Immunoglobulin variable region cassette exchange
AssigneeKaloBios Pharmaceuticals, Inc.
InventorsChristopher Robert Bebbington, Kenneth R. Luehrsen, Geoffrey T. Yarranton
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Abstract
The invention provides methods for generating human antibodies with the specificity of a reference antibody by replacement of portions of the VH and VL sequences of the reference antibody with sequences from human antibody repertoires. The invention also provides novel compositions comprising hybrid immunoglobulin variable domains containing a combination of frameworks (FRs) and CDRs from different antibody clones.
Claims20
A method of engineering an antibody that retains the binding specificity of a reference antibody for a target antigen, the method comprising:
- (a) obtaining a variable region from the reference antibody;
- (b) replacing at least one exchange cassette of a V gene segment of the variable region of the reference antibody with a library of corresponding exchange cassettes from human V-gene segments, thereby generating a library of hybrid V-regions,
- with the proviso that the exchange cassette has less than three framework regions:
- (c) pairing the library of hybrid V regions of (b) with a complementary V-region;
- and
- (d) selecting an antibody comprising a hybrid V region having at least one exchanged cassette that has a binding affinity for the target antigen.
A method of engineering an antibody that retains the binding specificity of a reference antibody for a target antigen, the method comprising:
- (a) obtaining a variable region of a reference antibody having a desired binding specificity;
- (b) replacing the FR1-CDR1-FR2 of the variable region of the reference antibody with a library of human FR1-CDR1-FR2 regions to create a library of hybrid variable regions, pairing the hybrid variable regions with a complementary variable region, and selecting an antibody having a detectable affinity for the target antigen;
- (c) replacing the FR2-CDR2-FR3 of the variable region of the reference antibody with a library of human FR2-CDR2-FR3 regions to create a library of hybrid variable regions, pairing the hybrid variable regions with a complementary variable region, and selecting an antibody having a detectable affinity for the target antigen;
- (d) combining the FR1-CDR1-FR2 of the hybrid variable region of the antibody selected in (b) with the FR2-CDR2-FR3 of the hybrid variable region of the antibody selected in (c) to obtain an antibody with a human variable region V segment, which antibody has the binding specificity of the reference antibody.
A method of engineering an antibody that retains the binding specificity of a reference antibody for a target antigen, the method comprising:
- (a) obtaining a variable region of a reference antibody having a desired binding specificity;
- (b) replacing the FR1-CDR1-FR2 of the variable region of the reference antibody with a library of human FR1-CDR1-FR2 regions to create a library of hybrid variable regions,
- pairing the hybrid variable regions with a complementary variable region, and
- selecting an antibody having a detectable affinity for the target antigen;
- (c) replacing the CDR2-FR3 of the variable region of the reference antibody with a library of human CDR2-FR3 regions to create a library of hybrid variable regions, wherein the CDR2 of the CDR2-FR3 of the reference antibody is a partial CDR2 and the library of human CDR2-FR3 sequences comprise corresponding partial CDR2-FR3 sequences,
- pairing the hybrid variable regions with a complementary variable region, and
- selecting an antibody having a detectable affinity for the target antigen,
- (d) combining the FR1-CDR1-FR2 of the hybrid variable region of the antibody selected in (b) with the CDR2-FR3 of the hybrid variable region of the antibody selected in (c) to obtain an antibody with a human variable region V segment, which antibody has the binding specificity of the reference antibody.
Dependencies are inferred from the claim text.