Phase II Study of Durvalumab Immediately after Completion of Chemoradiotherapy in Unresectable Stage III Non-small Cell Lung Cancer: TORG1937 (DATE Study).

Purpose: Concurrent chemoradiotherapy (CCRT) followed by durvalumab consolidation for up to 12 months is the standard of care for patients with unresectable stage III non-small cell lung cancer (NSCLC). However, exactly when to initiate durvalumab therapy after chemoradiation completion remains unknown. We evaluated the efficacy and safety of durvalumab, administered immediately after CCRT completion, for patients with unresectable stage III NSCLC.

Patients And Methods: This study was a prospective, single-arm, open-label phase II clinical trial. Patients without disease progression after definitive CCRT (two cycles of platinum-based doublet chemotherapy with 60 Gy/30 Fr radiotherapy) received durvalumab (every 2 weeks for up to 12 months) from the next day (up to 5 days) after the final radiation dose. The primary endpoint was the 1-year progression-free survival (PFS) from registration before the start of CCRT.

Results: From January 2020 to August 2020, 47 of 50 enrolled patients were evaluable for treatment efficacy and safety. The 1-year PFS from registration was 75.0% [60% confidence interval (CI), 69.0-80.0 and 95% CI, 59.4-85.3]. The objective response rate throughout the study treatment and median PFS from registration were 78.7% and 14.2 months (95% CI, 13.4 to not reached), respectively. Grade 3/4 pneumonitis and febrile neutropenia were each 4.3%.

Conclusions: Our study met the primary endpoint. The incidence of pneumonitis was similar to that of a Japanese subset in the PACIFIC study. Our data support the efficacy and safety of durvalumab administered immediately after the completion of CCRT for patients with unresectable stage III NSCLC.