Bio-Rad Laboratories introduce a range of antibodies that are specific to cemiplimab and inhibit the binding of the drug to its target, human programmed death receptor-1 (PD-1).
These ready-made antibodies are suitable for developing selective and sensitive assays for bioanalysis and drug monitoring of cemiplimab (Libtayo).
Cemiplimab acts as a checkpoint inhibitor by binding to PD-1 on T-cells and blocking the interaction with its ligands, PD-L1 and PD-L2, thereby activating T-cells to attack cancer cells. The new range of anti-cemiplimab antibodies offers optimal flexibility for bioanalytical ligand binding assays. Three fully human IgG1 antibodies with varying levels of affinity are ideal for use as surrogate positive controls or calibrators in anti-drug antibody assays. These are complemented by a TrailBlazer Antibody with a SpyTag2 incorporated into its heavy chain, which enables site-directed conjugation or fast conversion to a bivalent Fab or an Ig-like format within an hour. Using these antibodies, a highly sensitive pharmacokinetic bridging ELISA can be developed to measure free drug.
The recombinant antibodies are generated using the Human Combinatorial Antibody Libraries (HuCAL) and CysDisplay, a method of phage display, along with guided selection methods to obtain highly targeted reagents. The recombinant production method results in batch-to-batch consistency, ensuring reproducible results and a secure supply throughout the assay lifecycle.
“Bio-Rad’s portfolio of recombinant, monoclonal, anti-idiotypic antibodies continues to expand. These critical antibody reagents support researchers developing bioanalytical assays for checkpoint inhibitor drugs by providing sequence-defined, well-characterised reagents with stable supply,” said Amanda Turner, Bio-Rad product manager, Life Science Group. “The introduction of TrailBlazer Antibodies to the range brings added flexibility for bioanalytical assay design,” Amanda added.
The anti-cemiplimab antibodies are approved for in vitro research purposes, and for commercial applications providing in vitro testing services to support preclinical and clinical drug and biosimilar development.