EHMTI-0315. AMG 334, the first potent and selective human monoclonal antibody antagonist against the CGRP receptor

Blocking the CGRP Pathway for Acute and Preventive Treatment of Migraine: The Evolution of Success

The pivotal role of calcitonin gene-related peptide (CGRP) in migraine pathophysiology was identified over 30 years ago, but the successful clinical development of targeted therapies has only recently been realized. This Perspective traces the decades long evolution of medicinal chemistry required to advance small molecule CGRP receptor antagonists, also called gepants, including the current clinical agents rimegepant, vazegepant, ubrogepant, and atogepant. Providing clinically effective blockade of CGRP signaling required surmounting multiple challenging hurdles, including defeating a sizable ligand with subnanomolar affinity for its receptor, designing antagonists with an extended confirmation and multiple pharmacophores while retaining solubility and oral bioavailability, and achieving circulating free plasma levels that provided near maximal CGRP receptor coverage. The clinical efficacy of oral and intranasal gepants and the injectable CGRP monoclonal antibodies (mAbs) are described, as are recent synthetic developments that have benefited from new structural biology data. The first oral gepant was recently approved and heralds a new era in the treatment of migraine.

Erenumab in chronic migraine with medication overuse: Subgroup analysis of a randomized trial

Objective

To determine the effect of erenumab, a human anti-calcitonin gene-related peptide receptor monoclonal antibody, in patients with chronic migraine and medication overuse.

Methods

In this double-blind, placebo-controlled study, 667 adults with chronic migraine were randomized (3:2:2) to placebo or erenumab (70 or 140 mg), stratified by region and medication overuse status. Data from patients with baseline medication overuse at baseline were used to assess changes in monthly migraine days, acute migraine-specific medication treatment days, and proportion of patients achieving ≥50% reduction from baseline in monthly migraine days.

Results

Of 667 patients randomized, 41% (n = 274) met medication overuse criteria. In the medication overuse subgroup, erenumab 70 or 140 mg groups had greater reductions than the placebo group at month 3 in monthly migraine days (mean [95% confidence interval] −6.6 [−8.0 to −5.3] and −6.6 [−8.0 to −5.3] vs −3.5 [−4.6 to −2.4]) and acute migraine-specific medication treatment days (−5.4 [−6.5 to −4.4] and −4.9 [−6.0 to −3.8] vs −2.1 [−3.0 to −1.2]). In the placebo and 70 and 140 mg groups, ≥50% reductions in monthly migraine days were achieved by 18%, 36% (odds ratio [95% confidence interval] 2.67 [1.36–5.22]) and 35% (odds ratio 2.51 [1.28–4.94]). These clinical responses paralleled improvements in patient-reported outcomes with a consistent benefit of erenumab across multiple measures of impact, disability, and health-related quality of life. The observed treatment effects were similar in the non–medication overuse subgroup.

Conclusions

Erenumab reduced migraine frequency and acute migraine-specific medication treatment days in patients with chronic migraine and medication overuse, improving disability and quality of life.

Clinicaltrials.gov identifier

NCT02066415.

Classification of evidence

This study provides Class II evidence that erenumab reduces monthly migraine days at 3 months in patients with chronic migraine and medication overuse.

ARISE: A Phase 3 randomized trial of erenumab for episodic migraine

Background

Calcitonin gene-related peptide plays an important role in migraine pathophysiology. Erenumab, a human monoclonal antibody that inhibits the calcitonin gene-related peptide receptor, is being evaluated for migraine prevention.

Methods

In this randomized, double-blind, placebo-controlled, phase 3 study, 577 adults with episodic migraine were randomized to placebo or 70 mg erenumab; 570 patients were included in efficacy analyses. Primary endpoint was change in monthly migraine days. Secondary endpoints were ≥50% reduction in monthly migraine days, change in acute migraine-specific medication treatment days, and ≥5-point reduction in Physical Impairment and Impact on Everyday Activities domain scores measured by the Migraine Physical Function Impact Diary. All endpoints assessed change from baseline at month 3.

Results

Patients receiving erenumab experienced −2.9 days change in monthly migraine days, compared with −1.8 days for placebo, least-squares mean (95% CI) treatment difference of −1.0 (−1.6, −0.5) ( p < 0.001). A ≥ 50% reduction in monthly migraine days was achieved by 39.7% (erenumab) and 29.5% (placebo) of patients (OR:1.59 (95% CI: 1.12, 2.27) ( p = 0.010). Migraine-specific medication treatment days were reduced by −1.2 (erenumab) and −0.6 (placebo) days, a treatment difference of −0.6 (−1.0, −0.2) ( p = 0.002). The ≥5-point reduction rates in Migraine Physical Function Impact Diary – Physical Impairment were 33.0% and 27.1% (OR:1.33 (0.92, 1.90) ( p = 0.13) and in Migraine Physical Function Impact Diary – Everyday Activities were 40.4% and 35.8% (OR:1.22 (0.87, 1.71) ( p = 0.26). Safety and adverse event profiles of erenumab were similar to placebo. Most frequent adverse events were upper respiratory tract infection, injection site pain, and nasopharyngitis.

Conclusions

As a preventive treatment of episodic migraine, erenumab at a dosage of 70 mg monthly significantly reduced migraine frequency and acute migraine-specific medication use. (Funded by Amgen).

Trial registration

ClinicalTrials.gov, NCT02483585.

Erenumab (AMG 334) in episodic migraine: Interim analysis of an ongoing open-label study

OBJECTIVE

To assess long-term safety and efficacy of anti-calcitonin gene-related peptide receptor erenumab in patients with episodic migraine (EM).

METHODS

Patients enrolled in a 12-week, double-blind, placebo-controlled clinical trial (NCT01952574) who continued in an open-label extension (OLE) study will receive erenumab 70 mg every 4 weeks for up to 5 years. This preplanned interim analysis, conducted after all participants had completed the 1-year open-label follow-up, evaluated changes in monthly migraine days (MMD), achievement of ≥50%, ≥75%, and 100% reductions, Headache Impact Test (HIT-6) score, Migraine-Specific Quality of Life (MSQ), Migraine Disability Assessment (MIDAS), and safety. Data reported as observed without imputation for missing data.

RESULTS

Of 472 patients enrolled in the parent study, 383 continued in the OLE with a median exposure to erenumab of 575 days (range 28-822 days). Mean (SD) MMD were 8.8 (2.6) at parent study baseline, 6.3 (4.2) at week 12 (beginning of OLE), and 3.7 (4.0) at week 64 (mean change from baseline [reduction] of 5.0 days). At week 64, 65%, 42%, and 26% achieved ≥50%, ≥75%, and 100% reduction in MMD, respectively. Mean HIT-6 scores were 60.2 (6.3) at baseline and 51.7 (9.2) at week 64. MSQ and MIDAS improvements from baseline were maintained through week 64. Safety profiles during the OLE were similar to those in the double-blind phase, which overall were similar to placebo.

CONCLUSIONS

One-year efficacy, supported by functional improvements and favorable safety and tolerability profiles, supports further investigation of erenumab as a preventive treatment in patients with EM.

CLINICALTRIALSGOV IDENTIFIER

NCT01952574.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with episodic migraine, erenumab reduces long-term MMD and improves headache-related disability and migraine-specific quality of life.