Therapeutic novelties in migraine: new drugs, new hope?

Highly Sensitive Assays for detection of headache inducing neuropeptides, Pituitary adenylate cyclase-activating polypeptide (PACAP) and Calcitonin gene-related peptide (CGRP)

Background

Migraine is one of the most disabling diseases that continues to pose a significant societal burden. Although there are now treatment options for people with migraine, it remains challenging to identify them as clinical features are diverse and complex, and there are no validated diagnostic or treatment prediction biomarkers. Identification is based on either diagnostic coding or the use of certain acute headache abortive treatments. However, socioeconomic disparities can contribute to under-diagnosis and under-treatment of migraine. Thus, efforts to find biomarkers to identify individuals with migraine and which variables could explain migraine-related chronification and disability are warranted. We aimed to investigate the levels of migraine inducing neuropeptides; calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) in peripheral blood samples as potential biomarkers of migraine.

Methods

We developed highly sensitive assays for CGRP and PACAP on the MSD S-PLEX assay platform and used them for bioanalysis of preclinical and clinical samples. Wildtype and neuropeptide challenged mice and rats were profiled using the developed assay. To follow-up, commercially obtained plasma samples from healthy controls and migraineurs were initially profiled. Subsequently, we profiled plasma samples from people with migraine (during and after a headache attack and healthy controls. Both MSD S-PLEX assays were transferred to Celerion where they were validated for analysis of clinical samples.

Results

Using the highly sensitive PACAP assay, we were able to reliably measure circulating levels of endogenous and administrated PACAP38in mouse and rat plasma. Additionally, using the highly sensitive CGRP assay, we were able to reliably measure circulating levels of endogenous and administrated CGRP in mouse and rat plasma. Furthermore, in the initial human samples, circulating CGRP and PACAP levels were not significantly different in healthy controls compared to people with migraine patients. However, ≥50% people with migraine showed increased circulating CGRP and PACAP levels during their attack period compared to post attack. Overall, people with migraine showed a 3 - 396% increase in one or both neuropeptides during their attack period compared to post attack. Circulating plasma CGRP and PACAP levels in healthy control subjects were consistent with previously measured levels.

Conclusion

Our highly sensitive PACAP and CGRP assays were successful in measuring circulating levels of endogenous PACAP38 and CGRP in mouse and rat plasma. Our highly sensitive PACAP and CGRP assays were qualified for measurement of human CGRP and PACAP in healthy control and migraine samples. Plasma CGRP and PACAP levels are elevated in migraineurs during an attack period, and the increased plasma neuropeptide levels during an attack may help the differentiation of migraineurs from non-Migraineurs, or amongst people with migraines to help identify the best treatment for each patient.

Real-world adherence to erenumab, rescue medication utilization, and work absenteeism for patients with migraine: Results from an outcomes-based agreement

BACKGROUND

Migraine prevalence is estimated to be 15% (approximately 50 million people) in the United States, posing a significant burden on the health care system and a top cause of years lived with disability. Consequently, migraine leads to increased work-related disability, including presenteeism and absenteeism. Novel prophylactic treatments for migraine that target the calcitonin gene-related peptide pathway, including monoclonal antibodies to the calcitonin gene-related peptide ligand or the calcitonin gene-related peptide receptor (calcitonin gene-related peptide monoclonal antibodies) and gepants, offer new options for migraine prevention. The advent of new medications presents an opportunity for development of outcomes-based agreements, particularly because these agents are more costly than traditional, nonspecific treatment alternatives. Outcomes-based agreements are pricing agreements between pharmaceutical manufacturers and payers, centered around predefined performance metrics to better align incentives and create shared risk between them.

OBJECTIVE

To report results of an outcomes-based agreement that was executed in a large integrated delivery and finance health system for patients with migraine who were prescribed erenumab, an anti-calcitonin gene-related peptide pathway monoclonal antibody.

METHODS

This is a prospective real-world analysis of commercial or health insurance exchange data from a large regional health system, based on parameters of an outcomes-based agreement. Eligible patients were new to calcitonin gene-related peptide monoclonal antibodies. Outcomes of interest included an erenumab adherence metric and changes in work absenteeism and rescue medication use. Proportion adherent and rescue medication use were assessed for the entire eligible patient cohort, whereas work absenteeism was only evaluated for a subset of eligible patients for whom work outcomes data were available.

RESULTS

There were 5,507 patients who filled erenumab during the contract period, and 1,281 patients were new to calcitonin gene-related peptide monoclonal antibodies medications. Of those, 865 constituted the eligible patient cohort and 224 constituted the work outcomes cohort. Patient adherence to erenumab was 80.5% and 81.7% for the entire patient cohort and work outcomes cohort, respectively. Absenteeism was reduced by 5.5% (21.64 vs 20.44 hours; P = 0.664) and rescue medication use was decreased by 3.6% (0.362 vs 0.349 doses; P = 0.589). Absenteeism could have been impacted by the onset of the COVID-19 pandemic.

CONCLUSIONS

As measured, adherence to erenumab was high within the cohort. The inclusion of a work outcomes cohort provided valuable insights about the clinical benefits of erenumab for migraine prevention. Our findings provide additional insights on the real-world use of erenumab within the context of an outcomes-based agreement.

GPT meets PubMed: a novel approach to literature review using a large language model to crowdsource migraine medication reviews

OBJECTIVE

To evaluate the potential of two large language models (LLMs), GPT-4 (OpenAI) and PaLM2 (Google), in automating migraine literature analysis by conducting sentiment analysis of migraine medications in clinical trial abstracts.

BACKGROUND

Migraine affects over one billion individuals worldwide, significantly impacting their quality of life. A vast amount of scientific literature on novel migraine therapeutics continues to emerge, but an efficient method by which to perform ongoing analysis and integration of this information poses a challenge.

METHODS

"Sentiment analysis" is a data science technique used to ascertain whether a text has positive, negative, or neutral emotional tone. Migraine medication names were extracted from lists of licensed biological products from the FDA, and relevant abstracts were identified using the MeSH term "migraine disorders" on PubMed and filtered for clinical trials. Standardized prompts were provided to the APIs of both GPT-4 and PaLM2 to request an article sentiment as to the efficacy of each medication found in the abstract text. The resulting sentiment outputs were classified using both a binary and a distribution-based model to determine the efficacy of a given medication.

RESULTS

In both the binary and distribution-based models, the most favorable migraine medications identified by GPT-4 and PaLM2 aligned with evidence-based guidelines for migraine treatment.

CONCLUSIONS

LLMs have potential as complementary tools in migraine literature analysis. Despite some inconsistencies in output and methodological limitations, the results highlight the utility of LLMs in enhancing the efficiency of literature review through sentiment analysis.

Proteome-wide Mendelian randomization identified potential drug targets for migraine

BACKGROUND

Migraine is a highly prevalent and complex neurovascular disease. However, the currently available therapeutic drugs often fall to adequately meet clinical needs due to limited effectiveness and numerous undesirable side effects. This study aims to identify putative novel targets for migraine treatment through proteome-wide Mendelian randomization (MR).

METHODS

We utilized MR to estimate the causal effects of plasma proteins on migraine and its two subtypes, migraine with aura (MA) and without aura (MO). This analysis integrated plasma protein quantitative trait loci (pQTL) data with genome-wide association studies (GWAS) findings for these migraine phenotypes. Moreover, we conducted a phenome-wide MR assessment, enrichment analysis, protein-protein interaction networks construction, and mediation MR analysis to further validate the pharmaceutical potential of the identified protein targets.

RESULTS

We identified 35 protein targets for migraine and its subtypes (p < 8.04 × 10-6), with prioritized targets showing minimal side effects. Phenome-wide MR identified novel protein targets-FCAR, UBE2L6, LATS1, PDCD1LG2, and MMP3-that have no major disease side effects and interacted with current acute migraine medication targets. Additionally, MMP3, PDCD1LG2, and HBQ1 interacted with current preventive migraine medication targets. The causal effects of plasma protein on migraine were partly mediated by plasma metabolites (proportion of mediation from 3.8% to 21.0%).

CONCLUSIONS

A set of potential protein targets for migraine and its subtypes were identified. These proteins showed rare side effects and were responsible for biological mechanisms involved in migraine pathogenesis, indicating priority for the development of migraine treatments.

Upholding or Breaking the Law of Superposition in Pharmacokinetics

The law of superposition underpins first-order linear pharmacokinetic relationships. Most drugs, therefore, after a single dose can be described by first-order or linear processes, which can be superposed to understand multiple-dose regimen behavior. However, there are a number of situations where drugs could display behaviors after multiple dosing that leads to capacity-limited or saturation non-linear kinetics and the law of superposition is overruled. This review presents a practical guide to understand the equations and calculations for single and multiple-dosing regimens after intravenous and oral administration. It also provides the pharmaceutical basis for saturation in ADME processes and the consequent changes in the area under the concentration-time curve, which represents drug exposure that can lead to the modulation of efficacy and/or toxic effects. The pharmacokineticist must implicitly understand the principles of superposition, which are a central tenet of drug behavior and disposition during drug development.

Multi-omics Mendelian randomization integrating GWAS, eQTL and pQTL data revealed GSTM4 as a potential drug target for migraine

INTRODUCTION

Migraine, as a complex neurological disease, brings heavy burden to patients and society. Despite the availability of established therapies, existing medications have limited efficacy. Thus, we aimed to find the drug targets that improve the prognosis of migraine.

