By Daniel O’Loughlin, Sartorius Stedim BioOutsource Ltd.
Nivolumab (Opdivo®) is a human monoclonal antibody (IgG4 isotype) that binds to the protein PD-1. Nivolumab works as a checkpoint inhibitor, blocking the interaction between PD-1 and its ligands (PD-L1 and PD-L2), which would normally lead to the inhibition of T cell activation. Nivolumab was first approved for the treatment of melanoma in 2014, and, since then, the drug has also been approved for use in the treatment of other advanced cancers.
Surface Plasmon Resonance (SPR) is a label-free technique that can be used to probe molecular interactions in real-time, yielding information on interaction kinetics, binding affinity, and binding responses. Sartorius has developed a suite of SPR assays for evaluating the similarity of biosimilar versions of nivolumab using the Biacore T200 series of SPR instruments.
The PD-1 target binding assay has accuracy data available and can be qualified for a client’s specific product. Both the FcγRIIIa and FcγIIIb demonstrate the lack of nivolumab binding and therefore cannot be qualified. Example data and a schematic for a selection of the receptors is shown in the following application note.