Heterocyclic self-immolative linkers and conjugates
View Patent ↗The present invention provides heterocyclic linker compounds useful for linking drug moieties to ligands. The compounds also include drug-ligand conjugates comprising a ligand capable of targeting a selected cell population, and a drug connected to the ligand by a heterocyclic linker moiety. The linker moiety comprises a peptide sequence that is a substrate for an intracellular enzyme, for example a cathepsin, that cleaves the peptide at an amide bond. The peptide further contains a self-immolating moiety which connects the drug and the protein peptide sequence. Upon cleavage of the peptide sequence by an intracellular enzyme the self-immolating moiety cleaves itself from the drug moiety such that the drug moiety is in an underivatized and active form.
1. A heterocyclic linker compound selected from the group consisting of Formulas IIa and IIIa:
wherein
Q is CR 4 or N;
V 1 , V 2 and V 3 are independently CR 4 or N provided that for formula IIa and IIIa at least one of Q, V 1 and V 2 is N;
R 2 , R 3 and R 4 are independently selected from the group consisting of H, F, Cl, Br, I, OH, —N(R 5 ) 2 , —N(R 5 ) 3 + , C 1 -C 8 alkylhalide, carboxylate, sulfate, sulfamate, sulfonate, —SO 2 R 5 , —S(═O)R 5 , —SR 5 , —SO 2 N(R 5 ) 2 , —C(═O)R 5 , —CO 2 R 5 , —C(═O)N(R 5 ) 2 , —CN, —N 3 , —NO 2 , C 1 -C 8 alkoxy, C 1 -C 8 halosubstituted alkyl, polyethyleneoxy, phosphonate, phosphate, C 1 -C 8 alkyl, C 1 -C 8 substituted alkyl, C 2 -C 8 alkenyl, C 2 -C 8 substituted alkenyl, C 2 -C 8 alkynyl, C 2 -C 8 substituted alkynyl, C 6 -C 20 aryl, C 6 -C 20 substituted aryl, C 1 -C 20 heterocycle, and C 1 -C 20 substituted heterocycle; or when taken together, R 2 and R 3 form a carbonyl (═O), or spiro carbocyclic ring of 3 to 7 carbon atoms; and
R 5 and R 6 are independently selected from the group consisting of H, C 1 -C 8 alkyl, C 1 -C 8 substituted alkyl, C 2 -C 8 alkenyl, C 2 -C 8 substituted alkenyl, C 2 -C 8 alkynyl, C 2 -C 8 substituted alkynyl, C 6 -C 20 aryl, C 6 -C 20 substituted aryl, C 1 -C 20 heterocycle, and C 1 -C 20 substituted heterocycle;
where C 1 -C 8 substituted alkyl, C 2 -C 8 substituted alkenyl, C 2 -C 8 substituted alkynyl, C 6 -C 20 substituted aryl, and C 2 -C 20 substituted heterocycle are independently substituted with one or more substituents selected from the group consisting of F, Cl, Br, I, OH, —N(R 5 ) 2 , —N(R 5 ) 3 + , C 1 -C 8 alkylhalide, carboxylate, sulfate, sulfamate, sulfonate, C 1 -C 8 alkylsulfonate, C 1 -C 8 alkylamino, 4-dialkylaminopyridinium, C 1 -C 8 alkylhydroxyl, C 1 -C 8 alkylthiol, —SO 2 R 5 , —S(═O)R 5 , —SR 5 , —SO 2 N(R 5 ) 2 , —C(═O)R 5 , —CO 2 R 5 , —C(═O)N(R 5 ) 2 , —CN, —N 3 , —NO 2 , C 1 -C 8 alkoxy, C 1 -C 8 trifluoroalkyl, C 1 -C 8 alkyl, C 3 -C 12 carbocycle, C 6 -C 20 aryl, C 2 -C 20 heterocycle, polyethyleneoxy, phosphonate, and phosphate;
R 7 is the side chain of an amino acid and is optionally protected with a protecting group;
X and Y independently: are H; form a protecting group selected from the group consisting of Fmoc, Boc, carbobenzoxy (CBz), benzyhydryl, allyloxycarbonyl, and triphenylmethyl, or; form a reactive functional group selected from the group consisting of N-hydroxysuccinimide, para-nitrophenyl carbonate, para-nitrophenyl carbamate, pentafluorophenyl, haloacetamide, and maleimide; and
m is 1, 2, 3, 4, 5, or 6.
