Cancer-related overall survival for patients on durvalumab for stage III unresectable non–small cell lung cancer with PD-L1 positive and negative tumors.

Abstract

8026 Background: Durvalumab improves overall survival (OS) and progression free survival (PFS) when used as consolidation therapy for patients with stage III unresectable non-small cell lung cancer (UR-NSCLC) following chemoradiotherapy (CRT). However, it is uncertain if similar benefits are achieved for patients with PD-L1 positive (1% or greater) and negative (<1%) tumors. We previously found no difference in OS, but no study has yet compared cancer-related overall survival (OS). Methods: Patients with stage III UR-NSCLC on durvalumab following CRT, at any Veterans Health Administration (VHA) facility, from 1/1/17 to 6/30/20, were included. Patients were followed from durvalumab initiation through the earliest of their last VHA visit, loss to follow up, death, or end of study (6/30/25). Electronic health record data were retrospectively collected to determine durvalumab treatment course, OS, and cancer-related OS—as determined by review of each patient’s chart and death certificate. Kaplan-Meier and Cox regression methods were used to compare cancer-related OS. Results: Of the 340 eligible patients, 221 (65%) had PD-L1 positive and 119 (35%) had PD-L1 negative tumors. Groups were similar in age, sex assigned at birth, White race, smoking status, marital status, Charlson score, ECOG 1+ status (78% overall), histology, stage, EGFR, and RAS mutations. Patients with PD-L1 positive and negative tumors had similar median (interquartile range [IQR]) number of durvalumab doses (15 [6-24] vs 13 [5-24], p=0.55), months of durvalumab (8 [3-12] vs 6 [2-12]), and months of follow-up (33 [12-69] vs 28 [11-63], p=0.22). OS was similar for patients with PD-L1 positive and negative tumors in a multivariate model accounting for ECOG 1+ status (HR 0.93, 95% CI 0.70-1.24). Likewise, cancer-related OS was similar in the multivariate model (HR 0.87, 95% CI 0.63-1.21). Median OS was 33.3 months (95% CI 29.8-47.3) for patients with PD-L1 positive tumors and 28.5 months (95% CI 21.6-39.7) for patients with PD-L1 negative tumors. Likewise, median cancer-related OS was 20.4 months (95% CI 16.0-25.4) for patients with PD-L1 positive tumors and 20.6 months (95% CI 15.4-28.5) for patients with PD-L1 negative tumors. The table depicts common causes of death. Conclusions: In this real-world study of VHA patients on durvalumab for stage III UR-NSCLC, OS and cancer-related OS were similar for those with PD-L1 positive and negative tumors. Cause of death. Cause of death PDL1+, n=221 PDL1-, n=119 P-value Disease progression 84% 77% 0.19 Bleeding event 4% 3% 0.75 Cardiac event 14% 14% 1.00 Infection/sepsis 19% 6% 0.01 Intracranial embolism/hemorrhage 2% 3% 0.67 Multiorgan failure 1% 2% 0.56 Thromboembolic event 2% 0% 0.30 Unknown 3% 4% 0.73 Other 9% 19% 0.03