Agilent Technologies’ pharmDx PD-L1 immunohistochemistry (IHC) assay has received an expanded CE mark for identifying esophageal cancer patients who can be treated with Merck’s monoclonal antibody Keytruda (pembrolizumab).

The Santa Clara, Calif.-based company developed the assay as a companion diagnostic for Keytruda in partnership with Merck. Keytruda, which targets the PD-LI protein, has been approved for treatment of multiple cancers.

The PD-L1 IHC pharmDx is a standardized assay with all the necessary components for 50 tests in one kit.