PD-L1: An Important, But Imperfect Biomarker

Some immunotherapy drugs target the PD-L1 protein, though this expert says that it is still an imperfect biomarker.

In the lung cancer space, PD-L1 is not a perfect biomarker, says H. Jack West, M.D., thoracic oncologist, Swedish Cancer Institute at Swedish Medical Center.

PD-L1, a protein that immunotherapy drugs such as Keytruda (pembrolizumab) and Imfinzi (durvalumab) target, may not be as powerful a biomarker as ALK and EGFR. While PD-L1 status is often used to determine which patients should receive certain immunotherapy drugs, clinicians like West have also seen good promising response rates for patients given these agents who test low or negative for PD-L1.