Bio-Rad Laboratories, Hercules, Calif, has added to its range of recombinant monoclonal antiidiotypic antibodies with the introduction of antibodies specific for ipilimumab (Yervoy) and the ipilimumab/CTLA-4 drug-target complex. The highly specific and high-affinity antibodies are suitable for bioanalytical and patient drug level monitoring assays for the immune checkpoint inhibitor ipilimumab.


Amanda Turner, Bio-Rad Laboratories.

Used to treat cancers such as melanoma, ipilimumab activates the immune system by inhibiting cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), a protein receptor that hinders the destruction of cancerous cells. The four anti-ipilimumab antibodies inhibit the binding of the drug to its target, CTLA-4, and therefore detect free drug.

The antibodies are suitable for developing pharmacokinetic bridging enzyme-linked immunosorbent assays (ELISAs), and for use as a surrogate positive control (or reference standard) for antidrug antibody assays. The drug-target complex binder specifically recognizes the ipilimumab/CTLA-4 complex and can be used as the detection antibody in a pharmacokinetic antigen capture assay as an alternative format to the bridging ELISA.

“Bio-Rad’s offering of antiidiotypic antibodies continues to grow and is one of the largest portfolios available that includes antibodies targeting the immune checkpoint inhibitor drugs nivolumab and pembrolizumab—and now, ipilimumab,” says Amanda Turner, product manager in the life science group at Bio-Rad. “The in vitro production means researchers can rely on our highly specific and high-affinity recombinant monoclonal antibodies to deliver consistent results across pharmacokinetic assays.”

The anti-ipilimumab antibodies are approved for in vitro research and for commercial application in testing services that support preclinical and clinical drug and biosimilar development and patient monitoring.

For further information, visit Bio-Rad Laboratories.