Abstract: The invention relates to antigen-binding polypeptides comprising the CDR1, CDR2 and CDR3 region of a VHH domain of a camelid heavy chain antibody. The polypeptides bind specifically to CD73 and are therefore suitable for the diagnosis as well as for the therapeutic and prophylactic treatment of diseases characterised by increased CD73 expression. Conjugates and pharmaceutical compositions comprising the antigen-binding polypeptides are also disclosed. In addition, the invention relates to the use of such antigen-binding polypeptides in methods for detecting CD73 or CD73-expressing cells in a biological sample. Methods for purifying and concentrating CD73 or CD73-expressing cells using the antigen-binding polypeptides are also described.

Abstract: The invention relates to antigen-binding polypeptides comprising the CDR1, CDR2 and CDR3 region of a VHH domain of a camelid heavy chain antibody. The polypeptides bind specifically to CD39 and are therefore suitable for the diagnosis as well as for the therapeutic and prophylactic treatment of diseases characterised by increased CD39 expression. Conjugates and pharmaceutical compositions comprising the antigen-binding polypeptides are also disclosed. In addition, the invention relates to the use of such antigen-binding polypeptides in methods for detecting CD39 or CD39-expressing cells in a biological sample. Methods for purifying and concentrating CD39 or CD39-expressing cells using the antigen-binding polypeptides are also described.