Dr. Pinato on PD-L1 Testing in HCC

David J. Pinato, MD, NIHR Academic Clinical Lecturer in Medical Oncology, resident, Royal Brompton Hospital and Imperial College London, discusses the role of PD-L1 testing in hepatocellular carcinoma (HCC).

Clinical trial data have shown that PD-1 inhibitors are effective in about 20% of patients with HCC. The problem is that physicians don’t know which patients derive benefit and which don’t. Pinato says that in most other tumor types where PD-1 inhibition is approved, it is indicative that PD-L1 expression is predictive of response to this treatment. It is unclear if this translates to the HCC treatment paradigm, and recent studies looking at checkpoint inhibitors in this space have not led to an answer.

In the Blueprint-HCC study led by Pinato, researchers collected a large series of resected specimens. These specimens were profiled with the 4 monoclonal antibodies that are used in HCC. Unfortunately, Pinato says, there seems to be a lot of heterogeneity for most of the antibody platforms that measure the same protein. There was also significant heterogeneity observed in the sample specimens, suggesting that PD-L1 is not an effective biomarker in HCC.