Long-term efficacy and safety of erenumab in patients with chronic migraine in whom prior preventive treatments had failed: A subgroup analysis.

OBJECTIVE: To assess the long-term efficacy and safety of erenumab in the subgroup of patients with chronic migraine (CM) in whom prior preventive treatments had failed (TF) (≥1, ≥2, and ≥3 TF medication categories) and never failed (preventive naïve or prior preventive treatments had not failed), using the data from a 52-week, open-label treatment period (OLTP) of the parent study. BACKGROUND: Erenumab is a fully human monoclonal antibody that selectively binds to and inhibits the canonical calcitonin gene-related peptide receptor. There are limited long-term data evaluating the efficacy and safety of erenumab in patients with CM in whom prior preventive treatments had failed. METHODS: Patients who had completed the 12-week double-blind treatment period (DBTP) in the parent study were eligible to participate in the 52-week OLTP, during which they received erenumab every 4 weeks. The TF subgroups (≥1, ≥2, and ≥3 TF medication categories) were not mutually exclusive; patients in whom prior preventive treatments from ≥3 medication categories had failed were also counted in the ≥2 and ≥1 medication categories. Endpoints included monthly migraine days (MMD), monthly acute migraine-specific medication days (MSMD), achievement of ≥50%, ≥75%, and 100% reduction from baseline in MMD, and exposure-adjusted patient incidence rates of adverse events (AEs; per 100 patient-years). RESULTS: Erenumab treatment provided sustained mean reductions in MMD and MSMD relative to the parent study baseline throughout the 52 weeks of the OLTP across all TF subgroups. At Week 52, the mean MMD change was -8.6 (SD 6.6) (baseline: 18.4 [SD 4.5] days) in the ≥1 TF subgroup. A post hoc completer analysis (52 weeks [OLTP] erenumab) showed that compared with erenumab 70 mg, the 140 mg dose was associated with numerically greater reductions in the mean MMD (Week 40: -8.6 and -7.2 days; Week 52: -9.7 and -7.9 days [≥1 TF subgroup]) and a higher proportion of patients achieved ≥50%, ≥75%, and 100% response thresholds across all subgroups at Weeks 40 and 52. Overall the exposure-adjusted patient incidence rates of AEs did not increase during the OLTP versus the DBTP (≥1 TF subgroup: 141.9/100 versus 317.9/100 patient-years), and no new safety signals occurred. CONCLUSION: The long-term treatment with erenumab was well tolerated and showed sustained efficacy in patients with CM in whom prior preventive treatments had failed, with numerically greater treatment effects for 140 mg versus 70 mg.

A phase 2, randomized, double-blind, placebo-controlled trial of AMG 301, a pituitary adenylate cyclase-activating polypeptide PAC1 receptor monoclonal antibody for migraine prevention.

OBJECTIVE: To assess the safety and efficacy of AMG 301, an inhibitor of the pituitary adenylate cyclase-activating polypeptide (PACAP)-1 (PAC1) receptor, for prevention of migraine. METHODS: In a double-blind trial, patients were randomized 4:3:3 to placebo, AMG 301 210 mg every 4 weeks, or AMG 301 420 mg every 2 weeks for 12 weeks. Effect on monthly migraine days and other secondary measures were assessed over weeks 9-12. Safety and tolerability were assessed. RESULTS: Of 343 randomized patients (mean age, 41.8-42.5 years), the majority were women (85.4-90.4%), white (94.1-96.2%), and had episodic migraine (62.5-67.9%). A total of 305 patients completed treatment (placebo, n = 124; AMG 301 210 mg, n = 94; AMG 301 420 mg, n = 87). Least squares mean reduction at week 12 in monthly migraine days from baseline was -2.5 (0.4) days for placebo and -2.2 (0.5) days for both AMG 301 treatment groups. No difference between AMG 301 and placebo on any measure of efficacy was observed; mean (95% confidence interval) treatment difference versus placebo for monthly migraine days for AMG 301 210 mg, 0.3 (-0.9 to 1.4); AMG 301 420 mg, 0.3 (-0.9 to 1.4). The incidence of adverse events was similar across groups. CONCLUSION: AMG 301 offered no benefit over placebo for migraine prevention; further studies may be necessary to fully understand the role of PACAP isoforms and its receptors in migraine pathophysiology. STUDY REGISTRATION: ClinicalTrials.gov: NCT03238781.