METHOD

We used Mendelian Randomization (MR) and Summary-data-based MR (SMR) analyses to study possible drug targets of migraine by summary statistics from FinnGen cohorts (nCase = 44,616, nControl = 367,565), with further replication in UK Biobank (nCase = 26,052, nControl = 487,214). Genetic instruments were obtained from eQTLGen and UKB-PPP to verify the drug targets at the gene expression and protein levels. The additional analyses including Bayesian co-localization, the heterogeneity in dependent instruments(HEIDI), Linkage Disequilibrium Score(LDSC), bidirectional MR, multivariate MR(MVMR), heterogeneity test, horizontal pleiotropy test, and Steiger filtering were implemented to consolidate the findings further. Lastly, drug prediction analysis and phenome-wide association study(PheWAS) were employed to imply the possibility of drug targets for future clinical applications.

RESULT

The MR analysis of eQTL data showed that four drug targets (PROCR, GSTM4, SLC4A1, and TNFRSF10A) were significantly associated with migraine risk in both the FinnGen and UK Biobank cohorts. However, only GSTM4 exhibited consistent effect directions across the two outcomes(Discovery cohort: OR(95%CI) = 0.94(0.93-0.96); p = 2.70e - 10; Replication cohort: OR(95%CI) = 0.93(0.91-0.94); p = 4.21e - 17). Furthermore, GSTM4 passed the SMR at p < 0.05 and HEIDI test at p > 0.05 at both the gene expression and protein levels. The protein-level MR analysis revealed a strong correlation between genetically predicted GSTM4 with a lower incidence of migraine and its subtypes(Overall migraine: OR(95%CI) = 0.91(0.87-0.95); p = 6.98e-05; Migraine with aura(MA): OR(95%CI) = 0.90(0.85-0.96); p = 2.54e-03; Migraine without aura(MO): OR(95%CI) = 0.90(0.83-0.96); p = 2.87e-03), indicating a strong co-localization relationship (PPH4 = 0.86). Further analyses provided additional validation for the possibility of GSTM4 as a migraine treatment target.

CONCLUSION

This study identifies GSTM4 as a potential druggable gene and promising therapeutic target for migraine.

Therapeutic Approaches for Urologic Chronic Pelvic Pain Syndrome; Management: Research Advances, Experimental Targets, and Future Directions

Urologic chronic pelvic pain syndrome (UCPPS) is a painful chronic condition with persistent pain originating from the pelvis that often leads to detrimental lifestyle changes in the affected patients. The syndrome develops in both sexes, with an estimated prevalence of 5.7% to 26.6% worldwide. This narrative review summarizes currently recommended therapies for UCPPS, followed by the latest animal model findings and clinical research advances in the field. The diagnosis of UCPPS by clinicians has room for improvement despite the changes in the past decade aiming to decrease the time to treatment. Therapeutic approaches targeting growth factors (i.e., nerve growth factor, vascular endothelial growth factor), amniotic bladder therapy, and stem cell treatments gain more attention as experimental treatment options for UCPPS. The development of novel diagnostic tests based on the latest advances in urinary biomarkers would be beneficial to assist with the clinical diagnosis of UCPPS. Future research directions should address the role of chronic psychologic stress and the mechanisms of pain refractory to conventional management strategies in UCPPS etiology. Testing the applicability of cognitive behavioral therapy in this cohort of UCPPS patients might be promising to increase their quality of life. The search for novel lead compounds and innovative drug delivery systems requires clinically relevant translational animal models. The role of autoimmune responses triggered by environmental factors is another promising research direction to clarify the impact of the immune system in UCPPS pathophysiology. SIGNIFICANCE STATEMENT: This minireview provides an up-to-date summary of the therapeutic approaches for UCPPS with a focus on recent advancements in the clinical diagnosis and treatments of the disease, pathophysiological mechanisms of UCPPS, signaling pathways, and molecular targets involved in pelvic nociception.

Efficacy and safety of ubrogepant for migraine: a meta-analysis of randomized controlled studies

Introduction: The efficacy of ubrogepant 50 mg versus 100 mg daily for migraine remained controversial. We conducted a systematic review and meta-analysis to compare the efficacy and safety of ubrogepant 50 mg versus 100 mg daily on treatment in migraine patients.Methods: We have searched PubMed, EMbase, Web of science, EBSCO, Cochrane library databases and SCOPUS through 21 March 2022 for randomized controlled trials (RCTs) assessing the effect of ubrogepant 50 mg versus 100 mg on treatment efficacy in migraine patients. This meta-analysis was performed using the random-effect model.Results: Three RCTs were included in the meta-analysis. Overall, compared with ubrogepant 100 mg in migraine patients, ubrogepant 50 mg obtained comparable pain freedom at 2 h (OR = 0.86; 95% CI = 0.64-1.15; p = 0.310), sustained pain freedom 2-24 h (OR = 0.76; 95% CI = 0.54-1.07; p = 0.110), photophobia absence at 2 h (OR = 0.80; 95% CI = 0.63-1.02; p = 0.070), phonophobia absence at 2 h (OR = 1.07; 95% CI = 0.82-1.40; p = 0.620) and nausea absence at 2 h (OR = 1.02; 95% CI = 0.79-1.32; p = 0.880). In terms of safety, adverse events were found to be increased in ubrogepant 100 mg as compared to ubrogepant 50 mg (OR = 0.81; 95% CI = 0.67-0.99; p = 0.040), and there was no statistical difference of serious adverse events between two groups (OR = 0.87; 95% CI = 0.40-1.91; p = 0.720).Conclusions: Ubrogepant 50 mg and 100 mg may be equally effective to alleviate migraine, but ubrogepant 100 mg led to increase incidence of adverse events.

An update on migraine: Current and new treatment options

ABSTRACT

Migraine headache is a common and potentially debilitating disorder often treated by physician associates/assistants (PAs) and other providers. With the recent advances in new drugs and device technology for the treatment of migraine, the American Headache Society has released a consensus statement on both preventive and acute strategies for clinical practice. The US FDA has recently approved various types of medications and devices for the treatment and prevention of migraine attacks including several calcitonin gene-related peptide (CGRP) receptor inhibitors, a selective serotonin receptor agonist (SSRA), noninvasive vagus nerve stimulation (nVNS), external trigeminal nerve stimulation (e-TNS), and external concurrent occipital and trigeminal neurostimulation (eCOT-NS), among other pharmacologic and nonpharmacologic options. This article provides a review of migraine prevention and acute treatment protocol, highlighting new approaches to both.

Evaluation of the risk of hypertension in patients treated with anti-CGRP monoclonal antibodies in a real-life study

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.

Pharmacological management of migraine: current strategies and future directions

INTRODUCTION

Migraine is a complex neurological disorder that affects a significant portion of the global population. As traditional pharmacological approaches often fall short in alleviating symptoms, the development of innovative therapies has garnered significant interest. This text aims to summarize the current pharmacological options for managing migraine and to explore the potential impact of novel therapies.

AREAS COVERED

We focused on conventional treatments, emerging therapies, and novel compounds in clinical development, including therapies targeting the trigeminovascular system, cannabis-based therapies, hormonal and metabolic therapies, and other options. English peer-reviewed articles were searched in PubMed, Scopus, and ClinicalTrials.gov electronic databases.

EXPERT OPINION

Several novel treatment options for migraine have become available in recent years. Emerging pharmacological therapies targeting the trigeminovascular system, cannabis-based therapies, hormonal and metabolic interventions, and other emerging treatment modalities, may prove to be valuable for the treatment of migraine. Further research, clinical trials, and substantiated evidence are necessary to validate the efficacy, safety, and long-term outcomes of these therapeutic options.

Evaluating Ubrogepant-related adverse events using the FDA adverse event reporting system

BACKGROUND

Migraine has a high prevalence in the population and accounts for 12% of primary headaches. Ubrogepant is used for the treatment of acute migraine, and although some clinical trials have demonstrated the safety of Ubrogepant, its long-term safety in a large sample of the population remains to be investigated.

METHODS

We collected data from the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. We used reporting odds ratio (ROR), the proportional reporting ratio (PRR), the information component (IC) and the empirical Bayes geometric mean (EBGM) to evaluate Ubrogepant-induced adverse events (AEs).

RESULTS

We screened out 2,067 reports of Ubrogepant as primary suspected (PS) and 6,190 reports of Ubrogepant-induced AEs as PS. Our results showed that Ubrogepant-induced AEs targeted 4 system organ classes (SOCs), detected 32 Preferred terms (PTs) signals in 9 SOCs, including common Ubrogepant label consistent with Migraine, Nausea, Somnolence, Paraesthesia oral and Dizziness, It also includes the AEs of Hemiparesis, Mental impairment, Dysstasia, Tinnitus, Chest pain, Cold sweat, Neck pain, etc. that have not been demonstrated in previous studies.

CONCLUSIONS

Our study identified new AEs that have not been reported, which provides a new guidance to deepen the comprehension of the safety of Ubrogepant.

