PD-L1 IHC 22C3 pharmdx demonstrates precision and reproducibility in detecting PD-L1 expression in triple negative breast cancer.

Abstract

e13104 Background: PD-L1 IHC 22C3 pharmDx is an FDA-approved, companion diagnostic assay intended for use in the detection of PD-L1 protein in formalin-fixed paraffin-embedded (FFPE) non-small cell lung cancer (NSCLC), gastric or gastroesophageal junction (GEJ) adenocarcinoma, esophageal squamous cell carcinoma (ESCC), cervical cancer, urothelial carcinoma, and head and neck squamous cell carcinoma (HNSCC) tissues. Methods: Additionally, device precision (inter- and intra-observer, inter-instrument, inter-operator, inter-day, inter-lot, and intra-run) and robustness have been validated at Dako North America for triple negative breast cancer (TNBC) using the Combined Positive Score (CPS) ≥1 cutoff. Device precision (excluding inter- and intra-observer) has also been validated for TNBC using the CPS ≥10 cutoff. External validation studies for TNBC (inter- and intra-site, inter- and intra-observer) were conducted at three CAP-accredited and/or CLIA-licensed laboratories using the CPS ≥1 and CPS ≥10 cutoffs. Results: The precision, robustness, and external validation studies achieved point estimates greater than 85% for positive, negative, and overall percent agreement. Conclusions: Internal and external validation studies demonstrate that PD-L1 IHC 22C3 pharmDx is sensitive, specific, precise, robust, and reproducible in evaluating PD-L1 expression at CPS ≥1 and CPS ≥10 cutoffs using TNBC tissue.