biomarkersBiomarker

PD-L1 CPS (combined positive score)

aka PD-L1 CPS, CPS, combined positive score, PD-L1 combined positive score, CPS >= 1, CPS >= 10, PD-L1 CPS 1, PD-L1 CPS 10, CPS≥1, CPS≥10

CPS counts every PD-L1-stained cell in the tumour, immune cells included, and divides by the number of tumour cells. Pembrolizumab labels use CPS 1 or CPS 10 as the gate in head and neck, stomach, oesophageal, cervical, ovarian and triple-negative breast cancer.

The combined positive score is the 22C3 pharmDx read used outside lung cancer: the number of PD-L1-staining cells (tumour cells, lymphocytes and macrophages) divided by the total number of viable tumour cells, multiplied by 100, so it can exceed 100 in principle and is reported as a whole number. Pembrolizumab's US label gates first-line head and neck cancer, HER2-negative and HER2-positive gastric or GEJ adenocarcinoma, first-line oesophageal cancer with chemotherapy, cervical cancer and platinum-resistant ovarian cancer at CPS >= 1, and triple-negative breast cancer and second-line oesophageal squamous cancer at CPS >= 10. Nivolumab's label now restricts its gastric, GEJ and oesophageal indications to tumours expressing PD-L1 (>= 1), measured with the 28-8 pharmDx. Because the denominator is tumour cells only, CPS is not interchangeable with TPS or with the SP142 immune-cell score.

Part ofPD-L1· CD274Other readoutsPD-L1 IC score PD-L1 TC score PD-L1 TPS All readouts

PD-L1: what it is and how drugs act on it · animated schematic, not to scale

Target · the protein and the cell it sits on
Drug · antibody, small molecule, cell or radioligand
Effect · signal, damage or kill

In plain words · PD-L1 is the tumour's side of the PD-1 brake, and also the biomarker that decides who gets immunotherapy.

CPS 10 approval thresholds

What it means for a patient

Your report gives a CPS number. Whether it counts as positive depends on the cancer: the pembrolizumab label asks for 1 or more in head and neck, stomach, oesophageal, cervical and platinum-resistant ovarian cancer, and 10 or more in triple-negative breast cancer. The same number can open a treatment in one cancer and not in another, and a score below the cut-off does not mean immunotherapy can never be used, only that this particular indication does not apply.

Written only from the label or guideline text cited on this page. Not medical advice; your own report and the reading your team gives it come first.

Scoring rule

Count PD-L1-positive tumour cells, lymphocytes and macrophages; divide by the number of viable tumour cells; multiply by 100. A specimen must hold at least 100 viable tumour cells to be scored.

“PD-L1 protein expression [Combined Positive Score (CPS) ≥ 1]”
FDA: List of FDA-Authorized Companion Diagnostic Devices

Thresholds used in approvals

Threshold	Drug	Cancer	Regulator	Source
CPS >= 1	Pembrolizumab	Head and neck squamous cell carcinoma	FDA	label
CPS >= 1	Pembrolizumab	Gastric & gastro-oesophageal junction cancer	FDA	label
CPS >= 1	Pembrolizumab	HER2-positive gastric cancer	FDA	label
CPS >= 1 (with chemotherapy); CPS >= 10 (single agent, squamous, after prior therapy)	Pembrolizumab	Oesophageal cancer	FDA	label
CPS >= 1	Pembrolizumab	Cervical cancer	FDA	label
CPS >= 10	Pembrolizumab	Metastatic triple-negative breast cancer	FDA	label
CPS >= 10	Sacituzumab govitecan	Metastatic triple-negative breast cancer	FDA	label
CPS >= 1	Pembrolizumab	Platinum-resistant ovarian cancer	FDA	label
PD-L1 >= 1 (28-8 pharmDx)	Nivolumab	Gastric & gastro-oesophageal junction cancer	FDA	label
PD-L1 >= 1 (28-8 pharmDx)	Nivolumab	Oesophageal squamous cell carcinoma	FDA	label

Drugs whose label names it

Pembrolizumab Sacituzumab govitecan Nivolumab

Companion diagnostics (FDA list)

Device	Maker	Indication and sample	Drug	PMA / 510(k)
PD-L1 IHC 22C3 pharmDx	Agilent Technologies (Dako)	Head and Neck Squamous Cell Carcinoma (HNSCC) - Tissue	Pembrolizumab	P150013/S014 (06/10/2019)
PD-L1 IHC 22C3 pharmDx	Agilent Technologies (Dako)	Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma - Tissue	Pembrolizumab	P150013/S027 (11/07/2023)
PD-L1 IHC 22C3 pharmDx	Agilent Technologies (Dako)	Esophageal or Gastroesophageal Junction (GEJ) Carcinoma - Tissue	Pembrolizumab	P150013/S032 (02/11/2026)
PD-L1 IHC 22C3 pharmDx	Agilent Technologies (Dako)	Cervical Cancer - Tissue	Pembrolizumab	P150013/S009 (06/12/2018)
PD-L1 IHC 22C3 pharmDx	Agilent Technologies (Dako)	Triple-Negative Breast Cancer (TNBC) - Tissue	Pembrolizumab	P150013/S020 (11/13/2020)
PD-L1 IHC 22C3 pharmDx	Agilent Technologies (Dako)	Epithelial Ovarian, Fallopian Tube Cancer, or Primary Peritoneal Carcinoma (EOC) - Tissue	Pembrolizumab	P150013/S033 (02/10/2026)
PD-L1 IHC 28-8 pharmDx	Agilent Technologies (Dako)	Esophageal squamous cell carcinoma (ESCC), and gastric, gastroesophageal junction (GEJ), and esophageal adenocarcinoma - Tissue	Nivolumab	P150025/S018 (07/01/2026)

Tests that measure it

PD-L1 IHC 22C3 pharmDx PD-L1 IHC 28-8 pharmDx Caris MI Profile Labcorp OmniSeq INSIGHT

Trials that name this readout

Matched on the name and aliases of the readout in the title, setting and summary of each trial; a match is a mention, not proof the readout was an entry criterion.