Therapeutic innovation in high-prevalence chronic diseases: Challenges and opportunities for specialist care models

Therapeutic innovation is expected to change if not disrupt present care models for several chronic diseases in the coming years, as suggested by recent clinical trials. New drugs that anticipate and possibly delay the full expression of a disease will likely face some common challenges, such as the need of designing and implementing large scale interventions; the necessary engagement of multiple specialties for both diagnosis and treatment; the shift from specialist to non-specialist interventions and secondary prevention. Building on the case of HCV and other innovation in hepatology, we discuss common challenges caused by disruptive change that other chronic conditions faced in the past. The recent history of hepatology shows interesting examples of disruptive innovations that completely reverted traditional treatment approaches. As we learned from the slow early diffusion of antiviral drugs, without a clear information and a prompt design of the appropriate delivery modalities, the effectiveness of new treatments is undermined and care risk to be postponed for long time. This implies the definition of (i) new service models diversified by care phases and patients' target; (ii) horizontal integration: to go beyond the professional boundaries to build solid alliances; (iii) vertical integration between primary and secondary care.

Safety and Efficacy of Calcitonin Gene-related Peptide Receptor Antagonists and Selective Serotonin Receptor Agonist in the Management of Migraine: A Systematic Review and Meta-analysis

BACKGROUND

Recently, US Food and Drug Administration (FDA) has approved calcitonin gene-related peptide receptor antagonists (rimegepant, and ubrogepant), and selective serotonin receptor agonists (lasmiditan) in the management of migraine. However, the exact safety and efficacy profile of these drugs is unclear so far.

METHODS

The study's primary objective was to determine the exact safety and efficacy profile. The overall estimate was calculated in terms of risk ratios using a suitable model. The subgroup analysis was also performed to check the effect of individual drugs on the outcome, whereas sensitivity analysis was performed to check the effects of outliers on the outcome. All the analyses were performed using Rev Man 5. The drugs have shown significant improvement in efficacy parameters (pain freedom, most bothersome symptoms, phonophobia, nausea, and photophobia).

RESULTS

The subgroup analysis results have shown significant improvement in all efficacy parameters in the rimegepant and ubrogepant groups. The effect of ubrogepant on safety parameters was found to be non-significant, indicating a better safety profile of ubrogepant than lasmiditan.

CONCLUSION

The sensitivity analysis results have shown no effect of outliers on the efficacy parameters. Based on the available evidence, recently approved drugs are effective in the treatment of migraine, however, associated with few adverse drug reactions.

Real-world treatment satisfaction with erenumab in migraine: analysis of the US National Health and Wellness Survey

OBJECTIVE

The treatment landscape for the prevention of migraine has rapidly evolved in recent years with the advent of calcitonin gene-related peptide therapy, including erenumab. The objective of this study was to assess patient-reported treatment satisfaction among erenumab users.

METHODS

This retrospective, cross-sectional study used data from the 2019 US National Health and Wellness Survey collected during March-July 2019. Respondents self-reporting physician-diagnosed migraine and currently using erenumab were analyzed. Treatment satisfaction was measured on a seven-point Likert scale. Data were further reported by the duration of erenumab treatment. Data on respondents' socio-demographic characteristics and treatment patterns were also collected.

RESULTS

Overall, 67 respondents using erenumab with or without other migraine preventives for up to 1 year were included in the analysis. The mean (standard deviation) age was 46.7 (12.9) years. Most of the respondents were women (86.6%), White (74.6%), and commercially-insured (67.2%). Notably, 40.3% had ≥1 comorbidity per the Charlson Comorbidity Index. Approximately half of the respondents were college graduates and employed (49.3% each). Among the 67 respondents, 46 received erenumab exclusively. Across both cohorts, the percentage of respondents who were satisfied with erenumab treatment was slightly higher among those with a longer treatment duration (overall erenumab cohort: 63.6%, 69.6%, and 75.8% for 0-<3, 3-<6, and 6-12 months, respectively; erenumab monotherapy cohort: 62.5%, 71.4%, and 87.5% for 0-<3, 3-<6, and 6-12 months, respectively). Treatment patterns before switching to erenumab revealed that most respondents had used ≥1 preventive treatment for migraine (80.6%; 54/67), over two-thirds (33/54) of whom had ≥2 treatment failures owing to nonresponse.

CONCLUSION

Satisfaction was high among long-term erenumab users, indicating that those using erenumab for a longer duration are more satisfied. Furthermore, this study provided insights on the basic socio-demographics, disease characteristics, and health behaviors of erenumab users as well as their treatment patterns before switching to erenumab.

Consensus-Based Recommendations on the Use of CGRP-Based Therapies for Migraine Prevention in the UAE

INTRODUCTION

Migraine is a common debilitating neurological disorder affecting a large proportion of the general population. Calcitonin gene-related peptide (CGRP), a 37-amino acid neuropeptide, plays a key role in the pathophysiology of migraine, and the development of therapies targeting the anti-CGRP pathway has revolutionized the field of migraine treatment.

METHODS

An expert task force of neurologists in the United Arab Emirates (UAE) developed and critically assessed recommendations on the use of CGRP-based therapies in migraine treatment and management in the UAE, based on available published literature. A consensus was reached for each statement by means of an open-voting process, based on a predefined agreement level of at least 60%.

RESULTS

The consensus recommendations advocate the need for guidelines for the appropriate use of CGRP-based therapies by defining patient cohorts and appropriate monitoring of therapeutic response as well as standardizing the initiation, assessment, and cessation of treatment. The consensus recommendations were primarily formulated on the basis of international studies, because of the limited availability of regional and local data. As such, they may also act as guidelines for global healthcare providers.

CONCLUSIONS

These are the first consensus recommendations for the UAE that address the use of CGRP-based therapies in the treatment and management of migraine, integrating both clinical evidence and medical expertise to enhance clinical judgment and decision-making.

Treatment patterns for patients initiating novel acute migraine specific medications (nAMSMs) in the context of monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway

BACKGROUND

New acute and preventive migraine medications are available, but data on current treatment patterns are limited. This study describes migraine treatment patterns among patients initiating novel acute migraine specific medications (nAMSMs), overall and by prior use of anti-calcitonin gene-related peptide (CGRP) pathway monoclonal antibodies (mAbs).

METHODS

In this retrospective cohort study using IQVIA open-source pharmacy and medical claims data, we identified patients with ≥ 1 claim for a nAMSM (ubrogepant, rimegepant, lasmiditan) between 01/01/2020 and 09/30/2020 (index period). Patients were indexed on their first nAMSM claim and stratified into 2 cohorts: patients with prior mAb use (≥ 1 claim for erenumab, fremanezumab, galcanezumab in the 6-month pre-index period) or patients without prior mAb use. Treatment patterns were assessed during the 6-month post-index period.

RESULTS

Overall, 78,574 patients were identified (63% indexed on ubrogepant, 34% on rimegepant, and 3% on lasmiditan) with 26,656 patients (34%) having had prior mAb use. In the pre-index period, 79% of patients used non-mAb preventive medications and 75% of patients used acute medications. Following the index nAMSM claim, 65% of patients had ≥ 1 refill and 21% had ≥ 4 refills of their index nAMSM; 10% of patients switched to another nAMSM. Post-index mAb use was observed in 82% of patients with a prior mAb and 15% of patients without. Among patients with pre- and post-index use of acute medications, 38% discontinued ≥ 1 acute medication class in the post-index period. Among patients with concomitant use of traditional preventive medications at index, 30% discontinued ≥ 1 concomitant preventive anti-migraine medication in the post-index period.

CONCLUSIONS

Most patients initiating nAMSMs had prior treatment with acute and preventive medications. Approximately one-third of patients had prior treatment with anti-CGRP pathway mAbs. After starting nAMSMs, more than one-third of patients discontinued at least one traditional acute medication and one-third of patients discontinued at least one traditional preventive medication. Despite nAMSM initiation, most patients with prior anti-CGRP pathway mAb use continued mAb use. Around 15% of patients without a prior mAb newly started a mAb. These results provide insight into how nAMSMs and mAbs have been integrated into clinical management of migraine in the real-world.

A Comprehensive Review of the Mechanism, Efficacy, Safety, and Tolerability of Ubrogepant in the Treatment of Migraine

Ubrogepant is an innovative medication designed for the acute treatment of migraine, a debilitating neurological condition that profoundly impairs quality of life, productivity, and social interactions. This comprehensive review assesses the efficacy, safety, tolerability, and mechanism of action of ubrogepant through a rigorous methodology, including an in-depth literature review from reputable databases like PubMed, Web of Science, Embase, Scopus, and Cochrane. Classified as a calcitonin gene-related peptide (CGRP) receptor antagonist, ubrogepant has emerged as a potential revolutionary medication for migraine treatment. CGRP is a peptide integral to migraine pathophysiology, and its blockade has demonstrated great therapeutic potential. Unlike triptans, known for their cardiovascular risks, ubrogepant lacks vasoconstrictive properties, making it a safer alternative for a broader patient population. Ubrogepant offers significant potential for pain relief, symptom reduction, and restoration of normal function during a migraine attack, and it outperforms placebo in terms of efficacy. It also presents favorable safety, with generally mild adverse drug events (ADEs), such as nausea, dizziness, and somnolence, similar to placebo effects. Consistent results from clinical trials confirm its tolerability, with minor ADEs and no safety alerts for the tested doses, indicating that ubrogepant is a safe and well-tolerated option for migraine treatment. As an effective oral medication, ubrogepant could be an alternative to traditional acute migraine treatments. Its benefits include a unique mechanism of action, rapid onset, and favorable safety profile. However, specific contraindications, such as hypersensitivity, severe hepatic impairment, concurrent use of CYP3A4 inhibitors, pregnancy or breastfeeding, and uncontrolled hypertension, require caution or avoidance of ubrogepant. Despite these limitations, ubrogepant signals a promising new direction in migraine therapeutics.

