Immunohistochemistry (IHC)
colon carcinoma, cancer, tumor, Cancer
COLON CARCINOMA, CANCER, TUMOR, CANCER
Archival tumor tissue samples were collected from all patients enrolling in the study, but expression of NEO-201 target antigen was not an eligibility criterion. A qualitative IHC staining system was used to identify the expression of the antigen recognized by NEO-201 in formalin-fixed, paraffin-embedded (FFPE) neoplastic tissues from cancer patients. For accuracy and reproducibility in conducting IHC, automated immunohistochemical staining was run and analyzed using the Leica Bond Max Automated Immunohistochemical Staining Procedure (Leica Biosystem, Buffalo Grove, IL, USA). A minimum of 10% of tumor cells in cancer tissues stained at a minimum of 2 + or 3 + intensity of staining with m16C3 reagent antibody (murine version of NEO-201) was considered positive for the expression of the antigen recognized by the clinical NEO-201 mAb. Cancer tissue with 0 or 1 + staining with m16C3 and underlying stromal tissue with 0 intensity of staining with m16C3 were considered negative for the expression of the antigen recognized by NEO-201. In this study, colon carcinoma with 3 + intensity of staining and adjacent colonic mucosa stained at background level of 1 + intensity were used as positive controls for m16C3 antibody in each run.Additional details about IHC staining procedure are reported in Supplementary materials and methods.