Managing migraine over time

Clinical trial data support the effectiveness and safety of CGRP monoclonal antibodies (mAbs) for prevention of migraine, along with emerging real-world evidence.

• Does evidence indicate these treatments remain safe and effective over the longer term?
• Considering their monthly and/or quarterly dosing regimens, do CGRP mAbs show signs of ‘wearing-off’ towards the end of their dosing interval?

In this second article in the 3-part series on managing migraine, join Professor Egilius Spierings, Medical Director at the Boston Headache Institute at Boston PainCare in Massachusetts, United States, in exploring the evidence and what this may mean for prescribers who are managing patients with migraine.

Are CGRP mAbs safe and effective for long-term migraine prevention?

Professor Egilius Spierings describes key findings from the longer-term follow-up data on the safety and effectiveness of CGRP mAbs, and their implications for clinical practice.

Since the original clinical trials which led to regulatory approvals of CGRP mAbs for prevention of migraine, longer-term follow-up data has become available from open-label extensions, real-world studies, post-hoc and retrospective analyses (Table 1).

Overall, across patients with episodic migraine (EM) or chronic migraine (CM), long-term evidence indicates that CGRP mAbs have sustained efficacy and maintain a similar safety profile for up to 1 year with galcanezumab^1,2, 1.25 years with fremanezumab^3–9, 2 years with eptinezumab^10–13, and up to 5 years with erenumab^14–17

Table 1. Long-term efficacy/effectiveness and safety data for CGRP mAbs in managing migraine^1–3,5–23. AEs, adverse events; CGRP, calcitonin gene-related peptide; CM, chronic migraine; CVAE, cardiovascular adverse event; EM, episodic migraine; EQ-5D, EuroQol 5-Dimension 5-Level questionnaire; HFEM, high frequency episodic migraine; HIT-6, headache impact test; mAb, monoclonal antibody; MBS, patient-identified most bothersome symptom associated with migraine; MHD, mean headache days; MIDAS, migraine disability assessment questionnaire; MMD, mean migraine days; MSQoL, Migraine-Specific Quality of Life; PGIC, Patient global impression of change; PHQ-9, 9-Item Patient Health Questionnaire; PROs, patient-reported outcomes; SAE, serious adverse event; TEAE, treatment-emergent adverse event; TF, migraine preventative treatment failure; TR, treatment refractory; WPAI, Work Productivity and Activity Impairment.

Key findings from long-term studies

Higher dose of erenumab (140 mg monthly) may be favoured for longer-term migraine efficacy

A dose increase from 70 mg to 140 mg was reported for the majority of patients taking erenumab in over 1 to 5 years of treatment^15–17, either due to lack of response or loss of prior effectiveness¹⁷, or as required by protocol amendment^14,15. A post-hoc analysis of long-term trials favoured the 140 mg dose for efficacy at 1 year ¹⁵, and a comparison of raw efficacy data across trials suggested 140 mg monthly may be preferred over 70 mg in patients with prior preventative treatment²⁴. Indeed, the authors of one study concluded 140 mg monthly should be considered as the starting dose, particularly in treatment-refractory patients¹⁷.

Higher-than expected rates of constipation with erenumab in real-world migraine patients

Although the incidence of constipation and/or hypertension reported across long-term clinical trial data from CGRP mAbs was generally low (<2%) at 1 to 5 years of follow-up^{3,11,14,18,19}, constipation was reported in 10.3% of real-world patients treated with erenumab for up to 11 months¹⁷. This higher-than-expected rate of constipation with erenumab in real-world versus clinical trial patients has been reported across multiple studies^25–29, and may be associated with factors such as use of concomitant medications^29–31.

CGRP mAbs remain well-tolerated

Across the CGRP mAbs, the incidence of hypersensitivity treatment-emergent adverse events (TEAEs) (including rash, pruritus^11,19) was considered low; most were not serious, and a low proportion led to dose interruption or discontinuation for eptinezumab (i.e. 0.8% and 0.7%, respectively)^{11,13,18–20,22}. Injection or infusion-site reactions were reported for all CGRP mAbs, generally including erythema and pain, plus induration, bruising and/or haematoma in some studies^{3,11,15,17,19}. Although some studies reported injection or infusion-site reactions in >10% of patients (i.e. induration, pain and erythema for fremanezumab³; pain and general injection site reactions for galcanezumab¹⁹), such information was not clearly reported across all studies^10–13,22, and rates of reporting may have been influenced by active monitoring for injection site reactions in others³. Overall, injection site reactions were generally transient, not serious, and few resulted in dose interruption or discontinuation^{3,11,13,15,17,19}.

However, further long-term data is needed to characterise the long-term safety of CGRP mAbs, particularly in patients with comorbid cardiovascular disease or a history of those conditions^32,33.

