Abstract: The present disclosure relates to a modified antibody, or antigen-binding fragment thereof, specific for nectin cell adhesion molecule 4 (nectin-4). The present disclosure also relates to a method of detecting or diagnosing whether a subject has, or is at risk of developing a tumor, or assessing a prognosis of a tumor and a pharmaceutical composition for use in treating, prophylactic treating and/or preventing tumor in a subject afflicted with the tumor.