mol of n methacryloyl glycine units of formula 6 are prepared by copolymerization of n 2 hydroxypropyl methacrylamide with n methacryloyl glycine or methacryloyl glycine active ester derivatives as described in makromol chem 178 2159 1977 r 2 may represent a phenoxy group which is substituted on the phenyl ring by one ore more electron withdrawing groups such as nitro or halogen preferably r 2 represent p nitrophenoxy preferably the reaction between a polymer in which r 2 represents the residue of active ester and a compound of formula 5 to prepare the polymeric conjugate of the invention is carried out in an anhydrous polar organic solvent such as dimethylsulfoxide the reaction can typically carried out at temperature from 15 to 30 u00b0 c preferably at room temperature for 15 hours then the aminolysis of the remaining active ester groups can be performed in the presence of 1 amino 2 propanol at room temperature from 0 5 to 1 hour the conjugate suitably is precipitate with ethyl acetate dissolved in ethanol and reprecipitated with ethyl acetate for example the polymer in which r 2 represents the residue of an active ester provided at a concentration of 15 w v in dry dimethylsulfoxide is treated with 7 ethyl 10 hydroxy 20 o peptidyl camptothecin derivative of formula 5a 3 w v at room temperature for 15 hours then 1 amino 2 propanol 0 1 w v is added and the reaction mixture is kept at room temperature for 1 hour the conjugate can be precipitated with ethyl acetate collected washed with ethyl.