Neoadjuvant durvalumab for resectable non-small-cell lung cancer (NSCLC): results from a multicenter study (IFCT-1601 IONESCO)

Background: The IONESCO (IFCT-1601) trial assessed the feasibility of neoadjuvant durvalumab, for early-stage resectable non-small-cell lung cancer (NSCLC).

Methods: In a multicenter, single-arm, phase II trial, patients with IB (≥4 cm)-IIIA, non-N2, resectable NSCLC received three doses of durvalumab (750 mg every 2 weeks) and underwent surgery between 2 and 14 days after the last infusion. The primary endpoint was the complete surgical resection rate. Secondary endpoints included tumor response rate, major histopathological response (MPR: ≤10% remaining viable tumor cells), disease-free survival (DFS), overall survival (OS), durvalumab-related safety, and 90-day postoperative mortality (NCT03030131).

Results: Forty-six patients were eligible (median age 60.9 years); 67% were male, 98% were smokers, and 41% had squamous cell carcinoma. Regarding tumor response, 9% had a partial response, 78% had stable disease, and 13% had progressive disease. Among the operated patients (n=43), 41 achieved complete resection (89%, 95% CI 80.1% to 98.1%)), and eight achieved MPR (19%). The 12-month median OS and DFS rates were 89% (95% CI 75.8% to 95.3%) and 78% (95% CI 63.4% to 87.7%), respectively (n=46). The median follow-up was 28.4 months (12.8-41.1). All patients in whom MPR was achieved were disease-free at 12 months compared to only 11% of those with >10% residual tumor cells (p=0.04). No durvalumab-related serious or grade 3-5 events were reported. The unexpected 90-day postoperative mortality of four patients led to premature study termination. None of these four deaths was considered secondary to direct durvalumab-related toxicity.

Conclusions: Neoadjuvant durvalumab given as monotherapy was associated with an 89% complete resection rate and an MPR of 19%. Despite an unexpectedly high rate of postoperative deaths, which prevented us from completing the trial, we were able to show a significant association between MPR and DFS.