MONOMETHYLVALINE COMPOUNDS CAPABLE OF CONJUGATION TO LIGANDS
Auristatin peptides, including MeVal-Val-Dil-Dap-Norephedrine (MMAE) and MeVal-Val-Dil-Dap-Phe (MMAF), were prepared and attached to Ligands through various linkers, including maleimidocaproyl-val-cit-PAB. The resulting ligand drug conjugates were active in vitro and in vivo.
1 . (canceled)
2 . An antibody-drug conjugate having the formula:
or a pharmaceutically acceptable salt thereof, wherein:
Ab is an antibody,
A is a Stretcher unit, having the structure of
a is 1,
—W w — unit is a tetrapeptide; wherein each —W— unit is independently an Amino Acid unit having the formula denoted below in the square bracket:
wherein R 19 is hydrogen, methyl, isopropyl, isobutyl, sec-butyl, benzyl, p-hydroxybenzyl, —CH 2 OH, —CH(OH)CH 3 , —CH 2 CH 2 SCH 3 , —CH 2 CONH 2 , —CH 2 COOH, —CH 2 CH 2 CONH 2 , —CH 2 CH 2 COOH, —(CH 2 ) 3 NHC(═NH)NH 2 , —(CH 2 ) 3 NH 2 , —(CH 2 ) 3 NHCOCH 3 , —(CH 2 ) 3 NHCHO, —(CH 2 ) 4 NHC(═NH)NH 2 , —(CH 2 ) 4 NH 2 , —(CH 2 ) 4 NHCOCH 3 , —(CH 2 ) 4 NHCHO, —(CH 2 ) 3 NHCONH 2 , —(CH 2 ) 4 NHCONH 2 , —CH 2 CH 2 CH(OH)CH 2 NH 2 , 2-pyridylmethyl-, 3-pyridylmethyl-, 4-pyridylmethyl-, phenyl, cyclohexyl,
Y is a Spacer unit,
y is 0, 1, or 2,
D is a drug moiety, and
p ranges from 1 to about 20, and
wherein the Stretcher unit A is linked to the antibody via a sulfur atom on a cysteine residue of the antibody.
3 . The antibody-drug conjugate of claim 2 , wherein Y is a self-immolative spacer.
4 . The antibody-drug conjugate of claim 3 , wherein y is 1.
5 . The antibody-drug conjugate of claim 4 , wherein p is about 3 to about 8.
6 . The antibody-drug conjugate of claim 5 , wherein p is about 4.
7 . The antibody-drug conjugate of claim 5 , wherein p is about 8.
8 . The antibody-drug conjugate of claim 2 , wherein a substantial amount of the drug moiety is not cleaved from the antibody until the antibody-drug conjugate enters a cell with a cell-surface receptor specific for the antibody of the antibody-drug conjugate, and the drug moiety is cleaved from the antibody when the antibody-drug conjugate does enter the cell.
9 . The antibody-drug conjugate of claim 2 , wherein the bioavailability of the antibody-drug conjugate or an intracellular metabolite of the antibody-drug conjugate in a patient is improved when compared to a drug compound comprising the drug moiety of the antibody-drug conjugate.
10 . The antibody-drug conjugate of claim 2 , wherein the bioavailability of the antibody-drug conjugate or an intracellular metabolite of the antibody-drug conjugate in a patient is improved when compared to an analog of the antibody-drug conjugate not having the drug moiety.
11 . The antibody-drug conjugate of claim 2 , wherein the drug moiety is intracellularly cleaved in a patient from the antibody of the antibody-drug conjugate or an intracellular metabolite of the antibody-drug conjugate.
12 . The antibody-drug conjugate of claim 2 , wherein the antibody is a monoclonal antibody.
13 . A method of preparing an antibody-drug conjugate having the formula:
or a pharmaceutically acceptable salt thereof, wherein:
Ab is an antibody,
A is a Stretcher unit, having the structure of
a is 1,
—W w — unit is a tetrapeptide; wherein each —W— unit is independently an Amino Acid unit having the formula denoted below in the square bracket:
wherein R 19 is hydrogen, methyl, isopropyl, isobutyl, sec-butyl, benzyl, p-hydroxybenzyl, —CH 2 OH, —CH(OH)CH 3 , —CH 2 CH 2 SCH 3 , —CH 2 CONH 2 , —CH 2 COOH, —CH 2 CH 2 CONH 2 , —CH 2 CH 2 COOH, —(CH 2 ) 3 NHC(═NH)NH 2 , —(CH 2 ) 3 NH 2 , —(CH 2 ) 3 NHCOCH 3 , —(CH 2 ) 3 NHCHO, —(CH 2 ) 4 NHC(═NH)NH 2 , —(CH 2 ) 4 NH 2 , —(CH 2 ) 4 NHCOCH 3 , —(CH 2 ) 4 NHCHO, —(CH 2 ) 3 NHCONH 2 , —(CH 2 ) 4 NHCONH 2 , —CH 2 CH 2 CH(OH)CH 2 NH 2 , 2-pyridylmethyl-, 3-pyridylmethyl-, 4-pyridylmethyl-, phenyl, cyclohexyl,
Y is a Spacer unit,
y is 0, 1 or 2,
D is a drug moiety, and
p ranges from 1 to about 20, and
wherein the Stretcher unit A is covalently attached to the antibody via a sulfur atom on acystene residue of the antibody,
comprising conjugating a drug linker having the formula:
to the antibody Ab.
14 . The method of claim 13 , wherein A has the structure of
and R 19 is hydrogen or benzyl.
15 . The method of claim 14 , further comprising a step of partially or fully reducing cysteine disulfide residues of the antibody, and
wherein the conjugation is achieved via a chemical reaction between the maleimide group of the drug linker and the reduced cysteine disulfide residues of the antibody.
16 . The method of claim 14 , wherein Y in the antibody-drug conjugate is a self-immolative spacer.
17 . The method of claim 14 , wherein y in the antibody-drug conjugate is 1.
18 . The method of claim 14 , wherein p in the antibody-drug conjugate is about 3 to about 8.
19 . The method of claim 18 , wherein p in the antibody-drug conjugate is about 4.
20 . The method of claim 18 , wherein p in the antibody-drug conjugate is about 8.
21 . The method of claim 14 , wherein the antibody in the antibody-drug conjugate is a monoclonal antibody.