Evaluating therapeutic benefits of ubrogepant via latent class models: A post hoc exploratory analysis of the ACHIEVE I and ACHIEVE II trials

OBJECTIVE

To evaluate an alternative method of defining acute treatment success in migraine by combining multiple indicators into a single dichotomous measure of success.

BACKGROUND

Migraine is characterized by a symptom complex; combining these features as a single endpoint may improve the measurement of treatment effects and better predict patient satisfaction with treatment.

METHODS

We used a confirmatory latent class model (LCM) with two latent classes interpreted as treatment success and treatment failure. Pooled data for placebo and ubrogepant 50 mg from the ACHIEVE I and ACHIEVE II trials and data for ubrogepant 100 mg from ACHIEVE I were used. LCM inputs included pre-dose and 2-h post-dose measures of pain severity (0-3), the presence/absence of associated symptoms (nausea, photophobia, and phonophobia [0 or 1]), and functional disability (0-3). All definitions were validated against satisfaction with study medication (SWSM) at 24 h post-dose; results were compared with 2-hour pain freedom (2hPF).

RESULTS

This pooled analysis included 2247 participants. At 2 h post-dose in the ubrogepant 50 and 100 mg dose groups, 53.2% (472/887) and 54.9% (246/448) of participants, respectively, were classified as achieving treatment success using the LCM-based approach, compared to 39.0% (356/912) of participants in the placebo group. The results for treatment success using the 2hPF endpoint were 20.7% (184/887) and 21.5% (96/447) in the ubrogepant 50 and 100 mg dose groups, respectively, compared to 12.7% (116/912) for placebo. Using 24-h SWSM as an external validator, the LCM approach sensitivity and correct classification rates were higher than for 2hPF.

CONCLUSION

The LCM approach led to higher rates of treatment success and greater separation between ubrogepant and placebo and was a more sensitive predictor of treatment satisfaction than the regulatory endpoint of 2hPF.

Antinociceptive Effects of an Anti-CGRP Antibody in Rat Models of Colon-Bladder Cross-Organ Sensitization

Irritable bowel syndrome (IBS) and bladder pain syndrome/interstitial cystitis (BPS/IC) are comorbid visceral pain disorders seen commonly in women with unknown etiology and limited treatment options and can involve visceral organ cross-sensitization. Calcitonin gene-related peptide (CGRP) is a mediator of nociceptive processing and may serve as a target for therapy. In three rodent models, we employed a monoclonal anti-CGRP F(ab')2 to investigate the hypothesis that visceral organ cross-sensitization is mediated by abnormal CGRP signaling. Visceral organ cross-sensitization was induced in adult female rats via transurethral infusion of protamine sulfate (PS) into the urinary bladder or infusion into the colon of trinitrobenzene sulfonic acid (TNBS). Colonic sensitivity was assessed via the visceromotor response to colorectal distension (CRD). Bladder sensitivity was assessed as the frequency of abdominal withdrawal reflexes to von Frey filaments applied to the suprapubic region. PS- or TNBS-induced changes in colonic and bladder permeability were investigated in vitro via quantification of transepithelial electrical resistance (TEER). Peripheral administration of an anti-CGRP F(ab')2 inhibited PS-induced visceral pain behaviors and colon hyperpermeability. Similarly, TNBS-induced pain behaviors and colon and bladder hyperpermeability were attenuated by anti-CGRP F(ab')2 treatment. PS into the bladder or TNBS into the colon significantly increased the visceromotor response to CRD and abdominal withdrawal reflexes to suprapubic stimulation and decreased bladder and colon TEER. These findings suggest an important role of peripheral CGRP in visceral nociception and organ cross-sensitization and support the evaluation of CGRP as a therapeutic target for visceral pain in patients with IBS and/or BPS/IC. SIGNIFICANCE STATEMENT: A monoclonal antibody against calcitonin gene-related peptide (CGRP) was found to reduce concomitant colonic and bladder hypersensitivity and hyperpermeability. The results of this study suggest that CGRP-targeting antibodies, in addition to migraine prevention, may provide a novel treatment strategy for multiorgan abdominopelvic pain following injury or inflammation.

Migraine drugs

According to recent studies, migraine affects more than 1 billion people worldwide, making it one of the world’s most prevalent diseases. Although this highly debilitating illness has been known since ancient times, the first therapeutic drugs to treat migraine, ergotamine (Gynergen) and dihydroergotamine (Dihydergot), did not appear on the market until 1921 and 1946, respectively. Both drugs originated from Sandoz, the world’s leading pharmaceutical company in ergot alkaloid research at the time. Historically, ergot alkaloids had been primarily used in obstetrics, but with methysergide (1-methyl-lysergic acid 1′-hydroxy-butyl-(2S)-amide), it became apparent that they also held some potential in migraine treatment. Methysergide was the first effective prophylactic drug developed specifically to prevent migraine attacks in 1959. On the basis of significantly improved knowledge of migraine pathophysiology and the discovery of serotonin and its receptors, Glaxo was able to launch sumatriptan in 1992. It was the first member from the class of triptans, which are selective 5-HT1B/1D receptor agonists. Recent innovations in acute and preventive migraine therapy include lasmiditan, a selective 5-HT1F receptor agonist from Eli Lilly, the gepants, which are calcitonin gene-related peptide (CGRP) receptor antagonists discovered at Merck & Co and BMS, and anti-CGRP/receptor monoclonal antibodies from Amgen, Pfizer, Eli Lilly, and others.

Graphical abstract

Human Brain Organoids in Migraine Research: Pathogenesis and Drug Development

Human organoids are small, self-organized, three-dimensional (3D) tissue cultures that have started to revolutionize medical science in terms of understanding disease, testing pharmacologically active compounds, and offering novel ways to treat disease. Organoids of the liver, kidney, intestine, lung, and brain have been developed in recent years. Human brain organoids are used for understanding pathogenesis and investigating therapeutic options for neurodevelopmental, neuropsychiatric, neurodegenerative, and neurological disorders. Theoretically, several brain disorders can be modeled with the aid of human brain organoids, and hence the potential exists for understanding migraine pathogenesis and its treatment with the aid of brain organoids. Migraine is considered a brain disorder with neurological and non-neurological abnormalities and symptoms. Both genetic and environmental factors play essential roles in migraine pathogenesis and its clinical manifestations. Several types of migraines are classified, for example, migraines with and without aura, and human brain organoids can be developed from patients with these types of migraines to study genetic factors (e.g., channelopathy in calcium channels) and environmental stressors (e.g., chemical and mechanical). In these models, drug candidates for therapeutic purposes can also be tested. Here, the potential and limitations of human brain organoids for studying migraine pathogenesis and its treatment are communicated to generate motivation and stimulate curiosity for further research. This must, however, be considered alongside the complexity of the concept of brain organoids and the neuroethical aspects of the topic. Interested researchers are invited to join the network for protocol development and testing the hypothesis presented here.

Revisiting Migraine: The Evolving Pathophysiology and the Expanding Management Armamentarium

Migraine affects about one billion people worldwide yearly and is one of the most common neurologic illnesses, with a high prevalence and morbidity, particularly among young adults and females. Migraine is associated with many comorbidities, including stress, sleep difficulties, and suicidal ideation. Migraine, despite its widespread occurrence, is underdiagnosed and undertreated. Because of the complicated and primarily unknown mechanisms of migraine formation, several social and biological risk factors, such as hormone imbalances, genetic and epigenetic impacts, and cardiovascular, neurological, and autoimmune illnesses, have been proposed. Through the mid-20th century diversion of the now-defunct vascular theory, the pathophysiology of migraine has developed from a historical study of the "humours" to a distinct entity as a neurological disorder. The range of therapeutic targets has broadened significantly, increasing the number of specialized clinical trials. Understanding the biology of migraine through careful research has resulted in the identification of major therapeutic classes: (i) triptans, serotonin 5-HT1B/1D receptor agonists, (ii) gepants, calcitonin gene-related peptide (CGRP) receptor antagonists, (iii) ditans, 5-HT1F receptor agonists, (iv) CGRP monoclonal antibodies, and (v) glurants, mGlu5 modulators, with further targets being explored. This review provides a comprehensive overview of the most recent literature on epidemiology and risk factors and exposes knowledge gaps.

Exploration of phytochemicals and probing potential effects of Priva cordifolia active extract on PACAP 38 and its nociceptor in the human trigeminovascular system

Several tribal medicinal systems assert anti-migraine and common headache-remedying properties in all parts of Priva cordifolia (L.f.) Druce. Therefore, there are no clear scientific references to the validated traditional use of this plant. The present study provides a scientific basis for the ethnobotanical utility of P. cordifolia whose whole-plant extracts were evaluated against target proteins (PACAP 38 and PAC1-R) that cause migraine. Understanding the polarity-based distribution and oxidative stress scavenging ability was reported higher in ethyl acetate extracts due to the moderate distribution of secondary metabolites. Based on the preliminary analysis anti-migraine activity in the wet and dry lab experiments was compared with a commercial drug Sumatriptan. The GC-MS analysis revealed that two lead volatile compounds Bicyclo(3.2.1)oct-3-en-2-one,3,8-Dihydroxy-1-methoxy-7-(7-methoxy-1,3- and -Hexyl-2-nitrocyclohexane, present in the ethyl acetate extract showed favourable in silico anti-migraine efficiency. Notably, the ex-vivo results also showed considerable downregulation of the extract-induced mRNA expression of PACAP38. The conclusion of our study justifies that P. cordifolia has valuable plant metabolites that portray it as an efficient anti-oxidant and anti-migraine source.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03462-w.

