(AE) Shifting Treatment Landscape and Overall Survival by PD-L1 Expression Level Among Patients with Advanced Non-Small Cell Lung Cancer (aNSCLC)

Publication Number: 650

Background: Since 2016, when the FDA approved the first immune checkpoint inhibitor (ICI) for first-line (1L) treatment of patients with aNSCLC with ≥50% PD-L1 expression, some ICI indications have been expanded to include patients with PD-L1 ≥1% or regardless of expression level. Current National Comprehensive Cancer Network guidelines reflect these changes.

Objectives: To describe trends in real-world 1L ICI treatment and overall survival among patients with aNSCLC across PD-L1 expression levels.

Methods: We conducted a retrospective cohort study of patients with aNSCLC and a valid PD-L1 test result prior to or within 30 days of 1L initiation was conducted using a Flatiron Health electronic health records database (1 January 2015 to 30 November 2020), excluding patients with known ALK/EGFR/ROS1 alterations. Patient characteristics, type of 1L treatment, and overall survival were described by PD-L1 expression levels (negative: < 1%; low: 1–49%; high: ≥50%) and by year.

Results: The proportion of patients (n=11,141; median age 70 years [Q1–Q3: 62–77]; 45.5% female; 69.1% White) with negative, low, and high PD-L1 expression were 32.5%, 30.9%, and 36.5%, respectively. From 2015 to 2020, 1L chemotherapy-only treatment fell from 96.1% to 31.3% for PD-L1 negative, 81.0% to 25.1% for PD-L1 low, and 84.2% to 18.8% for PD-L1 high groups. Within the same period, 1L ICI treatment generally increased: from 2.0% to 66.4% for PD-L1–negative,14.3% to 72.2% for PD-L1–low, and 15.8% to 78.9% for PD-L1–high groups. From 2015 to 2019, median overall survival generally improved: from 8.6 to 11.2 months for PD-L1–negative, 10.2 to 12.3 months for PD-L1–low, and 9.9 to 16.3 months for PD-L1–high groups.

Conclusions: From 2015–2019, use of 1L ICI increased among real-world patients with aNSCLC across all known PD-L1 expression levels and overall survival generally improved, especially in patients with high PD-L1 expression. Research is needed to investigate the reasons for continued use of 1L chemotherapy only, especially among patients with high PD-L1 expression.