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

Real-world effectiveness and safety of erenumab for the treatment of migraine: A systematic review and meta-analysis

BACKGROUND

Migraine is a common and disabling primary headache disorder. Several drugs targeting calcitonin gene-related peptide (CGRP), such as erenumab (an anti-CGRP receptor mAb), have been developed recently. However, the real-world effects of erenumab are not well understood.

OBJECTIVE

To assess the clinical effectiveness and safety of erenumab for reducing migraine intensity and frequency in the real world.

METHODS

A systematic search of PubMed, Scopus, Web of Science and the Cochrane Library was conducted from inception to December 2023. Studies estimating the real-world effect of erenumab on monthly migraine days (MMD), monthly headache days (MHD), headache impact test (HIT-6), number of days in medication (NDM), acute monthly intake (AMI), pain intensity (PI) and safety outcomes were included. Meta-analyses of proportions or mean differences were performed.

RESULTS

Fifty-three studies were included. At 3-months, the effect was -7.18 days for MMD, -6.89 days for MHD, -6.97 for HIT-6, -6.22 days for NDM, -15.75 for AMI, and -1.71 for PI. Generally, the effect at 6- and 12-months increased slightly and gradually. The MMD/MHD response rates revealed that approximately one-third of patients exhibited a response greater than 30%, while one-sixth demonstrated a response exceeding 50%. Additionally, 3-4% of patients achieved a response rate of 100%. Adverse event rates were 0.34 and 0.43 at 6- and 12-months, respectively.

CONCLUSION

This study provides strong evidence of the effectiveness and safety of erenumab in the real world; to our knowledge, this is the first real-world meta-analysis specific to erenumab. Erenumab represents a solid therapeutic option for physicians.

Erenumab efficacy in migraine headache prophylaxis: A systematic review

OBJECTIVE

This systematic review aims to show the efficiency of Erenumab in the preventive therapy of episodic and chronic migraine, which is still under research.

BACKGROUND

Migraine is a chronic neurovascular disorder that causes disability and a social burden. There are various medications used for migraine prevention regimens, most of which have unwanted side effects and aren't often quite effective. Erenumab is a monoclonal antibody that targets calcitonin gene-related peptide receptors and was recently approved by the Food and Drug Administration for migraine prevention.

METHODS

For this systematic review, we searched through Scopus and PubMed databases using "Erenumab" or "AMG 334" and "migraine" as keywords, and all the studies from 2016 to March 18, 2022, were included. Original English articles assessing any outcomes referring to the efficacy of Erenumab in migraine headache treatment were included in this study.

RESULTS

We found 53 out of 605 papers eligible to be investigated. Erenumab in both dosages of 70 mg and 140 mg could decrease the mean of monthly migraine days and monthly acute migraine-specific medication days. Erenumab also has a higher rate of ≥ 50 %, ≥ 75 %, and 100 % reduction in monthly migraine days from the baseline in different regions. The efficacy of Erenumab was initiated in the first week of administration and sustained throughout and after treatment. Erenumab was also potent in the treatment of migraine with allodynia, aura, prior preventive therapy failure, medication overuse headache, and menstrual migraine. Erenumab also had favorable outcomes in combination therapy with other preventive drugs like Onabotulinumtoxin-A.

CONCLUSION

Erenumab had remarkable efficacy in the short and long-term treatment of episodic and chronic migraine, notably the patients with difficult-to-treat migraine headaches.

New migraine prophylactic drugs: Current evidence and practical suggestions for non-responders to prior therapy

BACKGROUND

Monoclonal antibodies against calcitonin gene-related peptide (CGRP) or its receptor (anti-CGRP(-R) mAbs) and small-molecule CGRP receptor antagonists (gepants) are new mechanism-based prophylactic drugs developed to address the unmet needs of pre-existing migraine prophylactic medications. However, several uncertainties remain in their real-world applications.

METHODS

This is a narrative review of the literature on the use of CGRP-targeting novel therapeutics in specific situations, including non-responders to prior therapy, combination therapy, switching, and treatment termination. In the case of lack of available literature, we made suggestions based on clinical reasoning.

RESULTS

High-quality evidence supports the use of all available anti-CGRP(-R) mAbs (erenumab, galcanezumab, fremanezumab, and eptinezumab) in non-responders to prior therapy. There is insufficient evidence to support or reject the efficacy of combining CGRP(-R) mAbs or gepants with oral migraine prophylactic agents or botulinum toxin A. Switching from one CGRP(-R) mAb to another might benefit a fraction of patients. Currently, treatment termination depends on reimbursement policies, and the optimal mode of termination is discussed.

