FDA Approves Expanded Automated PD-L1 Diagnostic Testing Across 4 Solid Tumor Types

The FDA has expanded the approved use of the PD-L1 IHC 22C3 pharmDx assay (Code GE006) on the automated Dako Omnis platform. The regulatory milestone allows pathology laboratories to utilize the immunohistochemistry (IHC) companion diagnostic to guide treatment decisions for 4 additional solid tumor indications using the anti-PD-1 immunotherapy pembrolizumab (Keytruda).¹

Previously restricted to the manual or lower-throughput Autostainer Link 48 (ASL48) platform for these specific malignancies, the expanded approval enables high-volume clinical laboratories to transition existing workflows to a fully automated system. The 4 newly included indications span advanced or metastatic presentations of esophageal squamous cell carcinoma (ESCC), triple-negative breast cancer (TNBC), cervical cancer, and gastric or gastroesophageal junction (GEJ) adenocarcinoma.

Clinical Indications and Cutoff Values

The expansion targets distinct patient populations defined by clinical trial parameters and programmatic biomarker cutoffs:

• Esophageal Squamous Cell Carcinoma: For patients with locally advanced or metastatic ESCC not amenable to surgical resection or definitive chemoradiation, eligible as a single agent following 1 or more prior systemic lines, requiring a cmbined positive score (CPS) of 10 or greater, supported by data from the KEYNOTE-590 trial (NCT03189719).
• Triple-Negative Breast Cancer: In combination with chemotherapy for patients with locally recurrent unresectable or metastatic TNBC, requiring a CPS of 10 or greater, as validated in the KEYNOTE-355 trial (NCT02819518).
• Cervical Cancer: As a single agent for patients with recurrent or metastatic cervical cancer showing disease progression on or after chemotherapy, requiring a CPS of 1 or greater, established via the KEYNOTE-826 trial (NCT03635567).
• Gastric or Gastroesophageal Junction Adenocarcinoma: In combination with trastuzumab (Herceptin), fluoropyrimidine-, and platinum-containing chemotherapy for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or GEJ adenocarcinoma, requiring a CPS of 1 or greater, evaluated in the KEYNOTE-811 trial (NCT03615326).

Analytical Validation and Laboratory Efficiency

To secure the expanded regulatory approval, a multisite external platform performance comparison study was conducted. Investigators evaluated the analytical concordance of the PD-L1 IHC 22C3 pharmDx assay between the established ASL48 platform (Code SK006) and the Dako Omnis platform (Code GE006). The comparison utilized patient specimens from all 4 solid tumor types, assessing tissue staining patterns at the clinically relevant diagnostic thresholds (CPS ≥1 and CPS ≥10).

The data met all prespecified statistical acceptance criteria for inter-platform concordance, confirming that the automated assay on Dako Omnis delivers analytical reproducibility equivalent to the manual reference standard.

For clinical pathologists and laboratory managers, this regulatory shift addresses operational bottlenecks. Prior to this approval, laboratories were forced to maintain dual staining platforms—the automated Dako Omnis for non–small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC), alongside the ASL48 for other indications. The expanded labeling permits diagnostic consolidation, allowing laboratories to manage their entire pembrolizumab companion diagnostic testing volume within a unified, high-throughput automated workflow.

REFERENCE

1. Agilent Receives FDA Approval for Expanded Use of PD-L1 IHC 22C3 pharmDx on Dako Omnis in Esophageal Squamous Cell Carcinoma, Triple-Negative Breast Cancer, Cervical Cancer, and Gastric or Gastroesophageal Junction Adenocarcinoma. News release. Agilent Technologies. June 3, 2026. Accessed June 3, 2026. https://tinyurl.com/3v8995za