2007P - Real-world (rw) outcomes to chemoimmunotherapy and biomarker analysis in extensive-stage small cell lung cancer (ES SCLC)

Background

The addition of programmed death-ligand 1 (PD-L1) inhibitors to chemotherapy in the first-line treatment of ES SCLC has improved survival outcomes compared with chemotherapy alone. Biomarkers for response to chemoimmunotherapy have not been clearly established yet.

Methods

We performed a retrospective chart review of patients diagnosed with ES SCLC who received chemoimmunotherapy in the first-line treatment setting at Sotiria General Hospital for Chest Diseases, National and Kapodistrian University of Athens, Athens, Greece, between October 2018 and February 2023. Kaplan-Meier analysis was utilized to calculate rw progression-free survival (rwPFS) and rw overall survival (rwOS). Cox proportional hazards regression analysis was utilized to identify associations between patient characteristics and outcome. All hypothesis testing was conducted at a two-sided significance level of α=0.05.

Results

Ninety patients were eligible for study inclusion. The median age at diagnosis was 69 years (range, 40-82 years). Forty patients received atezolizumab plus carboplatin/etoposide (EP) and 50 patients received durvalumab plus EP. The rw objective response rate (rwORR) was 48.2%. At a median follow-up of 6.8 months, median rwPFS and rwOS reached 5.8 months (95% confidence intervals [CI], 5.2-9.7 months) and 12.7 months (95% CI, 7.7-17.5 months), respectively. Notably, survival outcomes were equivalent among patients treated with atezolizumab and those treated with durvalumab. Median rw progression-free survival to subsequent therapy (rwPFS2) was 2.7 months (95% CI, 1.9 months-not estimable). At baseline, increased neutrophil-to-lymphocyte ratio (NLR; hazard ratio [HR], 1.51; 95% CI, 1.02-2.25) and increased number of metastatic sites (HR, 3.14; 95% CI, 1.38-7.11) were associated with a higher risk of death, while elevated BMI (HR: 0.47, 95% CI:0.28-0.81) was associated with lower.

Conclusions

Rw survival outcomes to chemoimmunotherapy in ES SCLC were consistent with the results of large-scale randomized clinical trials. Several baseline patient characteristics were associated with rwOS and merit further investigation in prospective studies.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.