Patent ID: 8609105

Claim:
A compound having the formula: (D-LU) p -L or a pharmaceutically acceptable salt or solvate thereof; wherein L is Ligand Unit, LU is a Linker unit, and D is a Drug unit; L is a peptide, polypeptide or protein that specifically binds to a target cell population; LU has the formula -W w -A a , W w is a sequence of w independently selected amino acid diradicals, wherein the W proximal to the Drug unit (W 1 ) is a natural (L) amino acid linked via a peptide bond to the Drug unit and the remaining Ws are D-amino acids, provided that W 1 cannot form secondary amide with C-terminal amino acid of D and that the peptide bond can be cleaved by an intracellular protease, w is an integer ranging from 1 to 12, A is Stretcher unit, and a is 1 or 2; p is an integer of from 1 to 20; and D has the formula: wherein the wavy line indicates the peptide bond to LU; R 1 and R 2 are independently selected from the group consisting of —H and —C 1 -C 8 alkyl, with the proviso that both R 1 and R 2 are not —H; R 3 is selected from the group consisting of —H, —C 1 -C 8 alkyl, —C 3 -C 8 carbocycle, -aryl, —C 1 -C 8 alkyl-aryl, —X 1 —(C 3 -C 8 carbocycle), —C 3 -C 8 heterocycle and —X 1 —(C 3 -C 8 heterocycle); R 4 is selected from the group consisting of —H, —C 1 -C 8 alkyl, —C 3 -C 8 carbocycle, -aryl, —X 1 -aryl, —C 1 -C 8 alkyl-(C 3 -C 8 carbocycle), —C 3 -C 8 heterocycle and —X 1 -(C 3 -C 8 heterocycle); R 5 is selected from the group consisting of —H and methyl; or R 4 and R 5 jointly form a carbocyclic ring and have the formula —(CR a R b ) n — wherein R a and R b are independently selected from the group consisting of —H and —C 1 -C 8 alkyl and n is selected from the group consisting of 2, 3, 4, 5 and 6; R 6 is selected from the group consisting of —H and —C 1 -C 8 alkyl; R 7 is selected from the group consisting of —H, —C 1 -C 8 alkyl, —C 3 -C 8 carbocycle, -aryl, —X 1 -aryl, —X 1 —(C 3 -C 8 carbocycle), —C 3 -C 8 heterocycle and —X 1 —(C 3 -C 8 heterocycle); each R 8 is independently selected from the group consisting of —H, —OH, —C 1 -C 8 alkyl, —C 3 -C 8 carbocycle and —O—(C 1 -C 8 alkyl); R 12 is selected from —H, —C 1 -C 8 alkyl, -aryl, —X 1 -aryl, —C 3 -C 8 carbocycle, —X 1 —(C 3 -C 8 heterocycle), —C 1 -C 8 alkylene-NH 2 , —C 3 -C 8 heterocycle and —X 1 -(C 3 -C 8 heterocycle); and each X 1 is independently —C 1 -C 10 alkylene-.