The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

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

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

Early Use of Erenumab vs Nonspecific Oral Migraine Preventives: The APPRAISE Randomized Clinical Trial

Importance

Patients with migraine often cycle through multiple nonspecific preventive medications due to poor tolerability and/or inadequate efficacy leading to low adherence and increased disease burden.

Objective

To compare the efficacy, tolerability, patient adherence, and patient satisfaction between erenumab and nonspecific oral migraine preventive medications (OMPMs) in patients with episodic migraine (EM) who had previously failed 1 or 2 preventive treatments.

Design, Setting, and Participants

The 12-month prospective, interventional, global, multicenter, active-controlled, randomized clinical trial comparing sustained benefit of 2 treatment paradigms (erenumab qm vs oral prophylactics) in adult episodic migraine patients (APPRAISE) trial was a 12-month open-label, multicenter, active-controlled, phase 4 randomized clinical trial conducted from May 15, 2019, to October 1, 2021. This pragmatic trial was conducted at 84 centers across 17 countries. Overall, participants 18 years or older with a 12-month or longer history of migraine, and 4 or more but fewer than 15 monthly migraine days (MMDs) were included.

Interventions

Patients were randomized (2:1) to receive erenumab or OMPMs. Dose adjustment was permitted (label dependent).

Main Outcomes and Measures

The primary end point was the proportion of patients completing 1 year of the initially assigned treatment and achieving a reduction of 50% or greater from baseline in MMDs at month 12. Secondary end points included the cumulative mean change from baseline in MMDs during the treatment period and the proportion of responders according to the Patients' Global Impression of Change (PGIC) scale at month 12 for patients taking the initially assigned treatment.

Results

A total of 866 patients were screened, of whom 245 failed the screening and 621 completed the screening and baseline period. Of the 621 randomized patients (mean [SD] age, 41.3 [11.2] years; 545 female [87.8%]; 413 [66.5%] in the erenumab group; 208 [33.5%] in the OMPM group), 523 (84.2%) completed the treatment phase, and 98 (15.8%) discontinued the study. At month 12, significantly more patients assigned to erenumab vs OMPM achieved the primary end point (232 of 413 [56.2%] vs 35 of 208 [16.8%]; odds ratio [OR], 6.48; 95% CI, 4.28-9.82; P <.001). Compared with OMPMs, treatment with erenumab showed higher responder rate (314 of 413 [76.0%] vs 39 of 208 [18.8%]; OR, 13.75; 95% CI, 9.08-20.83; P <.001) on the PGIC scale (≥5 at month 12). Significant reduction in cumulative average MMDs was reported with erenumab treatment vs OMPM treatment (-4.32 vs -2.65; treatment difference [SE]: -1.67 [0.35] days; P < .001). Substantially fewer patients in the erenumab arm compared with the OMPM arm switched medication (9 of 413 [2.2%] vs 72 of 208 [34.6%]) and discontinued treatment due to adverse events (12 of 408 [2.9%] vs 48 of 206 [23.3%]). No new safety signals were identified.

Conclusions and Relevance

Results of this randomized clinical trial demonstrated that earlier use of erenumab in patients with EM who failed 1 or 2 previous preventive treatments provided greater and sustained efficacy, safety, and adherence than continuous OMPM.

Trial Registration

ClinicalTrials.gov Identifier: NCT03927144.

Switching CGRP(r) MoAbs in migraine: what evidence?

INTRODUCTION

Approximately 50% of patients that receive a CGRP(r) MoAb for the preventative treatment of migraine are expected to discontinue therapy. For patients that discontinue CGRP(r) MoAb therapy, few clinical options are available. One potential option is to switch CGRP(r) MoAbs, however, data concerning the efficacy of this intervention is scarce.

AREAS COVERED

This manuscript aims to summarize all available data concerning the potential efficacy of switching CGRP(r) MoAbs following previous medication discontinuation. Data was sourced by completing a database search for the terms: 'CGRP monoclonal antibody switch OR CGRP monoclonal antibody switching.'

EXPERT OPINION

While data considering the potential efficacy of CGRP(r) switching continues to grow, our expert opinion supports the most recent European Headache Federation statement regarding CGRP(r) MoAb prescribing practices, concluding that there remains insufficient data to determine the efficacy of this intervention. As this topic is of significant clinical importance, we recommend a call-to-action to expand on current data considering the therapeutic options for patients that discontinue CGRP(r) MoAb therapy.

Calcitonin gene-related peptide: a possible biomarker in migraine patients with patent foramen ovale

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).

Population Dose-Response-Time Analysis of Itch Reduction and Patient-Reported Tolerability Supports Phase III Dose Selection for Linerixibat

