PD-L1 inhibitor-induced worsening of eosinophilic obstructive lung disease successfully rescued with anti-interleukin 5 receptor (IL-5R) therapy

Biologics positively transformed the world of asthma.1-3 Benralizumab, a monoclonal antibody that binds to the IL-5 receptor (IL-5R), induces sustained eosinophil depletion and improvement of asthma control.2 Surprisingly, this benefit could not be reproduced in chronic obstructive pulmonary disease (COPD) despite the choice of blood eosinophil count as an inclusion criterion.4 Whether asthmatics who smoke fit in these complex clinical situations is one aspect of the asthma-COPD overlap (ACO) debate.