Immunogenicity refers to a drug-elicited anti-drug immune response. Immunogenicity can be either non-neutralizing or neutralizing.

While a non-neutralizing immunogenicity may not have negative effect on the pharmacodynamics of the drug, the neutralizing immunogenicity can neutralize drug activity and alter drug clearance, plasma half-life, and tissue distribution.

Macromolecule drugs (e.g., peptides, proteins) with molecular weight over 10,000 Da are usually antigenic.

Sometimes compounds with molecular weight as low as 1,000 Da (e.g., penicillin, sulfonamides) may also be effective in eliciting immune response, probably through the covalent binding of parent drugs or metabolites to proteins to form hapten-protein conjugates.

Immunogenicity testing and associated services provided by QPS includes:

 ►Preparation of antigen-protein conjugates for plate coating
 ►Method development and validation using ELISA format
 ►Screening for positive responses in study samples
 ►Confirmation test for samples display positive responses during screening
 ►Titering of confirmed positive samples to determine the relative degree of antigenicity
 ►Detection and determination of various classes of antibodies (e.g., IgG, IgM, etc.)
 ►Neutralizing antibody assays