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Develop highly selective and sensitive PK and ADA assays for cetuximab (Erbitux) using our range of ready-made anti-idiotypic antibodies.
Table 1. Antibodies Specific to Cetuximab.
Specificity |
Catalog Number |
Clone |
Format |
Affinity* KD, nM |
Assay Recommendation |
Product Details |
---|---|---|---|---|---|---|
Cetuximab Inhibitory Type 1 |
HCA220 |
AbD19834 |
Fab-FH1 |
0.5 |
PK bridging ELISA |
|
HCA221 |
AbD19830_IgG1 |
hIgG1 HRP |
1.7 |
PK bridging ELISA ADA control |
||
HCA222 |
AbD19834_IgG1 |
hIgG1 |
0.5 |
ADA control |
||
HCA223 |
AbD19815_IgG1 |
hIgG1 |
10.5 |
ADA control |
||
Cetuximab & Cetuximab-EGFR 2 Non-Inhibitory Type 2 |
HCA228 |
AbD19376_IgG1 |
hIgG1 HRP |
39 |
PK bridging ELISA |
* Affinity measured in the monovalent Fab format
1 Monovalent Fab antibody DYKDDDDK- and His-6-tags
2 HCA228 binds to an epitope outside the drug-target binding site; this epitope is present on the chimeric monoclonal antibody drugs infliximab and cetuximab; HCA228 binds equally well to both drug antibodies
Type 1 anti-cetuximab antibodies inhibit the binding of the drug cetuximab to its target, epidermal growth factor receptor (EGFR). They are ideal for development of a pharmacokinetic (PK) bridging ELISA to measure free drug. In fully human IgG1 format they are available in high, medium and lower affinity, and are suitable as a surrogate positive control or calibrator for an anti-drug antibody (ADA) assay.
The type 2 anti-cetuximab antibody binds to the cetuximab idiotope, but does not inhibit the binding of cetuximab to EGFR. It can therefore be used in combination with a type 1 antibody in a PK bridging ELISA to measure free and partially bound drug, which is equivalent to total drug when trough serum levels are above 4 μg/ml.
Fig. 1. Cetuximab PK bridging ELISA using antibodies HCA220 and HCA221P.
Schematic image of PK bridging ELISA measuring free drug. Anti-idiotypic capture antibody, Fab format (purple), monoclonal antibody drug (gold), anti-idiotypic detection antibody, Ig format (blue), labeled with HRP.
Fig. 2. Cetuximab PK bridging ELISA using antibodies HCA220 and HCA228P
Schematic image of PK bridging ELISA measuring free and partially bound drug. Type 1 anti-idiotypic capture antibody, Fab format (purple), monoclonal antibody drug (gold), drug target (red), type 2 anti-idiotypic detection antibody, Ig format (blue), labeled with HRP.
Fig. 3. Cetuximab ADA bridging ELISA using antibody HCA221, HCA222 or HCA223.
Schematic image of ADA bridging assay. Monoclonal antibody drug as capture antibody and detection antibody labeled with HRP (gold), fully human anti-idiotypic antibody, Ig format (blue).
Licensed Use: For in vitro research purposes and for commercial applications for the provision of in vitro testing services to support preclinical and clinical drug development. Any re-sale in any form or any other commercial application needs a written agreement with Bio-Rad.