The present invention relates to a novel drug delivery system comprising a drug(s)-protein- polymer triple conjugate. The triple conjugate employes a (i) protein moiety capable of binding selectively to a particular target site possessed by a cell/affected organ, (ii) a polymer moiety, covalently linked to the protein and (iii) an active drug moiety that includes one or more drug(s) covalently linked to either said polymer moiety or to a protein moiety. The conjugates of the present invention have target specificity and better selectivity to a defined population of cells/organs(s). The present invention further relates to methods of preparation and methods of treatment comprising administering said conjugate as a single unit. The conjugates of the present invention are usefully employed in therapeutic as well as non-therapeutic, e.g., diagnostic applications.
