Clinical activity of programmed cell death 1 (PD-1) blockade in never, light, and heavy smokers with non-small-cell lung cancer and PD-L1 expression ≥50.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are standard therapies for patients with advanced non-small-cell lung cancer (NSCLC) and a programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) ≥50%. Tumor mutation burden (TMB) also predicts response to ICIs but is often not available in real time for decision making in the first-line setting. Smoking exposure can be a proxy for TMB in NSCLC. The impact of smoking status on efficacy of PD-1 blockade in NSCLC patients with PD-L1 TPS ≥50% has not been well defined. PATIENTS AND METHODS: To investigate the relationship between smoking and activity of ICIs in NSCLC, we retrospectively studied 315 patients with NSCLC and PD-L1 TPS ≥50% at five USA academic medical centers. Objective response rates (ORRs), progression-free survival (PFS), and duration of response (DOR) were compared between never (<100 lifetime cigarettes), light (≤10 pack-years), and heavy (>10 pack-years) smokers. A subset of patients underwent next-generation sequencing to estimate TMB. RESULTS: We identified 36 (11%) never, 42 (13%) light, and 237 (75%) heavy smokers with NSCLC and PD-L1 TPS ≥50% treated with ICIs. Objective responses were observed in 27%, 40%, and 40% of never, light, and heavy smokers, respectively (P = 0.180 never versus heavy; P = 1.000 light versus heavy). Median PFS and median DOR were numerically shorter in never and light smokers compared with heavy smokers (PFS 3.0 versus 4.0 versus 5.4 months; median DOR 6.9 versus 10.8 versus 17.8 months), but were not statistically different [PFS: hazard ratio (HR) 1.37, P = 0.135 and HR 1.24, P = 0.272; DOR: HR 1.92, P = 0.217 and HR 1.79, P = 0.141]. CONCLUSIONS: PD-(L)1 inhibitors are associated with antitumor activity in NSCLC with PD-L1 TPS ≥50% regardless of smoking status. Nevertheless, there is a signal of potentially decreased durability among never and light smokers that should be further evaluated. Distinct immunobiologic features may affect initial response versus durability of antitumor immunity to programmed cell death 1 (PD-1) blockade.

Outcomes to first-line pembrolizumab in patients with non-small-cell lung cancer and very high PD-L1 expression.

BACKGROUND: In non-small-cell lung cancers with programmed death-ligand 1 (PD-L1) expression on ≥50% of tumor cells, first-line treatment with the PD-1 inhibitor pembrolizumab improves survival compared with platinum-doublet chemotherapy. Whether higher PD-L1 levels within the expression range of 50%-100% predict for even greater benefit to pembrolizumab is currently unknown. PATIENTS AND METHODS: In this multicenter retrospective analysis, we analyzed the impact of PD-L1 expression levels on the overall response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) in patients who received commercial pembrolizumab as first-line treatment of non-small-cell lung cancer (NSCLC) with a PD-L1 expression of ≥50% and negative for genomic alterations in the EGFR and ALK genes . RESULTS: Among 187 patients included in this analysis, the ORR was 44.4% [95% confidence interval (CI) 37.1% to 51.8%], the mPFS was 6.5 months (95% CI 4.5-8.5), and the mOS was not reached. The median PD-L1 expression level among patients who experienced a response to pembrolizumab was significantly higher than among patients with stable or progressive disease (90% versus 75%, P < 0.001). Compared with patients with PD-L1 expression of 50%-89% (N = 107), patients with an expression level of 90%-100% (N = 80) had a significantly higher ORR (60.0% versus 32.7%, P < 0.001), a significantly longer mPFS [14.5 versus 4.1 months, hazard ratio (HR) 0.50 (95% CI 0.33-0.74), P < 0.01], and a significantly longer mOS [not reached versus 15.9 months, HR 0.39 (95% CI 0.21-0.70), P = 0.002]. CONCLUSION: Among patients with NSCLC and PD-L1 expression of ≥50% treated with first-line pembrolizumab, clinical outcomes are significantly improved in NSCLCs with a PD-L1 expression of ≥90%. These findings have implications for treatment selection as well as for clinical trial interpretation and design.