Abstract 78P
Background
Anti-PD1/PD-L1-directed immune checkpoint inhibitors (ICI) are game changers in advanced non-small-cell lung cancer (NSCLC), but biomarkers are lacking. The aim of our study was to find clinically relevant biomarkers of the efficacy of ICI in non-squamous NSCLC.
Methods
We conducted a retrospective study of patients receiving ICI for advanced non squamous NSCLC in two cohorts. For a subset of patients, RNAseq data were generated on tumor biopsy taken before ICI. The primary end point was progression-free survival (PFS) under ICI. Secondary end point was overall survival (OS) from ICI initiation.
Results
In our cohort, we studied 231 patients. Clinical characteristics included KRAS mutant status (n=88), TTF1-positive expression (n=136), LIPI (Lung Immune Prognostic Index) score of 0 (n=116). In the training set, by multivariate Cox analysis, lack of TTF1 expression, LIPI score>0, line of treatment>1, and presence of liver metastases were associated with poorer PFS, while WHO performance status, lack of TTF1 expression, LIPI score>0, line of treatment>1, and presence of liver or bone metastases were associated with poorer OS. TTF1 and PD-L1 status could be used to stratify PFS and OS and improve the AUC for prediction of prognosis in comparison with the PD-L1 gold standard. Using an external validation cohort of 154 patients treated with ICI for non-squamous NSCLC, we confirmed the independent prognostic role of TTF1. Similarly, use of TTF1 with PD-L1 status could be used to stratify PFS and OS and improve the AUC for the prediction of prognosis in comparison to the PD-L1 gold standard.
Conclusions
TTF1 expression and PD-L1 can be used to stratify risk and predict PFS and OS in patients treated with ICI for NS-NSCLC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Centre Georges-François Leclerc.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.