Optimal Duration of Consolidation Durvalumab Following Chemoradiotherapy in Stage III Non-Small Cell Lung Cancer: A Multi-institutional Retrospective Study.

Background: Although durvalumab has shown promise in improving survival rates in patients with locally advanced non-small cell lung cancer (NSCLC), the ideal duration of treatment has yet to be established.

Objective: The primary objective of this study was to determine the optimal number of durvalumab cycles following definitive chemoradiotherapy for locally advanced NSCLC.

Patients and methods: A total of 178 patients who received chemoradiotherapy for stage III NSCLC at 15 institutions were retrospectively analyzed. Progression-free survival (PFS) and overall survival (OS) were assessed according to the number of consolidation durvalumab cycles by landmark analysis. Landmark analyses were performed at 3-month intervals from the start of durvalumab treatment to 9 months.

Results: The median number of durvalumab cycles was 16 (range 1-27). PFS and OS were significantly better in patients who received ≥20 cycles of durvalumab than in those who did not (p < 0.001 and p < 0.001, respectively). In landmark analysis, significant differences were observed in PFS from 0 to 6 months and OS from 3 to 6 months between patients who continued durvalumab after the time point and those who did not. However, there were no significant differences in PFS or OS between patients who received 13-19 or ≥20 cycles of durvalumab at 9 months.

Conclusions: Durvalumab should be administered for more than 6 months to contribute to the main benefits of consolidation therapy following chemoradiotherapy.