Polycystic kidney disease is a condition in which clusters of benign cysts develop within the kidneys. A novel strategy was developed targeting therapeutic antibodies to polycystic kidneys. Therapeutic antibodies - a class of biologics which are generally used in diseases such as cancer to autoimmune disorders are used presently for PKD. These biologic therapies use an antibody class called immunoglobulin-G (IgG) for activity of specific proteins or growth factors. In, PKD the growth factors shown to promote cyst growth reside in fluid trapped in the interior space of a cyst, called a lumen, to which IgG antibodies have no access.