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Mavoglurant binds to same allosteric site on metabotropic glutamate receptor 5 (mGluR5) as [11C]-ABP688, a radioligand. This open-label, single-center pilot study estimates extent of occupancy of mGluR5 receptors following single oral doses of mavoglurant, using [11C]-ABP688 positron emission tomography (PET) imaging, in six healthy males aged 20–40 years. This study comprised three periods and six subjects were divided into two cohorts. On Day 1 (Period 1), baseline clinical data and safety samples were obtained along with PET scan. During Period 2 (1–7 days after Period 1), cohort 1 and 2 received mavoglurant 25 mg and 100 mg, respectively. During Period 3 (7 days after Period 2), cohort 1 and 2 received mavoglurant 200 mg and 400 mg, respectively. Mavoglurant showed the highest distribution volumes in the cingulate region with lower uptake in cerebellum and white matter, possibly because myelinated axonal sheets maybe devoid of mGlu5 receptors. Maximum concentrations of mavoglurant were observed around 2–3.25 h post-dose. Mavoglurant passed the blood–brain barrier and induced dose- and exposure-dependent displacement of [11C]-ABP688 from the mGluR5 receptors, 3–4 h post-administration (27%, 59%, 74%, 85% receptor occupancy for mavoglurant 25 mg, 100 mg, 200 mg, 400 mg dose, respectively). There were no severe adverse effects or clinically significant changes in safety parameters.This is the first human receptor occupancy study completed with Mavoglurant. It served to guide the dosing of mavoglurant in the past and currently ongoing clinical studies. Furthermore, it confirms the utility of [11C]-ABP688 as a unique tool to study drug-induced occupancy of mGlu5 receptors in the living human brain.

Food allergy (FA) is a growing healthcare problem worldwide and the rising prevalence in many countries can be attributed to lifestyle, environmental, and nutritional changes. Immunoglobulin E (IgE)-mediated FA is the most common form of FA affecting approximately 3%–10% of adults and 8% of children across the globe. Food allergen–induced immediate hypersensitivity reactions mediated by IgE and high-affinity IgE receptor (FcεRI) complexes on mast cells and basophils are a major hallmark of the disease. FA can affect several aspects of health-related quality of life and impose a substantial financial burden on patients and healthcare systems. Although currently there is one United States Food and Drug Administration (FDA) and European Medicines Agency (EMA)–approved treatment for peanut allergy (Palforzia), the main treatment approaches are based on allergen avoidance and symptom management. Thus, there is an urgent need for more effective and ideally disease-modifying strategies. Given the crucial role of IgE in FA, anti-IgE monoclonal antibodies are considered promising therapeutic agents. Talizumab was the first humanized anti-IgE antibody to demonstrate substantial protection against allergic reactions from accidental peanut exposure by substantially increasing the peanut reactivity threshold on oral food challenge. However, development of talizumab was discontinued and further trials were performed using omalizumab. In double-blind, Phase 2, placebo-controlled trials in patients with multi-FAs, sustained dosing with omalizumab, or omalizumab in combination with oral immunotherapy, enabled rapid desensitization to multiple trigger foods. In this review, we describe the development of ligelizumab (a derivative of talizumab), a next generation, humanized monoclonal anti-IgE antibody, its existing clinical evidence, and its potential in the management of FA. When compared with omalizumab, ligelizumab binds with ∼88-fold higher affinity for human IgE and recognizes a different epitope that substantially overlaps with the binding site of FcεRI. These properties translate into a high potency to block IgE/FcεRI signaling in both in vitro and in vivo studies. Given its efficient suppression of IgE levels, good safety and pharmacokinetic/pharmacodynamic profile, ligelizumab clearly warrants further studies for the potential management of FA.

Abstract Objective Ligelizumab is a humanised IgG1 anti‐IgE antibody that binds IgE with higher affinity than omalizumab. Ligelizumab had greater efficacy than omalizumab on inhaled and skin allergen provocation responses in mild allergic asthma. This multi‐centre, randomised, double‐blind study was designed to test ligelizumab in severe asthma patients not adequately controlled with high‐dose inhaled corticoids plus long‐acting β2‐agonist. Methods Patients received 16 weeks ligelizumab (240 mg q2w), omalizumab or placebo subcutaneously, and ACQ‐7 was measured as primary outcome at Week 16. In addition, the study generated dose‐ranging data of ligelizumab and safety data. Results A total of 471 patients, age 47.4 ± 13.36 years, were included in the study. Treatment with ligelizumab did not significantly improve asthma control (ACQ‐7) and exacerbation rates compared to omalizumab and placebo. Therefore, primary and secondary objectives of the study were not met. The compound was well tolerated, and the safety profile showed no new safety findings. Pharmacokinetic data demonstrated faster clearance and lower serum concentrations of ligelizumab than historical omalizumab data, and exploratory in vitro data showed differential IgE blocking properties relative to FcεRI and FcεRII/CD23 between the two compounds. Conclusion Ligelizumab failed to demonstrate superiority over placebo or omalizumab. Although ligelizumab is more potent than omalizumab at inhibiting IgE binding to the high‐affinity FcεRI, there is differential IgE blocking properties relative to FcεRI and FcεRII/CD23 between the two compounds. Therefore, the data suggest that different anti‐IgE antibodies might be selectively efficacious for different IgE‐mediated diseases.