Trial results for a Phase 2/3 study evaluating tiragolumab in combination with atezolizumab plus chemotherapy for previously untreated advanced non-squamous non-small cell lung cancer (NSCLC) were posted on ClinicalTrials.gov on 2026-06-03. The study found that the tiragolumab and atezolizumab arm had shorter median progression-free survival and overall survival compared to the pembrolizumab plus chemotherapy arm.
Background
The study investigated tiragolumab in combination with atezolizumab plus pemetrexed and carboplatin/cisplatin in participants with previously untreated, locally advanced unresectable or metastatic non-squamous non-small cell lung cancer (NSCLC). This experimental regimen was compared against pembrolizumab plus pemetrexed and carboplatin/cisplatin, a standard immunotherapy-chemotherapy combination for this patient population.
Trial design
The Phase 2/3 study (NCT04619797) enrolled 542 participants with previously untreated, locally advanced unresectable or metastatic non-squamous non-small cell lung cancer (NSCLC). Participants were randomized in a 1:1 ratio to receive either tiragolumab plus atezolizumab plus pemetrexed and carboplatin/cisplatin (Arm A) or placebo in combination with pembrolizumab plus pemetrexed and carboplatin/cisplatin (Arm B).
Key results
The trial reported the following key measurements:
- For Progression-free Survival (PFS) as determined by the investigator, the median PFS was 8.31 months for the Tiragolumab + Atezolizumab + Chemotherapy group, compared to 9.89 months for the Placebo + Pembrolizumab + Chemotherapy group.
- For Overall Survival (OS), the median OS was 18.89 months for the Tiragolumab + Atezolizumab + Chemotherapy group, compared to 23.10 months for the Placebo + Pembrolizumab + Chemotherapy group.
Results for participants with PD-L1 expression at TPS/TC >=1%:
- Investigator Assessed PFS: 9.82 months (Tiragolumab + Atezolizumab + Chemotherapy) vs. 11.96 months (Placebo + Pembrolizumab + Chemotherapy).
- OS: 20.70 months (Tiragolumab + Atezolizumab + Chemotherapy) vs. 33.58 months (Placebo + Pembrolizumab + Chemotherapy).
Results for participants with PD-L1 expression at TPS/TC >=50%:
- Investigator Assessed PFS: 11.76 months (Tiragolumab + Atezolizumab + Chemotherapy) vs. 14.09 months (Placebo + Pembrolizumab + Chemotherapy).
- OS: 23.79 months (Tiragolumab + Atezolizumab + Chemotherapy) vs. 33.58 months (Placebo + Pembrolizumab + Chemotherapy).
Key analyses were also conducted:
- One analysis, using a one-sided, inverse normal combination method, reported a Hazard Ratio (HR) of 1.27 (95.0% Confidence Interval: 1.02, 1.57) with a p-value of 0.9912.
- Another analysis, using a one-sided, inverse normal combination method, reported a Hazard Ratio (HR) of 1.33 (95.0% Confidence Interval: 1.02, 1.73) with a p-value of 0.9838.
- A Log Rank analysis reported a Hazard Ratio (HR) of 1.34 (95.0% Confidence Interval: 1.0, 1.79) with a p-value of 0.0488.
- Another Log Rank analysis reported a Hazard Ratio (HR) of 1.31 (95.0% Confidence Interval: 0.85, 2.01) with a p-value of 0.2228.
What this means
The results from this Phase 2/3 study indicate that the combination of tiragolumab and atezolizumab with chemotherapy did not demonstrate an improvement in efficacy compared to pembrolizumab with chemotherapy in previously untreated advanced non-squamous non-small cell lung cancer. Across all measured endpoints, including overall Progression-free Survival and Overall Survival, as well as in subgroups stratified by PD-L1 expression levels (TPS/TC >=1% and >=50%), the tiragolumab and atezolizumab regimen showed shorter median survival times. The reported Hazard Ratios and p-values also suggest that the experimental arm did not offer a benefit over the comparator arm. These findings suggest that this particular combination strategy may not be a viable treatment option for this patient population.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT04619797, titled "A Study of Tiragolumab in Combination With Atezolizumab Plus Pemetrexed and Carboplatin/Cisplatin Versus Pembrolizumab Plus Pemetrexed and Carboplatin/Cisplatin in Participants With Previously Untreated Advanced Non-Squamous Non-Small Cell Lung Cancer", were posted on 2026-06-03 on clinicaltrials.gov.