EP08.01-027 Durvalumab (D) ± Tremelimumab (T) + Chemotherapy (CT) in 1L Metastatic NSCLC: Outcomes by Tumour PD-L1 Expression in POSEIDON

In the Phase 3 POSEIDON study (NCT03164616), first-line T+D+CT demonstrated statistically significant improvements in both progression-free survival (PFS) (HR, 0.72; 95% CI, 0.60-0.86; p=0.0003) and overall survival (OS) (HR, 0.77; 95% CI, 0.65-0.92; p=0.0030) versus CT in patients with EGFR/ALK wild-type metastatic NSCLC (mNSCLC). CT supports initial tumour control, and can prime an anti-tumour immune response, while PD-(L)1 inhibition prevents local immune evasion to enhance tumour killing by activated T cells, and CTLA-4 inhibition has been shown to promote T-cell expansion, diversification and activation, potentially generating new anti-tumour T-cell responses.