A prodrug or a pharmaceutically acceptable salt thereof comprising a drug linker conjugate D-L, wherein D is a biologically active moiety containing an aliphatic amine containing group; and L is a non-biologically active linker containing i) a moiety L 1 represented by formula, wherein the dashed line indicates the attachment of L 1 to the aliphatic amine group of D by forming an amide bond; X 1 is selected from O, S or CH-R 1a, R 1 and R 1a are independently selected from H, OH, CH 3, R 2, R 2a are independently selected from C 1-4 alkyl, R 4 and R 4a are independently selected from H and C 1-4 alkyl, and one of R 4 /R 4a isH, R 3, R 3a are independently selected from H, C 1-4 alkyl, and R 5, R 5 is selected from -H —— optionally, one or more of the pairs R 3 /R 3a, R 4 /R 4a, R 3 /R 4 may independently form one or more cyclic fragments selected from C 3-7 cycloalkyl, 4 to 7 membered heterocyclyl, or 9 to 11 membered heterobicyclyl, optionally, R 3, R 3a, R 4 and R 4a are further substituted, ii) a moiety L 2, which is a chemical bond or a spacer, and L 2 is bound to a carrier group Z, and wherein the carrier group Z is a polymer with a molecular weight ≥ 500 g/mol, wherein L 1 is substituted with one to four L 2 moieties, Z is PEG or a hydrogel, more preferably Z is a hydrogel, even more preferably Z is a PEG-based hydrogel; optionally, L is further substituted. i) a moiety L 1 represented by formula, wherein the dashed line indicates the attachment of L 1 to the aliphatic amine group of D by forming an amide bond; X 1 is selected from O, S or CH-R 1a, R 1 and R 1a are independently selected from H, OH, CH 3, R 2, R 2a are independently selected from C 1-4 alkyl, R 4 and R 4a are independently selected from H and C 1-4 alkyl, and one of R 4 /R 4a isH, R 3, R 3a are independently selected from H, C 1-4 alkyl, and R 5, R 5 is selected from -H —— optionally, one or more of the pairs R 3 /R 3a, R 4 /R 4a, R 3 /R 4 may independently form one or more cyclic fragments selected from C 3-7 cycloalkyl, 4 to 7 membered heterocyclyl, or 9 to 11 membered heterobicyclyl, optionally, R 3, R 3a, R 4 and R 4a are further substituted, wherein the dashed line indicates the attachment of L 1 to the aliphatic amine group of D by forming an amide bond; X 1 is selected from O, S or CH-R 1a, R 1 and R 1a are independently selected from H, OH, CH 3, R 2, R 2a are independently selected from C 1-4 alkyl, R 4 and R 4a are independently selected from H and C 1-4 alkyl, and one of R 4 /R 4a isH, R 3, R 3a are independently selected from H, C 1-4 alkyl, and R 5, R 5 is selected from -H —— optionally, one or more of the pairs R 3 /R 3a, R 4 /R 4a, R 3 /R 4 may independently form one or more cyclic fragments selected from C 3-7 cycloalkyl, 4 to 7 membered heterocyclyl, or 9 to 11 membered heterobicyclyl, optionally, R 3, R 3a, R 4 and R 4a are further substituted, ii) a moiety L 2, which is a chemical bond or a spacer, and L 2 is bound to a carrier group Z, and wherein the carrier group Z is a polymer with a molecular weight ≥ 500 g/mol, wherein L 1 is substituted with one to four L 2 moieties, Z is PEG or a hydrogel, more preferably Z is a hydrogel, even more preferably Z is a PEG-based hydrogel; optionally, L is further substituted. wherein L 1 is substituted with one to four L 2 moieties, Z is PEG or a hydrogel, more preferably Z is a hydrogel, even more preferably Z is a PEG-based hydrogel; optionally, L is further substituted.