A phase 3 trial evaluating tiragolumab in combination with atezolizumab (Tecentriq®) in adults with PD-L1 high locally advanced or metastatic non-small cell lung cancer (NSCLC) did not meet its coprimary endpoint of progression-free survival (PFS), according to Genentech. 

Tiragolumab is a novel immune checkpoint inhibitor that binds to TIGIT, a protein receptor on immune cells, which suppresses the immune response to cancer. The Company believes that combining tiragolumab with atezolizumab, a PD-L1 blocking antibody, will increase anti-tumor activity by enhancing the body’s immune response to cancer cells. 

The global, randomized, double-blind, SKYSCRAPER-01 study (ClinicalTrials.gov Identifier: NCT04294810) compared the efficacy and safety of tiragolumab plus atezolizumab with placebo plus atezolizumab in 534 adults with PD-L1 high locally advanced, unresectable or metastatic NSCLC. Patients were randomly assigned 1:1 to receive tiragolumab plus atezolizumab or placebo plus atezolizumab until disease progression, loss of clinical benefit or unacceptable toxicity. 

Results showed that treatment with tiragolumab plus atezolizumab did not meet the coprimary endpoint of PFS. According to Genentech, the other coprimary endpoint of overall survival was immature and will be evaluated at the next planned analysis. The Company did note a numerical improvement for both endpoints. 

The combination therapy was well tolerated with no new safety signals identified.

“While these results are not what we hoped for in our first analysis, we look forward to seeing mature overall survival for this study to determine next steps,” said Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development. “We continue to believe that TIGIT may have a role in cancer treatment and we will share additional results from our tiragolumab program as they emerge.”

The Company is also investigating the combination of tiragolumab and atezolizumab for the treatment of extensive-stage SCLC (SKYSCRAPER-02 [ClinicalTrials.gov Identifier: NCT04256421), stage III NSCLC (SKYSCRAPER-03 [ClinicalTrials.gov Identifier: NCT04513925]), and locally advanced esophageal cancer (SKYSCRAPER-07 [ClinicalTrials.gov Identifier: NCT04543617]). Tiragolumab is also being evaluated for the treatment of metastatic esophageal squamous cancer (SKYSCRAPER-08 [ClinicalTrials.gov Identifier: NCT04540211]).

Reference

Genentech reports interim results for phase III SKYSCRAPER-01 study in PD-L1-high metastatic non-small cell lung cancer. News release. Genentech. May 10, 2022. Accessed May 11, 2022. https://www.gene.com/media/press-releases/14951/2022-05-10/genentech-reports-interim-results-for-ph