Global Epidemiology, Clinical Features, Diagnosis and Current Therapeutic Novelties in Migraine Therapy and their Prevention: A Narrative Review

INTRODUCTION

The current article reviews the latest information on epidemiology, clinical features, diagnosis, recent advancements in clinical management, current therapeutic novelties, and the prevention of migraines. In a narrative review, all studies as per developed MeSH terms published until February 2023, excluding those irrelevant, were identified through a PubMed literature search.

METHODS

Overall, migraine affects more than a billion people annually and is one of the most common neurological illnesses. A wide range of comorbidities is associated with migraines, including stress and sleep disturbances. To lower the worldwide burden of migraine, comprehensive efforts are required to develop and enhance migraine treatment, which is supported by informed healthcare policy. Numerous migraine therapies have been successful, but not all patients benefit from them.

RESULTS

CGRP pathway-targeted therapy demonstrates the importance of translating mechanistic understanding into effective treatment. In this review, we discuss clinical features, diagnosis, and recently approved drugs, as well as a number of potential therapeutic targets, including pituitary adenylate cyclase-activating polypeptide (PACAP), adenosine, opioid receptors, potassium channels, transient receptor potential ion channels (TRP), and acid-sensing ion channels (ASIC).

CONCLUSION

In addition to providing more treatment options for improved clinical care, a better understanding of these mechanisms facilitates the discovery of novel therapeutic targets.

Safety and tolerability results of atogepant for the preventive treatment of episodic migraine from a 40-week, open-label multicenter extension of the phase 3 ADVANCE trial

BACKGROUND

Atogepant is a United States Food and Drug Administration-approved oral calcitonin gene-related peptide receptor antagonist for the preventive treatment of episodic migraine. The study objective was to evaluate the long-term safety and tolerability of atogepant in participants who completed the phase 3 ADVANCE trial (NCT03777059).

METHODS

This 40-week, open-label extension trial (NCT03939312) monitored safety in participants receiving oral atogepant 60 mg once daily, followed by a four-week safety follow-up period.

RESULTS

Of the 685 participants taking at least one dose of atogepant, the treatment period was completed by 74.6% of participants with a mean (standard deviation) treatment duration of 233.6 (89.3) days. Treatment-emergent adverse events occurred in 62.5% of participants, with upper respiratory tract infection (5.5%), urinary tract infection (5.3%), nasopharyngitis (4.8%), sinusitis (3.6%), constipation (3.4%), and nausea (3.4%) occurring at ≥3%. Serious adverse events were observed in 3.4% of participants (none were treatment-related), and there were no deaths. Adverse events leading to discontinuation occurring at >0.1% were nausea (0.4%) and abdominal pain, vomiting, weight decrease, dizziness, and migraine (0.3% each).

CONCLUSION

These results are consistent with atogepant's known safety profile and support long-term use of atogepant 60 mg once daily dosing as safe and well tolerated.ClinicalTrials.gov Registration Number: NCT03939312.

Advances in CGRP Monoclonal Antibodies as Migraine Therapy: A Narrative Review

Migraine is a potentially disabling disorder, yet it remains underdiagnosed and undertreated. The release of the neuropeptide calcitonin gene-related peptide (CGRP) in the trigemino-cerebrovascular system plays a vital role in the evolution of migraine. It enhances peripheral sensitization by mediating neurogenic inflammation and also influences central sensitization. The majority of the drug classes available for migraine prophylaxis are nonspecific and associated with numerous side effects and drug interactions. Anti-CGRP monoclonal antibodies (mAb) are an innovative therapeutic class that fulfills the need for more efficacious and tolerable preventive therapy. While erenumab is a mAb to the CGRP receptor, eptinezumab, fremanezumab, and galcanezumab bind to the CGRP molecule. They decrease the number of headache days and improve disability. Upper respiratory tract infection, nausea, constipation, pain at the site of injection, and fatigue are the associated side effects. CGRP mAbs are an excellent advancement in translational research and are a promising addition in migraine therapy. This article discusses the recent advances in the development of the CGRP mAbs.

Trends in utilization and costs of migraine medications, 2017–2020

Objective

This study examines changes in utilization and costs trends associated with migraine medications.

Background

Migraine attacks are a burden to many patients. There are many pharmacotherapy options available with newer migraine drug classes entering the market in the past decade. Little is known about the use, associated costs, and the impact of the newer agents.

Methods

This retrospective, cross-sectional study examined 2017–2020 administrative claims from a large national pharmacy benefits manager. Patients aged ≥ 18 years enrolled in commercial, Medicare, Medicaid, or health insurance exchange insurance plans who filled ≥ 2 prescription claims for triptans, ergotamines, isometheptenes, gepants, ditans, and CGRP mABs were included. A two-sample t-test was conducted to estimate whether differences in mean utilization and costs between 2017 and 2020 were statistically significant for migraine drug classes, except for CGRP mABs, which were estimated between 2018 and 2020.

Results

The sample ranged from 161,369 (2017) to 240,330 (2020) patients. 84.5% (n = 203,110; 2020) of patients were women. The number of 30-day adjusted prescription fills for prophylaxis remained stable over the four-year period, except for CGRP mABs, which increased from 0.5% (n = 0.007; 2018) to 5.3% (n = 0.075; 2020). Antiepileptics, antidepressants and beta blockers were the most common prophylaxes, while triptans, non-steroidal anti-inflammatory drugs/non-narcotic analgesics and opioids were the most common treatments utilized. CGRP mABs were the most expensive, while utilization of triptans were the highest. CGRP mABs had the largest increase in utilization (177.5%) and costs (166.3%) PPPM in 2020 ($291.17) compared to 2018 ($109.35), the year they were first available (p < 0.001). Between 2018 and 2020, costs increased overall and for commercial and Medicare enrollees, but remained unchanged for Medicaid and HIX members.

Conclusion

Our study demonstrates a shift in migraine medication utilization from 2017–2020, where increased use of CGRP mABs had a significant contribution to increased costs. These increased pharmacy costs must be weighed against the improved tolerability of these agents likely resulting in other healthcare and indirect cost savings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01476-y.

Eptinezumab-jjmr, a humanized monoclonal specific to Calcitonin Gene Related Peptide, for the preventive treatment of migraine in adults

PURPOSE OF REVIEW

Migraines are prevalent and cause significant morbidity, decline in quality of life and healthcare costs universally. Treatment options are varied, but efficacy is limited. This review centers on Eptinezumab-jjmr, a humanized monoclonal specific to CGRP for the prevention of migraines in adults. Herein presented are the science and mechanism of action, indication and clinical evidence for use.

RECENT FINDINGS

Migraines are severe, recurrent headaches, which are either episodic or chronic in nature. The pain is severe, often accompanied by co-morbid symptoms, such as photophobia, phonophobia, nausea and emesis, and is limiting in nature. It is a prevalent disorder that causes significant, worldwide disability, morbidity, suffering, and costs.The pathophysiology of migraines is actively studied, though recent research points to an initiating event causing migraine generation, that is then propagated by other brain regions, a significant one being the trigeminocervical complex. This is driven by biochemical transmitters, chiefly CGRP. This discovery led to the development of CGRP-targeting drugs, including gepants (small molecular antagonists) and anti-CGRP antibodies, such as Eptinezumab-jjmr.Traditional therapy includes preventative and abortive treatment; however, adherence with preventative treatment has been historically poor, and certain types of abortive therapy carry risks and side effects that preclude them from a large patient population. Moreover, traditional therapy often falls short in migraine therapy. CGRP antagonist, including Eptinezumab, aims to cover the gaps in migraine therapy. We present here evidence to support the safe and effective use of Eptinezumab for the prevention of migraines.

SUMMARY

Migraines are a prevalent primary headache disorder causing significant morbidity worldwide. Traditional abortive and preventative treatments fall short for many patients. Eptinezumab is part of new generation of CGRP-targeting medications and has shown significant evidence to support its use for the prevention of migraines. Further research is required to properly compare eptinezumab with existing pharmacotherapy and update guidelines on the appropriate combinations of therapies that are not available and the correct patient selection for each.

Rimegepant for the treatment of migraine

Migraine is a common form of primary headache, affecting up to 1 in every 6 Americans. The pathophysiology is an intricate interplay of genetic factors and environmental influence and is still being elucidated in ongoing studies. The trigeminovascular system is now known to have a significant role in the initiation of migraines, including the release of pain mediators such as CGRP and substance P. Traditional treatment of migraine is usually divided into acute and preventive treatment. Acute therapy includes non-specific therapy, such as NSAIDs and other analgesics, which may provide relief in mild to moderate migraines. 5-HT1 agonists may provide relief in severe migraine, but are not universally effective and carry a significant side-effect profile with frequent redosing requirement. Prophylactic therapy may reduce the occurrence of acute migraine attacks in selected patients, but does not completely eliminate it. More recently, CGRP antagonism has been studied and shown to be effective in both abortion and prevention of migraine. Novel medications, targeting CGRP, divide into CGRP antibodies and receptor antagonists (gepants). Rimegepant, a second-generation gepant, has shown efficacy in several clinical trials in treating acute migraine. Ongoing trials are also evaluating its role in migraine prophylaxis, and results are promising. It is also generally safer for use than existing options, does not appear to increase the chance of developing chronic migraines, and carries a very tolerable side effects profile. It is a part of a growing arsenal in migraine treatment, and may present the silver bullet for treatment of this disease.

Migraine: interactions between brain's trait and state

It is well established that migraine is a multifactorial disorder. A deep understanding of migraine should be based upon both the underlying traits and the current states affected by different physiological, psychological, and environmental factors. At this point, there is no framework fully meeting these criteria. Here, we describe a broader view of the migraine disorder defined as a dysfunctional brain state and trait interaction. In this model, we consider events that may enhance or diminish migraine responsivity based on an individual's trait and state. This could provide an expanded view for considering how migraine attacks are sometimes precipitated by "triggers" and sometimes not, how these factors only lead to migraine attacks in migraine patients, or how individuals with an increased risk for migraine do not show any symptoms at all. Summarizing recent studies and evidence that support the concept of migraine as a brain state-trait interaction can also contribute to improving patient care by highlighting the importance of precision medicine and applying measures that are able to capture how different traits and states work together to determine migraine.

Headache: Treatment update

Primary headache disorders in particular migraine are one of the most common causes of disability worldwide. Given the high burden of migraine in terms of disability, there has been an effort to develop migraine specific therapies that has led to the availability of new drugs including 5HT_1F receptor agonists-ditans (lasmiditan), small molecule calcitonin gene-related peptide (CGRP) receptor antagonists-gepants: (ubrogepant, rimegepant, atogepant) and anti-CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab and eptinezumab). However, some of these treatments incur a high cost and may not be a feasible option for most patients in resource limited settings. Lasmiditan and the gepants are a good option for patients with moderate-severe migraine attacks who cannot use triptans due variously to poor tolerability, or cardio- or cerebrovascular disease. For practical purposes, the new anti-CGRP monoclonal antibodies are best reserved for patients who have failed to have efficacy or had intolerable side effects from multiple traditional oral preventives.

Recently approved and emerging drug options for migraine prophylaxis

INTRODUCTION

: Migraine occupies the first position regarding to the disability caused in female working population (15-49 years). Research in the field of prophylaxis of this pathology has made enormous strides in recent years.

AREAS COVERED

In this narrative review we retrace the most important scientific evidence regarding recently approved and emerging drug for prophylactic treatment of migraine. The purpose of this article is in fact to evaluate currently approved or emerging pharmacological agents for migraine prophylaxis. This review is based on literature published in peer review journal obtained through PubMed, Cochrane library, Clinicaltrials.gov and US FDA.

EXPERT OPINION

: Monoclonal antibodies (mAbs) that target the calcitonin gene-related peptide signalling pathway (CGRP) have marked an innovation in prophylactic migraine therapy. The combination of Onabotulinumtoxin-A (OBTA) and mAbs appears to be an effective, but costly, therapeutic option for resistant cases. New classes of molecules like gepants and ditans seem to give exceptional results. In addition, new prophylactic drugs are emerging with several targets: the pituitary adenylate cyclase-activating polypeptide (PACAP), ion channels, several receptors coupled to G proteins, orexin, and glutamate. All these therapies will implement and improve migraine management, as well as personalized medicine for each patient.

Galcanezumab effect on "whole pain burden" and multidimensional outcomes in migraine patients with previous unsuccessful treatments: a real-world experience

BACKGROUND

Clinical trials have demonstrated galcanezumab as safe and effective in migraine prevention. However, real-life data are still lacking and overlook the impact of galcanezumab on those different migraine facets strongly contributing to migraine burden. Herein we report the clinical experience from an Italian real-world setting using galcanezumab in patients with migraine experiencing previous unsuccessful preventive treatments.

METHODS

Forty-three patients with migraine and failure of at least 3 migraine preventive medication classes received monthly galcanezumab 120 mg s.c. At the first administration and after 3 and 6 months, patients underwent extensive interviews to assess clinical parameters of disease severity. Furthermore, validated questionnaires were administered to explore migraine-related disability, impact, and quality of life as well as symptoms of depression or anxiety, pain catastrophizing, sleep quality and the ictal cutaneous allodynia.

RESULTS

After the third and the sixth administration of monthly galcanezumab 120 mg s.c., headache attacks frequency reduced from 20.56 to 7.44 and 6.37 headache days per month, respectively. Moreover, a significant improvement in headache pain intensity (from 8.95 to 6.84 and 6.21) and duration (from 9.03 to 3.75 and 2.38) as well as in scores assessing migraine related disability and impact, depressive and anxious symptoms, and pain catastrophizing was observed. Furthermore, we demonstrated a significant reduction in the values of "whole pain burden", a composite score derived from the product of the average of headache frequency, intensity, and duration in the last three months.

CONCLUSION

Real-world data support monthly galcanezumab 120 mg s.c. as a safe and effective preventive treatment in reducing headache frequency, intensity, and duration as well as comorbid depressive or anxious symptoms, pain catastrophizing and quality of life in both episodic and chronic migraine patients with previous unsuccessful preventive treatments. Furthermore, we demonstrated that monthly galcanezumab 120 mg s.c. is able to induce a significant improvement in the scores of "whole pain burden". The latter is a reliable and easy-to-handle tool to be employed in clinical setting to evaluate the effectiveness of preventive drugs (in this case, galcanezumab) or when the decision of continuing the treatment with anti-CGRP mAbs is mandatory.

Is calcitonin gene-related peptide a reliable biochemical marker of migraine?

PURPOSE OF REVIEW

The aim of this study was to provide an overview of clinical studies on calcitonin gene-related peptide (CGRP) measurements in body fluids of migraine patients and to discuss the validity of CGRP measurement as a clinical biomarker of migraine.

RECENT FINDINGS

Several studies have reported increased CGRP levels in venous blood, saliva and tear fluid of migraine patients compared with healthy controls and in migraine patients during attacks compared with the interictal state, suggesting that CGRP may be a feasible biomarker of migraine. However, the findings of studies investigating CGRP levels in migraine patients are generally conflicting and measurements of CGRP levels are challenged by several methodological issues. Reported differences in CGRP levels between patients with chronic migraine relative to episodic migraine have also been inconsistent. There is also a well documented involvement of CGRP in several nonmigraine pain disorders, including cluster headache and common pain conditions such as osteoarthritis.

SUMMARY

Current evidence does not justify the usage of CGRP levels as a biomarker for diagnosing migraine or for determining the severity of the disease in individual patients. However, CGRP measurements could prove useful in the future as clinically relevant biomarkers for predicting the response to therapy, including anti-CGRP migraine drugs.

Why are CGRP monoclonal antibodies not yet the first line treatment in migraine prevention?

Migraine is a prevalent disorder and a cause of high disability, influenced by modifiable and non-modifiable risk factors. Comorbid and psychiatric illnesses are prevalent in migraine patients and should be considered when choosing preventive drugs. There have been unforeseen problems with the use of preventive treatment of migraine with oral drugs, mainly due to side-effects that cannot be tolerated and lack of efficacy, leading to high discontinuation rates. Anti-CGRP monoclonal antibodies (mAbs) have shown better tolerance profiles, based on the low dropout rates in clinical trials due to adverse events. First-line therapy is a term most expressed in some medical specialties that adopt standardized protocol treatments and may not be suitable for treating migraine. Regarding efficacy, mAbs don't seem to perform much better than the current prophylactic oral drugs in reduction of monthly migraine days compared to placebo. Monoclonal antibodies against CGRP pathway have been prescribed recently, which raises some concern about their safety in the long term. Only side effects observation will confirm whether CGRP blockade causes susceptibility to severe side-effects, at least to specific subpopulations. CGRP may play a role in regulating uteroplacental blood flow and myometrial and uterine relaxation, as well as blood pressure control, raising the suspicion that its blockade could cause complications during pregnancy. Recent guidelines retain the recommendation of starting preventive treatment of migraine with oral drugs. Both the fact that it is new and costs are the reason why guidelines recommend the prescription of mAbs only after failure of at least two oral drugs.

Functionality, satisfaction, and global impression of change with ubrogepant for the acute treatment of migraine in triptan insufficient responders: a post hoc analysis of the ACHIEVE I and ACHIEVE II randomized trials

Background

Triptans are the first-line option for the acute treatment of migraine attacks; however, triptans are contraindicated in people with certain underlying cardiovascular risk factors and are associated with inadequate efficacy or poor tolerability in some individuals. Ubrogepant is an oral calcitonin gene–related peptide receptor antagonist approved for the acute treatment of migraine.

