CGRP Monoclonal Antibodies May Be Beneficial for Migraine Prevention

BOSTON—A new class of drugs for the prevention of chronic and episodic migraine demonstrated promising results in recent phase II and phase III trials. Data for four humanized calcitonin gene–related peptide (CGRP) monoclonal antibodies—eptinezumab, erenumab, fremanezumab, and galcanezumab—were presented at the 59th Annual Scientific Meeting of the American Headache Society. Previous research has long implicated CGRP (which is elevated in jugular vein blood during acute migraine and cluster headaches) in disease pathophysiology. Recent advances in molecular neuroscience have helped shed further light on the pathogenic mechanisms and possible targets for treatment.

Eptinezumab

In a phase II study, a single infusion of eptinezumab (which Alder BioPharmaceuticals is developing under the name ALD403) reduced the number of migraine days per month, as well as the number of migraines classified as severe, in patients with chronic migraine. Of the four drugs presented at the meeting, eptinezumab was the only one to have an IV mode of delivery.

“We used International Classification of Headache Disorders 3 criteria to define chronic migraine, which is at least 15 headache days per month, of which eight must be migraine-like,” said Jeffrey T. L. Smith, MD, Senior Vice President of Translational Medicine at Alder BioPharmaceuticals in Bothell, Washington. “Patients also had to have a history of migraine for a year or more.”

Jeffrey T. L. Smith, MD

On average, the patients included in this multisite study were slightly younger than 40. Most patients were women, and the average number of migraine days was between 16.2 and 16.5. After a one-month run-in period, patients were randomized to receive placebo or one of four doses of eptinezumab (ie, 300 mg, 100 mg, 30 mg, or 10 mg).

Reporting 12-week data from the 48-week trial, Dr. Smith and colleagues found that significantly more patients taking the 300-mg (33%) and 100-mg (31%) doses of eptinezumab reached the primary end point of a 75% reduction from baseline in migraine days, compared with patients who received placebo (21%). Differences in patients taking the 30-mg and 10-mg doses (28% and 27%, respectively) were not statistically significant. “Overall, approximately half of patients treated with eptinezumab experienced a 50% reduction in migraine days versus 41% of patients on placebo,” Dr. Smith added. Eptinezumab was well tolerated, and no serious adverse events were reported.

Post hoc analyses indicated that of the migraines that were not eliminated as a result of treatment, the percentage classified as severe was significantly reduced from baseline in each of the eptinezumab groups, compared with placebo. Also, fewer patients in the eptinezumab groups than in the placebo group experienced a migraine within the first 24 to 48 hours after infusion. “Although the post hoc results are exploratory, these findings are important as well,” said Dr. Smith. “Other things are happening besides the reduction in migraine frequency that may be of benefit.”

Erenumab

A registration, pivotal study on erenumab for chronic migraine prevention was reported at the meeting. “Unlike eptinezumab, fremanezumab, and galcanezumab, which are monoclonal antibodies against the CGRP ligand, erenumab is an anti-CGRP receptor monoclonal antibody,” said Stewart J. Tepper, MD, Professor of Neurology at the Geisel School of Medicine at Dartmouth in Hanover, New Hampshire. Amgen is developing this antibody.

Stewart J. Tepper, MD

In the 12-week randomized controlled trial, patients were enrolled in the US and around the world, Dr. Tepper noted. He and his colleagues included patients who had 15 or more headache days per month with at least eight days of migraine per month. Patients were excluded if they had experienced treatment failure with more than three classes of preventive agents. Mean age was 40, about 80% of patients were women, and roughly half of patients had previously experienced treatment failure with at least two preventive agents.

A total of 667 patients were randomized 3:2:2 to placebo, erenumab (70 mg), or erenumab (140 mg). Treatment was given monthly via subcutaneous injection. The primary end point was change from baseline in monthly migraine days (MMD). Secondary end points included at least a 50% reduction in MMD, change from baseline in acute migraine-specific medication days, and cumulative headache hours.

