Pharmacological, Pharmacokinetic, Pharmacodynamic and Physicochemical Characterization of FE 205030: A Potent, Fast Acting, Injectable CGRP Receptor Antagonist for the Treatment of Acute Episodic Migraine

CGRP physiology, pharmacology, and therapeutic targets: migraine and beyond

Calcitonin gene-related peptide (CGRP) is a neuropeptide with diverse physiological functions. Its two isoforms (α and β) are widely expressed throughout the body in sensory neurons as well as in other cell types, such as motor neurons and neuroendocrine cells. CGRP acts via at least two G protein-coupled receptors that form unusual complexes with receptor activity-modifying proteins. These are the CGRP receptor and the AMY1 receptor; in rodents, additional receptors come into play. Although CGRP is known to produce many effects, the precise molecular identity of the receptor(s) that mediates CGRP effects is seldom clear. Despite the many enigmas still in CGRP biology, therapeutics that target the CGRP axis to treat or prevent migraine are a bench-to-bedside success story. This review provides a contextual background on the regulation and sites of CGRP expression and CGRP receptor pharmacology. The physiological actions of CGRP in the nervous system are discussed, along with updates on CGRP actions in the cardiovascular, pulmonary, gastrointestinal, immune, hematopoietic, and reproductive systems and metabolic effects of CGRP in muscle and adipose tissues. We cover how CGRP in these systems is associated with disease states, most notably migraine. In this context, we discuss how CGRP actions in both the peripheral and central nervous systems provide a basis for therapeutic targeting of CGRP in migraine. Finally, we highlight potentially fertile ground for the development of additional therapeutics and combinatorial strategies that could be designed to modulate CGRP signaling for migraine and other diseases.

A systematic review with expert opinion on the role of gepants for the preventive and abortive treatment of migraine

INTRODUCTION

Gepants are small molecules targeting the calcitonin gene-related peptide (CGRP) that have been recently introduced and are under additional clinical development as preventive and abortive treatment options for migraine.

AREAS COVERED

After providing a narrative overview of current preventive and acute treatment options for migraine and summarizing the pathophysiology of migraine attack and the role of CGRP, we performed a systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, on trials on gepants in preventive and acute treatment of migraine. Studies and results were reviewed and discussed, and expert opinion was presented. We also collected data on relevant ongoing trials.

EXPERT OPINION

Whether direct targeting CGRP pathways within the central nervous system or indirectly modulating them from the peripheral nervous system is more effective and safer in migraine remains still unclear. The available data on the efficacy and safety of gepants suggest they may represent an abortive, and to some extent, preventive treatment option for migraine, in patients who do not respond or have adverse effects to first/second line treatments or at high risk for medication overuse headache; thus opening new therapeutic horizons.

Lipidated Calcitonin Gene-Related Peptide (CGRP) Peptide Antagonists Retain CGRP Receptor Activity and Attenuate CGRP Action In Vivo

Signaling through calcitonin gene-related peptide (CGRP) receptors is associated with pain, migraine, and energy expenditure. Small molecule and monoclonal antibody CGRP receptor antagonists that block endogenous CGRP action are in clinical use as anti-migraine therapies. By comparison, the potential utility of peptide antagonists has received less attention due to suboptimal pharmacokinetic properties. Lipidation is an established strategy to increase peptide half-life in vivo. This study aimed to explore the feasibility of developing lipidated CGRP peptide antagonists that retain receptor antagonist activity in vitro and attenuate endogenous CGRP action in vivo. CGRP peptide analogues based on the archetypal CGRP receptor antagonist, CGRP_8-37, were palmitoylated at the N-terminus, position 24, and near the C-terminus at position 35. The antagonist activities of the lipidated peptide analogues were tested in vitro using transfected Cos-7 cells expressing either the human or mouse CGRP receptor, amylin subtype 1 (AMY₁) receptor, adrenomedullin (AM) receptors, or calcitonin receptor. Antagonist activities were also evaluated in SK-N-MC cells that endogenously express the human CGRP receptor. Lipidated peptides were then tested for their ability to antagonize endogenous CGRP action in vivo using a capsaicin-induced dermal vasodilation (CIDV) model in C57/BL6J mice. All lipidated peptides except for the C-terminally modified analogue retained potent antagonist activity compared to CGRP_8-37 towards the CGRP receptor. The lipidated peptides also retained, and sometimes gained, antagonist activities at AMY₁, AM₁ and AM₂ receptors. Several lipidated peptides produced robust inhibition of CIDV in mice. This study demonstrates that selected lipidated peptide antagonists based on αCGRP_8-37 retain potent antagonist activity at the CGRP receptor and are capable of inhibition of endogenous CGRP action in vivo. These findings suggest that lipidation can be applied to peptide antagonists, such as αCGRP_8-37 and are a potential strategy for antagonizing CGRP action.

Novel Macrocyclic Antagonists of the Calcitonin Gene-Related Peptide Receptor: Design, Realization, and Structural Characterization of Protein-Ligand Complexes

A series of macrocyclic calcitonin gene-related peptide (CGRP) receptor antagonists identified using structure-based design principles, exemplified by HTL0028016 (1) and HTL0028125 (2), is described. Structural characterization by X-ray crystallography of the interaction of two of the macrocycle antagonists with the CGRP receptor ectodomain is described, along with structure-activity relationships associated with point changes to the macrocyclic antagonists. The identification of non-peptidic/natural product-derived, macrocyclic ligands for a G protein coupled receptor (GPCR) is noteworthy.