Methods

This post hoc analysis of the phase 3 ACHIEVE trials examined the impact of ubrogepant on the Functional Disability Scale (FDS), satisfaction with medication, and Patient Global Impression of Change (PGIC) in participants who were self-reported triptan insufficient responders (TIRs), defined as those who are unable to take triptans due to contraindications, tolerability issues, or insufficient efficacy. Responder definitions for the FDS, satisfaction measures, and PGIC were based on qualitative interpretation of the respective response options for the pooled ubrogepant 50 mg and placebo groups.

Results

In the pooled analysis population (n = 1799), 451 (25%) participants were TIRs, with most (80%) reporting insufficient efficacy with triptan use. A significantly higher proportion of TIRs treated with ubrogepant vs placebo reported being able to function normally from 2 to 8 h post dose (P < 0.05). Notably, significance was demonstrated at the time of the primary outcome assessments (2 h post dose), where rates of normal function were 38% for ubrogepant vs 29% for placebo (P = 0.048). A greater proportion of TIRs in the ubrogepant arm vs the placebo arm were satisfied with treatment at 2 (33% vs 21%, P = 0.006) and 24 h (58% vs 28%, P < 0.001) and indicated that their migraine improved at 2 h vs placebo (30% vs 18%, P = 0.006). Results were generally similar in the insufficient efficacy subpopulation of TIRs as in the overall TIRs group. Ubrogepant was safe and well tolerated in TIRs, with no new safety signals identified.

Conclusions

In people with migraine who are TIRs, individuals treated with ubrogepant had favorable 2-h outcomes, as measured by the FDS, satisfaction with medication, and PGIC, compared with placebo.

Trial registration

ClinicalTrials.gov: NCT02828020 (ACHIEVE I), registered July 11, 2016; NCT02867709 (ACHIEVE II), registered August 16, 2016.

Genome-wide analysis of 102,084 migraine cases identifies 123 risk loci and subtype-specific risk alleles

Migraine affects over a billion individuals worldwide but its genetic underpinning remains largely unknown. Here, we performed a genome-wide association study of 102,084 migraine cases and 771,257 controls and identified 123 loci, of which 86 are previously unknown. These loci provide an opportunity to evaluate shared and distinct genetic components in the two main migraine subtypes: migraine with aura and migraine without aura. Stratification of the risk loci using 29,679 cases with subtype information indicated three risk variants that seem specific for migraine with aura (in HMOX2, CACNA1A and MPPED2), two that seem specific for migraine without aura (near SPINK2 and near FECH) and nine that increase susceptibility for migraine regardless of subtype. The new risk loci include genes encoding recent migraine-specific drug targets, namely calcitonin gene-related peptide (CALCA/CALCB) and serotonin 1F receptor (HTR1F). Overall, genomic annotations among migraine-associated variants were enriched in both vascular and central nervous system tissue/cell types, supporting unequivocally that neurovascular mechanisms underlie migraine pathophysiology.

Effectiveness of Calcitonin Gene-Related Peptide Receptor Antagonists for Migraine Treatment: A Meta-Analysis

INTRODUCTION

The pathophysiology of migraine has been researched incessantly, and it has been suggested that calcitonin gene-related peptide (CGRP) is associated with migraine attacks. CGRP receptor blockers are attracting attention as potential agents for migraine prevention and treatment of acute episodes. This meta-analysis aimed to assess the effects of available CGRP receptor antagonists, focusing on their therapeutic doses for acute migraine treatment.

METHODS

We systematically searched MEDLINE and Embase from inception to March 27, 2021, for English-language publications using the keywords "migraine" and "calcitonin gene-related peptide"; the searches were limited to human studies.

RESULTS

Five studies that focused on examining the effects of CGRP receptor antagonists on acute migraine treatment met the eligibility criteria for this meta-analysis. A pooled analysis demonstrated that CGRP receptor antagonists significantly increased freedom from pain (odds ratio [OR] = 2.066, 95% confidence interval [CI] 1.766-2.418, I2 = 0%) and from bothersome symptoms in general (OR = 1.606, 95% CI = 1.408-1.830, I2 = 0%); reduced the intensity of pain (OR = 1.791, 95% CI = 1.598-2.008, I2 = 0%); and increased freedom from nausea (OR = 1.361, 95% CI = 1.196-1.548, I2 = 0%) compared to a placebo.

CONCLUSIONS

CGRP receptor antagonists are effective for acute migraine treatment and are expected to be used clinically as emerging therapeutic agents.

Regular Practice of Autogenic Training Reduces Migraine Frequency and Is Associated With Brain Activity Changes in Response to Fearful Visual Stimuli

Several factors can contribute to the development and chronification of migraines, including stress, which is undoubtedly a major trigger. Beyond pharmacotherapy, other treatment methods also exist, including behavioral techniques aiming at reducing patients’ stress response. However, the exact brain mechanisms underlying the efficacy of such methods are poorly understood. Our pilot study examined whether the regular practice of autogenic training (AT) induces functional brain changes and if so, how it could be associated with the improvement of migraine parameters. By exploring neural changes through which AT exerts its effect, we can get closer to the pathomechanism of migraine. In particular, we investigated the effect of a headache-specific AT on brain activation using an implicit face emotion processing functional MRI (fMRI) task in female subjects with and without episodic migraine. Our focus was on migraine- and psychological stress-related brain regions. After a 16-week training course, migraineurs showed decreased activation in the migraine-associated dorsal pons to fearful compared with neutral visual stimuli. We also detected decreasing differences in supplementary motor area (SMA) activation to fearful stimuli, and in posterior insula activation to happy stimuli between healthy subjects and migraineurs. Furthermore, migraineurs reported significantly less migraine attacks. These brain activation changes suggest that AT may influence the activity of brain regions responsible for emotion perception, emotional and motor response integration, as well as cognitive control, while also being able to diminish the activation of regions that have an active role in migraine attacks. Improvements induced by the training and the underlying neurophysiological mechanisms are additional arguments in favor of evidence-based personalized behavioral therapies.

Ubrogepant Is Safe and Efficacious in Participants Taking Concomitant Preventive Medication for Migraine: A Pooled Analysis of Phase 3 Trials

INTRODUCTION

Ubrogepant is a calcitonin gene-related peptide receptor antagonist indicated for acute treatment of migraine that can be used to treat breakthrough attacks in individuals taking preventive treatment for migraine. We evaluated the impact of preventive medication use on the efficacy and safety of ubrogepant for the acute treatment of migraine.

METHODS

This was an analysis of pooled efficacy data from the ACHIEVE I and ACHIEVE II phase 3 trials, in which efficacy of ubrogepant was assessed at 2 h after taking study medication for pain freedom, absence of most bothersome symptom (MBS), and pain relief. In addition, a long-term safety (LTS) extension trial was completed where safety was assessed on the basis of incidence and severity of treatment-emergent adverse events (TEAEs). Outcomes were compared between participants with or without prior (within 6 months) preventive medication use (anticonvulsants, beta blockers, antidepressants, or onabotulinumtoxinA). For efficacy analyses, data were pooled across ACHIEVE trials for the 50 mg and placebo groups; for safety analyses, data for all dose groups (50 mg and 100 mg) in the LTS trial were pooled.

RESULTS

Preventive treatments were used by 417 of 2247 (18.6%) participants analyzed in the ACHIEVE trials and by 143 of 813 (17.5%) participants in the LTS trial. Responder rates for all outcomes were similar between participants with or without preventive treatment within each dose group (p > 0.05). No significant differences were noted across the different preventive medications. Rates and types of TEAEs were similar between participants with or without preventive treatment. No serious treatment-related adverse events were reported.

CONCLUSION

Efficacy and safety of ubrogepant for the acute treatment of migraine were similar between participants with or without prior or current use of concomitant preventive medication.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT02828020 (ACHIEVE I), NCT02867709 (ACHIEVE II), and NCT02873221 (long-term safety trial).

Roles of calcitonin gene-related peptide in the skin, and other physiological and pathophysiological functions

Skin immunity is regulated by many mediator molecules. One is the neuropeptide calcitonin gene-related peptide (CGRP). CGRP has roles in regulating the function of components of the immune system including T cells, B cells, dendritic cells (DCs), endothelial cells (ECs), and mast cells (MCs).

Herein we discuss actions of CGRP in mediating inflammatory and vascular effects in various cutaneous models and disorders.

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CGRP can help to recruit immune cells through endothelium-dependent vasodilation.

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CGRP plays an important role in the pathogenesis of neurogenic inflammation.

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Functions of many components in the immune system are influenced by CGRP.

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CGRP regulates various inflammatory processes in human skin by affecting different cell-types.

Locating Organizations and Their Methods in Registrations of Clinical Migraine Trials: Analysis of ClinicalTrials.gov

Background and Objective:ClinicalTrials.gov is a centralized venue for monitoring clinical research and allows access to information on publicly and privately funded studies. To better recognize influential institutions in the field of headache, we identified major organizations conducting clinical trials in migraine research. Furthermore, we examined the frequency of different study designs.

Methods: Utilizing the ClinicalTrials.gov application programming interface, we extracted studies including individuals with migraine from February 29, 2000, to July 28, 2020, for the following: (1) host organization, (2) study type, (3) primary purpose, (4) intervention model, and (5) allocation.

Results: We included 921 entries encompassing 423 organizations. Thirty-two organizations produced ≥5 entries each and 40.0% of all entries. Most, 86%, were interventional studies while 13.6% were observational studies. The most common study design had a randomized allocation of participants. The most frequent primary purpose was treatment (62.4%) followed by prevention (13.0%). There were 56.9% parallel assignment models, 15.2% single group assignment models, and 12.4% crossover assignment models.

