Patent ID: 11897961
Assignee: IMMUNOGEN, INC.
Field: Pharmaceuticals (Chemistry)
Classification: CPC C  A | IPC A  C

Claim 0:
1. An immunoconjugate having the following formula:

CBACyL1)wL,

wherein:
WL is an integer from 1 to 20; and
CyL1 is represented by the following formula:, or a pharmaceutically acceptable salt thereof, wherein:
the double line  between N and C represents a single bond or a double bond, provided that when it is a double bond, X is absent and Y is —H or a (C1-C4)alkyl; and when it is a single bond, X is —H or an amine protecting moiety, and Y is —OH or —SO3M;
wherein M is H+ or a cation;
L′ is represented by the following formula:

—NR5—P—C(═O)—(CRaRb)m—C(═O)—  (B1′);

R5 is —H or a (C1-C3)alkyl;
P is an amino acid residue or a peptide containing between 2 to 20 amino acid residues;
Ra and Rb, for each occurrence, are each independently —H, (C1-C3)alkyl, or a charged substituent or an ionizable group Q, wherein Q is —SO3M; and
m is an integer from 1 to 6; and
CBA is an anti-CD123 antibody or antigen-binding fragment thereof that is covalently linked through a lysine residue to CyL1, wherein the antibody or antigen-binding fragment thereof comprises:

a) a heavy chain variable region CDR1 having the amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 5, and 12; a heavy chain variable region CDR2 having the amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 3, 6-10, 13, and 14; and a heavy chain variable region CDR3 having the amino acid sequence selected from the group consisting of: SEQ ID NOs: 4, 11, 15, and 70; and
b) a light chain variable region CDR1 having the amino acid sequence selected from the group consisting of: SEQ ID NOs: 16, 19, 20, 23 and 72; a light chain variable region CDR2 having the amino acid sequence selected from the group consisting of: SEQ ID NOs: 17, 21, 24 and 71; and a light chain variable region CDR3 having the amino acid sequence selected from the group consisting of: SEQ ID NOs: 18, 22, and 25;
wherein the antibody or antigen-binding fragment thereof binds an epitope within amino acids 101 to 346 of human CD123 or IL3-Rα antigen and inhibits IL3-dependent proliferation in antigen-positive TF-1 cells.