2. A drug-ligand conjugate compound comprising a cell-specific ligand and a drug moiety conjugated by a linker wherein said linker comprises a heterocyclic self-immolative moiety selected from the group consisting of Formulas II and III
where the wavy lines indicate the covalent attachment sites to the cell-specific ligand and the drug moiety, and wherein:
Q is CR 4 or N;
V 1 , V 2 and V 3 are independently CR 4 or N provided that at least one of Q, V 1 and V 2 is N;
T is NH, NR 6 , O or S pending from said drug moiety;
R 2 , R 3 and R 4 are independently selected from the group consisting of H, F, Cl, Br, I, OH, —N(R 5 ) 2 , —N(R 5 ) 3 + , C 1 -C 8 alkylhalide, carboxylate, sulfate, sulfamate, sulfonate, —SO 2 R 5 , —S(═O)R 5 , —SR 5 , —SO 2 N(R 5 ) 2 , —C(═O)R 5 , —CO 2 R 5 , —C(═O)N(R 5 ) 2 , —CN, —N 3 , —NO 2 , C 1 -C 8 alkoxy, C 1 -C 8 halosubstituted alkyl, polyethyleneoxy, phosphonate, phosphate, C 1 -C 8 alkyl, C 1 -C 8 substituted alkyl, C 2 -C 8 alkenyl, C 2 -C 8 substituted alkenyl, C 2 -C 8 alkynyl, C 2 -C 8 substituted alkynyl, C 6 -C 20 aryl, C 6 -C 20 substituted aryl, C 1 -C 20 heterocycle, and C 1 -C 20 substituted heterocycle; or when taken together, R 2 and R 3 form a carbonyl (═O), or spiro carbocyclic ring of 3 to 7 carbon atoms; and
R 5 and R 6 are independently selected from the group consisting of H, C 1 -C 8 alkyl, C 1 -C 8 substituted alkyl, C 2 -C 8 alkenyl, C 2 -C 8 substituted alkenyl, C 2 -C 8 alkynyl, C 2 -C 8 substituted alkynyl, C 6 -C 20 aryl, C 6 -C 20 substituted aryl, C 1 -C 20 heterocycle, and C 1 -C 20 substituted heterocycle;
where C 1 -C 8 substituted alkyl, C 2 -C 8 substituted alkenyl, C 2 -C 8 substituted alkynyl, C 6 -C 20 substituted aryl, and C 2 -C 20 substituted heterocycle are independently substituted with one or more substituents selected from the group consisting of F, Cl, Br, I, OH, —N(R 5 ) 2 , —N(R 5 ) 3 + , C 1 -C 8 alkylhalide, carboxylate, sulfate, sulfamate, sulfonate, C 1 -C 8 alkylsulfonate, C 1 -C 8 alkylamino, 4-dialkylaminopyridinium, C 1 -C 8 alkylhydroxyl, C 1 -C 8 alkylthiol, —SO 2 R 5 , —S(═O)R 5 , —SR 5 , —SO 2 N(R 5 ) 2 , —C(═O)R 5 , —CO 2 R 5 , —C(═O)N(R 5 ) 2 , —CN, —N 3 , —NO 2 , C 1 -C 8 alkoxy, C 1 -C 8 trifluoroalkyl, C 1 -C 8 alkyl, C 3 —C 12 carbocycle, C 6 -C 20 aryl, C 2 -C 20 heterocycle, polyethyleneoxy, phosphonate, and phosphate.
