ADA Assay, Cell-Based NAb and Immunogenicity Testing by PhDs at 20+ Year, FDA-Inspected Lab

Immunogenicity testing plays a crucial role in measuring the immune response elicited by large molecule drugs during biotherapeutics R&D. Given its defense mechanism, the human immune system marks large molecules as foreign invaders and mounts a subsequent reaction. Typically, this happens through the production of antibodies to remove or destroy the external elements. During the immune response, the large molecules can create even larger macromolecules that further change the immunogenicity profile of the underlying drug. In other words, the immune response triggered by the therapeutic compound or its delivery vehicle can impact the efficacy and safety of the drug. Thus, immunogenicity testing methods is an essential step in immunogenicity assay development.

Immunogenicity assays are complicated because of multiple interactions that occur between the drug, target, and sample matrices. Thus, careful selection of the assay format is critical for further optimization and validation. NorthEast Biolab has extensive experience in designing, validating, and optimizing antibody immunogenicity assays according to regulatory and safety guidelines by the FDA. Our scientists systematically develop your immunogenicity testing methods for high quality and reproducible antibody immunogenicity assays. Usually, we support clients in developing a screening assay to measure immunogenicity. This is followed by ADA titer assay and confirmation assays. We also help in developing custom antibody immunogenicity assays by checking the risk or safety profile of the antibody and the intended purpose of the drug.

The body produces Anti-drug antibodies (ADA) as an immunogenic response against therapeutic proteins, enzymes, antibodies, peptides, and other biologic combination products. ADAs, somewhat identical to the proteins found in the human body, are complex macromolecules composed of hundreds of amino acids. The generated ADA antibodies could bind to various epitopes of the biologics, making them ineffective. Additionally, these antibodies can neutralize or break down the biologics or drug products into their components in many ways. The human body makes five different antibodies called immunoglobulins (Ig) to combat different antigens, namely IgA, IgG, IgM, IgE, and IGD. We test all relevant Ig isotypes in the initial ADA screening assay, depending on the route of administration and clinical evidence or risk of anaphylaxis. We also perform ELISA ADA assays. Generally, the FDA doesn’t mandate the determination of Ig isotype in screening assays. That said, assessment of antigen-specific Ig assays and evaluation of the generated Ig ADA subtype is sometimes deemed informative based on the drug therapy.

Immunogenicity is defined as any drug compound’s ability to evoke an immune response. Immunogenicity testing in clinical trials is necessary because sponsors seeking regulatory approval must ensure that their drug doesn’t elicit an adverse immune response upon administration. Typically, immunogenicity results from the detection of drug biomaterial as a foreign object by the body’s immune response. Depending upon the biomaterial, the T-helper cells usually form a cascade and migrate towards the drug. It is challenging to predict how these T- helper cells would respond to a specific therapy. This immunogenic response could be the reason for the limited binding between the biomaterial and the site of action or the rejection of biomaterial altogether. The immunogenicity prediction for immunogenicity testing in clinical trials could be based upon drug performance in preclinical testing. NorthEast BioLab performs antibody immunogenicity assays such as ADA and NAb Testing to evaluate antibodies produced against your biologics.

For comprehensive immunogenicity bioanalytical services, NorthEast BioLab offers specialized ADA and NAb Testing to assess immune responses to biologics during immunogenicity testing in clinical trials, ensuring regulatory compliance and drug safety.

Immunogenicity assays can be involved, given the complexities and interferences associated with the various sample matrices, drug therapy, and targeted site of action. That said, the Anti-drug Antibody (ADA) assays (screening, confirmation, and titration) and Neutralizing Antibody (NAb) assay are the most common assays during the drug development process. The ADA and NAb assays are completed to identify and evaluate the antibody that binds with any therapeutic product. Our scientists obtain rigorous and actionable data for your drug development through highly sensitive and precise Anti-drug Antibody and Neutralizing Antibody assays.

It is the build and proof of the assays that detect anti-drug antibodies in preclinical and clinical samples. Development establishes format and reagents, bridging on MSD or ELISA with in-house labeled drug, and engineers drug tolerance in from the start. Validation then proves cut points, sensitivity, precision, specificity and drug tolerance to FDA’s immunogenicity guidance, with the plan agreed with the sponsor before the first run.

