A head-to-head observational cohort study on the efficacy and safety of monoclonal antibodies against calcitonin gene-related peptide for chronic and episodic migraine

Pharmacological differences and switching among anti-CGRP monoclonal antibodies: A narrative review

Antibodies targeting either the calcitonin gene-related peptide (CGRP), such as galcanezumab, fremanezumab, and eptinezumab, or the receptor (erenumab) have been approved for the prevention of episodic and chronic migraine. Although widely used and generally effective, a proportion of patients discontinue treatment due to lack of efficacy. In both randomized controlled trials and observational studies, all anti-CGRP monoclonal antibodies (mAbs) have consistently demonstrated comparable efficacy and tolerability, suggesting a pharmacological class effect. However, differences in therapeutic targets, structure, and pharmacokinetic characteristics may influence their efficacy and safety differently. Therefore, in patients not achieving a clinically meaningful response with one anti-CGRP antibody, switching to a different antibody may be a viable option. This review examines the pharmacological characteristics and distinctions among anti-CGRP mAbs, highlighting their mechanisms of action and pharmacokinetic profiles, along with the clinical observational data of switching. Finally, we summarize suggestions from international guidelines.

Adding corticosteroids to galcanezumab in medication overuse headache: A three-arm head-to-head prospective observational cohort study

BACKGROUND

Medication overuse headache (MOH) is a condition where pain relief medications cause chronic headaches due to excessive use. Recent advancements highlight the effectiveness of preventive treatments like anti-CGRP monoclonal antibodies. Current strategies combine medication withdrawal and preventive treatments, with corticosteroids traditionally used to ease withdrawal symptoms.

METHODS

This is a prospective three-arm observational cohort study comparing the effectiveness and safety of galcanezumab alone, galcanezumab plus prednisone and prednisone alone for the treatment of MOH. We enrolled 75 patients. Prednisone was administered at an initial dose of 50mg daily, and then tapered off over 28days. Duration of follow-up was 3months.

RESULTS

All treatments proved effective (P<0.001). We found a significant reduction of mean monthly days with headache in the galcanezumab plus prednisone group (baseline: 25, IQR: 20-30; after 3months: 7, IQR: 5-10), in the galcanezumab group (baseline: 25, IQR: 20-30; after 3months: 10, IQR: 5-14) and in the Prednisone group (baseline: 25, IQR: 20-28; after 3months: median: 15 days, IQR: 8-22days). Patients treated with prednisone reported a higher incidence of side effects (P=0.002).

CONCLUSION

Our study indicates that both galcanezumab and prednisone decrease the frequency of headaches in patients with MOH. The combined usage of these treatments showed the highest reduction in mean monthly headache days. However, treatment with prednisone determined a significant rate of adverse events, therefore we suggest its use only in unresponsive patients. In all other patients galcanezumab appears to be a safe and effective option.

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.

Medication "underuse" headache

BACKGROUND

Many risk factors have been associated with migraine progression, including insufficient and ineffective utilization of migraine medications; however, they have been inadequately explored. This has resulted in suboptimal usage of medications without effective altering of prescribing recommendations for patients, posing a risk for migraine chronification.

METHODS

Our aim is to conduct a comprehensive review of the available evidence regarding the underuse of migraine medications, both acute and preventive. The term "underuse" includes, but is not limited to: (1) ineffective use of appropriate and inappropriate medication; (2) underutilization; (3) inappropriate timing of usage; and (4) patient dissatisfaction with medication.

RESULTS

The underuse of both acute and preventive medications has been shown to contribute to the progression of migraine. In terms of acute medication, chronification occurs as a result of insufficient drug use, including failure of the prescriber to select the appropriate type based on pain intensity and disability, patients taking medication too late (more than 60 minutes after the onset or after central sensitization has occurred as evidenced by allodynia), and discontinuation because of lack of effect or intolerable side effects. The underlying cause of inadequate effectiveness of acute medication lies in its inability to halt the propagation of peripheral activation to central sensitization in a timely manner. For oral and injectable preventive migraine medications, insufficient efficacy and intolerable side effects have led to poor adherence and discontinuation with subsequent progression of migraine. The underlying pathophysiology here is rooted in the repetitive stimulation of afferent sensory pain fibers, followed by ascending brainstem pain pathways plus dysfunction of the endogenous descending brainstem pain inhibitory pathway. Although anti-calcitonin gene-related peptide (CGRP) medications partially address pain caused by the above factors, including decreased efficacy and tolerability from conventional therapy, some patients do not respond well to this treatment. Research suggests that initiating preventive anti-CGRP treatment at an early stage (during low frequency episodic migraine attacks) is more beneficial than commencing it during high frequency episodic attacks or when chronic migraine has begun.

CONCLUSIONS

The term "medication underuse" is underrecognized, but it holds significant importance. Optimal usage of acute care and preventive migraine medications could potentially prevent migraine chronification and improve the treatment of migraine attacks.