Long-term safety and efficacy of erenumab in patients with chronic migraine: Results from a 52-week, open-label extension study.

BACKGROUND: This study reports the long-term safety and efficacy of erenumab in chronic migraine patients. METHODS: This was a 52-week open-label extension study of a 12-week double-blind treatment phase study. During the double-blind treatment phase, patients received placebo or once-monthly erenumab 70 mg or 140 mg. During the open-label treatment phase, the initial monthly dose was erenumab 70 mg. Following protocol amendment, patients continued to receive erenumab 70 mg if they had already completed their Week 28 visit, otherwise, patients switched from 70 mg to 140 mg; if enrolled after the amendment, patients received 140 mg monthly throughout. RESULTS: In all, 451/609 (74.1%) enrolled patients completed the study. The exposure-adjusted patient incidence rate for any adverse event was 126.3/100 patient-years for the overall erenumab group. Overall, the adverse event profile was similar to that observed in the double-blind treatment phase. Adverse event incidence rates did not increase with long-term erenumab treatment compared with the double-blind treatment phase, and no new serious or treatment-emergent events were seen. Efficacy was sustained throughout the 52 weeks. Clinically significant reductions from double-blind treatment phase baseline (about half) were observed for monthly migraine days and migraine-specific medication days. Achievement of ≥50%, ≥75% and 100% reductions from the double-blind treatment phase baseline in monthly migraine days at Week 52 were reported by 59.0%, 33.2% and 8.9% of patients, respectively, for the combined dose group. A numerically greater benefit was observed with 140 mg compared with 70 mg at Weeks 40 and 52. CONCLUSIONS: Sustained efficacy of long-term erenumab treatment in patients with chronic migraine is demonstrated, with safety results consistent with the known safety profile of erenumab and adverse event rates comparable to placebo adverse event rates in the double-blind treatment phase. TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT02174861).

The spectrum of response to erenumab in patients with chronic migraine and subgroup analysis of patients achieving ≥50%, ≥75%, and 100% response.

OBJECTIVE: To assess the efficacy of erenumab across the spectrum of response thresholds (≥50%, ≥75%, 100%) based on monthly migraine days (MMD) reduction in patients with chronic migraine from a 12-week, randomized study (NCT02066415). METHODS: Patients (n = 667) received (3:2:2) placebo or erenumab 70/140 mg once-monthly. The proportion of patients achieving a given response threshold was assessed. A post-hoc analysis was conducted to contextualize the actual treatment benefit in subgroups of patients achieving (or not) specified response thresholds. Outcome measures included MMD, acute migraine-specific medication treatment days (MSMD) and disability. RESULTS: The proportion of patients responding to erenumab exceeded that of placebo at the ≥50% and ≥75% response thresholds. At month 3, 39.9% and 41.2% of patients on erenumab 70 and 140 mg, respectively, achieved ≥50% response versus placebo (23.5%). Similarly, at month 3, 17.0% and 20.9% of patients on erenumab 70 and 140 mg, respectively, achieved ≥75% response versus placebo (7.8%). Compared with the overall erenumab-treated population (change in MMD: -6.6 [both 70 and 140 mg]), ≥50% responders showed MMD reductions of -12.2/-12.5 for 70 mg/140 mg versus -2.6/-2.2 for those not achieving ≥50% response. ≥75% responders showed MMD reductions of -13.9/-14.8 for 70 mg/140 mg versus -5.0/-4.3 for those not achieving ≥75% response. Relative improvements in MSMD and disability were observed in responders versus overall erenumab-treated population. CONCLUSION: For erenumab-treated patients achieving ≥50% response, the actual reduction in MMD was almost twice that of the overall population. These findings provide context for setting realistic expectations regarding actual treatment benefit experienced by patients responding to treatment.

Long-term tolerability and nonvascular safety of erenumab, a novel calcitonin gene-related peptide receptor antagonist for prevention of migraine: A pooled analysis of four placebo-controlled trials with long-term extensions.

