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

Abstract

Background and ObjectiveErenumab 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.

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

“…Importantly, both participants and physicians reported improvement in ≥50% of treated subjects over the treatment period. This finding aligns with a recent real‐life case series in which 50% of erenumab users reported ≥50% reduction in migraine frequency after 12 months of treatment 21 …”

“…This finding aligns with a recent real-life case series in which 50% of erenumab users reported ≥50% reduction in migraine frequency after 12 months of treatment. 21 While MAGIC allowed the enrollment of real-world patients who previously experienced inadequate efficacy with two to six categories of migraine prophylactic therapies, most participants had only had such occurrences with two or three categories of prophylactic migraine therapies. These observations contrast with another recent real-world report in which the participants had experienced inadequate effectiveness with, on average, 4.8 categories of prophylactic therapies.…”

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

“…A number of "real-world" studies and registries of migraine treatment with erenumab in North American (18)(19)(20)(21)(22)(23)(24)(25), European (26)(27)(28)(29)(30)(31)(32)(33), or Australian patients (34) have been published recently and included mainly patients with CM (Supplementary Table 1). With one exception (21), all the studies from North America were retrospective (18-20, 22, 23, 26), while all studies but two (26,30) studies from other geographic areas had a prospective design.…”

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

“… 59 Data from real-world showed a delayed response to these treatments recommending a treatment duration of 3–6 months before declaring treatment failure due to non-response. 40 , 49 , 52 Both persistent effect and delayed response might result from modulation of central neural circuits, which should be further investigated through functional neuroimaging and neurophysiology. A persistent and beneficial remodulation of dysfunctional neural circuits 67 might also prevent disease chronification 68 and encourage a prompt treatment with anti-CGRP mAbs even in patients with less severe forms of disease.…”