Anti-Omalizumab Antibodies

Antibodies for bioanalytical assays to measure omalizumab and biosimilar products

Ready-made recombinant monoclonal anti-idiotypic antibodies, highly specific for the humanized monoclonal antibody drug omalizumab (Xolair®).

Type 1 anti-idiotypic antibody

Type 1 Anti-Omalizumab Antibodies

The Type 1 anti-omalizumab antibodies specifically recognize the free humanized monoclonal antibody omalizumab. HCA235 and HCA236 do not recognize free human IgE (hIgE) or omalizumab in complex with hIgE. These antibodies are ideal for use in direct ELISA, pharmacokinetic (PK) bridging assays and to develop and calibrate immune response (IR) assays to measure the anti-drug antibody (ADA) response in patient sera.

Product codes: HCA235, HCA235P, HCA236

Type 3 anti-drug-target complex specific antibody

Type 3 Anti-Omalizumab Antibodies

The Type 3 antibodies specifically recognize the omalizumab/hIgE complex. HCA237 and HCA238 detect omalizumab only when it is bound to hIgE.  These antibodies do not bind to free omalizumab or hIgE. With these antibodies, PK assays can be built that avoid the bridging format. In addition, they allow detection of omalizumab bound to its target in serum as opposed to free omalizumab.

Product codes: HCA237, HCA237P, HCA238

The recombinant anti-omalizumab antibodies are generated using the HuCAL® antibody library and a modified and improved form of phage display. Antibody generation using HuCAL technology results in highly specific and sensitive antibodies, which are ideal for PK and PD assays. Antibodies are fully human, so are also suitable as controls or calibrators for ADA assays. The in vitro production of recombinant antibodies means that there is a consistent, secure supply throughout preclinical development and clinical trials, avoiding the need to develop new reagents.

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

Anti-biotherapeutic antibody quality control and characterization


Antibodies Specific to Omalizumab

Product Code Clone Antibody Specificity Binding Type Format Affinity KD, nM Assay Development Recommendations
HCA236 AbD20669 Omalizumab Type 1 Fab-FH1 1.1 Indirect ELISA 
PK bridging ELISA with HCA235
HCA235 AbD20669_hIgG1 Omalizumab Type 1 human IgG1 1.12 Indirect ELISA 
PK bridging ELISA with HCA236 
ADA bridging ELISA
HCA235P AbD20669_hIgG1 Omalizumab Type 1 human IgG1
HRP labeled
1.12 Direct ELISA 
PK bridging ELISA with HCA235
HCA238 AbD20760 Omalizumab/hIgE3 Type 3 Fab-FH1 0.58 
(on complex)
PK ELISA antigen capture format
HCA237 AbD20760_hIgG1 Omalizumab/hIgE3 Type 3 human IgG1 0.58
(on complex)
PK ELISA antigen capture format
HCA237P AbD20760_hIgG1 Omalizumab/hIgE3 Type 3 human IgG1
HRP labeled
0.58
(on complex)
PK ELISA antigen capture format

Table 1 Antibody specifications
F=DYKDDDDK-tag; H=His-6-tag
Affinity measured in the monovalent Fab form
hIgE = human IgE

Related Products

Omalizumab drug target Recombinant human IgE lambda (HCA171)
Omalizumab drug isotype control Recombinant human IgG1 kappa (HCA192)


Pharmacokinetic Assay – 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

Figure 1: PK assay, bridging format, using antibodies HCA235 and HCA236

Human anti-omalizumab antibodies, product codes HCA235 and HCA236

Figure 1: Anti-omalizumab antibody, clone AbD20669 (HCA236) was coated at 1.0 µg/ml on a microtiter plate and left over night. After washing and blocking with PBST+5% BSA, 10% human serum was added spiked with increasing concentrations of omalizumab. Detection was performed by adding HRP conjugated anti-omalizumab antibody, clone AbD20669_hIgG1  (HCA235P) at a concentration of 2 µg/ml in HISPEC assay diluent (BUF049A) and QuantaBlu™ fluorogenic peroxidase substrate. Data are shown as the mean of three measurements.