Is wearing-off an issue for CGRP mAbs in patients with migraine?

Wearing-off has been reported previously with migraine preventive medications such as onabotulinumtoxinA for prevention of CM, and as early as 4 weeks prior to next treatment⁷.

Is there evidence to suggest wearing-off with CGRP mAbs? Professor Spierings discusses the evidence and outlines some possible contributing factors.

In patients with migraine, wearing-off has been consistently reported for erenumab across multiple studies^28,34, and inconsistent results have been reported across studies for wearing-off with fremanezumab and galcanezumab in patients with CM and EM^7,34–36 (Figure 1)

Across the CGRP mAbs, published evidence indicates wearing-off can occur with erenumab, but not with fremanezumab or galcanezumab.

• Wearing-off was self-reported in 34.7% of real-world patients with CM or EM treated with erenumab (70 mg or 140 mg), in most cases occurring at 1 week prior to the next monthly injection²⁸
• In two post-hoc analyses of clinical trial data, no wearing off effect was reported towards the end of the dosing interval for monthly galcanezumab³⁶ for up to 6 months, or fremanezumab (monthly or quarterly⁷) for up to 15 months

However, when unpublished preliminary data is considered, wearing-off has been reported for all three of these CGRP mAbs.

• In a single-centre retrospective analysis, 20% of real-world patients with CM or EM who were prescribed a CGRP mAb had wearing-off documented in their electronic medical record³⁴. Of these patients, 50% were prescribed galcanezumab, 16% were prescribed fremanezumab, and 24% were prescribed erenumab³⁴. On average, wearing-off was 8 days prior to their next injection³⁴
• A further preliminary post-hoc analysis reported wearing-off with galcanezumab in HFEM or CM patients in clinical trials, and the reported incidence of wearing-off in CM patients was higher with galcanezumab compared to placebo (9% versus 3%, respectively)³⁵

However, limited details for these preliminary findings were available, and they remain to be confirmed in peer-reviewed publications.

For eptinezumab, no published or preliminary data were located on the presence/absence of wearing-off.

Figure 1. Do CGRP mAbs show signs of ‘wearing-off’ in patients with migraine?^7,28,34–36 CGRP, calcitonin gene-related peptide; CM, chronic migraine; EM, episodic migraine; HFEM, high-frequency episodic migraine; mAb, monoclonal antibody.*For erenumab, 34.7% of real-world patients self-reported wearing-off, and in 80% of these cases this was at 1 week prior to next injection²⁸; preliminary data reported wearing-off was reported on average at 8 days prior to next injection for erenumab, galcanezumab or fremanezumab³⁴. †For eptinezumab, no publications or preliminary data reporting on presence/absence of wearing-off were found.

CGRP mAbs and wearing-off: what does this mean for managing patients with migraine?

Professor Spierings discusses the implications of long-term efficacy and safety data, and wearing off on the use of CGRP mAbs in clinical practice.

Considering the inconsistent findings between studies, more research will be required to determine implications for prescribing, including factors which may impact the likelihood and timing of wearing-off. At this stage, it is unclear whether frequency of dosing and/or patient characteristics such as treatment history, migraine severity or concomitant medications play a role in likelihood of wearing-off ^7,34.

There is currently a lack of practical guidance to help prescribers to manage wearing-off. Although a shorter dosing interval or use of a higher dose have been suggested to reduce the risk of wearing-off, the safety implications of these approaches are not yet clear^7,28. In the meantime, prescribers are encouraged to document use of any bridging therapies during the wearing-off period^28,34.

Summary

Overall, results from longer-term follow up indicate CGRP mAbs have sustained efficacy and a similar safety profile for 1 to 5 years of treatment. Evidence favours use of the 140 mg dose of erenumab for efficacy in the longer term, and real-world evidence suggests a higher rate of constipation with erenumab compared to clinical trials. Wearing-off has been reported towards the end of the dosing interval for erenumab, and mixed evidence has been reported for wearing-off with fremanezumab and galcanezumab.

Which anti-CGRP treatment is the best option for your patient? Keep an eye out for the third and final article in this 3-part article series on managing migraine, where we will explore some key factors to consider when choosing between the available anti-CGRP treatments

Learn more about the real-world evidence on CGRP mAbs for managing migraine

About Professor Egilius Spierings

Professor Egilius Spierings is the medical director of The Boston Headache Institute at Boston PainCare in Waltham, Massachusetts, United States. He is a former clinical professor of neurology and craniofacial pain at Tufts University Schools of Medicine and Dental Medicine in Boston, Massachusetts, and a former associate clinical professor of neurology at Harvard Medical School.

Disclosures

Professor Spierings is a member of the speaker bureaus of Abbvie, Amgen, Biohaven Pharmaceuticals, Lundbeck, Teva Pharmaceuticals, and Eli Lilly.