Anti-Panitumumab Antibodies

Antibodies for bioanalytical assays to measure panitumumab and biosimilar products

Ready-made recombinant monoclonal anti-idiotypic antibodies, highly specific for the fully human antibody drug panitumumab (Vectibix®).

Type 1 anti-idiotypic antibody

Anti-Panitumumab Type 1 Antibodies

The Type 1 anti-panitumumab antibodies inhibit the binding of the monoclonal antibody drug panitumumab to its target, epidermal growth factor receptor (EGFR). These antibodies are ideal for use in indirect ELISA and in a bridging ELISA to develop pharmacokinetic (PK) assays to detect free drug, or as a reference standard for anti-drug antibody (ADA) assays. 

Product codes: HCA264, HCA265, HCA265P, HCA266

These recombinant, monoclonal, anti-idiotypic antibodies are generated using HuCAL®, a sophisticated antibody library, and a proprietary method of phage display, which results in highly specific and sensitive reagents, ideal for PK and PD assays. Because these antibodies are fully human, they are also perfect as controls or calibrators for ADA assays. The in vitro production of recombinant antibodies results in a consistent, secure supply of these critical reagents throughout preclinical development and clinical trials.

More information about anti-idiotypic antibodies and their binding types and properties

Anti-biotherapeutic antibody quality control and characterization


Antibodies Specific to Panitumumab

Product Code Clone Antibody Specificity Binding Type Format Affinity KD, nM Assay Development Recommendations
HCA264 AbD23894 Panitumumab Type 1 Fab-FH1 0.3 Indirect ELISA
PK bridging ELISA with HCA265
HCA265 AbD23897_hIgG1 Panitumumab Type 1 Human IgG1 0.3* Indirect ELISA
PK bridging ELISA with HCA264
ADA assay
HCA265P AbD23897_hIgG1 Panitumumab Type 1 Human IgG1
HRP labeled
0.3* Direct ELISA
PK bridging ELISA with HCA264
HCA266 AbD23895_hIgG1 Panitumumab Type 1 Human IgG1 0.6* Indirect ELISA
PK bridging ELISA with HCA264
ADA assay

Table 1 Antibody Specifications
1F=DYKDDDDK-tag H=His-6-tag 
*Affinity measured in the monovalent Fab form


Pharmacokinetic Assay – Bridging ELISA

Schematic image of anti-idiotypic antibodies in PK bridging ELISA format

Schematic image of PK Bridging ELISA. Anti-idiotypic capture antibody, Fab format (purple), monoclonal antibody drug (gold), anti-idiotypic detection antibody, Ig format (blue), labeled with HRP

Use of anti-panitumumab antibody pair in PK bridging ELISA

Figure 1: Panitumumab PK ELISA bridging format using antibodies HCA264 and HCA265P

Human anti-panitumumab antibodies, product codes HCA264 and HCA265P

Figure 1: Anti-panitumumab antibody, clone AbD23894 (HCA264) was coated on a microtiter plate at 1 µg/ml and left over night. Washing and blocking was performed with PBST + 5% BSA. 10% human serum was added, spiked with increasing concentrations of panitumumab. Detection was performed using HRP conjugated anti-panitumumab antibody clone AbD23897_hIgG1 (HCA265P) diluted to 2 µg/ml in HISPEC assay diluent (BUF049A), plus QuantaBlu™ fluorogenic peroxidase substrate. Data are shown as the mean of three measurements.

Protocol: PK bridging ELISA protocol panitumumab HCA264 and HCA265P


Anti-Drug Antibody Assay – Bridging ELISA

Schematic image of fully human anti-idiotypic antibody in anti-drug antibody (ADA) assay

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).

Use of fully human anti-panitumumab antibodies as calibrator in ADA assay

Figure 2: ADA assay, bridging format using anti-panitumumab antibodies HCA265 or HCA266

Human anti-panitumumab antibody, product codes HCA265 or HCA266

Figure 2: Panitumumab was coated at 1 µg/ml on a microtiter plate overnight. After washing and blocking with PBST + 5% BSA, PBST with 10% human serum was added spiked with increasing concentrations of the human anti-panitumumab antibody clone AbD23897_hIgG1 (HCA265) or clone AbD23895_hIgG1 (HCA266). Detection was performed using HRP conjugated panitumumab at 2 µg/ml in HISPEC assay diluent and QuantaBlu fluorogenic peroxidase substrate. Data are shown as the mean of three measurements. HRP conjugation of panitumumab was performed using a LYNX Rapid HRP Antibody Conjugation Kit.

Protocol: ADA bridging ELISA protocol panitumumab HCA265 or HCA266


Inhibition ELISA

Inhibition of panitumumab binding to EGFR using antibody HCA264

Figure 3: Inhibition of panitumumab binding to EGFR using antibody HCA264

Human anti-panitumumab antibody, product code HCA264

Figure 3: Human EGFR was coated on a microtiter plate at 1 µg/ml overnight. After washing and blocking with PBST + 5% BSA, a pre-incubated mixture of panitumumab (0.3 µg/ml) plus increasing concentrations of anti-panitumumab clone AbD23894 (HCA264) in the monovalent Fab format was added. Free panitumumab, still capable of binding to the human EGFR coated plate, was detected using an HRP conjugated goat anti-human Fab antibody and QuantaBlu fluorogenic peroxidase substrate. Data are shown as the mean of three measurements.


Demonstration of Antibody Specificity

Demonstration of the specificity of antibody HCA264 to panitumumab

Figure 4: Demonstration of the specificity of antibody HCA264 to panitumumab

Human anti-panitumumab antibody, product code HCA264

Figure 4: A microtiter plate was coated overnight with various antigens at a concentration of 5 µg/ml. After washing and blocking with PBST + 5% BSA, detection was performed using anti-panitumumab antibody clone AbD23894 (HCA264) at a concentration of 2 µg/ml followed by an HRP conjugated anti-DYKDDDDK tag antibody in HISPEC assay diluent and QuantaBlu fluorogenic peroxidase substrate.


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.

HuCAL® is a registered trademark of MorphoSys AG. QuantaBlu™ is a trademark of Thermo Fisher Scientific. Vectibix® is a registered trademark of Amgen.