Protocol: PK bridging ELISA for use with anti-omalizumab antibodies HCA236 and HCA235P


Pharmacokinetic Assay – Antigen Capture Format

Schematic image of PK antigen capture format ELISA. Drug target (red), monoclonal antibody drug (gold), drug-target complex detection antibody, Ig format (blue) labeled with HRP

Figure 2: Antigen Capture ELISA using antibody HCA237P

Human anti-omalizumab antibody, product codes HCA237 or HCA237P

Figure 2: A microtiter plate was coated over night with human IgE (HCA171) at a concentration of 5 µg/ml. After washing and blocking with PBST+5% BSA, 10% human serum was added spiked with increasing concentrations of omalizumab. Detection was performed using HRP conjugated human anti-human IgE/omalizumab antibody, clone AbD20760_hIgG1 (HCA237P) at a concentration of 2 µg/ml in HISPEC assay diluent (BUF049A) followed by QuantaBlu fluorogenic peroxidase substrate. Data are shown as the mean of three measurements.

Protocol: PK antigen capture ELISA for use with anti-omalizumab antibodies HCA237P or HCA238


Inhibition ELISA - Inhibition of omalizumab binding to human IgE

Schematic image of inhibition assay. Drug target capture antigen (red), monoclonal antibody drug (gold), anti-IgG Fc specific detection antibody (gray) labeled with HRP

Figure 3: Inhibition of omalizumab to human IgE by antibody HCA236

Human anti-omalizumab antibody, product code HCA236

Figure 3: A microtiter plate was coated over night with human IgE (HCA171) at a concentration of 1 µg/ml. After washing and blocking with PBST+5% BSA, a pre-incubated mixture of omalizumab (0.3 µg/ml) plus increasing concentrations of human anti-omalizumab antibody, clone AbD20669 (HCA236) was added. Free omalizumab, still capable of binding to the human IgE-coated plate, was detected using a goat anti human IgG (Fc specific) HRP labeled antibody and QuantaBlu fluorogenic peroxidase substrate. Data are shown as the mean of three measurements. 


Anti-Drug Antibody Assay - Bridging ELISA

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)

Figure 4: ADA bridging format, using antibody HCA235

Human anti-omalizumab antibody, product code HCA235

Figure 4: A microtiter plate was coated over night with omalizumab at a concentration of 1 µg/ml. After washing and blocking with PBST+5% BSA, PBST with or without 10% human serum was added spiked with increasing concentrations of human anti-omalizumab antibody, clone AbD20669_hIgG1  (HCA235). Detection was performed using HRP conjugated omalizumab*. Data are shown as the mean of three measurements. Note: Addition of serum changes the binding curve of the assay due to presence of endogeneous IgE, which interferes with the assay. 

Protocol: ADA bridging ELISA for use with anti-omalizumab antibody HCA235

* Antibody conjugated to HRP using a LYNX Rapid Conjugation Kit® (product codes LNK001P - LNK006P)


Demonstration of Anti-Omalizumab/IgE Drug-Target Complex Antibody Specificity

Figure 5: Specificity of anti-omalizumab drug-target antibody

Human anti-omalizumab antibody, product codes HCA237 or HCA237P

Figure 5: Demonstration of the specificity of antibodies to the omalizumab/hIgE complex.  Antibodies HCA237 and HCA238 will detect omalizumab only when bound to its target hIgE (drug-target complex binders). These antibodies do not detect either omalizumab or hIgE when they are not in a drug-target complex. A microtiter plate was coated over night with various antigens at a concentration of 5 μg/ml. After washing and blocking with PBST+5% BSA, detection was performed using HRP conjugated human anti-human IgE/omalizumab antibody, clone AbD20760_hIgG1  (HCA237P) at a concentration of 2 μg/ml 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.

Xolair® is a registered trademark of Genentech and Novartis. HuCAL® is a registered trademark of MorphoSys AG.
QuantaBlu™ is a trademark of Thermo Fisher Scientific. LYNX Rapid Conjugation Kit® is a registered trademark of Bio-Rad AbD Serotec Ltd.