Monoclonal Antibodies to CGRP or Its Receptor for Migraine Prevention

Biomarkers of Migraine: An Integrated Evaluation of Preclinical and Clinical Findings

In recent years, numerous efforts have been made to identify reliable biomarkers useful in migraine diagnosis and progression or associated with the response to a specific treatment. The purpose of this review is to summarize the alleged diagnostic and therapeutic migraine biomarkers found in biofluids and to discuss their role in the pathogenesis of the disease. We included the most informative data from clinical or preclinical studies, with a particular emphasis on calcitonin gene-related peptide (CGRP), cytokines, endocannabinoids, and other biomolecules, the majority of which are related to the inflammatory aspects and mechanisms of migraine, as well as other actors that play a role in the disease. The potential issues affecting biomarker analysis are also discussed, such as how to deal with bias and confounding data. CGRP and other biological factors associated with the trigeminovascular system may offer intriguing and novel precision medicine opportunities, although the biological stability of the samples used, as well as the effects of the confounding role of age, gender, diet, and metabolic factors should be considered.

Impact of fremanezumab on disability outcomes in patients with episodic and chronic migraine: a pooled analysis of phase 3 studies

Background

Migraine is the second leading cause of disability worldwide. Although many preventive treatments reduce migraine frequency and severity, it is unclear whether these treatments reduce migraine-related disability in a clinically meaningful way. This pooled analysis evaluated the ability of fremanezumab to reduce migraine-related disability, based on responses and shifts in severity in patient-reported disability outcomes.

Methods

This pooled analysis included 3 double-blind phase 3 trials (HALO EM, HALO CM, FOCUS) in which patients with episodic or chronic migraine were randomly assigned 1:1:1 to quarterly or monthly fremanezumab or matched placebo for 12 weeks. Migraine-related disability was assessed using the 6-item Headache Impact Test (HIT-6) and Migraine Disability Assessment (MIDAS) questionnaires. A clinically meaningful improvement in disability was defined per American Headache Society guidelines: for HIT-6, a ≥ 5-point reduction; for MIDAS, a ≥ 5-point reduction when baseline score was 11 to 20 or ≥ 30% reduction when baseline score was > 20. Proportions of patients who demonstrated shifts in severity for each outcome were also evaluated.

Results

For patients with baseline MIDAS scores of 11 to 20 (n = 234), significantly higher proportions achieved 5-point reductions from baseline in MIDAS scores with fremanezumab (quarterly, 71%; monthly, 70%) compared with placebo (49%; both P ≤ 0.01). For patients with baseline MIDAS scores of > 20 (n = 1266), proportions achieving ≥30% reduction from baseline in MIDAS scores were also significantly higher with fremanezumab (quarterly, 69%; monthly, 79%) compared with placebo (58%; both P < 0.001). For HIT-6 scores, proportions of patients achieving 5-point reductions from baseline were significantly higher with fremanezumab (quarterly, 53%; monthly, 55%) compared with placebo (39%; both P < 0.0001). Proportions of patients with shifts of 1 to 3 grades down in MIDAS or HIT-6 disability severity were significantly greater with quarterly and monthly fremanezumab compared with placebo (all P < 0.0001).

Conclusion

Fremanezumab demonstrated clinically meaningful improvements in disability severity in this pooled analysis.

Trial registrations

HALO CM, NCT02621931; HALO EM, NCT02629861; FOCUS, NCT03308968.

Epigenetic Connection of the Calcitonin Gene-Related Peptide and Its Potential in Migraine

The calcitonin gene-related peptide (CGRP) is implicated in the pathogenesis of several pain-related syndromes, including migraine. Targeting CGRP and its receptor by their antagonists and antibodies was a breakthrough in migraine therapy, but the need to improve efficacy and limit the side effects of these drugs justify further studies on the regulation of CGRP in migraine. The expression of the CGRP encoding gene, CALCA, is modulated by epigenetic modifications, including the DNA methylation, histone modification, and effects of micro RNAs (miRNAs), circular RNAs, and long-coding RNAs (lncRNAs). On the other hand, CGRP can change the epigenetic profile of neuronal and glial cells. The promoter of the CALCA gene has two CpG islands that may be specifically methylated in migraine patients. DNA methylation and lncRNAs were shown to play a role in the cell-specific alternative splicing of the CALCA primary transcript. CGRP may be involved in changes in neural cytoarchitecture that are controlled by histone deacetylase 6 (HDAC6) and can be related to migraine. Inhibition of HDAC6 results in reduced cortical-spreading depression and a blockade of the CGRP receptor. CGRP levels are associated with the expression of several miRNAs in plasma, making them useful peripheral markers of migraine. The fundamental role of CGRP in inflammatory pain transmission may be epigenetically regulated. In conclusion, epigenetic connections of CGRP should be further explored for efficient and safe antimigraine therapy.

Comparing the Efficacy, Safety, and Superiority of Calcitonin Gene-Related Peptide Monoclonal Antibodies and Botox in Preventing and Treating Migraines

Both calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) and OnabotulinumtoxinA (botox) are used in the prevention of chronic migraines. However, it is not clear which is more effective overall. This review will compare the efficacy, side effects, cost-effectiveness, and other factors between CGRP mAbs and botox. We searched Pubmed and Google Scholar using the keywords migraines, CGRP mAbs, botox, efficacy, side effects, aura. All articles, including case-control/cohort studies, case series, case reports, randomized control trials, traditional/systematic reviews, were analyzed. CGRP mAbs and botox both reduce the frequency of migraines in patients. Patients have reported they decreased migraines' frequency and intensity in several studies after being given each medication. While CGRP mAbs are more recent medications, botox has been studied for more than a decade as a migraine preventative. Both drugs have minor short-term side effects, but some CGRP mAbs may cause persistent constipation too. CGRP mAbs are self-injected every month, and botox is physician-injected every three months, making it easier to stay compliant. While both medications are expensive, botox has a lower cost over time. Botox is more effective prophylaxis of migraines based on the articles that were reviewed. While both CGRP mAbs and botox are efficacious and tolerable, botox has been studied longer, has fewer side effects, is more cost-effective, and is easier to comply with.