Atisnolerbart is a human monoclonal antibody of the IgG4 isotype. It is designed as a therapeutic agent for the treatment of allergic diseases, specifically those triggered by birch pollen. The antibody functions as a neutralizing agent by binding directly to its target, thereby preventing the allergen from interacting with IgE antibodies on mast cells and basophils, which is the initiating step of the allergic cascade. The use of the IgG4 isotype is intended to minimize the antibody's pro-inflammatory Fc effector functions, focusing purely on neutralizing the antigen. Atisnolerbart has been investigated in clinical trials for the treatment of Seasonal Allergic Rhinitis and Conjunctivitis caused by birch pollen.