BACKGROUND: Efficacy and safety of erenumab have been evaluated in a comprehensive clinical development program resulting in approval for migraine prevention in over 40 countries to date. METHODS: This integrated safety analysis included four double-blind randomized trials and their extensions (up to three-plus years). Safety endpoints included exposure-adjusted patient incidences of adverse events, serious adverse events, and anti-erenumab antibodies. RESULTS: In all, 2375 of the patients randomized across the four studies received at least one dose of erenumab (70 mg or 140 mg), with cumulative exposure of 2641.2 patient-years. Exposure-adjusted adverse event rates during the double-blind treatment phase were similar to placebo, with the exception of injection-site reactions (17.1 vs. 10.8 per 100 patient-years), constipation (7.0 vs. 3.8 per 100 patient-years), and muscle spasm (2.3 vs. 1.2 per 100 patient-years). During the long-term extensions, adverse events reported were similar to those observed during the double-blind treatment phase, and rates of injection site reactions, constipation, and muscle spasm were reported at lower rates than in the double-blind treatment phase. There were two deaths reported, both confounded by pre-existing conditions. CONCLUSIONS: This pooled safety analysis revealed a favorable and stable adverse event profile over time for erenumab with more than three years of exposure. TRIAL REGISTRATION: ClinicalTrials.gov NCT01952574, NCT02483585, NCT02456740, NCT02066415, and NCT02174861.

Efficacy and safety of erenumab (AMG334) in chronic migraine patients with prior preventive treatment failure: A subgroup analysis of a randomized, double-blind, placebo-controlled study.

Background Erenumab was effective and well tolerated in a pivotal clinical trial of chronic migraine. Here, we evaluated efficacy and safety of monthly erenumab (70 mg or 140 mg) versus placebo in the subgroup of patients who had previously failed preventive treatment(s) (≥ 1, ≥ 2 prior failed medication categories) and in patients who had never failed. Methods Subgroup analyses evaluated change from baseline in monthly migraine days; achievement of ≥ 50% and ≥ 75% reduction in monthly migraine days; and change in monthly acute migraine-specific medication days. Adverse events were evaluated for each subgroup. Results Treatment with both doses of erenumab resulted in greater reductions in monthly migraine days (primary endpoint) at Month 3 (treatment difference [95% CI], never failed subgroup: -2.2 [-4.1, -0.3] for 70 mg and -0.5 [-2.4, 1.5] for 140 mg; ≥ 1 prior failed medication categories subgroup: -2.5 [-3.8, -1.2], for 70 mg and -3.3 [-4.6, -2.1] for 140 mg; ≥ 2 prior failed medication categories subgroup: -2.7 [-4.2, -1.2], for 70 mg and -4.3 [-5.8, -2.8] for 140 mg). Similar results were observed in the monthly acute migraine-specific medication days endpoint, and in the achievement of ≥ 50% and ≥ 75% reduction in monthly migraine days. There were no new or unexpected safety issues. Conclusion Erenumab showed consistent efficacy in chronic migraine patients who had failed prior preventive treatments and was well tolerated across subgroups.

Early Use of Erenumab vs Nonspecific Oral Migraine Preventives: The APPRAISE Randomized Clinical Trial.

Importance: Patients with migraine often cycle through multiple nonspecific preventive medications due to poor tolerability and/or inadequate efficacy leading to low adherence and increased disease burden. Objective: To compare the efficacy, tolerability, patient adherence, and patient satisfaction between erenumab and nonspecific oral migraine preventive medications (OMPMs) in patients with episodic migraine (EM) who had previously failed 1 or 2 preventive treatments. Design, Setting, and Participants: The 12-month prospective, interventional, global, multicenter, active-controlled, randomized clinical trial comparing sustained benefit of 2 treatment paradigms (erenumab qm vs oral prophylactics) in adult episodic migraine patients (APPRAISE) trial was a 12-month open-label, multicenter, active-controlled, phase 4 randomized clinical trial conducted from May 15, 2019, to October 1, 2021. This pragmatic trial was conducted at 84 centers across 17 countries. Overall, participants 18 years or older with a 12-month or longer history of migraine, and 4 or more but fewer than 15 monthly migraine days (MMDs) were included. Interventions: Patients were randomized (2:1) to receive erenumab or OMPMs. Dose adjustment was permitted (label dependent). Main Outcomes and Measures: The primary end point was the proportion of patients completing 1 year of the initially assigned treatment and achieving a reduction of 50% or greater from baseline in MMDs at month 12. Secondary end points included the cumulative mean change from baseline in MMDs during the treatment period and the proportion of responders according to the Patients' Global Impression of Change (PGIC) scale at month 12 for patients taking the initially assigned treatment. Results: A total of 866 patients were screened, of whom 245 failed the screening and 621 completed the screening and baseline period. Of the 621 randomized patients (mean [SD] age, 41.3 [11.2] years; 545 female [87.8%]; 413 [66.5%] in the erenumab group; 208 [33.5%] in the OMPM group), 523 (84.2%) completed the treatment phase, and 98 (15.8%) discontinued the study. At month 12, significantly more patients assigned to erenumab vs OMPM achieved the primary end point (232 of 413 [56.2%] vs 35 of 208 [16.8%]; odds ratio [OR], 6.48; 95% CI, 4.28-9.82; P <.001). Compared with OMPMs, treatment with erenumab showed higher responder rate (314 of 413 [76.0%] vs 39 of 208 [18.8%]; OR, 13.75; 95% CI, 9.08-20.83; P <.001) on the PGIC scale (≥5 at month 12). Significant reduction in cumulative average MMDs was reported with erenumab treatment vs OMPM treatment (-4.32 vs -2.65; treatment difference [SE]: -1.67 [0.35] days; P < .001). Substantially fewer patients in the erenumab arm compared with the OMPM arm switched medication (9 of 413 [2.2%] vs 72 of 208 [34.6%]) and discontinued treatment due to adverse events (12 of 408 [2.9%] vs 48 of 206 [23.3%]). No new safety signals were identified. Conclusions and Relevance: Results of this randomized clinical trial demonstrated that earlier use of erenumab in patients with EM who failed 1 or 2 previous preventive treatments provided greater and sustained efficacy, safety, and adherence than continuous OMPM. Trial Registration: ClinicalTrials.gov Identifier: NCT03927144.