In both erenumab groups, patients experienced a mean 6.6-day reduction in MMD from a baseline of 18.0 days, which was significantly different, compared with the 4.2-day reduction seen in the placebo group. Furthermore, a significantly greater proportion of patients in the 70-mg and 140-mg groups (40% and 41%, respectively) experienced at least a 50% reduction in MMD, compared with the placebo group (23%). For the secondary end points, both erenumab groups had significantly greater reductions in acute migraine-specific medication days versus placebo. However, the difference in the reduction of cumulative headache hours did not reach statistical significance. “We speculated that this was because headache hours is a relatively variable end point, and it is collected in differing ways, with wide confidence intervals,” Dr. Tepper said.

The safety profile for both erenumab groups and the placebo group was similar. “No serious adverse events were reported by more than one patient in any treatment arm, and no serious adverse events were considered related to treatment,” he said.

Another erenumab trial enrolled patients with episodic migraine. Randomization was stratified by region and current and prior migraine preventive medication, said Daniel Mikol, MD, PhD, Executive Medical Director of Neuroscience Development at Amgen in Thousand Oaks, California. Patients included in the phase III study could be taking a single concomitant migraine preventive therapy. “Patients could have also failed previous preventive therapies due to poor tolerability or lack of efficacy,” he said. “There was no limit regarding the number of previous failures due to poor tolerability. With regard to lack of efficacy, patients could have no therapeutic response to two or fewer preventive therapies.”

Adults with episodic migraine (n = 955) were randomized 1:1:1 to monthly subcutaneous injections of placebo, erenumab (70 mg), or erenumab (140 mg) for 24 weeks. The primary end point was change from baseline in MMD from weeks 13 to 24. Secondary end points included achievement of 50% or more reduction in MMD, change in mean acute migraine-specific medication days, and changes in mean physical impairment and impact on everyday activity scores, as measured by the Migraine Physical Function Impact Diary, a novel patient-reported instrument, Dr. Mikol explained.

Subjects had a mean of 8.3 MMD at baseline. This measurement was reduced by 3.2, 3.7, and 1.8 days in the 70-mg, 140-mg, and placebo groups, respectively—a statistically significant difference in favor of the erenumab groups. Statistically superior results for erenumab 70 mg and 140 mg over placebo also were seen in the secondary end points of > 50% response (43%, 50%, and 27%, respectively), reduction from baseline in monthly acute migraine-specific medication days (1.1, 1.6, and 0.2), improved physical impairment score from baseline (4.2, 4.8, and 2.5), and improved everyday activity scores from baseline (5.5, 5.9, and 3.3).

“The safety profiles for erenumab were similar to that of placebo,” Dr. Mikol said. “Specifically, 63% of patients on placebo had adverse events, compared with 56% to 57% of patients in the erenumab groups. Serious adverse events and adverse events leading to treatment discontinuation were low in frequency and balanced across the groups.”

Galcanezumab

The efficacy, tolerability, and safety of galcanezumab, an investigational drug for the treatment of episodic migraine, was assessed in a six-month phase III study called EVOLVE-2. In this study, patients with episodic migraine experienced four to 14 migraine headache days per month with or without aura. “Our patient population had a mean age of about 40, and most [participants] were Caucasian women,” said Robert Conley, MD, Distinguished Lilly Scholar of Neuroscience at Eli Lilly and Company (the developer of galcanezumab) in Indianapolis.

Robert Conley, MD

“Half of our subjects were from North America, a quarter from Europe, and a quarter from the rest of the world.” Subjects had a 20-year migraine history on average and a mean of nine headache days per month at baseline, he noted. “In addition, two-thirds had been on prior preventive treatment, and they had relatively severe levels of disease.”

After screening 1,700 patients for the study, Dr. Conley and colleagues randomized 914 patients 1:1:2 to subcutaneous injection of galcanezumab (120 mg/month), galcanezumab (240 mg/month), or placebo. “There was about an 87% completion rate for the galcanezumab groups and an 83% completion rate in the placebo group. The higher number of dropouts in the placebo group was due to lack of efficacy,” said Dr. Conley. The primary end point was change from baseline in MMD at the end of six months. Secondary end points were percentages of patients with 50%, 75%, and 100% response rates; reduction in MMD requiring acute migraine medication; change in function score on the Migraine-Specific Quality of Life Questionnaire (MSQ); and change in the Patient Global Impression of Severity (PGI-S) rating.