CONCLUSIONS

New prophylactic drugs that target the CGRP pathway are promising treatment options for patients with difficult-to-treat migraine. Individualized approaches using a combination of new substances with oral prophylactic drugs or botulinum toxin A, switching between new drugs, and adjusting treatment duration could enhance excellence in practice.

Medium-term real-world data for erenumab in 177 treatment resistant or difficult to treat chronic migraine patients: persistence and patient reported outcome measures after 17-30 months

BACKGROUND

Many migraine patients do not respond adequately to conventional preventive treatments and are therefore described as treatment/medically resistant or difficult to treat cases. Calcitonin gene-related peptide monoclonal antibodies are a relatively novel molecular treatment for episodic and chronic migraine that have been shown to be effective in short duration clinical trials in approximately 40-50% of all chronic migraine patients. Patient Related Outcome Measures (PROM) or Quality of Life (QoL) questionnaires are used to help measure response to treatment in migraine. Although some open label extension studies have become available for erenumab, there is a lack of real-world data pertaining to quality of life in the medium to long-term for chronic and treatment resistant migraine patients.

METHODS

A total of 177 treatment resistant CM patients were started on erenumab (70 mg or 140 mg subcutaneous injection every 4 weeks) in our three specialist Headache Clinics. Of these, 174 had their first injection between December 2018 and October 2019. All patients were evaluated with the following PROM: the Headache Impact Test- 6, Migraine Associated Disability Assessment test and Migraine-Specific QoL Questionnaire, before starting treatment with erenumab and at intervals of 3-12 months after starting treatment. The decision to continue treatment was based on subjective clinical improvement of at least 30% (as reported by the patient), supported with diaries and QoL questionnaires. We present here the QoL measurements for this group of 177 patients. Prior preventive migraine treatments included conventional oral prophylactic medications (such as topiramate, candesartan, propranolol, or amitriptyline), at least two cycles of PREEMPT protocol onabotulinumtoxin A or (in a small number of cases) neuromodulation with single pulse Transcranial Magnetic Stimulation.

RESULTS

Of the 177 patients who started treatment with erenumab, 68/177 (38.4%) stopped during the first year, either due to lack of efficacy (no significant benefit or only minimal improvement) and/or possible side effects. 109/177 (61.6%) patients reported clinically significant improvement after 6-12 months and wished to stay on treatment. Twelve of these 109 patients subsequently stopped treatment in the period between 1 year and up to June 2021 (mainly due to a worsening of their migraine). Therefore, a total of 97/177 patients (54.8%) remained on treatment as of June 2021 (duration of treatment 17-30 months, median of 25 months).

CONCLUSION

Approximately 55% of treatment resistant or difficult to treat CM patients who trialled erenumab in our clinics reported a subjective benefit and were still on treatment after 17-30 months.

Long-Term Safety and Effectiveness of Erenumab in Patients with Migraine: A Systematic Review and Single-Arm Meta-analysis

BACKGROUND AND OBJECTIVE

Several studies on use of erenumab for migraine treatment have been published over recent years. However, its long-term safety and effectiveness have not been consistently established in the literature yet. We aimed to perform a qualitative and quantitative analysis of the long-term safety and effectiveness of erenumab for the treatment of migraine headaches.

METHODS

Long-term follow-up was defined as ≥ 1 year. PubMed, Embase and Cochrane Library were systematically searched from inception to 14 June 2022 for studies meeting the inclusion criteria. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

Fourteen studies, comprising 3574 patients, were included. The total follow-up period ranged from 48 to 268 weeks (i.e., 1 year to 5.6 years). Pooled estimate rates for all adverse events (AEs) were 63% (95% CI 46-78); for serious AEs, 3% (95% CI 1-7); and for AEs leading to discontinuation of erenumab, 3% (95% CI 2-5). Reduction in monthly migraine days (MMDs) was -6.98 (95% CI -8.90 to -5.05) and in migraine-specific medication days (MSMDs) was - 6.09 (95% CI - 9.43 to - 2.75). More than half (57%; 95% CI 51-63) and around one-third (35%; 95% CI 28-42) of patients presented with reductions of ≥ 50% and ≥ 75% in MMDs, respectively. Headache Impact Test-6 (HIT-6) score was decreased by -9.68 points (95% CI - 12.03 to - 7.34). Nine studies were considered of poor methodological quality and five of fair quality.

CONCLUSIONS

Erenumab has a favorable safety profile, with a low incidence of serious AEs, and sustained efficacy over ≥1 year of follow-up in the treatment of migraine.