Hypnic headache - a rare primary headache disorder with very good response to indomethacin.

Hypnic headache (HH) is considered as a disorder of the circadian rhythm, mostly affecting the elderly and generally considered a benign disorder, but the pathophysiology of hypnic hedache remains unclear. Various treatments have been suggested for hypnic headache, especially lithium and indomethacin. We report the case of HH fulfilling The International Classification Headache Disorders, 2nd edition criteria (ICHD-II). A 64-year-old woman, who suffered from dull headaches strictly during the night for a period of 5 months. Attacks of headache lasted from 30 to 150 minutes, with a frequency usually 4 times per week. The patient was started on indomethacin 50 mg twice a day (BID). From day 25 on she was free of hypnic headache. On day 31 we tapered the daily dose of indomethacin to 50mg at bedtime, the patient was still without headache. On day 60 the treatment was stopped. 30 months after day 60, the patient was still headache free. We reported the first Czech patient with HH with very good therapeutic response to indomethacin. The effect of therapy with indomethacin 50mg BID was very fast and stable.

Physiotherapy as an immunoactive therapy? A pilot study.

OBJECTIVES: The aim of this study was to confirm the immunoregulatory and anti-inflammatory changes in the immunologic profile after two months of the facilitation physiotherapy in patients with multiple sclerosis; and to determine whether the changes in the immunologic profile correlate with the changes in dehydroepiandrosterone, the brain microstructure and clinical functions. DESIGN & SETTING: A group of 12 patients with multiple sclerosis was examined twice: at the beginning and 2 months later after the patients had undergone the facilitation therapy. Standardized tests evaluating chosen clinical functions (balance, righting, equilibrium and protective reactions, tremor, dysdiadochokinesis, dysmetry, fine hand function and walking), immune parameters (parameters of the humoral and cellular immunity), dehydroepiandrosterone and diffusion tensor imaging (the fractional anisotropy, mean diffusivity) were measured. The patients underwent the facilitation physiotherapy in two sessions lasting two hours each week for two months. RESULTS: All clinical and diffusion tensor imaging parameters significantly improved following the therapy. Without the correction for multiple comparisons, there were significant changes in the IgG, IgG1 subclasses, in the numbers of Neutrophils and Lymphocytes, the T cells (CD3+) absolute number, the T cytotoxic subpopulation (CD3+CD8+) absolute number, B cells (CD19+) and the Natural killer cells. In addition, there was a significant correlation between the changes in the clinical functions and the changes in IgG1 (r=0.67), and between the changes in the mean diffusivity and the changes in CD3+CD8+ absolute (r=-0.61). The changes in the immune parameters and the mentioned correlations were not significant in view of the number of comparisons and thus necessitate further validation. No changes in the dehydroepiandrosterone concentration after the therapy were confirmed. CONCLUSION: The study suggests new possibilities of physiotherapy to influence the psycho-neuro-endocrine-immune response in patients with multiple sclerosis.

