Dupilumab (Dupixent) is a fully human IgG4 monoclonal antibody against the interleukin (IL)-4 receptor α (IL-4Rα) subunit, which is shared by the type I IL-4 and the type II IL-4/IL-13 receptor complexes. By binding to and blocking this subunit, dupilumab inhibits IL-4 and IL-13, which are the major drivers of human type 2 inflammatory disease [e.g. asthma, atopic dermatitis and chronic rhinosinusitis with nasal polyps (CRSwNP)]. Dupilumab, administered subcutaneously, is the first biological therapy to be approved for the treatment of adults with inadequately controlled CRSwNP in the EU and the USA. In two placebo-controlled, multinational, phase III studies of 24 and 52 weeks’ duration, the addition of dupilumab (300 mg every 2 weeks) to the intranasal corticosteroid treatment of adults with severe, inadequately controlled CRSwNP was generally well tolerated and improved nasal polyp size, sinus opacification and health-related quality of life (HR-QOL), relieved the major symptoms of CRSwNP (nasal congestion or obstruction, nasal discharge and loss of smell) and reduced the use of systemic corticosteroids and the need for nasal polyp surgery. Improvements in nasal polyp size, sinus opacification and nasal congestion or obstruction were achieved regardless of the presence of comorbid asthma or NSAID-exacerbated respiratory disease, or a history of previous nasal polyp surgery, with patients with comorbid asthma also demonstrating improvements in lung function and asthma control regardless of their baseline eosinophil count. Thus, add-on subcutaneous dupilumab is a valuable treatment option for adults with inadequately controlled CRSwNP.