Dr. Goldberg on PD-L1 as a Biomarker in Lung Cancer

Sarah B. Goldberg, MD, MPH, assistant professor of Medicine, Yale Cancer Center, discusses the use of PD-L1 as a biomarker in treating patients with lung cancer.

PD-L1 is a very important biomarker, says Goldberg, especially when determining whether to use immunotherapy for patients in the first-line setting.

Goldberg cites a recent trial of pembrolizumab (Keytruda) versus chemotherapy in the first-line setting, in which patients were selected based on a PD-L1 threshold of 50% or greater. This particular trial yielded significant benefit for patients who received immunotherapy, thus underscoring the importance of the PD-L1 biomarker in this context.

However, Goldberg notes that PD-L1 is being tested in a variety of different ways, and its expression can look very different depending on what data one looks at. Oncologists use multiple types of assays, and several different cutpoints are used, as well.

If one tries to come up with a comprehensive understanding of PD-L1 as a biomarker, Goldberg claims there does generally seem to be an increasing benefit with immunotherapy in patients with higher levels of PD-L1 expression. However, she also notes that it is clear that even patients without PD-L1 expression—with 0% positive cells staining for PD-L1—can still benefit from treatment, although there is less of a chance of benefit.