Incidence of Pneumonitis With Use of Programmed Death 1 and Programmed Death-Ligand 1 Inhibitors in Non-Small Cell Lung Cancer

BACKGROUND: Programmed death 1 (PD-1) programmed death-ligand 1 (PD-L1) inhibitors show significant clinical activity in non-small cell lung carcinoma (NSCLC). However, they are often associated with potentially fatal immune-mediated pneumonitis. Preliminary reports of trials suggest a difference in the rate of pneumonitis with PD-1 and PD-L1 inhibitors. We sought to determine the overall incidence of pneumonitis and differences according to type of inhibitors and prior chemotherapy use. METHODS: MEDLINE, Embase, and Scopus databases were searched up to November 2016. Rates of pneumonitis of any grade and grade >= 3 from all clinical trials investigating nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab as single agents in NSCLC were collected. The incidence of pneumonitis across trials was calculated using DerSimonian-Laird random effects models. We compared incidences between PD-1 and PD-L1 inhibitors and between treatment naive and previously treated patients. RESULTS: Nineteen trials (12 with PD-1 inhibitors [n = 3,232] and 7 with PD-L1 inhibitors [n = 1,806]) were identified. PD-1 inhibitors were found to have statistically significant higher incidence of any grade pneumonitis compared with PD-L1 inhibitors (3.6%; 95% CI, 2.4%4.9% vs 1.3%; 95% CI, 0.8%-1.9%, respectively; P =.001). PD-1 inhibitors were also associated with higher incidence of grade 3 or 4 pneumonitis (1.1%; 95% CI, 0.6%-1.7% vs 0.4%; 95% CI, 0%-0.8%; P =.02). Treatment naive patients had higher incidence of grade 1 through 4 pneumonitis compared with previously treated patients (4.3%; 95% CI, 2.4%-6.3% vs 2.8%; 95% CI, 1.7%-4%; P =.03). CONCLUSIONS: There was a higher incidence of pneumonitiswith use of PD-1 inhibitors compared with PD-L1 inhibitors. Higher rate of pneumonitis was more common in treatment naive patients.