Dr. David L. Rimm on the Continued Role for PD-L1 Testing in NSCLC

David L. Rimm, MD, PhD, professor of pathology and of medicine, director of pathology tissue services, director of translational pathology, Yale Cancer Center, discusses the continued role for PD-L1 testing to predict response with checkpoint inhibitors in non­—small cell lung cancer (NSCLC).

PD-L1 IHC 22C3 pharmDx is the first FDA-approved companion diagnostic test for PD-L1 testing in NSCLC. This test, used with pembrolizumab (Keytruda), is going to around for a long time, says Rim. This is because recent data demonstrated that pembrolizumab was more effective than chemotherapy in frontline metastatic NSCLC, but only for patients whose tumors have ≥50% PD-L1 expression. This means that patients will want to have this test to determine if they are a candidate for frontline pembrolizumab, says Rimm. Patients who respond to frontline pembrolizumab may not need chemotherapy for a long time, if ever, he says. This is really a breakthrough in the management of lung cancer, he says. For that reason, PD-L1 testing is not going to go away anytime soon.

The FDA approved pembrolizumab for the frontline treatment of patients with PD-L1 positive, metastatic NSCLC who do not harbor EGFR or ALK aberrations in October 2016.

The approval was based on data from the phase III KEYNOTE-024 trial, in which single-agent pembrolizumab reduced the risk of death by 40% and improved progression-free survival (PFS) by 4.3 months compared with doublet chemotherapy for untreated patients with advanced NSCLC with PD-L1 expression on ≥50% of cells.