Targeted pyrrolobenzodiazapine conjugates
Provided are Conjugate comprising PBDs conjugated to a targeting agent and methods of using such PBDs.
1. A method for preparing a Drug linker compound, or a salt thereof, the method comprising the steps of:
a) contacting a PBD compound having the formula of:
wherein —R 2 has the formula of:
wherein A is a C 5-7 aryl group and X is
wherein R N is selected from the group consisting of H and C 1-4 alkyl;
the asterisk indicates the point of attachment to Q 2 , and either:
(i) Q 1 is a single bond and Q 2 is a single bond or —Z—(CH 2 ) n —, wherein Z is selected from the group consisting of a single bond, O, S and NH; and subscript n is from 1 to 3, or
(ii) Q 1 is —CH═CH— and Q 2 is a single bond;
and
R 12 is a C 5-10 aryl group, substituted by a group selected from the group consisting of —OH, —CO 2 H, and —C 2 R O , where R O is C 1-4 alkyl;
R 6 and R 9 are independently selected from the group consisting of H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo, wherein R and R′ are independently selected from the group consisting of optionally substituted C 1-12 alkyl, C 3-20 heterocyclyl and C 5-20 aryl groups, wherein C 3-20 heterocyclyl is a monovalent moiety derived from removing a hydrogen atom of a heterocyclic compound which has 3 to 20 ring atoms, of which 1 to 10 are heteroatoms selected from the group consisting of N, O and S;
R 7 is selected from the group consisting of H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo,
R″ is a C 3-12 alkylene group, which chain is optionally interrupted by one or more heteroatoms selected from the group consisting of O, S, and NR N2 , wherein R N2 is H or C 1-4 alkyl, and/or by an aromatic ring;
Y and Y′ are independently selected from the group consisting of O, S, and NH;
R 6′ , R 7′ , R 9′ are selected from the same groups as R 6 , R 7 and R 9 , respectively, with a peptide coupling agent and a compound of formula G 1 -L 1 , wherein
L 1 is a dipeptide of formula —NH—X 1 —X 2 —CO 2 H, wherein —NH— is the amino group of X 1 , and CO 2 H is the carboxylic acid functional group of X 2 for peptide coupling by the peptide coupling agent to the nitrogen atom of X of the PBD compound and wherein the peptide is cleavable by the action of an enzyme for release of the PBD compound; and
G 1 is a Stretcher Unit for connection to an antibody or antigen-binding fragment thereof, wherein G 1 is comprised of a maleimide group for reaction with a reactive thiol functional group provided by the antibody or antigen-binding fragment for said connection, and wherein G 1 further comprises the functionality —CO— connected directly to the amino terminus of X 1 , thereby forming an amide link with —X 1 —,
wherein said contacting provides the Drug Linker compound having the formula of G 1 -L 1 -D, wherein G 1 is the Stretcher Unit and L 1 and D correspond in structure to the dipeptide and PBD compound, respectively.
2. The method of claim 1 , wherein G 1 is selected from the group consisting of:
wherein the asterisk indicates the point of attachment to the amino group of X 1 and subscript n is an integer ranging from 0 to 6,
wherein the asterisk indicates the point of attachment to the amino group of X 1 , subscript n is 0 or 1, and subscript m is an integer ranging from 0 to 30,
wherein the asterisk indicates the point of attachment to the amino group of X 1 and subscript n is an integer ranging from 0 to 6, and
wherein the asterisk indicates the point of attachment to the amino group of X 1 , subscript n is 0 or 1, and subscript m is an integer ranging from 0 to 30.
3. The method of claim 1 , wherein R 7 is selected from the group consisting of H, OH and OR.
4. The method of claim 2 , wherein R 7 is a C 1-4 alkyloxy group.
5. The method of claim 2 , wherein Y and Y′ are O.
6. The method of claim 5 , wherein R″ is C 3-7 alkylene.
7. The method of claim 6 , wherein R 9 is H.
8. The conjugate according to claim 7 , wherein R 6 is selected from the group consisting of H and halo.
9. The conjugate according to claim 1 , wherein A is phenyl, X is —NH 2 , and Q 1 is a single bond.
10. The conjugate according to claim 9 , wherein Q 1 is a single bond and Q 2 is a single bond.
11. The method of claim 1 , wherein R 12 is a C 5-7 aryl group optionally substituted by one or more substituents selected from the group consisting of halo, nitro, cyano, C 1-7 alkoxy, C 5-20 aryloxy, C 3-20 heterocyclyoxy, C 1-7 alkyl, C 3-7 heterocyclyl and bis-oxy-C 1-3 alkylene, wherein the C 1-7 alkoxy group is optionally substituted by an amino group, and if the C 3-7 heterocyclyl group is a C 6 nitrogen containing heterocyclyl group, it is optionally substituted by a C 1-4 alkyl group.
12. The method of claim 11 , wherein the C 5-7 aryl group is an optionally substituted phenyl group.
13. The method of claim 12 , wherein R 12 bears one to three substituent groups.
14. The method of claim 1 , wherein R 6′ , R 7′ , R 9′ , and Y′ are the same as R 6 , R 7 , R 9 , and Y, respectively.
15. The method of claim 1 , wherein G is:
wherein the asterisk indicates the point of attachment to L 1 ; and subscript n is an integer ranging from 0 to 6.
16. The method of claim 15 , wherein subscript n is 5.
17. The method of claim 16 , wherein the dipeptide is selected from the group consisting of valine-alanine, valine-citrulline and phenylalanine-lysine.
18. The conjugate of claim 1 , wherein the PBD compound has the formula:
19. The method of claim 1 , wherein G 1 -L 1 -D has the formula:
wherein subscript n is an integer ranging from 1 to 11; R′ is —CH 3 and R″ is CH(CH 3 ) 2 .
20. The method of claim 1 , wherein G 1 -L 1 -D has the formula:
21. The method of claim 1 , wherein the peptide coupling agent is N-ethoxylcarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ).
22. The method of claim 21 , wherein G 1 -L 1 -D has the formula of: