With an increasing number of biomarkers, and often limited availability of biopsy material, there is a growing need for multiplexed assays for both research and clinical purposes. IHC based solutions are particularly attractive in the field of immuno-oncology, as maintaining special context within the tumor microenvironment provides meaningful, and potentially actionable, information. Immuno-assays with high specificity and sensitivity are a powerful tool; however, there are challenges associated with antibody based multiplexing when more than 2-3 markers are required. A multiplex IHC solution that bypasses antibody species/isotype concerns, while providing signal amplification, was used to examine the co-expression of immune checkpoint control proteins, such as PD-L1, B7-H3, B7-H4, VISTA, in breast and ovarian cancer.

Citation Format: Matthew R. Silver, Jennifer E. Ziello, Herbert Haack. Analysis of immune checkpoint control protein co-expression in breast and ovarian cancer using novel rabbit monoclonal antibodies and multiplex IHC. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A006.