At Antibodies Inc, we understand the crucial role positive control antibodies play in the drug testing and approval process. It's hard to overstate the importance of safe, effective drugs, and we provide top quality controls for ADA assays. Our scientists have years of experience in the design and production of these essential reagents.
We will work with you every step of the way, from assessment to generation to affinity purification. Complete the form to get your project started today >>>
Introduction to Anti-Drug Antibody (ADA) Assays:
Anti-drug antibody assays, sometimes referred to as "immunogenicity" assays and often abbreviated as simply "ADA," require the custom development of a positive control antibody. This positive control antibody becomes a critical reagent in the drug development process for biologic drug candidates.
Biologic drugs are commonly antibodies, but can be proteins, fusion proteins, cytokines, gene therapy protein products and cell therapies. The positive control becomes a reference reagent when assessing the immune response to a dosed biologic drug. The development by the host (animal or human) of antibodies against a dosed biologic drug can have negative consequences. These negative consequences can include interference with the intended mechanism of action of the biologic drug, complete neutralization of the biologic drug or an over aggressive immune response by the host. Immune responses to therapeutic protein products (biologics) have the potential to impact pharmacokinetics, pharmacodynamics, safety, and efficacy.
Interested in enhancing your ADA assays with high-quality controls?
Request a Custom Positive Control Antibody quote today >>>
FDA Guidance and Recommendations
The FDA (Food and Drug Administration) issues guidance for the development and validation of anti-drug antibody assays to support the development of biologic drugs. The FDA defines immunogenicity as "the propensity of a therapeutic protein product to generate immune responses to itself and to related proteins or to induce immunologically related adverse clinical events." (1)
The FDA's guidance is based on the "three-tiered approach." In this approach, samples are first evaluated in a screening assay. Samples that test positive in the initial screen are then evaluated in a confirmatory assay to demonstrate that ADAs are specific for the therapeutic protein product. Samples that were positive in the confirmatory assay should be further characterized in other assays, such as titration and neutralization assays.
Three Tiers of Immunogenicity Assessment
Figure 1. The three tiers of immunogenicity assessment.
Generation of a Positive Control
The FDA makes recommendations on how to generate a positive control that is used to develop and validate ADA assays. The FDA recommends that positive controls are to be generated by immunizing animals (often rabbits). The FDA also recommends that the resulting sera be affinity purified against the immunogen (therapeutic protein). This approach concentrates and purifies the polyclonal antibody which may enable a better interpretation of the sensitivity limits of the assay.
Immunization and Bleed Schedule
Figure 2. Typical immunization and bleed schedule.
Immunization and Bleed Schedule (Cont.)
Table 1. Typical titer test data day 42. All of the rabbits have experienced a robuts response to the human IgG immunogen.
Affinity Purification
Figure 3. Our strategy for affinity purification against a human IgG immunogen.
Bridging Assay Format
Screening ADA assays are often of the "bridging" format. Bridging assays are commonly run as homogeneous assays - the reagents are mixed in solution, incubated, and then the immune complex is captured and a readout generated. These assays can be performed using a number of immunoassay platforms including ELISA, Meso Scale Discovery (MSD), and Gyros.
Figure 4. Representation of a bridging formatted assay for the detection of anti-drug antibodies. The immunogen used to generate the positive control is a biologic drug candidate. In this case, one fraction of the immunogen is labeled with biotin and one fraction is labeled with HRP.
Ready to Get Started?
At Antibodies Inc., we take pride in providing the highest quality Positive Control Antibodies for Anti-Drug Antibody (ADA) Assays. From custom antibody generation to FDA-compliant testing, we ensure the success of your biologic drug development.
For questions or a personalized quote, submit your details and our team will respond right away.
Related Products
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- Blocking Buffers: Block Buffers target antibody-sandwich or antigen-down ELISAs, preserve hydration of dried coat proteins, mitigate non-specific binding, enhance protein stability, and decrease assay variability for prolonged shelf-life.
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Sample and Assay Diluents: ICT's Sample Diluents are suitable for antibody-sandwich or antigen-down ELISAs. They minimize non-specific binding interactions during the assay process, reduce sample variation and matrix interference, and decrease background noise.
- Protein-Free Sample Diluent: a protein-free matrix used for the dilution of biological samples (e.g. serum, cell culture media) into the useful range of antibody-sandwich or antigen-down ELISA format assays. This unique buffer contains a heterogeneous mixture of proprietary molecules that help reduce background noise associated with non-specific bridging of signal-generating conjugates to the plate well surface.
- Neptune Assay Diluent: formulated to address non-specific binding issues with human, porcine, or bovine serum or plasma samples. This non-mammalian assay additive works to enhance the specific anti-analyte/antigen antibody signal.
- Assay Diluent Optimization Pack: our optimization pack contains 4 100 mL ELISA development buffers (General Assay Diluent, IgM-Reducing Assay Diluent, Neptune Assay Diluent, and Antigen-Down Assay Diluent) and offers an economical method of addressing matrix effects and optimizing signal-to-noise ratio in ELISA development projects.
- Sample Diluent Optimization Pack: our optimization pack provides 4 x 100 mL bottles of Sample Diluent formulations (General Serum Diluent, Plasma Sample Diluent, Neptune Sample Diluent, and Protein-Free Sample Diluent) for an economical and fast method to screen for the best Sample Diluent for an assay.
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Substrates and STOP Solutions: Substrates improve ELISA sensitivity, minimize background noise, ensure reproducible linearity, and are eco-friendly, while STOP solutions standardize readings, halt color development, and reduce variation for enhanced reproducibility.
Coming Soon - Generic PK Assays and Reagents
Kits and reagents for "generic" or "universal" pharmacokinetic (PK) assays!
- Biologic drug (IgG) concentration determination (PK) - mouse, rat, and NHP
- Capitalizes on similarity in IgG structure between humans and preclinical species
- Useful in early toxicology studies
- Assists in drug candidate selection process
- Minimal assay develpment or optimization time required
- Rapid results in a non-GLP environment
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References
- Immunogenicity Testing of Therapeutic Protein Products - Developing and Validating Assays for Anti-Drug Antibody Detection Guidance for Industry. 2019
What Our Customers Are Saying:
"Our experience working with Antibodies Incorporated exceeded our expectations. We have had numerous projects with them to develop rabbit polyclonal antibodies. All projects went exactly according to plan as they were extremely communicative and responsive to our needs and timelines. The new antibodies showed excellent properties and were of a high quality and the antibody products allowed us to move into the assay development phase without delay. We hope to continue to work with Antibodies Incorporated on new projects and value them as a partner."
Senior VP, Solve Therapeutics
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