Patterns and Incidence of Pneumonitis and Initial Treatment Outcomes with Durvalumab Consolidation Therapy after Radical Chemoradiotherapy for Stage III Non-Small Cell Lung Cancer

Durvalumab consolidation after chemoradiotherapy for stage III non-small cell lung cancer (NSCLC) has become the standard of care. Single-center results were examined for treatment outcomes and patterns of pneumonitis in clinical practice. Patients with stage III NSCLC who underwent chemoradiotherapy at our institution (n = 150) were included. The patients were treated with chemoradiotherapy and durvalumab consolidation (Group D, n = 69) or chemoradiotherapy alone (Group N, n = 81). The overall survival (OS), progression-free survival (PFS), and the incidence of and risk factors for 12-month pneumonitis grade ≥ 2 (G2) were investigated. Two-year OS rates were 71.6% in Group D and 52.7% in Group N (p = 0.052). Two-year PFS rates were 43.0% in Group D and 26.5% in Group N (p = 0.010), although a propensity score matched analysis showed no significant difference. The incidence of 12-month pneumonitis ≥ G2 tended to be higher in Group D than in Group N (41.9% vs. 26.3%, p = 0.080). However, there was no difference in pneumonitis ≥ G3 rates (10.5% vs. 12.6%, p = 0.657). A multivariate analysis showed that the lung volume spared from 5 Gy (VS5) < 1800 cm3 was a risk factor for pneumonitis ≥ G2 in Group D. Durvalumab consolidation showed the potential to prolong PFS without increasing the severity of pneumonitis.