Trial results for a Phase 3 study evaluating atezolizumab in combination with tiragolumab compared to durvalumab for locally advanced, unresectable Stage III non-small cell lung cancer (NSCLC) were posted on ClinicalTrials.gov on 2026-06-03. The study found no statistically significant difference in overall survival between the two treatment arms, with a Hazard Ratio of 0.99 (95% CI: 0.73-1.34; p=0.9601).
Background
The study investigated atezolizumab in combination with tiragolumab, compared to durvalumab, for participants with locally advanced, unresectable Stage III non-small cell lung cancer (NSCLC). Participants had received at least two cycles of concurrent platinum-based chemoradiotherapy (CRT) and had not experienced radiographic disease progression.
Trial design
The Phase 3 study (NCT04513925) enrolled 829 participants with locally advanced, unresectable Stage III non-small cell lung cancer (NSCLC). The trial's purpose was to evaluate the efficacy and safety of atezolizumab in combination with tiragolumab compared with durvalumab. Participants had previously received at least two cycles of concurrent platinum-based chemoradiotherapy (CRT) and had no radiographic disease progression. Specific primary outcomes were not detailed in the posted results.
Key results
The trial reported the following key efficacy measurements:
- Overall Survival (OS):
- Median OS for the durvalumab arm was 54.83 months.
- Median OS for the atezolizumab + tiragolumab arm was NA months.
- The hazard ratio for OS was 0.99 (95% CI: 0.73-1.34), with a p-value of 0.9601.
- Progression-Free Survival (PFS), as assessed by the investigator:
- Median PFS for the durvalumab arm was 18.53 months.
- Median PFS for the atezolizumab + tiragolumab arm was 19.35 months.
- The hazard ratio for PFS was 0.89 (95% CI: 0.7-1.14), with a p-value of 0.3542.
- Confirmed Objective Response Rate (ORR), as assessed by an Independent Review Facility (IRF):
- The ORR for the durvalumab arm was 47.5 percentage of participants.
- The ORR for the atezolizumab + tiragolumab arm was 45.5 percentage of participants.
- The difference in ORR was -2.08 (95% CI: -12.57-8.47), with a p-value of 0.6387.
- Confirmed Objective Response Rate (ORR), as assessed by the investigator:
- The ORR for the durvalumab arm was 37.2 percentage of participants.
- The ORR for the atezolizumab + tiragolumab arm was 37.0 percentage of participants.
- The difference in ORR was -0.22 (95% CI: -9.9-9.49), with a p-value of 0.9545.
- Duration of Response (DOR), as assessed by an IRF:
- Median DOR for the durvalumab arm was 28.09 months.
- Median DOR for the atezolizumab + tiragolumab arm was 43.63 months.
- The hazard ratio for DOR was 1.14 (95% CI: 0.8-1.63), with a p-value of 0.4647.
- Duration of Response (DOR), as assessed by the investigator:
- Median DOR for the durvalumab arm was 30.16 months.
- Median DOR for the atezolizumab + tiragolumab arm was 36.17 months.
- The hazard ratio for DOR was 1.07 (95% CI: 0.82-1.4), with a p-value of 0.6343.
What this means
The results of this Phase 3 study indicate that the combination of atezolizumab and tiragolumab did not demonstrate a statistically significant improvement in overall survival (OS), progression-free survival (PFS), or objective response rate (ORR) when compared to durvalumab in participants with locally advanced, unresectable Stage III NSCLC who had received prior chemoradiotherapy. While the median duration of response (DOR) was numerically higher in the atezolizumab + tiragolumab arm compared to the durvalumab arm, this difference was not statistically significant. Clinicians should consider these findings when evaluating treatment strategies for this specific patient population, noting the lack of a clear efficacy advantage for the combination therapy in the measured endpoints.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT04513925, titled 'A Study of Atezolizumab and Tiragolumab Compared With Durvalumab in Participants With Locally Advanced, Unresectable Stage III Non-Small Cell Lung Cancer (NSCLC)', were posted on 2026-06-03 on clinicaltrials.gov.