389P - Risk factors of nivolumab-induced pneumonitis in patients with solid tumors

Abstract

Background: Nivolumab is an anti-programmed death 1 (PD-1) monoclonal antibody, which has demonstrated antitumor efficacy in clinical trials of various malignant tumors. Pneumonitis is a common adverse event in patients treated with nivolumab. However, the difference of the frequency and severity of nivolumab-induced pneumonitis across different tumor types is not clear. Methods: We retrospectively reviewed 311 patients who were diagnosed as non-small cell lung cancer (NSCLC), head and neck cancer (HNC), or gastric cancer (GC), and treated with nivolumab at Aichi Cancer Center Hospital, Japan, between December, 2015 and April, 2018. Patients who underwent chest computed tomography (CT) right before starting of nivolumab and have not received chemotherapy after the last chest CT were included in the analysis. Patients who previously received thoracic radiotherapy were excluded from the analysis. Pulmonary fibrosis score (scores 0–5) on baseline chest CT was assessed by two independent radiologists. Results: 196 patients were included in the analysis, and 96 patients were NSCLC, 50 patients were HNC, and 50 patients were GC, respectively. Pulmonary fibrosis score ≥1 was found in 27.1% in NSCLC, 10.0% in HNC, and 12.0% in GC (p = 0.02). Twenty-two patients (11.2%) experienced nivolumab-induced pneumonitis, of which three (1.5%) were grade ≥3. The median onset time of pneumonitis after starting nivolumab was 61 days (range, 2–634 days). According to the analysis of tumor types, the rates of pneumonitis were 14.6% in NSCLC, 10.0% in HNC, and 6.0% in GC, respectively. There were no significant differences in the incidences of pneumonitis between three tumor types. Univariate and multivariate logistic regression analysis revealed that male and pulmonary fibrosis score ≥1 significantly increased the risk of developing nivolumab-induced pneumonitis. Conclusions: Pulmonary fibrosis was found more frequently in NSCLC than HNC and GC. Our results indicated that male and pulmonary fibrosis are the risk factors for nivolumab-induced pneumonitis. Legal entity responsible for the study: Toyoaki Hida. Funding: Has not received any funding. Disclosure: K. Muro: Research grants: Ono Pharmaceutical. T. Hida: Research grants: Ono Pharmaceutical, Chugai Pharmaceutical, AstraZeneca, Pfizer, Bristol-Meyers Squibb, MSD. All other authors have declared no conflicts of interest.