Antibodies selective for cells presenting ErbB2 at high density
An erbB2 antibody is provided that binds preferentially to disease cells having an erbB2 density greater than a normal erbB2 density. The erbB2 antibody comprises a heavy chain and a light chain. Each chain has a constant region and a variable region. Each variable region comprises framework regions and complementarity determining regions (CDRs), wherein the CDRs have an amino acid sequence set forth below: For the heavy chain: CDR1 GFNIKDTYIH (SEQ ID No. 1) CDR2 RIYPTNGY 57 TR 59 YADSVKG (SEQ ID No. 2) CDR3 WGGDGFYAMDY (SEQ ID No. 3) For the light chain: CDR1 RASQDVN 30 TAVA (SEQ ID No. 4) CDR2 SASF 53 LYS (SEQ ID No. 5) CDR3 QQHY 92 TTPPT (SEQ ID No. 6). At least one of Y57, R59, N30, F53, and Y92 is substituted by an amino acid that confers on said antibody a reduced erbB2 binding affinity (Kd) that is in the range from 0.1 nM to 100 nM. The substitution is other than N30A, F53N, Y92A and Y92F when there is a single substitution in the antibody light chain.
1. An antibody or a bivalent fragment thereof that binds preferentially to disease cells having an erbB2 density greater than a normal erbB2 density, the antibody comprising a heavy chain (HC) comprising
a complementarity determining region (CDR)1 comprising the sequence GFNIKDTYIH (SEQ ID No. 1); a CDR2 comprising the sequence RIYPTNGY 57 TR 59 YADSVKG (SEQ ID No. 2); and a CDR3 comprising the sequence WGGDGFYAMDY (SEQ ID No. 3); and,
a light chain (LC) comprising
a CDR1 comprising the sequence RASQDVN 30 TAVA (SEQ ID No. 4); a CDR2 comprising the sequence SASF 53 LYS (SEQ ID No. 5); and a CDR3 comprising the sequence QQHY 92 TTPPT (SEQ ID No. 6), wherein the light chain contains substitutions consisting of LC F53N and LC Y92A.
2. An antibody or a bivalent fragment thereof that binds preferentially to disease cells having an erbB2 density greater than a normal erbB2 density, the antibody comprising a heavy chain (HC) comprising
a complementarity determining region (CDR)1 comprising the sequence GFNIKDTYIH (SEQ ID No. 1); a CDR2 comprising the sequence RIYPTNGY 57 TR 59 YADSVKG (SEQ ID No. 2); and a CDR3 comprising the sequence WGGDGFYAMDY (SEQ ID No. 3); and,
a light chain (LC) comprising
a CDR1 comprising the sequence RASQDVN 30 TAVA (SEQ ID No. 4); a CDR2 comprising the sequence SASF 53 LYS (SEQ ID No. 5); and a CDR3 comprising the sequence QQHY 92 TTPPT (SEQ ID No. 6), wherein the light chain and heavy chain contain substitutions consisting of HC Y57A and LC N300.
3. An antibody according to claim 1 , the antibody having the framework region sequences of trastuzumab.
4. An antibody according to claim 1 , the antibody having the framework region sequences and the constant region sequence of trastuzumab.
5. A bivalent fragment of an antibody according to claim 1 .
6. A conjugate comprising a cytotoxin or a detectable label and, conjugated thereto, an antibody or bivalent fragment thereof as defined according to claim 1 .
7. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and an antibody in an amount useful to control the growth of cells presenting erbB2 at a density greater than the normal erbB2 density, in a subject in need thereof, wherein the antibody is an antibody or bivalent fragment thereof as defined according to claim 1 .
8. An antibody according to claim 2 , the antibody having the framework region sequences of trastuzumab.
9. An antibody according to claim 2 , the antibody having the framework region sequences and the constant region sequence of trastuzumab.
10. A bivalent fragment of an antibody according to claim 2 .
11. A conjugate comprising a cytotoxin or a detectable label and, conjugated thereto, an antibody or bivalent fragment thereof as defined according to claim 2 .
12. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and an antibody in an amount useful to control the growth of cells presenting erbB2 at a density greater than the normal erbB2 density, in a subject in need thereof, wherein the antibody is an antibody or bivalent fragment thereof as defined according to claim 2 .