PD-L1 as a Biomarker in Treating Patients with Lung Cancer

Sarah Goldberg, MD, MPH, Assistant Professor of Medicine (Medical Oncology)

Dr. Goldberg is available anytime at [email protected]

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.