The present invention is directed to double prodrugs containing polymeric-based transport forms. These polymeric prodrugs are preferably of the formula:wherein:B is H, OH, OSiR13, a residue of an amine-containing target moiety or a residue of a hydroxyl-containing target moiety,G isor CH2；Y1-2 are independently O or S；M is X or Q； where X is an electron withdrawing group and Q is a moiety containing a free electron pair positioned three to six atoms from C(=Y2)；R1, R4, R7, R8, R9, R10 and R13 are independently one of hydrogen, C1-6 alkyls, C3-12 branched alkyls, C3-8, cycloalkyls, C1-6 substituted alkyls, C3-8 substituted cycloalkyls, aryls, substituted aryls, aralkyls, C1-6 heteroalkyls, substituted C1-6 heteroalkyls, C1-6 alkoxy, phenoxy, C1-6 heteroalkoxy, except that R1 and R4 can also be a cyano, nitro, carboxyl, acyl, substituted acyl, carboxyalkyl；Ar is a moiety which when included in Formula (I) forms a multi-substituted aromatic hydrocarbon or a multi-substituted heterocyclic group；(m) is zero or one；(n) is zero or a positive integer；(p) is zero, one or two；(q) is three or four； andR11 is a substantially non-antigenic polymer.
