Potential for treatment benefit of small molecule CGRP receptor antagonist plus monoclonal antibody in migraine therapy

Safety of Rimegepant, an Oral CGRP Receptor Antagonist, Plus CGRP Monoclonal Antibodies for Migraine

Objective

Evaluate the safety and tolerability of oral rimegepant when used for acute treatment concomitantly with a monoclonal antibody (mAb) targeting the calcitonin gene‐related peptide (CGRP) ligand or receptor (CGRP mAb) for the preventive treatment of migraine.

Background

The efficacy of CGRP mAbs for the preventive treatment of migraine and the small molecule CGRP receptor antagonist rimegepant for acute treatment has been demonstrated in randomized controlled clinical trials. Over the past few years, the US Food and Drug Administration has approved 4 CGRP mAbs for the preventive treatment of migraine and 2 small molecule CGRP receptor antagonists for the acute treatment of migraine. A previous case report of 2 patients receiving concomitant treatment with rimegepant and erenumab suggested that rimegepant may be safely used as acute treatment in patients who are also receiving a preventive regimen involving CGRP mAbs. We report here 13 additional patients with migraine who simultaneously used rimegepant and either erenumab, fremanezumab, or galcanezumab and assess the rate of on‐treatment adverse events (AEs).

Methods

This was a substudy nested within a multicenter, open‐label, long‐term safety study in adults with 2‐14 monthly migraine attacks of moderate to severe pain intensity. A subgroup experiencing 2‐8 monthly attacks and taking a stable dose of a CGRP mAb also took rimegepant 75 mg as needed up to once daily for acute treatment for 12 weeks.

Results

The 13 patients (11 women [85%]; mean age 49.9 years) enrolled in the substudy were being treated with CGRP mAbs (erenumab [n = 7], fremanezumab [n = 4], or galcanezumab [n = 2]). Mean (SD) time in the rimegepant treatment period was 9.6 (4.6) weeks. Mean (SD) 4‐week rimegepant exposure was 7.8 (5.5) doses; a total of 224 doses were taken. Five (38%) patients reported ≥1 on‐treatment AE. Of these, 2 (15%) patients had mild or moderate nasopharyngitis; no other AEs occurred in ≥2 patients. Three patients had AEs of mild or moderate severity that were considered potentially treatment‐related. No patients had serious AEs, AEs leading to discontinuation, or aminotransferase levels >3× the upper limit of normal.

Conclusion

Rimegepant, when used as an oral acute treatment in patients receiving CGRP mAbs as preventive treatment, was well tolerated; no safety issues were identified. Studies involving larger patient populations are needed to confirm these findings.

Targeting CGRP for migraine treatment: mechanisms, antibodies, small molecules, perspectives

INTRODUCTION

Calcitonin Gene-Related Peptide (CGRP) has gradually emerged as a suitable therapeutic target to treat migraine. Considering the social and economic burden of migraine, it is fundamental to optimize the disease management with efficacious and safe treatments. In this scenario, drugs targeting GCRP, monoclonal antibodies (MoAbs) and gepants, represent new therapeutic strategies.

AREAS COVERED

In the present work, the authors aim at appraising the main insights and implications of treatments targeting CGRP by reviewing pathophysiology and clinical information.

EXPERT OPINION

Anti-CGRP MoAbs are the first migraine-specific preventive treatments representing a suitable option especially for difficult-to-treat patients. They can be safely administered for long periods even in association with preventatives acting on different targets. Gepants are a safe alternative to triptans for the acute management of migraine and are currently being tested for prevention, thus representing the first transitional molecules for disease therapy. In the future, it might be possible to adapt the treatment according to patients' characteristics and disease phenotype even combining the two treatments targeting the CGRP pathway.

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.

Clinician-Patient Dialogue About Preventive Chronic Migraine Treatment

Many new medications for the treatment of migraine are now available on the market. In the current evolving migraine treatment landscape, an individualized treatment approach is needed. This review provides practical recommendations on how to obtain a correct diagnosis and then engage in a long-term partnership with patients with the most severe form of migraine: chronic migraine (CM). Given the need to effectively treat this complex neurological disease, clinicians in primary care, general neurologists, and headache specialists are at the forefront to ease the burden of this disease for their patients. This manuscript will review how to discuss the currently available treatment options to help control migraine attacks, manage expectations, and, together with the patient, determine the most effective and appropriate treatment. The goal is to create an environment where the clinician partners with the patient in shared decision-making to choose the most effective appropriate treatment for the individual patient.