P77.02 Efficacy of Tiragolumab + Atezolizumab in PD-L1 IHC and TIGIT Subgroups in the Phase II CITYSCAPE Study in First-Line NSCLC

The immunomodulatory receptor TIGIT (T-cell Immunoreceptor with Ig and ITIM domains) is a novel inhibitory immune checkpoint on activated T cells and natural killer cells in multiple cancers. Tiragolumab (tira) is a humanized IgG1/kappa monoclonal antibody that binds TIGIT to prevent its interaction with its ligand PVR (CD155). Because PD-L1 expression is considered a hallmark of pre-existing immunity and is positively correlated with TIGIT expression, we investigated the combination of tira + atezolizumab (atezo) in patients with newly diagnosed PD-L1-positive metastatic NSCLC in the phase II CITYSCAPE trial.