The present invention relates to new anti-cancer compounds and in particular to new compounds for use in nuclide activation therapy, such as neutron capture therapy. Specifically this invention provides a conjugate having the general formula P-(L-NAT).sub.n wherein P represents an N-hydroxypropylmethacrylamide-methacrylate copolymer having a molecular weight of 5-6,000 kDa; NAT represents a nuclide activation therapy agent; L represents a linker moiety capable of linking the polymer to the neutron capture therapy agent; and n represents an integer from 1-1,000.