The FDA has handed Agilent’s companion diagnostic, the PD-L1 IHC 22C3 pharmDx assay, expanded use approval for identifying patients with esophageal squamous cell carcinoma (ESCC).

The diagnostic is now approved to aid in identifying patients with ESCC for treatment with Keytruda (pembrolizumab). The Merck blockbuster drug is approved for recurrent locally advanced or metastatic ESCC whose tumors express PD-L1 as determined by an FDA-approved test, with disease progression on or after one prior line of systemic therapy.

ESCC is the sixth cancer type for which Agilent’s companion diagnostic has gained approval for in the U.S.