Monoclonal Antibodies against Calcitonin Gene-Related Peptide for Migraine Prophylaxis: A Systematic Review of Real-World Data

OBJECTIVE

To perform a systematic review of real-world outcomes for anti-CGRP-mAbs.

METHODS

Following the PRISMA guidelines, we searched PubMed for real-world data of erenumab, galcanezumab, fremanezumab, or eptinezumab in patients with migraines.

RESULTS

We identified 134 publications (89 retrospective), comprising 10 pharmaco-epidemiologic and 83 clinic-based studies, 38 case reports, and 3 other articles. None of the clinic-based studies provided follow-up data over more than one year in more than 200 patients. Findings suggest that there are reductions in health insurance claims and days with sick-leave as well as better treatment adherence with anti-CGRP-mAbs. Effectiveness, reported in 77 clinic-based studies, was comparable to randomized controlled trials. A treatment pause was associated with an increase in migraine frequency, and switching to another antibody resulted in a better response in some of the patients. Adverse events and safety issues were addressed in 86 papers, including 24 single case reports.

CONCLUSION

Real-world data on anti-CGRP-mAbs are limited by retrospective data collection, small patient numbers, and short follow-up periods. The majority of papers seem to support good effectiveness and tolerability of anti-CGRP-mAbs in the real-world setting. There is an unmet need for large prospective real-world studies providing long-term follow-ups of patients treated with anti-CGRP-mAbs.

Migraine Prevention with Erenumab: Focus on Patient Selection, Perspectives and Outcomes

Erenumab is a monoclonal antibody targeting the calcitonin gene-related peptide (CGRP) receptor suitable for episodic and chronic migraine prevention. Randomized clinical trials proved the superiority of erenumab to placebo in a strictly selected population, while real-world studies confirmed treatment efficacy in more severe forms of disease – most patients suffered from chronic migraine with medication overuse headache, had prior treatment failures, and long disease duration. According to guidelines, anti-CGRP pathway monoclonal antibodies should be reserved to patients who failed or have contraindication to several classes of preventive treatments. However, their ease of use, tolerability and efficacy make these monoclonal antibodies ideally suitable for most patients with migraine; cost-effectiveness needs to be considered when looking at expanding current prescription criteria. Also, data from open label extensions of randomized control trials confirmed sustained benefits of prolonged treatment up to 5 consecutive years without significant risk of adverse events. Further studies will provide insights on optimal treatment duration to achieve migraine remission and predictors of treatment response. In the present work, we aimed at reviewing design and results of the main studies on erenumab and discussing treatment use in the current migraine prevention scenario; we also summarized the main ongoing research projects and provided clinical perspectives for the future.

A real-world, observational study of erenumab for migraine prevention in Canadian patients

Objectives

To assess real‐world effectiveness, safety, and usage of erenumab in Canadian patients with episodic and chronic migraine with prior ineffective prophylactic treatments.

Background

In randomized controlled trials, erenumab demonstrated efficacy for migraine prevention in patients with ≤4 prior ineffective prophylactic migraine therapies. The “Migraine prevention with AimoviG: Informative Canadian real‐world study” (MAGIC) assessed real‐world effectiveness of erenumab in Canadian patients with migraine.

Methods

MAGIC was a prospective open‐label, observational study conducted in Canadian patients with chronic migraine (CM) and episodic migraine (EM) with two to six categories of prior ineffective prophylactic therapies. Participants were administered 70 mg or 140 mg erenumab monthly based on physician’s assessment. Migraine attacks were self‐assessed using an electronic diary and patient‐reported outcome questionnaires. The primary outcome was the proportion of subjects achieving ≥50% reduction in monthly migraine days (MMD) after the 3‐month treatment period.

Results

Among the 95 participants who mostly experienced two (54.7%) or three (32.6%) prior categories of ineffective prophylactic therapies and who initiated erenumab, treatment was generally safe and well tolerated; 89/95 (93.7%) participants initiated treatment with 140 mg erenumab. At week 12, 32/95 (33.7%) participants including 17/64 (26.6%) CM and 15/32 (48.4%) EM achieved ≥50% reduction in MMD while 30/86 (34.9%) participants including 19/55 (34.5%) CM and 11/31 (35.5%) EM achieved ≥50% reduction in MMD at week 24. Through patient‐reported outcome questionnaires, 62/95 (65.3%) and 45/86 (52.3%) participants reported improvement of their condition at weeks 12 and 24, respectively. Physicians observed improvement in the condition of 78/95 (82.1%) and 67/86 (77.9%) participants at weeks 12 and 24, respectively.

