A new therapy to calm down mast cells

Published online: April 4, 2019

Physiologically, mast cells are very useful immune cells involved in allergic and inflammatory reactions. They can however lead to very disabling pathologies, including various diseases usually known as “mast cell disorders.” Patients with mast cell disorders may suffer from many distressing symptoms, severely affecting their quality of life. Available therapies can only partially control these symptoms, thus, there is a need for new and safe treatment options. Omalizumab is an anti-IgE monoclonal antibody already approved for other allergic diseases, but not yet assessed in mast cell disorders.

Since mast cells express the high-affinity IgE receptor FcεRI, Lemal et al. aimed to evaluate the safety and efficacy of omalizumab administration in patients with mast cell disorders. In a recent article published in The Journal of Allergy and Clinical Immunology: In Practice, they detail a study on 55 French patients with mast cell disorders responsible for distressing symptoms, who received omalizumab therapy. All symptoms were assessed before treatment, and the change of each symptom was assessed every 4 to 6 weeks under therapy (worsening, no change, or improvement – and degree of improvement).

The overall best response rate was 78.2% (43/55 patients), including a persistent response (≥ 3 months) in 76.7% of responding patients. Median time to first response was 2 months and median time to best response was 6 months. Omalizumab was dramatically effective on all superficial and general vasomotor symptoms and on most gastrointestinal or urinary symptoms, and partially effective on most neuropsychiatric symptoms. Safety profile was acceptable, except for one severe adverse event (edema of the larynx and dyspnea after the first injection of omalizumab), advocating for in-hospital initiation of treatment.

Omalizumab appears to be a useful therapeutic option to control symptoms from mast cell disorders and displays a favorable safety profile. Prospective randomized studies should confirm these encouraging results and allow more patients to benefit from this effective and safe treatment option.  

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.