Introduction: The safety and efficacy of first-line durvalumab in PS2 patients with advanced NSCLC is unknown. Here, we present the primary analysis of first-line durvalumab in PS2 patients, unsuitable for combination chemotherapy.

Methods: In this single-arm, multicenter, phase II trial patients with PD-L1 positive (tumor proportional score ≥25%), advanced NSCLC with PS2, received four-weekly durvalumab 1500 mg. The primary endpoint was overall survival (OS) at 6 months.

Results: Forty-eight patients were included. Median follow-up was 23.3 months (95% CI: 14.3-28.6). OS at 6 months was 60% (95% CI: 45-74%). Median OS was 8.5 months (95%CI: 4.4-16.7). Objective response rate and median progression free survival were 17% (95% CI: 8-30%) and 2.5 months (95% CI: 1.8-7.1), respectively. Thirty-three deaths were observed at the time point of the analysis. Seven early fatal events considered not treatment-related occurred during the first 5 weeks of treatment. Four out of the first 7 early fatal events (4/7; 57%) were respiratory failure in patients with advanced symptomatic primary lung tumors. Three more early fatal events occurred after exclusion of patients with grade ≥ 3 dyspnea. Treatment-related AEs ≥G3 were reported in 9 patients (19%) and included colonic perforation in one patient (grade 5), colitis in 4 patients (8%), increased lipase in 3 patients (6%), and hepatitis in 2 patients (4%).

Conclusions: First-line durvalumab in PS2 patients with advanced PD-L1 positive NSCLC results in a high number of early fatal events. When patients with grade ≥ 3 dyspnea are excluded a promising 6-month OS with an acceptable toxicity profile can be observed. Durvalumab could be an option instead of single agent chemotherapy for PS2 patients who are not candidates for platinum doublet chemotherapy provided they are well selected.