One of the major bottlenecks in the development of biosimilars is the need for good bioassays to create potency, stability and neutralizing antibody (NAb) assays. Ideal bioassays need to refl ect the clinical mechanism of action (MOA) of the biopharmaceutical drug and should be simple, precise, reproducible and robust. To further enable NAb assays, there is an added need for serum/matrix tolerance and sensitivity.
Here, we discuss the development and application of diverse PathHunter® cell-based assays that cover distinct cellular mechanisms either downstream of or at the level of receptor engagement by large molecules. Importantly many of these assays rely on expression of native receptors thereby refl ecting the clinical MOA of the biopharmaceutical drug. These assays are highly specific, quantitative, scalable, robust and utilize a homogenous mix-and-read protocol, which facilitates rapid and reproducible detection of drug potency. The technology is also amenable to accurate and sensitive detection of neutralizing antibodies, even in high concentrations of human serum through a simple chemiluminescent output. The assays are developed in a convenient ready-to-use format that minimizes assay variability often occurring due to cell culture. The cell preparation, bioassay protocol and reagents have been optimized to provide superior bioassay performance with high reproducibility (<7% RSD).