3. The drug-ligand conjugate compound of claim 2 having Formula IV:
L-[A n -Z m -X-D] p IV
wherein
L is a cell-specific ligand;
A is a Spacer unit;
Z is an Amino Acid;
X is a heterocyclic self-immolative moiety selected from the group consisting of Formula II and III;
D is a drug moiety;
m is 1, 2, 3, 4, 5 or 6;
n is 0 or 1; and
p is 1, 2, 3, 4, 5, 6, 7 or 8.
4. The drug-ligand conjugate compound of claim 3 , wherein X is Formula II.
5. The drug-ligand conjugate compound of claim 4 , wherein Q is N; V 1 is CH; and V 2 is CH.
6. The drug-ligand conjugate compound of claim 4 , wherein Q is CH; V 1 is CH; and V 2 is N.
7. The drug-ligand conjugate compound of claim 4 , wherein Q is N; V 1 is CH; and V 2 is N.
8. The drug-ligand conjugate compound of claim 4 , wherein Q is N; and V 1 is N; and V 2 is N.
9. The drug-ligand conjugate compound of claim 4 , wherein Q is N; V 1 is N; and V 2 is CH.
10. The drug-ligand conjugate compound of claim 4 , wherein T is N or NH.
11. The drug-ligand conjugate compound of claim 3 , wherein X is Formula III.
12. The drug-ligand conjugate compound of claim 11 , wherein Q is N; and V 1 , V 2 and V 3 are each CH.
13. The drug-ligand conjugate compound of claim 11 , wherein Q is CH; and V 1 , V 2 and V 3 are each CH.
14. The drug-ligand conjugate compound of claim 11 , wherein T is N or NH.
15. The drug-ligand conjugate compound of claim 3 wherein m is 1, and Z is selected from the group consisting of alanine, 2-amino-2-cyclohexylacetic acid, 2-amino-2-phenylacetic acid, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, γ-aminobutyric acid, α,α-dimethyl γ-aminobutyric acid, β,β-dimethyl γ-aminobutyric acid, ornithine, citrulline; and protected forms thereof.
16. The drug-ligand conjugate compound of claim 3 , wherein m is 2, and Z m is a dipeptide selected from the group consisting of glycine-glycine, alanine-phenylalanine, phenylalanine-lysine, valine-citrulline and valine-lysine.
17. The drug-ligand conjugate compound of claim 3 , wherein n is 1, and A is attached to a Cys residue of L which is an antibody.
18. The drug-ligand conjugate compound of claim 3 ,
wherein n is 1, and A has the structure:
where the wavy lines indicate the covalent attachment sites to a sulfur atom of L and to Z m , and wherein R 17 is selected from the group consisting of (CH 2 ) r , C 3 -C 8 carbocyclyl, O(CH 2 ) r , arylene, (CH 2 ) r -arylene, -arylene-(CH 2 ) r —, (CH 2 ) r —(C 3 -C 8 carbocyclyl), (C 3 -C 8 carbocyclyl)—(CH 2 ) r , C 3 -C 8 heterocyclyl, (CH 2 ) r —(C 3 -C 8 heterocyclyl), —(C 3 -C 8 heterocyclyl)—(CH 2 ) r —, —(CH 2 ) r C(O)NR b (CH 2 ) r —, —(CH 2 CH 2 O) r —, —(CH 2 CH 2 O) r —CH 2 —, —(CH 2 ) r C(O)NR b (CH 2 CH 2 O) r —, —(CH 2 ) r C(O)NR b (CH 2 CH 2 O) r —CH 2 —, —(CH 2 CH 2 O) r C(O)NR b (CH 2 CH 2 O) r —, —(CH 2 CH 2 O) r C(O)NR b (CH 2 CH 2 O) r —CH 2 —, and —(CH 2 CH 2 O) r C(O)NR b (CH 2 ) r —; where r is independently an integer ranging from 1-10.
19. The drug-ligand conjugate compound of claim 3 , wherein D is an auristatin drug moiety.