PD-L1 testing is now cleared to help identify patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma who may be eligible for anti–PD-1 therapy.
The US Food and Drug Administration (FDA) has approved Agilent Technologies‘ PD-L1 IHC 22C3 pharmDx test as a companion diagnostic for patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma (EOC) who may be eligible for treatment with Keytruda (pembrolizumab).
The approval makes Agilent’s test the only FDA-approved companion diagnostic indicated to help identify EOC patients whose tumors express PD-L1 and who may benefit from Merck’s anti-PD-1 therapy, according to Agilent Technologies. This marks the seventh FDA-approved companion diagnostic indication for the PD-L1 IHC 22C3 pharmDx test for use with Keytruda.
The test enables pathologists to assess PD-L1 expression at the time of diagnosis, supporting treatment decisions in a disease where therapeutic options remain limited for many patients.
“Delivering effective precision oncology requires close collaboration between diagnostics and therapeutics, and this FDA approval reflects Agilent’s long-standing industry partnership in companion diagnostics,” says Nina Green, vice president and general manager of Agilent’s clinical diagnostics division, in a release. “We are proud to enable pathologists to identify patients with EOC who may benefit from immunotherapy.”
Clinical Trial Data Supports Approval
PD-L1 expression in EOC was evaluated using the Agilent test in the KEYNOTE-B96 clinical trial, which supported its use in identifying patients who may benefit from Keytruda treatment.
Ovarian cancer caused approximately 12,730 deaths in the US in 2025 and has a five-year survival rate of 51.6% between 2015 to 2021, according to the company.
Expanding Diagnostic Portfolio
The PD-L1 IHC 22C3 pharmDx test is now indicated in the US to help physicians identify patients with multiple cancer types who may benefit from Keytruda treatment, including non-small cell lung cancer, esophageal squamous cell carcinoma, cervical cancer, head and neck squamous cell carcinoma, triple-negative breast cancer, and gastric or gastroesophageal junction adenocarcinoma.
Agilent developed the test in partnership with Merck as a companion diagnostic specifically for Keytruda. The approval expands PD-L1 testing options to support treatment decisions across a broader range of cancer types where immunotherapy may be beneficial.
