WCLC 2025 - Posters & ePosters-P2.08 .47 Lymphocyte Recovery and Risk for Immune Pneumonitis After Chemoradiation in Locally Advanced NSCLC

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This retrospective study from The Ohio State University investigated the relationship between lymphocyte recovery after chemoradiotherapy (CRT) and the risk of immune checkpoint inhibitor (ICI)-related pneumonitis in patients with unresectable Stage III non-small cell lung cancer (NSCLC) treated with consolidation durvalumab. Among 117 patients who received CRT followed by durvalumab, absolute lymphocyte counts (ALC) were measured before CRT, at the nadir during CRT, and 30 days post-CRT. Pneumonitis diagnosis was established through clinical and radiological review.<br /><br />Results showed that while post-CRT ALC level alone was not significantly associated with pneumonitis risk, the magnitude of ALC recovery—from the lowest point during CRT to post-CRT—trended toward significance in predicting pneumonitis. Specifically, every 10-cell/μL increase in absolute lymphocyte recovery correlated with a 0.8% higher pneumonitis risk after adjusting for confounders such as age, performance status, tumor histology, and PD-L1 expression. Notably, 37% of patients developed pneumonitis with a median onset of about 11 months after starting durvalumab.<br /><br />Interestingly, patients who developed ICI-pneumonitis had significantly longer median overall survival (57.0 months) compared to those who did not (27.6 months), suggesting that lymphocyte recovery and the subsequent immune activation may contribute both to pneumonitis risk and improved immunotherapy response.<br /><br />In conclusion, the study suggests that absolute lymphocyte recovery post-CRT may serve as a useful biomarker to predict ICI-related pneumonitis in locally advanced NSCLC patients receiving durvalumab consolidation. Moreover, the association between pneumonitis and improved overall survival highlights the potential link between immune system recovery, toxicity, and therapeutic benefit. Further research is needed to understand the underlying mechanisms driving these observations.

Asset Subtitle

Monika Satoskar

Meta Tag

Speaker Monika Satoskar

Topic Local-Regional Non-small Cell Lung Cancer

Keywords

lymphocyte recovery

chemoradiotherapy

immune checkpoint inhibitor

pneumonitis

non-small cell lung cancer

durvalumab

absolute lymphocyte count

overall survival

biomarker

immunotherapy toxicity