Are anti-calcitonin gene-related peptide monoclonal antibodies effective in treating migraine aura? A pilot prospective observational cohort study

BACKGROUND

About 15% to one third of migraineurs experience aura symptoms. Aura is a reversible focal neurological phenomenon involving visual, sensory, speech, and motor symptoms that usually precede migraine pain. Monoclonal antibodies against calcitonin-related peptide (anti- CGRP mAbs) are effective in preventing chronic and episodic migraine, but little is known about their effectiveness on specifically preventing migraine with aura.

METHODS

This is a pilot prospective observational cohort study, aiming at evaluating the effectiveness and safety of Erenumab, Fremanezumab or Galcanezumab for the treatment of migraine aura. We enrolled 14 patients at the Headache Centre of University Federico II of Naples. Duration of follow-up was 12 months. We assessed mean monthly days with aura symptoms, with or without subsequent headache, as well as mean monthly days with headache and mean monthly MIDAS score, by reviewing standardized paper patient headache diaries every three months.

RESULTS

A significant decrease in mean monthly aura days was observed throughout the observation period (median baseline: 13, interquartile range: 4-16; after 12 months: 1, interquartile range: 0-3, p < 0.001). We observed a statistically significant decrease in mean monthly headache days as well (median baseline 21, interquartile range: 16-30; after 12 months: 5, interquartile range: 4-7, p < 0.001). During the 12-month treatment period, none of the 14 patients reported mild or serious adverse events.

CONCLUSION

Our findings suggest that anti-CGRP mAbs are highly effective in migraine with aura, both in reducing mean monthly aura days and mean monthly days with headache.

Real-world experience with calcitonin gene-related peptide-targeted antibodies for migraine prevention: a retrospective observational cohort study at two Japanese headache centers

BACKGROUND

Although randomized controlled trials (RCTs) have shown that calcitonin gene-related peptide (CGRP)-targeted monoclonal antibodies (CGRP mAbs) are an efficacious and safe therapeutic modality for migraine prevention, their clinical benefits have not been well validated in Japanese patients in the real-world setting. The present study aimed to evaluate the real-world efficacy and safety of galcanezumab, fremanezumab, and erenumab in Japanese patients with migraine.

METHODS

This observational retrospective cohort study was conducted at two headache centers in Japan. Patients with migraine who had experienced treatment failure with at least one traditional oral migraine preventive agent were treated with a CGRP mAb de novo. The primary efficacy endpoints were the changes from baseline in monthly migraine days (MMDs) and Headache Impact Test-6 (HIT-6) score after 3 dosing intervals (V3). We explored whether demographic and clinical characteristics predicted therapeutic outcomes at V3.

RESULTS

Sixty-eight patients who completed three doses of a CGRP mAb (85.3% female [58/68], mean age: 46.2 ± 13.1 years) were included in the analysis. There were 19 patients with chronic migraine. The baseline MMDs were 13.4 ± 6.0. After 3 doses, the MMDs significantly decreased to 7.4 ± 5.5 (p < 0.0001), and the 50% response rate was 50.0%. HIT-6 score was significantly reduced from 66.7 ± 5.4 to 56.2 ± 8.7 after 3 doses (P = 0.0001). There was a positive correlation between the changes in MMDs and HIT-6 score from baseline after 2 doses (p = 0.0189). Those who achieved a ≥ 50% therapeutic response after the first and second doses were significantly more likely to do so at V3 (crude odds ratio: 3.474 [95% CI: 1.037 to 10.4], p = 0.0467). The most frequent adverse event was constipation (7.4%). None of the adverse events were serious, and there was no need for treatment discontinuation.

CONCLUSIONS

This real-world study demonstrated that CGRP mAbs conferred Japanese patients with efficacious and safe migraine prevention, and an initial positive therapeutic response was predictive of subsequent favorable outcomes. Concomitant measurement of MMDs and HIT-6 score was useful in evaluating the efficacy of CGRP mAbs in migraine prevention.

Twelve-month efficacy of CGRP monoclonal antibodies and predictive value of short-term response: results of an Australian multicentre study

Introduction

Clinical trials show that calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) are effective preventative treatments for chronic migraine. Their efficacy over longer time periods and in cohorts originally excluded from trials remains uncertain. This study aims to explore the impact of CGRP mAbs in an Australian real-life setting.

Methods

A multicentre cohort study was performed in the tertiary headache clinics of the Alfred and Austin Hospitals, Melbourne, Australia. Patients were commenced on a CGRP mAb for chronic migraine and asked to keep a headache diary, recorded at 3 monthly appointments for 12 months. Primary outcome was a ≥50% reduction in monthly headache days (MHD).

