The present invention relates to conjugate comprising a carrier substituted with one or more occurrences of a moiety having the structure:wherein each occurrence of M is independently a modifier having a molecular weight ≦10 kDa； denotes direct of indirect attachment of M to linker LM； andeach occurrence of LM is independently an optionally substituted succinamide-containing linker, whereby the modifier M is directly or indirectly attached to the succinamide linker through an amide bond, and the carrier is linked directly or indirectly to each occurrence of the succinamide linker through an ester bond.In another aspect, the invention provides compositions comprising the conjugates, methods for their preparation, and methods of use thereof in the treatment of various disorder, including, but not limited to cancer.
