Durvalumab With Radiation Therapy in Patients With Inoperable Locally Advanced Non–Small Cell Lung Cancer Ineligible for Concurrent Chemoradiotherapy (DART)

PURPOSE: Concurrent platinum-based chemotherapy and radiation therapy (cCRT) followed by consolidative durvalumab is the standard of care (SoC) for fit patients with inoperable, locally advanced non-small cell lung cancer (LA-NSCLC). However, no SoC exists for patients who are cCRT-ineligible because of age, comorbidities, or frailty. Here, we investigated the efficacy and adverse events (AEs) of concurrent and consolidative durvalumab with definitive radiation therapy (RT) without chemotherapy. METHODS: In this multicenter, single-arm, prospective phase II study, patients received conventionally fractionated RT plus concurrent and consolidative durvalumab (1,500 mg fixed dose once every 4 weeks) for up to 12 months. The primary end point was 2-year progression-free survival (PFS) of 36% compared with historical results of 20% with sequential CRT (86% power). Additional end points included overall survival (OS) and cancer-specific survival (CSS). RESULTS: Fifty-eight patients (median age 82 years [IQR, 76-86]; 16 [28%] PD-L1-negative; eight [14%] Eastern Cooperative Oncology Group [ECOG] score 2; 46 [79%] ECOG score 1; four [7%] ECOG score 0) were treated per protocol. The study met its primary end point with a 2-year PFS of 39% (one-sided CI, 29 to 100) and a 2-year OS of 54%. Better performance status and PD-L1 positivity were associated with improved PFS; better ECOG was associated with improved OS; PD-L1 positivity was associated with better CSS. Grade 3/4 treatment-related AEs occurred in 12 (21%) patients. Grade 5 AEs occurred in four (7%) patients (radiation pneumonitis (n = 2) and cardiac arrest (n = 2)). Durvalumab was discontinued early because of AEs in 18 (31%) patients. CONCLUSION: Thoracic RT with concurrent and consolidative durvalumab is a promising treatment option for cCRT-ineligible patients with LA-NSCLC, demonstrating better PFS with a favorable safety profile compared with historical controls.