Few patients treated with immunotherapy for metastatic non–small cell lung cancer (NSCLC) at United States community practices receive appropriate programmed death-ligand 1 (PD-L1) expression testing, according to research presented at the 2017 ASCO Annual Meeting (June 2-6, 2017; Chicago, IL).
Although testing increased following Food and Drug Administration (FDA) approval of nivolumab (Opdivo, Bristol-Myers Squibb) and pembrolizumab (Keytruda, Merck), few patients were tested using FDA-approved companion diagnostics.
The FDA approved nivolumab for patients with metastatic, previously treated NSCLC in March 2015, regardless of PD-L1 expression. Pembrolizumab was approved in October 2015 for patients with tumors expressing PD-L1, as identified by a companion diagnostic.
Sean Khozin, MD, MPH, senior medical officer with the FDA (Silver Spring, MD), and colleagues accessed electronic health record (EHR) data of patients with clinically confirmed metastatic NSCLC treated between January 2011 and March 2016. The researchers documented the administration of nivolumab or pembrolizumab in the patient population, with PD-L1 testing status abstracted from EHRs.
The study included data from 1362 patients, the majority of whom (96.2%) were prescribed nivolumab. The remaining patients were treated with pembrolizumab (3.3%), or a combination of both therapies (0.5%).
PD-L1 testing occurred in 11.2% of patients, with positive test results returned for 42.2% of patients. As compared with the quarter prior to FDA approval, testing increased in the first quarter following FDA approval (3% vs 12.8%). The FDA-approved companion diagnostic was used in 30.5% of testing.
When the researchers considered testing based on therapy type, they found that 90.5% of patients prescribed nivolumab and 32.7% of patients prescribed pembrolizumab did not receive PD-L1 testing. Fifty percent of patients on pembrolizumab and 3.2% of patients on nivolumab testing positive for PD-L1; negative testing occurred in 1.9% of patients on pembrolizumab and 4.7% of patients on nivolumab.
Researchers noted that additional data are being collected to investigate the impact of PD-L1 testing strategy on patient outcomes.—Cameron Kelsall
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