) and MMD was 4 (5); at T‐worsening, the median (IQR) MHD was 16 (13) and MMD was 12 (6); and at T‐reintroduction, the median (IQR) MHD was 8 (8) and MHD was 5 (5). In the second period of treatment, a 50% response rate was achieved by 57.4% of patients in MHD and 65.8% in MMD. Multivariate models showed significant differences in MHD between the third month after reintroduction and last month before suspension of first treatment period (p < 0.001). Conclusion: The results suggest that anti‐CGRP MAb therapy is effective after reintroduction. However, 3 months after resumption, one third of the sample reached the same improvement as after the first treatment period. [ABSTRACT FROM AUTHOR]

In this study, dissolving microneedles (MNs) using polyvinyl alcohol (PVA) and poly (1-vinylpyrrolidone-co-vinyl acetate) (P(VP-co-VA)) as matrix materials were developed for transdermal delivery of rizatriptan benzoate (RB) for acute migraine treatment. In-vitro permeation studies were conducted to assess the feasibility of the as-fabricated dissolving MNs to release RB. Drug skin penetration were tested by Franz diffusion cells, showing an increase of the transdermal flux compared to passive diffusion due to the as-fabricated dissolving MNs having a sufficient mechanical strength to penetrate the skin and form microchannels. The pharmacological study in vivo showed that RB-loaded dissolving MNs significantly alleviated migraine-related response by up-regulating the level of 5-hydroxytryptamine (5-HT) and down-regulating the levels of calcitonin gene-related peptide (CGRP) and substance P (SP). In conclusion, the RB-loaded dissolving MNs have advantages of safety, convenience, and high efficacy over conventional administrations, laying a foundation for the transdermal drug delivery system treatment for acute migraine. [ABSTRACT FROM AUTHOR]