Assay Purpose:
Diagnostic : Gastric, gastro-oesophageal junction, and oesophageal adenocarcinoma
Drug: Nivolumab (Bristol Myers Squibb)
Diagnostic test: PDL1 Dako 28-8 pharmDX

Result: Positive CPS >= 5

Interpretation: Combined Positive Score (CPS) - Negative (< 5), *Positive (>= 5)

Batch control: Adequate; on slide controls: Adequate Disclaimer: Please note the PD-L1 IHC (28-8 pharm Dx) with the combined positive score (CPS) utilized herein has been developed for use of first line Nivolumab plus chemotherapy for advanced gastric, gastro-oesophageal junction, and oesophageal adenocarcinoma (Checkmate 649) and is not interchangeable with other PD-L1 assays. PD-L1 28-8 pharm Dx was validated with tissue fixed in 10% neutral buffered formalin (NBF) for 12 to 72 hours. The method is not fully validated for shorter or longer fixation in NBF, other fixatives, extended ischemic time, treatment of tissue with microwaves or decalcification. Batch control includes 2 pelleted, formalin fixed paraffin embedded cell lines: NCI-H226 with moderate PD-L1 protein expression and MCF-7 with negative PD-L1 protein expression. On slide controls include one piece of tonsil (with expected PD-L1 staining positive in immune cells and keratinocytes) and one piece of liver (with expected PD-L1 staining negative in hepatocytes). Furthermore for specimen adequacy, this assessment should only rely on tissue showing invasive carcinoma and must include a minimum of 100 malignant cells.

Reference: A randomized, open-label, phase 3 trial. Lancet. 2021 Jul 3;398 (10294):27-40. https://pubmed.ncbi.nlm.nih.gov/34102137/