Conclusion

One‐third of patients with EM and CM achieved ≥50% MMD reduction after 3 months of erenumab treatment. This study provides real‐world evidence of erenumab effectiveness, safety, and usage for migraine prevention in adult Canadian patients with multiple prior ineffective prophylactic treatments.

Constipation Caused by Anti-calcitonin Gene-Related Peptide Migraine Therapeutics Explained by Antagonism of Calcitonin Gene-Related Peptide's Motor-Stimulating and Prosecretory Function in the Intestine

The development of small-molecule calcitonin gene-related peptide (CGRP) receptor antagonists (gepants) and of monoclonal antibodies targeting the CGRP system has been a major advance in the management of migraine. In the randomized controlled trials before regulatory approval, the safety of these anti-CGRP migraine therapeutics was considered favorable and to stay within the expected profile. Post-approval real-world surveys reveal, however, constipation to be a major adverse event which may affect more than 50% of patients treated with erenumab (an antibody targeting the CGRP receptor), fremanezumab or galcanezumab (antibodies targeting CGRP). In this review article we address the question whether constipation caused by inhibition of CGRP signaling can be mechanistically deduced from the known pharmacological actions and pathophysiological implications of CGRP in the digestive tract. CGRP in the gut is expressed by two distinct neuronal populations: extrinsic primary afferent nerve fibers and distinct neurons of the intrinsic enteric nervous system. In particular, CGRP is a major messenger of enteric sensory neurons which in response to mucosal stimulation activate both ascending excitatory and descending inhibitory neuronal pathways that enable propulsive (peristaltic) motor activity to take place. In addition, CGRP is able to stimulate ion and water secretion into the intestinal lumen. The motor-stimulating and prosecretory actions of CGRP combine in accelerating intestinal transit, an activity profile that has been confirmed by the ability of CGRP to induce diarrhea in mice, dogs and humans. We therefore conclude that the constipation elicited by antibodies targeting CGRP or its receptor results from interference with the physiological function of CGRP in the small and large intestine in which it contributes to the maintenance of peristaltic motor activity, ion and water secretion and intestinal transit.

Erenumab for Migraine Prevention in a 1-Year Compassionate Use Program: Efficacy, Tolerability, and Differences Between Clinical Phenotypes

During a 1-year compassionate use program, 156 patients with migraine self-administered a monthly dose of erenumab 140 mg with a subcutaneous autoinjector. Main inclusion criteria were: ≥ 4 migraine days/month and ≥two prior prophylactic treatment failures. The patients covered the migraine severity spectrum from episodic migraine (EM) (n = 80) to chronic migraine (CM) (n = 76). During the 3rd month of treatment, monthly headache days decreased by 45.7% in EM and 35.5% in CM. The 50% responder rate for reduction in monthly headache days was significantly higher in EM (55%) than in CM (43%) (p = 0.05). In both the migraine subgroups, the clinical improvement vs. baseline was already significant during the 1st month of treatment (p < 0.001). There were also significant reductions in mean headache severity, duration, and monthly days with acute drug intake. The 30% responder rate at 3 months was 60% in CM and 54.1% of patients reversed from CM to EM. The therapeutic effect was maintained at 12 months when 50% responder rates, considering discontinuation for lack of efficacy or adverse effects as 0% response, still were 51% in EM and 41% in CM. A total of 10 patients with EM (12.5%) and 23 patients with CM (30.3%) had discontinued treatment, considering the treatment as ineffective. At 3 months, 48% of patients reported non-serious adverse events among which the most frequent was constipation (20.5%); corresponding figures at 12 months were 30 and 15%. Discontinuation due to an adverse effect for the entire 12 month period was rare (3.8%). The lower efficacy in CM than in EM was mainly due to a very low 50% responder rate in patients with CM with continuous pain (13%) as compared to CM with pain-free periods (58%) (p < 0.001). Similarly, the 50% responder rate was lower in patients with ≥two prior prophylactic treatment failures (40.5%) compared to those with two failures (70%) (p < 0.05). There was no significant efficacy difference between low (4-7 migraine days/month, n = 22) and high frequency (8-14 days, n = 59) EM nor between patients with CM with (n = 50) or without (n = 26) acute medication overuse. Erenumab had no effect on the frequency of auras. Taken together, erenumab 140 mg monthly was highly effective for migraine prophylaxis over the whole severity spectrum of the disease, except in patients with continuous headaches. Its effect is significant after the first injection, quasi-maximal after the second injection, and does not wear off after 12 months. The most frequent adverse effect was constipation. These results are compared to those published for erenumab in the pivotal randomized placebo-controlled trials and to those reported in several recent real-world studies.