Antibodies for bioanalysis and drug monitoring of cetuximab and biosimilars

Develop highly selective and sensitive PK and ADA assays for cetuximab (Erbitux) using our range of ready-made anti-idiotypic antibodies.

  • Inhibitory and non-inhibitory antibodies specific to cetuximab
  • Fully human surrogate positive control or calibrator
  • Sequence defined, well characterized reagents with secure supply
  • Recombinant production, stringent quality control for batch to batch consistency
  • Non-animal-derived antibodies, reducing the use of animals in science

Table 1. Antibodies Specific to Cetuximab.

Specificity
Binding Type

Catalog Number

Clone

Format

Affinity* KD, nM

Assay Recommendation

Product Details

Cetuximab Inhibitory Type 1

HCA220

AbD19834

Fab-FH1

0.5

PK bridging ELISA

Order HCA220

HCA221
HCA221P

AbD19830_IgG1

hIgG1

HRP

1.7

PK bridging ELISA

ADA control

Order HCA221
Order HCA221P

HCA222

AbD19834_IgG1

hIgG1

0.5

ADA control

Order HCA222

HCA223

AbD19815_IgG1

hIgG1

10.5

ADA control

Order HCA223

Cetuximab & Cetuximab-EGFR 2

Non-Inhibitory

Type 2

HCA228
HCA228P

AbD19376_IgG1

hIgG1

HRP

39

PK bridging ELISA

Order HCA228
Order HCA228P

* 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


Anti-Cetuximab Inhibitory Antibodies (Type 1)

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.


Anti-Cetuximab Non-Inhibitory Antibody (Type 2)

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.


ELISA Protocols to Get You Started

PK Bridging ELISA


Fig. 1. Cetuximab PK bridging ELISA using antibodies HCA220 and HCA221P.

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.

 

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

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), type 2 anti-idiotypic detection antibody, Ig format (blue), labeled with HRP.

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.


ADA Bridging ELISA


Fig. 3. Cetuximab ADA bridging ELISA using antibody HCA221, HCA222 or HCA223.

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).

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).


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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.