Choosing an immunotherapy approach in patients with advanced non-small-cell lung cancer
Pembrolizumab was approved in 2016 as a single agent in the first-line treatment of advanced non-small-cell lung cancer (NSCLC) patients with PD-L1 expression on at least 50% of their tumor cells (tumor proportion score (TPS)≥50%). In June 2018, the phase III clinical trial KEYNOTE-042 was presented in the Plenary Session of the 2018 Annual Meeting of the American Society of Clinical Oncology (ASCO). This study demonstrated significant survival gains with pembrolizumab over platinum-based chemotherapy in untreated patients with advanced NSCLC and any level of PD-L1 positivity (TPS≥1%) . At first glance, these data appear to show an extension of the benefits of pembrolizumab from the minority of patients with high PD-L1 expressing tumors to the majority of patients with any level of PD-L1 positivity. However, consideration of these data in greater detail indicates that rigorous selection of patients based on PD-L1 expression is still needed.