ADA assay development is a multi-step bioanalytical approach that includes several assay formats and method validation for suitable immunoassays. In the first tier, our scientists utilize a sensitive screening assay, aka binding antibody assay, to analyze biological samples for low and high-affinity ADA antibodies. In the second tier of our Anti-drug Antibody testing, we perform a cut point analysis to determine positive or negative ADA samples. Any samples that demonstrate potential binding get re-tested for specificity by competition with the therapeutic protein in a confirmatory assay. At this point, the FDA recommends that sponsors conduct risk-based characterization testing for any cross-reactivity, isotypes assessment, and epitope specificity. After ADA confirmatory assay, positive samples need to be tested further for neutralizing and titration assays.

Neutralizing Antibody (NAb) assays are a necessary component for immunogenicity testing in clinical trials when anti-drug antibodies are detected in patient samples. NAbs can neutralize the effects of biomaterials and are evoked in the body as an adverse immune response to therapeutic proteins. In these NAb assay, it is crucial to observe whether i) patients are producing anti-drug antibodies and ii) these antibodies are neutralizing the therapeutic drug effects. NorthEast BioLab immunogenicity professionals design and develop your customized and specific Neutralizing Antibody assay. We utilize MSD Quickplex 120 to increase NAb assay sensitivity and dynamic range, as well as limit matrix effects as compared to traditional ELISA.

Through the tiered flow regulators expect: a screening assay flags potential positives against a statistically set cut point, a confirmatory assay strips false positives by competition with drug, and a titer assay sizes the confirmed response. The workhorse format is a bridging assay on ELISA or MSD, with acid dissociation or a related step where circulating drug at trough would otherwise mask the antibodies, and cell-based NAb follows where neutralization must be characterized.

Immunogenicity testing is crucial because the protein-based therapeutics, such as monoclonal antibodies and vaccines, are sometimes recognized as foreign particles by the body and induce an unwanted immunogenic response. Thus, immunogenicity assessment of biologics or therapeutic proteins is mandatory for regulatory approval. Often immune response involves B or T cell epitopes. For immunogenicity prediction, histocompatibility complex class II/ MHC is identified as an immunogenic molecule that shows T-epitopes as the receptors for cascade responses. These types of cells are responsible for producing antibodies and inactivating the administered protein-based drugs. Other risk factors for immunogenicity testing include dosage, administration route, delivery vehicle, and immune system activation to predict the immunogenicity of protein. Thus, measuring the capacity of producing antibodies is an essential aspect for the safety of immunogenicity testing in clinical trials and for the success of therapeutic drugs. Immune tolerance can also significantly affect the therapeutics product design in many cases. Rheumatoid Arthritis and Hemophilia A exemplify health conditions that have complicated treatments due to immunogenicity. Immunogenicity bioanalytical services are indispensable for evaluating the safety and efficacy of protein-based therapeutics, ensuring regulatory compliance and optimizing treatment outcomes.

That is the problem this lab builds ADA assays around. Circulating drug binds the very antibodies you need to detect, so drug tolerance is engineered in from the start: acid dissociation, SPEAD, ACE, BEAD or PandA depending on your molecule, with tolerance established during validation at the drug levels your dosing actually produces. An assay that only works in drug-free serum is not an assay for a real trial.

The mechanism decides. If neutralization means blocking a biological activity, agonism, signaling, transduction, a cell-based format is usually expected, and always for high-risk products homologous to endogenous proteins with non-redundant function. Where the mechanism is competitive binding to a soluble target, a competitive ligand-binding NAb can satisfy the requirement at lower cost. We put the reasoning in the validation plan so the format choice defends itself in review.

For AAV programs, yes, routinely. Anti-capsid neutralizing antibodies can block transduction, so trials screen candidates before enrollment. We run AAV NAb assays measuring transduction inhibition, validated to the rigor enrollment decisions demand, with turnaround built around screening windows rather than batch convenience.