What is dupilumab biosimilar research grade? Dupilumab is a monoclonal antibody blocking interleukin 4 and interleukin 13, used for allergic diseases such as eczema (atopic dermatitis), asthma and nasal polyps which result in chronic sinusitis. It is also used for the treatment of eosinophilic esophagitis and prurigo nodularis. Dupilumab binds to the alpha subunit of the interleukin-4 receptor (IL-4Ra), making it a receptor antagonist. Through blockade of IL-4Ra, dupilumab modulates signaling of both the interleukin 4 and interleukin 13 pathways. Dupilumab biosimilar uses the same protein sequences as the therapeutic antibody dupilumab.