Long-term treatment with galcanezumab in patients with chronic migraine: results from the open-label extension of the REGAIN study.

BACKGROUND: Galcanezumab, a monoclonal antibody to calcitonin gene-related peptide, was found to be safe and efficacious for the preventive treatment of chronic migraine based on the randomized, placebo-controlled double-blind period of the REGAIN study. Long-term safety and efficacy were assessed in an open-label extension. METHODS: Patients 18-65 years old with chronic migraine completing the 3-month double-blind period of REGAIN could enter a 9-month open-label extension (OLE; months 4-12). Upon entering the OLE, patients received a 240-mg galcanezumab loading dose, then 120 mg at the next month, with flexible dosing thereafter (120 or 240 mg/month). The primary efficacy measure was the mean change in the number of monthly migraine headache days from double-blind baseline to month 12. Other endpoints included response rates (based on percent reduction in monthly migraine headache days from double-blind baseline to month 12), safety and tolerability. RESULTS: Of patients who completed double-blind treatment, 1022 (99%) entered the OLE, with 81% completing month 12. From a baseline of 19.4 monthly migraine headache days at the beginning of the double-blind period, patients at month 12 in the previous placebo, 120-mg, and 240-mg galcanezumab groups had a mean change of -8.5, -9.0, and -8.0, respectively (SE = 0.43 to 0.55, within-group p's < .001). At month 12, the percentage of patients with ≥50% response was 57%, 57%, and 53%, respectively. Percentage with ≥75% response was 32%, 31%, and 30%, respectively. Percentage with 100% response was 8%, 6%, and 6%, respectively. There were no significant new safety findings during the open-label period. The incidence of discontinuation from the OLE due to adverse events was 5%. CONCLUSION: Galcanezumab was effective, safe, and well-tolerated, with high adherence, for up to 12 months of treatment in patients with chronic migraine. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02614261; www.clinicaltrials.gov/ct2/show/NCT02614261.

Galcanezumab in Patients with Multiple Previous Migraine Preventive Medication Category Failures: Results from the Open-Label Period of the CONQUER Trial.

INTRODUCTION: Results from the open-label extension of the phase 3b CONQUER trial are presented to evaluate the effectiveness and safety of galcanezumab, a monoclonal antibody targeting calcitonin gene-related peptide, for up to 6 months in patients with multiple prior migraine preventive treatment failures. METHODS: Patients were 18-75 years old with episodic or chronic migraine and 2-4 standard-of-care migraine preventive medication category failures. After 3 months of randomized treatment with galcanezumab (120 mg/month with 240 mg loading dose; n = 232) or placebo (n = 230), patients entered a 3-month open-label extension (120 mg/month galcanezumab with a blinded 240 mg loading dose for previous-placebo patients). Primary efficacy measure was mean change from double-blind baseline in monthly migraine headache days. RESULTS: A total of 432/449 patients (96%) who entered open-label treatment completed the study. Mean change in monthly migraine headache days in the total population, which was - 1.3 for placebo and - 4.4 for galcanezumab patients at the end of double-blind treatment (p < 0.001), was - 5.2 and - 5.6, respectively, at the end of open-label treatment with galcanezumab. Among patients with episodic migraine, mean change in monthly migraine headache days had been - 0.6 for placebo and - 2.8 for galcanezumab after double-blind treatment (p < 0.001) and was - 4.5 and - 3.8, respectively, after open-label treatment. Among patients with chronic migraine, mean change in monthly migraine headache days had been - 2.5 for placebo and - 6.6 for galcanezumab after double-blind treatment (p < 0.001) and was - 6.5 and - 8.2, respectively, after open-label treatment. Adverse events were similar to those observed during double-blind placebo treatment. Review of data in elderly patients (65-75 years of age) indicated that galcanezumab was well tolerated in this age group, with no safety issues identified. CONCLUSIONS: Galcanezumab was effective and safe during open-label treatment in patients who had experienced failures of previous migraine preventives. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03559257.

An Investigation into the Prevalence of Migraine and Its Prophylactic Treatment Patterns in the Czech Republic: An Observational Study.

