Humira ADCC & CDC Assays
BioOutsource has the experience, expertise and capabilities to provide complete ADCC and CDC testing solutions for Humira using our off-the-shelf methods for both Humira CDC and ADCC. In order for the methods to be successful, Humira CDC and ADCC assays require TNF-Alpha to be present as the membrane-bound form at sufficiently high levels. A target cell line engineered to express membrane bound TNF-Alpha is required for these assays. Our classical ADCC assays are performed using PBMCs from a variety of genotyped donors that are specifically harvested on the day of assay. Our ADCC assay portfolio also includes a surrogate ADCC assay which uses an engineered cell line stably expressing the FcgRIIIa receptor to negate donor-specific variability. We offer a range of Fc Receptor binding assays to complement our ADCC assay, and C1q binding assays to complement our CDC assay.
The Humira CDC and ADCC bioassays measure the combined activity of the Fab binding and effector functions of Humira, mediated through an initial interaction with C1q (CDC) or the Fc-Gamma Receptor IIIa (FcRIIIa) (ADCC). BioOutsource are industry experts in the development, optimization and qualification/validation of bioassays and have applied this expertise to Humira (adalimumab) to offer ADCC and CDC assays to our customers. We have provided services to support clone selection, comparability and biosimilarity activities with assays performed using our existing methodology, adapted to incorporate the customer’s reference standard of choice. Where required, rapid assay qualification and/or validation can be achieved using customer’s material.
The principle of both Humira (adalimumab) ADCC and CDC assays is that the target cell line, expressing the membrane bound form of TNF-Alpha, is prepared in cell plates. A dilution series of Humira is then prepared, added to the plate and allowed to bind to the target cells for period of time. PBMCs (Humira ADCC bioassay) or complement (Humira CDC bioassay) are then added; this will bind to Humira that is already bound to the membrane bound TNF-Alpha, initiating a cell death cascade resulting in target cell lysis. The assays are performed with appropriate assay controls, utilising a non-radioactive assay endpoint. Sample results can be reported as a per cent of total cell death or as a relative potency measurement against the reference standard.
ADCC assays are well known for day to day variability arising from the donor PBMCs that are used in the methodology and BioOutsource have implemented a number of different strategies to control this variation. These include donor screening programmes so that assays are only performed using qualified individuals, and a standardized cell culture regime. Our standard CDC assay methodologies have been optimized using a specific complement source.