Development Of The Combined Positive Score (Cps) For The Evaluation Of Pd-L1 In Solid Tumors With The Immunohistochemistry Assay Pd-L1 Ihc 22c3 Pharmdx.

e14589Background: Developing clinically relevant and highly reproducible scoring methods for PD-L1 to identify patients who will respond effectively to anti-PD-1 therapy is key in the development of companion or complementary diagnostic assays. Methods: Scoring method for PD-L1 IHC 22C3 pharmDx in NSCLC have only captured the percentage on stained tumor cells using the tumor proportion score (TPS) (Roach et al. 2016, Appl Immunohistochem Mol Morphol.) (Garon et al. 2015, N Engl J Med.). In the KN012 study 2 out of 11 responders to pembrolizumab were detected with the TPS for the gastric indication. More and more additional data indicate that in some tumor indications PD-L1 staining on both tumor and tumor-associated immune cells is associated with clinical outcome. Therefore a method evaluating both tumor and immune cells in one sitting using the combined positive score was evaluated. Results: Scoring the same patient specimens with the new combined positive score method resulted in the detection of 9 out...