PD-L1 IHC (22C3 pharm Dx) result: {*Positive [CPS >= 1 and < 20] OR *Positive [CPS >= 20] OR Negative CPS < 1 OR Inadequate}

Interpretation: Combined Positive Score (CPS) - Negative (< 1), *Positive (>= 1 and < 20) or *Positive (>= 20)

Batch control: Adequate; on slide controls: Adequate Disclaimer: Please note the PD-L1 IHC (22C3 pharm Dx) with the combined positive score (CPS) utilized herein has been developed for use of Pembrolizumab in advanced head and neck squamous cell carcinoma and is not interchangeable with other PD-L1 assays. PD-L1 22C3 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 (except rare instances, should not be performed on cytological specimen) and must include a minimum of 100 malignant cells.

*PD-L1 expression level CPS = 20 may be of interest to treating physician but does not determine eligibility for first-line treatment with KEYTRUDA® (pembrolizumab) as a single agent. https://ascopubs.org/doi/full/10.1200/JCO.21.02508