Real-World Efficacy of First-Line Pembrolizumab in Patients With Advanced or Recurrent Non-Small-Cell Lung Cancer and High PD-L1 Tumor Expression.

Background: In clinical trials, first-line treatment with pembrolizumab improved overall survival (OS) in patients with advanced non-small-cell lung cancer (NSCLC) with a programmed death ligand 1 (PD-L1) tumor proportion score of ≥ 50%. However, data on the efficacy of this treatment between clinical trials and actual clinical practice are inconsistent.

Patients And Methods: Ninety-five patients with histologically diagnosed advanced or recurrent NSCLC and a PD-L1 tumor proportion score of ≥ 50% who received pembrolizumab as first-line treatment were consecutively enrolled onto this multicenter retrospective study from February 2017 to December 2018. Clinical data were collected from electronic medical records. We assessed the objective response rate, progression-free survival (PFS), OS, and immune-related adverse events (irAE), and determined their associations with clinical characteristics.

Results: The objective response rate was 40.0%. The median PFS was 6.1 months, and OS did not reach the median. Multivariate analyses revealed that nonadenocarcinoma histology (hazard ratio, 1.78; 95% confidence interval, 1.05-3.03; P = .015) and ≥ 3 metastatic sites (hazard ratio, 3.97; 95% confidence interval, 1.97-8.01; P < .001) were independently correlated with poor PFS. Patients with irAE and patients without interstitial lung disease had significantly longer PFS (14.0 and 4.9 months, respectively; P = .011) than patients without irAE or patients with interstitial lung disease.

Conclusion: The outcome of patients receiving first-line pembrolizumab treatment was worse in those with nonadenocarcinoma and with a large number of metastatic sites. Patients with irAE and without interstitial lung disease had a more favorable outcome.