During the past decade, biological agent usage has rapidly increased. However, many reasons still limit their usage, and one of them is related to their immunogenicity, namely, the immune system may react against these biological molecules by producing anti-drug antibodies (ADAs). ADAs may lead to allergic reactions, altered pharmacokinetics and reduced efficacy. The evaluation of ADA is the most frequently used to study unwanted immunogenicity in clinical studies and post marketing clinical monitoring.
ADA evaluation is a multi-step analytical approach including a broad range of different assay formats and methodologies. Profacgen’s complete analytical assessment of ADAs includes the following steps:
ADA screening assay: Screening assays are performed to identify ADA presence in the samples. Common methods include direct or bridging ELISA, ECL, RIA and Biacore. Non-specific background (NSB) is usually determined by testing couples of serum samples of untreated animals on several different days. Afterwards, the cut point of ADA assay is determined according to the NSB.
ADA confirmatory assay: Positive screened samples must be analyzed in a confirmatory assay to rule out any false-positive results.
ADA characterization assay: Confirmed positive samples will be further characterized for their binding affinity, isotyping, and other characteristics.
In addition, methods to improve drug tolerance, such as affinity capture elution (ACE) and solid phase extraction with acid dissociation (SPEAD), have also be incorporated into our ADA assays. These methodology advances have increased assay sensitivity, making the assay background clean.
Positive evaluated samples can be further characterized for the presence of neutralizing antibodies against the drug. Assay formats are cell based techniques with carefully selected biological readouts (See NAb test).
Please feel free to contact us if you are interested in or have any questions for our ADA evaluation service.