Drug to antibody ratio (DAR) determination
Protein molecular weight and incorporation of small molecule drug is determined using LC-HR/MS.
Background
Depending on the conjugation strategy, the developed ADCs may vary in the number of payload conjugated per antibody molecule. The average number of payload in the antibody is defined as drug-antibody ratio (DAR). It is essential to define DAR since it affects the efficacy of ADCs and the metabolites. DAR can be determined by analyzing intact protein using LC-HR/MS. Prior to analysis, protein is typically enzymatically deglycosylated to remove carbohydrate structures since this simplifies the analysis.