Conclusion: A minority of organizations contribute to a significant number of registrations of clinical migraine trials, suggesting that clinical research in migraine is oligarchic. The most common study is interventional and randomized, with parallel assignment of participants with treatment as the primary purpose. This likely reflects the need to evaluate novel putative pharmacological medications.

The locus of Action of CGRPergic Monoclonal Antibodies Against Migraine: Peripheral Over Central Mechanisms

Migraine is a complex neurovascular disorder characterized by attacks of moderate to severe unilateral headache, accompanied by photophobia among other neurological signs. Although an arsenal of antimigraine agents is currently available in the market, not all patients respond to them. As Calcitonin Gene-Related Peptide (CGRP) plays a key role in the pathophysiology of migraine, CGRP receptor antagonists (gepants) have been developed. Unfortunately, further pharmaceutical development (for olcegepant and telcagepant) was interrupted due to pharmacokinetic issues observed during the Randomized Clinical Trials (RCT). On this basis, the use of monoclonal antibodies (mAbs; immunoglobulins) against CGRP or its receptor has recently emerged as a novel pharmacotherapy to treat migraines. RCT showed that these mAbs are effective against migraines producing fewer adverse events. Presently, the U.S. Food and Drug Administration approved four mAbs, namely: (i) erenumab; (ii) fremanezumab; (iii) galcanezumab; and (iv) eptinezumab. In general, specific antimigraine compounds exert their action in the trigeminovascular system, but the locus of action (peripheral vs. central) of the mAbs remains elusive. Since these mAbs have a molecular weight of ∼150 kDa, some studies rule out the relevance of their central actions as they seem unlikely to cross the Blood-Brain Barrier (BBB). Considering the therapeutic relevance of this new class of antimigraine compounds, the present review has attempted to summarize and discuss the current evidence on the probable sites of action of these mAbs.

Efficacy and Safety of Lasmiditan for Acute Treatment of Migraine in Adults: A Meta-Analysis

Monotherapy with triptans in acute migraine is ineffective in many patients and contraindicated in certain cardiovascular diseases where alternative therapeutic options are necessary to explore. This meta-analysis has evaluated the efficacy and safety of lasmiditan for the treatment of acute migraine in adults. After performing a literature search on MEDLINE/PubMed, Scopus, Cochrane databases, and International Clinical Trial Registry Platform, reviewers assessed eligibility and extracted data from 4 relevant articles. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed in the selection, analysis, and reporting of findings. A random-effects model was used to estimate effect size. Quality assessment was done using the risk of bias assessment tool and meta-regression for probable variables affecting effect size. Subgroup analysis was done depending on the dose of lasmiditan. Lasmiditan use was associated with a significantly higher percentage of patients with pain freedom (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.72-2.39; P < .00001), sustained pain freedom (OR, 1.93; 95%CI, 1.55-2.39; P <.00001), headache response (OR, 2.05; 95%CI, 1.77-2.36; P < .00001), clinical disability level (OR, 1.36; 95%CI, 1.20-1.55; P < .00001), patients' global impression (OR, 1.88; 95%CI, 1.69-2.10; P < .00001), and significantly lower use of rescue medication (OR, 0.49; 95%CI, 0.38-0.63; P < .00001) compared to placebo. Lasmiditan use was also associated with a higher likelihood of adverse effects like dizziness (OR, 6.54; 95%CI, 4.24-10.07; P < .00001), paresthesia (OR, 4.28; 95%CI, 2.97-6.17; P < .00001), and fatigue (OR, 5.67; 95%CI, 3.78-8.52; P < .00001) compared to placebo. Subgroup analysis showed a dose-dependent effect of lasmiditan on pain freedom, sustained pain freedom, patient's global impression, and occurrence of adverse drug reactions. Prediction probability for effect estimate favoring placebo was calculated to be 0.0017%. Lasmiditan has shown a favorable effect in terms of efficacy and safety in the treatment of an acute attack of migraine in comparison to placebo. Further studies are needed to evaluate long-term safety, efficacy, and use in specific subgroups of patients. PROSPERO Registration Number: CRD42020177838.

Pharmacological treatment of migraine: Drug classes, mechanisms of action, clinical trials and new treatments

Migraine is the sixth most prevalent disease globally, a major cause of disability, and it imposes an enormous personal and socioeconomic burden. Migraine treatment is often limited by insufficient therapy response, leading to the need for individually adjusted treatment approaches. In this review, we analyse historical and current pharmaceutical development approaches in acute and chronic migraine based on a comprehensive and systematic analysis of Food and Drug Administration (FDA)-approved drugs and those under investigation. The development of migraine therapeutics has significantly intensified during the last 3 years, as shown by our analysis of the trends of drug development between 1970 and 2020. The spectrum of drug targets has expanded considerably, which has been accompanied by an increase in the number of specialised clinical trials. This review highlights the mechanistic implications of FDA-approved and currently investigated drugs and discusses current and future therapeutic options based on identified drug classes of interest.

Real-Life Response to Erenumab in a Therapy-Resistant Case Series of Migraine Patients From the Province of Québec, Eastern Canada

BACKGROUND AND OBJECTIVE

Erenumab is the first migraine-specific preventive therapy approved by Health Canada since the approval of onabotulinumtoxinA 10 years ago. It is one of four calcitonin gene-related peptide antagonist monoclonal antibodies that have been commercialized worldwide for use in the headache pipeline. The objective of our study was to determine real-life efficacy of monthly erenumab for the prevention of migraine in a small case series of difficult-to-treat patients followed at a tertiary headache clinic from the Canadian province of Québec.

METHODS

We performed a retrospective chart audit of patients having failed four or more conventional migraine oral preventive therapies and who were treated with monthly self-administered subcutaneous erenumab (70 or 140 mg/mL dose) over a 1-year period. We assessed the patients' baseline characteristics, response to treatment, and tolerability.

RESULTS

A total of 18 patients with a diagnosis of high-frequency episodic migraines or chronic migraine met criteria (83.3% female; mean age: 48.7 years; mean duration of migraine condition: 32.9 years). Patients self-administered erenumab using a prefilled disposable autoinjector on a monthly basis; 16 patients received a 140 mg/mL dosage, two patients received a 70 mg/mL dosage. At 1 year follow-up, 50% of patients reported ≥ 50% reduction in migraine frequency and were deemed responders. Patients attempted six doses of erenumab therapy prior to discontinuation for non-response, except for two patients with other concomitant chronic pain conditions, who required ten doses to reach a 50% response. For the overall cohort, there was a decrease of 5.2 monthly migraine days; 9 days for responders and 1.3 days for non-responders (t-test (df = 16) = - 2.77, p = 0.014). There was an additional decrease of 7 monthly non-migraine days amongst patients with unremitting daily headaches; 8 days for responders and 5 days for non-responders (p > 0.05). There was a decrease of 5.4 monthly days using acute analgesics; 8.9 days for responders and 2 days for non-responders (T(16) = - 2.33, p = 0.033). The overall mean reduction in disability using the Headache Impact Test (HIT-6) score was 5.6 points; only responders showed a reduction in HIT-6 severity category (p > 0.05). The most commonly reported adverse event was constipation (16.7%), which did not lead to treatment discontinuation and was successfully managed in all patients with early counselling and intervention.

CONCLUSION

This study supports the efficacy of erenumab in a case series of therapy-resistant migraine patients from the region of Québec. A high rate of previously failed preventive oral agents and medication overuse did not predict response in our patient cohort. In the presence of real-world complexity factors, such as psychological distress, regular opioid consumption and concomitant chronic pain conditions, a longer therapy trial may be warranted in obtaining optimal response.

Patients and general practitioners assessment of the main outcomes employed in the acute and preventive treatment of migraine: a cross sectional study

Background

We aim to describe and compare patients and general practitioners’ opinions about the different variables related to acute and preventive treatment for migraine.

Patients and methods

An observational descriptive study was performed. Patients with episodic migraine and general practitioners, from our healthcare area, were invited to answer a survey about the different variables related to migraine treatment. They were asked for their opinions on the different variables, and to consider the desired efficacy in percentage terms and the desired action times of treatment.

Results

Fifty-five patients and fifty-five general practitioners were selected. Effectiveness was considered the most important variable for symptomatic and preventive treatment. Cost was considered the least important variable. Patients desired percentage of efficacy was 84.0% (±16.7%) for symptomatic treatment and 79.9% (±17.1%) for preventive treatment. General practitioners desired percentage of efficacy was 75.0% (±14.0) for symptomatic treatment and 70.4% (±14.3) for preventive treatment. For symptomatic treatment the desired action time for pain cessation was selected as 27.5 min (±13.8) for patients and 24.0 min (±18.3) for GPs. For preventive treatment the desired action time for effect was 7.1 days (±4.5) for patients and 13.9 days (±8.9) for general practitioners.

Conclusion

The most important endpoints were, for acute: effectiveness, a short action time and a persistent effect. For prophylactic: effectiveness, sustained effect and tolerability. Both patients and general practitioners agreed on the most and least preferred endpoints. Desired percentage of efficacy was above 75% for both symptomatic and preventive treatment; and the desired action time was below 30 min for acute treatment and 2 weeks for preventive treatment.