Increase in serum bile acids (BAs) in patients with primary biliary cholangitis (PBC) may play a causal role in cholestatic pruritus (itch). Linerixibat is a selective small molecule inhibitor of the ileal bile acid transporter, which blocks re-absorption of BAs in the gastrointestinal tract thereby lowering BAs in the systemic circulation and reducing itch. One consequence is excess BAs in the colon, leading to diarrhea and abdominal pain. GLIMMER (NCT02966834) was a placebo-controlled phase IIb dose-ranging trial of linerixibat once (q.d.) or twice daily (b.i.d.) in adults with moderate to severe pruritus and PBC. To determine the optimal dose for maximum itch reduction while minimizing diarrhea, a kinetic-pharmacodynamic (k-PD) model was developed using data from GLIMMER. The PD end point modeled was worst daily itch, derived from itch score reported by patients b.i.d. A proportional odds model was developed post hoc to indicate the probability of diarrhea occurrence, a patient-reported outcome (GI-5) recorded weekly. The final k-PD model successfully described the effects of linerixibat and placebo on itch. Model simulations were consistent with the observed dose-dependent increase in the average number of itch responders (patients with a ≥ 2-point improvement in itch). This was paralleled by a dose-dependent increase in the probability of higher diarrhea frequency scores. The b.i.d. dosing regimens led to a modest increase in the number of itch responders as compared with q.d. dosing. This quantitative framework highlights the trade-off between benefit and tolerability and supported the selection of 40 mg b.i.d. in the phase III GLISTEN trial (NCT04950127).

Placebo and nocebo in the treatment of migraine: How much does real world effectiveness depend on contextual effects?

PURPOSE

Treatments in medicine impact individuals beyond their intended effects, due to phenomena such as the placebo and nocebo effects. The placebo effect arises from the positive expectation of a treatment being beneficial, while the nocebo effect stems from the negative expectation of a treatment causing harm. Both in real-world practice and clinical trials, treatments can lead to outcomes unrelated to their intended mechanism of action, which we categorize as placebo and nocebo responses. These responses, combined with the inherent fluctuation in a condition's natural progression, regression to the mean, and random comorbidities, make up a significant part of the therapeutic experience. Particularly in pain management, placebo and nocebo effects play a substantial role. By addressing modifiable contextual factors such as patient expectations, lifestyle choices, and the therapeutic relationship, healthcare providers can enhance the effectiveness of migraine treatments, paving the way for a more comprehensive, individualized approach to patient care. We must also consider non-modifiable factors like personal experiences, beliefs, and information from social media and the internet.

CONCLUSION

This review offers a summary of our current understanding of the placebo and nocebo effects in migraine management.

The Analgesic Effect and Potential Mechanisms of Acupuncture for Migraine Rats: A Systematic Review and Meta-Analysis

Purpose

To assess the inhibitory effect of acupuncture on pain symptoms in migraine models, and to further summarize the potential mechanisms of acupuncture in regulating hyperalgesia in the treatment of migraine.

Materials and Methods

Literature search in databases such as China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science (WOS) etc. The quality was evaluated by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) bias risk assessment tool and Collaborative Approach to Meta-analysis and Review of Animal Data from Experimental Studies (CAMARADES) checklist. Meta-analyses were performed using Stata 17.0 software.

Results

Twenty-one studies involving 489 animals were identified. The qualitative score ranged from 3 to 9 points. Facial mechanical withdrawal threshold (FMWT) and paw mechanical withdrawal threshold (PMWT) measured by Von Frey filaments were selected as major outcomes, and serum calcitonin gene-related peptide (CGRP) levels measured by ELISA were selected as secondary outcome. Meta-analysis results revealed that true acupuncture (TA) group significantly increased FMWT, PMWT and CGRP compared to model group. TA group showed superior effect in FMWT, PMWT relative to sham acupuncture (SA) group. Subgroup analysis results showed that high risk of bias scores may be responsible for the high heterogeneity of FMWT; additionally, CGRP analysis suggests that acupoint selection and blood collection sites may be sources of heterogeneity. In the treatment of migraine pain symptoms, the underlying mechanism of acupuncture treatment is either the regulation of hyperalgesia and neurotransmitters, or the reduction of inflammatory factors.

Conclusion

The results indicate that TA treatment effectively increased the pain threshold and reduced hyperalgesia in migraine rats. In summary, our study highlights the potential of TA as an effective treatment for migraine, but further investigation is required to fully comprehend its mechanism of action and optimize its clinical application.

Meta-regression to explain the placebo effects in clinical trials of anti-CGRP monoclonal antibodies for migraine prevention

Background: Commonly used methods of comparison (e.g. network meta-analyses) require common comparator(s) across trials, such as placebo in placebo-controlled trials. Recent literature indicates that route of administration differences across placebo arms of clinical trials in pain disorders may contribute to differences in placebo effect.Methods: We conducted a meta-regression on placebo data from pivotal clinical trials of anti-calcitonin gene-related peptide (anti-CGRP) monoclonal antibodies for migraine prevention to quantify the impact of route of administration, migraine type (episodic/chronic), and number of prior treatment failures on placebo reduction in monthly migraine days (MMDs) across weeks 1-12 of treatment. A systematic literature review of Embase, MEDLINE, the Cochrane Library, and grey literature conducted in June 2021 identified 14 relevant, randomized placebo-controlled trials for analysis.Results: After testing models with different covariates, a meta-regression was fitted to the extracted placebo data with the covariates of route of administration, migraine type, and proportion of patients with ≥2 prior preventive treatment failures. An intravenous route of administration for the placebo arm was a predictor for higher MMD reduction. Predictors of lower MMD reduction were migraine type (episodic migraine) and a higher proportion of patients having ≥2 failed preventive treatments.Conclusions: The efficacy of intravenous anti-CGRP monoclonal antibodies are likely underestimated, and differences in the route of administration of placebo may necessitate use of alternative methods that do not assume the presence of a common comparator when comparing anti-CGRP monoclonal antibodies in migraine prevention. Further research into the contextual effects of the placebo effect is warranted.