PURPOSE: A national primary and secondary healthcare-level study in the Czech Republic has not yet been conducted to evaluate the prevalence of migraine. We analyzed the current treatment patterns (acute and prophylactic) in migraine patients and the number of migraine patients potentially eligible for treatment with recent calcitonin gene-related peptide (CGRP) pathway-targeted therapies. METHODS: This retrospective study utilized the Ministry of the Interior Health Insurance Fund claims database of the Czech Republic wherein every citizen is insured. Migraine patients with or without aura, and potentially on triptan therapy were included in this study (index years 2012-2016). The prevalence approach included all patients (new and old) present in each index year. Prophylactic therapies were followed f0or three and seven years prior to the index year, including the index year, until 2010. The incidence approach included all patients first diagnosed in each index year. Prophylactic therapies were followed for the next three years, including the index year, until 2017 following incidence approach. The primary endpoint of this study was to determine the rate of migraine prevalence and diagnosis for each index year during the period 2012-2016. The study also evaluated prophylactic and acute treatment patterns and comorbidities among patients in 2016. RESULTS: The rate of migraine prevalence was 1% and the rate of diagnosis was 0.2-0.4%. By prevalence approach, approximately 39% of the patients were on prophylactics, and 11.2% and 21.6% of the patient population had two prior treatment failures (three- and seven-year recall period, respectively). Antiepileptics (26%) and beta blockers (15.8%) were the most prescribed prophylactics, and sumatriptan was the predominant triptan used (12%) for acute treatment. CONCLUSION: Taking into account the number of inhabitants in the Czech Republic (10.7 million), there could be up to 23,000 adult patients eligible for novel CGRP therapies.

Safety and efficacy of erenumab for preventive treatment of chronic migraine: a randomised, double-blind, placebo-controlled phase 2 trial.

BACKGROUND: The calcitonin gene-related peptide (CGRP) pathway is important in migraine pathophysiology. We assessed the efficacy and safety of erenumab, a fully human monoclonal antibody against the CGRP receptor, in patients with chronic migraine. METHODS: This was a phase 2, randomised, double-blind, placebo-controlled, multicentre study of erenumab for adults aged 18-65 years with chronic migraine, enrolled from 69 headache and clinical research centres in North America and Europe. Chronic migraine was defined as 15 or more headache days per month, of which eight or more were migraine days. Patients were randomly assigned (3:2:2) to subcutaneous placebo, erenumab 70 mg, or erenumab 140 mg, given every 4 weeks for 12 weeks. Randomisation was centrally executed using an interactive voice or web response system. Patients, study investigators, and study sponsor personnel were masked to treatment assignment. The primary endpoint was the change in monthly migraine days from baseline to the last 4 weeks of double-blind treatment (weeks 9-12). Safety endpoints were adverse events, clinical laboratory values, vital signs, and anti-erenumab antibodies. The efficacy analysis set included patients who received at least one dose of investigational product and completed at least one post-baseline monthly measurement. The safety analysis set included patients who received at least one dose of investigational product. The study is registered with ClinicalTrials.gov, number NCT02066415. FINDINGS: From April 3, 2014, to Dec 4, 2015, 667 patients were randomly assigned to receive placebo (n=286), erenumab 70 mg (n=191), or erenumab 140 mg (n=190). Erenumab 70 mg and 140 mg reduced monthly migraine days versus placebo (both doses -6·6 days vs placebo -4·2 days; difference -2·5, 95% CI -3·5 to -1·4, p<0·0001). Adverse events were reported in 110 (39%) of 282 patients, 83 (44%) of 190 patients, and 88 (47%) of 188 patients in the placebo, 70 mg, and 140 mg groups, respectively. The most frequent adverse events were injection-site pain, upper respiratory tract infection, and nausea. Serious adverse events were reported by seven (2%), six (3%), and two (1%) patients, respectively; none were reported in more than one patient in any group or led to discontinuation. 11 patients in the 70 mg group and three in the 140 mg group had anti-erenumab binding antibodies; none had anti-erenumab neutralising antibodies. No clinically significant abnormalities in vital signs, laboratory results, or electrocardiogram findings were identified. Of 667 patients randomly assigned to treatment, 637 completed treatment. Four withdrew because of adverse events, two each in the placebo and 140 mg groups. INTERPRETATION: In patients with chronic migraine, erenumab 70 mg and 140 mg reduced the number of monthly migraine days with a safety profile similar to placebo, providing evidence that erenumab could be a potential therapy for migraine prevention. Further research is needed to understand long-term efficacy and safety of erenumab, and the applicability of this study to real-world settings. FUNDING: Amgen.