After adjusting for multiplicity, the investigators found statistically significant differences between placebo and the galcanezumab arms in the primary end point. Mean reductions in headache days were 4.29 in the 120-mg group and 4.18 in the 240-mg group. Patients in the placebo group experienced a reduction of 2.28 days. “We looked at the early effects of treatment and found statistically significant improvements within a few days of injection that persisted over time,” Dr. Conley said.

In addition, statistically significant differences between galcanezumab and placebo were observed for all secondary end points. “In the 120-mg and 240-mg treatment groups, 59.3% and 56.5%, respectively, had at least a 50% reduction in monthly headache days, which was significantly different from placebo, but not different from each other,” said Dr. Conley. “We also saw that approximately one-third of patients in the galcanezumab arms experienced 75% response rates, which is double that seen in the placebo group. The 100% response rate was 11.5% to 13.8% in the treated groups—again, not a significant difference between them, but significantly different from placebo.” The change in the MSQ function score and the PGI-S rating averaged for months 4, 5, and 6 were significantly improved in the galcanezumab arms, compared with the placebo arm.

For most of the safety parameters, there were no significant differences between either dose of galcanezumab and placebo. However, the rates of injection-site reactions and pruritus were significantly higher for both drug doses, compared with placebo. Injection-site erythema was significantly higher in the 240-mg dose only.

Fremanezumab

“The phase III trial for fremanezumab in chronic migraine investigated a flexible dose for a quarterly and a monthly regimen,” said Ernesto Aycardi, MD, Vice President and Therapeutic Area Head for Migraine and Headache at Teva Pharmaceuticals. Teva is developing fremanezumab, a fully humanized monoclonal antibody targeting the CGRP ligand. After a run-in period of 28 days, 1,130 patients were randomized 1:1:1 to three monthly doses of placebo; 675 mg fremanezumab for the first month, followed by placebo for two months (ie, the quarterly dose regimen); or 675 mg fremanezumab at initiation, followed by monthly 225-mg doses of fremanezumab for two months (the monthly dose regimen). The study allowed the inclusion of patients who were on monotherapy or on stable doses of other prophylactic medication.

Ernesto Aycardi, MD

The primary end point of this multicenter trial was the mean change from baseline in monthly days of headache of at least moderate severity. The four main secondary end points were the proportion of patients with at least a 50% reduction in headache days, mean change in the number of days using acute headache medication at the end of the 12-week period of the trial, mean change from baseline in the days of at least moderate severity in the first four weeks of the trial, and change in disability scale (HIT-6) score from baseline. In this trial, patients treated with fremanezumab experienced significant improvement, compared with placebo on all primary and secondary end points for both monthly and quarterly dosing regimens.

“The average age of the study population was 41, with an average history of migraine of about 20 years,” Dr. Aycardi said. “All demographic characteristics, including weight, height, and ethnicity, were well balanced between the groups.”

Patients on the monthly regimen had a mean reduction of 4.6 headache days of at least moderate severity, and patients on the quarterly regimen had a reduction of 4.3 headache days of at least moderate severity, which was significantly different from the placebo group (2.5 headache days). Researchers also observed significant differences for each of the four secondary end points in favor of the monthly and quarterly regimens.

“Fremanezumab was well tolerated, compared with placebo,” Dr. Aycardi said. “The most commonly reported adverse event in the study was injection-site pain, with similar rates in the placebo and active groups.”

Dr. Aycardi highlighted how phase II results validated that target in chronic migraine. “With these phase III results, this is confirmed, bringing hope for patients with this disabling condition.”

—Adriene Marshall

Suggested Reading

Durham PL. Calcitonin gene-related peptide (CGRP) and migraine. Headache. 2006;46(Suppl 1):S3–S8.

Reuter U. Anti-CGRP antibodies: a new approach to migraine prevention. Lancet Neurol. 2014;13(9):857-859.

Tepper S, Ashina M, Reuter U, et al. Safety and efficacy of erenumab for preventive treatment of chronic migraine: a randomised, double-blind, placebo-controlled phase 2 trial. Lancet Neurol. 2017;16(6):425-434.