WCLC 2025 - Posters & ePosters-P1.11.48 Scoreit - Is IC3 Similarly Predictive as TC3 for Single Agent PD-1/PD-L1 Immune Checkpoint Inhibition in Metastatic NSCLC (mNSCLC)

P1.11.48 Scoreit - Is IC3 Similarly Predictive as TC3 for Single Agent PD-1/PD-L1 Immune Checkpoint Inhibition in Metastatic NSCLC (mNSCLC)

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Pdf Summary

This retrospective single-center study investigates the predictive value of PD-L1 expression on immune cells (IC) and tumor cells (TC) in metastatic non-small cell lung cancer (mNSCLC) patients treated with single-agent PD-1/PD-L1 immune checkpoint inhibitors (ICI) as first-line palliative therapy. Specifically, it compares two expression patterns: IC3/TC3 (≥10% PD-L1 on immune cells with variable tumor cell expression) and TC3/IC3 (≥50% PD-L1 on tumor cells with variable immune cell expression) to determine if high PD-L1 on immune cells is similarly predictive as on tumor cells for treatment outcomes.<br /><br />The study included 269 patients with high PD-L1 expression out of 593 tested between 2021-2023, with 87 patients receiving ICI monotherapy: 22 with IC3/TC3 treated mostly with PD-L1 inhibitor atezolizumab, and 40 with TC3/IC3 treated with PD-1 inhibitors pembrolizumab or cemiplimab. Median overall survival (OS) was longer in the IC3/TC3 group at 28.6 months versus 13.3 months in TC3/IC3 (HR=0.58, p=0.112), though not statistically significant. Median progression-free survival (PFS) was comparable (8.6 vs. 10.1 months, p=0.398). Objective response rates were higher in IC3/TC3 (41% vs. 33%, p=0.85).<br /><br />Clinical characteristics such as age, sex, smoking status, and histology were similar across groups. The data suggest that PD-L1 expression on immune cells (IC3) might have predictive value comparable to tumor cell PD-L1 (TC3) for ICI response, especially in atezolizumab-treated mNSCLC patients.<br /><br />The authors conclude that IC3 expression may be as important as TC3 in predicting outcomes with single-agent PD-1/PD-L1 therapy in mNSCLC and highlight the need for further validation in larger prospective cohorts such as the German CRISP registry. These findings may inform patient selection for checkpoint inhibition, underscoring the relevance of immune cell PD-L1 levels beyond tumor cell expression.

Asset Subtitle

Nadine Olejnik

Meta Tag

Speaker Nadine Olejnik

Topic Metastatic Non-small Cell Lung Cancer – Immunotherapy

Keywords

PD-L1 expression

immune cells

tumor cells

metastatic non-small cell lung cancer

PD-1/PD-L1 immune checkpoint inhibitors

IC3/TC3 pattern

TC3/IC3 pattern

overall survival

progression-free survival

atezolizumab