Fibronectin-binding peptides for use in tumor or fibrosis diagnosis and therapy

The present invention is directed to a composition comprising at least one fibronectin binding polypeptide (FnBP) linked to at least one diagnostic or therapeutic agent, a nucleic acid encoding a fusion polypeptide comprising at least one fibronectin binding polypeptide (FnBP) linked to at least one diagnostic or therapeutic polypeptide agent as well as a corresponding recombinant vector and host cell comprising such a nucleic acid and preferably expressing said fusion polypeptide. The invention also relates to a kit of parts comprising at least one fibronectin binding polypeptide (FnBP), at least one diagnostic or therapeutic agent, and optionally one or more chemical agents for linking the fibronectin binding polypeptide (FnBP) to the diagnostic or therapeutic agent. In addition, the present invention intends said composition, nucleic acid, vector, host cell and kit for use in the therapeutic or prophylactic treatment of a disease, preferably a disease associated with abnormal fibronectin accumulation such as cancer, fibrosis or immune diseases.