Abstract: A polymeric drug comprising an inert synthetic polymeric carrier combined through aminoacid or peptide spacers with a bioactive molecule, a targeting moiety, and an optional cross-linkage, comprises:(a) 5.0 to 99.7 mol % of units derived from N-(2-hydroxypropyl)methacrylamide,(b) 0.2 to 20.0 mol % of units derived from an N-methylacrylcylated peptide, the peptide groups being bound to a bioactive moiety,(c) 0.1 to 94.8 mol % of units derived from N-methacrylamide, N-methacrylic acid or an N-methacrylolated aminoacid or peptide, to which are bound a determinant capable of interacting with specific receptors on cell surfaces,(d) optionally, 0 to 5 mol % of units derived from an N-methacryloylated peptide, the peptide groups being bound to a linking group which is similarly to a similar peptide group attached to another polymer chain, and(e) optionally, as a bioassay label, 0 to 2 mol % units derived from N-methyacryloylated tyrosinamide.

Abstract: Polymeric form of a biologically active compound containing at least one -NH.sub.2 group in its molecule, adapted for the protracted release of said biologically active compound by enzymatic cleavage of the polymer in vivo in the organism. The active compound is bonded by its -NH.sub.2 group to the carboxylic group of an L-amino acid as for instance, .beta.-phenylalanine, tyrosine, tryptophane, lysine, arginine, glycine, alanine, leucine, citruline or ornithine, which latter is in twin bonded by its amino group to the terminal carboxylic group of the side chain of a substituted amide or ester of acrylic or methacrylic acid, said side chain constituting a linear moiety containing at least 3 carbon atoms.