1103P Drug-related pneumonitis induced by osimertinib as first-line treatment for EGFR-positive non-small cell lung cancer: A real-world setting

Abstract

Osimertinib has demonstrated impressive efficacy as a first-line treatment for patients with advanced epidermal growth factor receptor (EGFR) mutation-positive (m+) lung cancer. Drug-related pneumonitis (DRP) is a potentially lethal complication of osimertinib treatment, but reliable real-world data are currently lacking. We conducted a retrospective multicenter cohort study of patients who received osimertinib as a first-line treatment for advanced EGFR m+ non-small cell lung cancer (NSCLC) between August 2018 and December 2019. All chest computed tomography (CT) scans and clinical information during osimertinib exposure were collected until June 2020. The primary endpoint was DRP incidence identified through central review. A total of 452 patients from 18 institutions were evaluated. Eighty patients (18%) were diagnosed with DRP (all grades), and 21 patients (4.6%) had ≥grade 3 DRP. Among the patients with DRP, 46% were identified as having transient asymptomatic pulmonary opacity (TAPO). Regarding the CT patterns, organizing pneumonia, simple pulmonary eosinophilia, hypersensitivity pneumonia, diffuse alveolar damage, and non-specific interstitial pneumonia were found in 30, 21, 18, 9, and 2 patients (38%, 26%, 23%, 11%, and 3%), respectively. In multivariate analysis, smoking history was identified as an independent risk factor for DRP (hazard ratio: 1.72, 95% confidence interval: 1.01–2.89, P=0.046). In the 3-month landmark analysis, DRP was associated with poor treatment efficacy; however, the presence of TAPO did not negatively affect treatment efficacy. For osimertinib treatment in first-line settings, the frequency of DRP was considerably elevated to 18 %, and half of these patients exhibited TAPO features.