The invention provides compounds comprising a therapeutic agent coupled to a carrier molecule, with a minimum coupling ratio of 5:1; wherein the carrier molecule is (i) an antibody fragment or derivative thereof or (ii) an antibody mimetic or derivative thereof; and wherein the therapeutic agents are coupled onto a lysine amino acid residue; and further wherein the therapeutic agent is not a photosensitising agent. There is also provided uses, methods relating to such compounds, as well as processes for their manufacture.