SAKK 19/17: safety analysis of first-line durvalumab in patients with PD-L1 positive, advanced nonsmall cell lung cancer and a performance status of 2.

INTRODUCTION: The safety of first-line (1L) durvalumab in patients with advanced nonsmall-cell lung cancer (NSCLC) and an Eastern Cooperative Oncology Group (ECOG) performance status of 2 (PS2) is unknown. This is an interim unplanned safety analysis of the study SAKK 19/17 for patients with metastatic NSCLC with programmed death-ligand 1 (PD-L1) expression in ≥ 25% of tumor cells and an ECOG PS2 treated with 1L durvalumab. This safety analysis was triggered by the SAKK data and safety monitoring board due to a high mortality rate observed after the recruitment of the first 21 patients.
METHODS: This single-arm phase II study recruited patients with metastatic NSCLC with PD-L1 in ≥ 25% and ECOG PS2. Patients received durvalumab 1500 mg every four weeks. The trial aims to recruit 48 patients in total. This report includes safety analyses only. Adverse events (AEs) were assessed using National Cancer Institute Common Terminology Criteria for AEs (NCI CTCAE) Version 5.0. Efficacy data including the primary endpoint overall survival at 6 months and secondary endpoints (objective response rate, progression-free survival, and quality of life) will be reported at a later time point.
RESULTS: The data from 21 patients were available at this interim safety analysis. Among these, 13 deaths (13/21; 62%) were reported, including one treatment-related fatal colonic perforation at 9 months after treatment initiation (1/13; 8%). Twelve deaths were not treatment-related (12/13; 92%), and mostly attributed to tumor progression (10/13; 77%). Of note, seven deaths (7/13; 54%) occurred during the first 5 weeks (range 0.6-4.7 weeks) after treatment initiation. Four (4/7; 57%) were respiratory failures attributed to tumor progression. One of these patients (25%) had pre-existing COPD, and three (75%) had baseline dyspnea grade 2-3 related to the tumor. Grade ≥ 3 treatment-related AEs (TRAEs) included colonic perforation (grade 5), abdominal pain, and colitis (grade 3 each) in one patient, and fatigue (grade 3) in another. Other Grade ≥ 3 AEs unrelated to treatment were all of pulmonary origin: lung infections (19%), dyspnea (24%), cough (5%), and bronchial obstruction (5%).
CONCLUSIONS: 1L durvalumab in patients with ECOG PS2 and metastatic NSCLC with PD-L1 expression ≥ 25% resulted in an unexpectedly high number of fatal early events due to rapid tumor progression. We recommend to avoid treatment with 1 L durvalumab of patients who are highly symptomatic from the tumor, particularly those with respiratory symptoms. The study is continuing its accrual after an amendment excluding these patients.