SKYSCRAPER-01: Tiragolumab in Combination With Atezolizumab in Previously Untreated PD-L1-High, Locally Advanced, Unresectable or Metastatic Non-Small Cell Lung Cancer

The phase 3 SKYSCRAPER-01 trial (n=521) did NOT show a significant benefit from adding tiragolumab, an anti-TIGIT antibody, to atezolizumab as first-line treatment of PD-L1-high non-small cell lung cancer. Median progression-free survival was 7.0 versus 5.6 months (HR 0.78; 95% CI 0.63-0.97; P=.02, nonsignificant against the prespecified threshold) and median overall survival was 23.1 versus 16.9 months (HR 0.87; 95% CI 0.7-1.1; P=.22). Adding tiragolumab did increase toxicity: grade 3-4 adverse events occurred in 41.2% versus 33.8% of patients, with four treatment-related deaths versus two. This is one of the pivotal failures for the TIGIT inhibitor class as a whole.