Results

From a population of 105 patients, 90 patients commenced galcanezumab and 15 commenced fremanezumab. The ≥50% responder rate of the cohort was 52.4% after 3 months. Over 12 months follow-up, 25.7% of the cohort ceased due to a lack of efficacy and 16.2% ceased due to an adverse event. There was no difference in response or cessation between medications. There was poor agreement in 3-month and 12-month response rates (Cohen's κ=0.130; p=0.171). On subgroup analysis, continuous headache at baseline and number of trialled preventative treatments were the only factors associated with efficacy.

Conclusion

CGRP mAbs were associated with sustained reductions in MHD over 12-month follow-up in patients with resistant migraine in Australia. Further studies are required to determine treatment options for patients with continuous headache. Poor agreement between outcomes at 3 and 12 months highlights the need to assess some patients at later timepoints.

Characteristics associated with response to subcutaneously administered anti-CGRP monoclonal antibody medications in a real-world community cohort of persons living with migraine: A retrospective clinical and genetic study

OBJECTIVE

To evaluate response to anti-calcitonin gene-related peptide (CGRP) migraine preventives in a real-world community cohort of persons living with migraine and to identify clinical and genetic characteristics associated with efficacious response.

BACKGROUND

Erenumab-aooeb, fremanezumab-vrfm, and galcanezumab-gnlm target CGRP or its receptor; however, many patients are non-responsive.

METHODS

In this retrospective clinical and genetic study, we identified 1077 adult patients who satisfied the International Classification of Headache Disorders, 3rd edition, criteria for migraine without aura, migraine with aura, or chronic migraine and who were prescribed an anti-CGRP migraine preventive between May 2018 and May 2021. Screening of 558 patients identified 289 with data at baseline and first follow-up visits; data were available for 161 patients at a second follow-up visit. The primary outcome was migraine days per month (MDM). In 198 genotyped patients, we evaluated associations between responders (i.e., patients with ≥50% reduction in MDM at follow-up) and genes involved in CGRP signaling or pharmacological response, and genetic and polygenic risk scores.

RESULTS

The median time to first follow-up was 4.4 (0.9-22) months after preventive start. At the second follow-up, 5.7 (0.9-13) months later, 145 patients had continued on the same preventive. Preventives had strong, persistent effects in reducing MDM in responders (follow-up 1: η2  = 0.26, follow-up 2: η2  = 0.22). At the first but not second follow-up: galcanezumab had a larger effect than erenumab, while no difference was seen at either follow-up between galcanezumab and fremanezumab or fremanezumab and erenumab. The decrease in MDM at follow-up was generally proportional to baseline MDM, larger in females, and increased with months on medication. At the first follow-up only, patients with prior hospitalization for migraine or who had not responded to more preventive regimens had a smaller decrease in MDM. Reasons for stopping or switching a preventive varied between medications and were often related to cost and insurance coverage. At both follow-ups, patient tolerance (1: 92.2% [262/284]; 2: 95.2% [141/145]) and continued use (1: 77.5% [224/289]; 2: 80.6% [116/145]) were high and similar across preventives. Response consistency (always non-responders: 31.7% [46/145]; always responders: 56.5% [82/145], and one-time only responders: 11.7% [17/145]) was also similar across preventives. Non-responder status had nominally significant associations with rs12615320-G in RAMP1 (odds ratio [95% confidence interval]: 4.7 [1.5, 14.7]), and rs4680-A in COMT (0.6[0.4, 0.9]). Non-responders had a lower mean genetic risk score than responders (1.0 vs. 1.1; t(df) = -1.75(174.84), p = 0.041), and the fraction of responders increased with genetic and polygenic risk score percentile.

CONCLUSIONS

In this real-world setting, anti-CGRP preventives reduced MDM persistently and had similar and large effect sizes on MDM reduction; however, clinical and genetic factors influenced response.

Ten open questions in migraine prophylaxis with monoclonal antibodies blocking the calcitonin-gene related peptide pathway: a narrative review

The monoclonal antibodies (mAbs) blocking the calcitonin-gene related peptide (CGRP) pathway, collectively called here "anti-CGRP/rec mAbs", have dramatically improved preventive migraine treatment. Although their efficacy and tolerability were proven in a number of randomized controlled trials (RCTs) and, maybe even more convincingly, in real world settings, a number of open questions remain. In this narrative review, we will analyze published data allowing insight in some of the uncertainties related to the use of anti-CGRP/rec mAbs in clinical practice: their differential efficacy in migraine subtypes, outcome predictors, switching between molecules, use in children and adolescents, long-term treatment adherence and persistence, effect persistence after discontinuation, combined treatment with botulinum toxin or gepants, added-value and cost effectiveness, effectiveness in other headache types, and potential contraindications based on known physiological effects of CGRP. While recent studies have already provided hints for some of these questions, many of them will not find reliable and definitive answers before larger studies, registries or dedicated RCTs are available.