Biotherapeutics have the potential to induce anti-drug antibodies (ADA) in patients. Anti-drug antibodies may impact drug pharmacokinetics, pharmacodynamics, bioavailability, safety, and efficacy. Hence, it is critical to assess the potential of a biotherapeutic in generating neutralizing and non-neutralizing anti-drug antibodies. Today, scientists have multiple methodologies for ADA analysis, including ELISA, electrochemical luminescence-based detection, surface plasmon resonance, and radioimmunoassay. The bridging ELISA assay format is one of the most commonly used techniques in ADA studies. The current article focuses on emerging neutralizing antibody assay technology that can complement traditional ELISA assays.
Technological advancement in NAb assay development
Biotherapeutics can induce unwanted immune responses and produce neutralizing and non-neutralizing anti-drug antibodies. The US FDA recommends a multitiered approach for immunogenicity testing where both types of ADAs are screened and confirmed using robust immunoassays. The bridging format is an industry-standard for ADA analysis. However, it has limitations. So, let us focus on some emerging technologies in ADA analysis.
Gyrolab is an emerging platform for immunogenicity testing. This system incorporates partial automation and microfluidics in ligand binding assay format. Today, researchers use the gyrolab platform for quantifying drug candidates and determining their affinity and pharmacokinetic properties.
Interfering circulating drugs is a critical challenge for ADA testing. Scientists often include large dilutions to minimize drug concentrations in samples and improve drug tolerance. Immune PCR is a reliable technique with the highest sensitivity for detecting anti-drug antibodies in diluted samples.
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Often, additional immune response characterization may require assays to isotype anti-drug antibodies. Today, technology such as SQI diagnostics squid-lid platform can detect and isotype ADA in the same well. This feature eliminates the need for multiple assays and reduces the required sample volumes. Moreover, the Genelite Maverick system is another platform that can simultaneously detect and isotype ADA.
Liquid chromatography-mass spectrometry is a critical tool for large-molecule drug development. Besides, LC-MS systems are employed increasingly for quantifying biotherapeutics and endogenous protein biomarkers in biological samples. LC-MS are generally used in PK bioanalysis. However, today, they are increasingly employed for ADA analysis. Assay formats such as immunocapture-LC-MS systems can simultaneously detect and isotype anti-drug antibodies in study samples.
ADA analysis often requires drug-specific reagents. This requirement needs resources and time for preparation. However, time and resources are crucial deciding factors in drug development studies. This generic assay can be employed in all human monoclonal antibody therapeutics in nonclinical studies. They require minimum optimization and are ideal for early candidate selection studies.
Generic ADA ELISA assays have been developed to measure ADA responses in mouse and cynomolgus monkey studies. This assay uses anti-human antibodies for capturing anti-mouse IGg or anti-cynomolgus IGg and uses them to determine drug ADA complexes. Similarly, the development of universal ADA-ECL immunoassays is further simplifying nonclinical ADA analysis. These assay systems include ADA assays such as universal indirect species-specific immunoassays for ADA analysis in three animal species, including rat, mouse, and cynomolgus monkey.
In conclusion
Identifying the neutralizing capacities of anti-drug antibodies is critical for biotherapeutic drug development.
