P2.04-79 High Rate of Immune Related Pneumonitis in Lung Cancer Patients Treated with Anti PD-1 Antibodies

Treatment with anti PD-1/PD-L1 antibodies has demonstrated survival improvement in several malignancies, including non small cell lung cancer (NSCLC), but these therapies are not exempt from risks. Meta-analysis and clinical trials have reported immune related (ir) pneumonitis of any grade in 3-5% of patients treated with anti PD-1/PD-L1 antibodies, including grade 3 or higher in 0.8% to 1.8% of patients. We have retrospectively reviewed clinical reports from 125 cancer patients treated at our center with anti PD-1/PD-L1 antibodies (55 were treated with nivolumab, 27 with pembrolizumab, 33 with atezolizumab, 6 with avelumab, and 4 with durvalumab) from January 2016 to January 2019. Nineteen patients (15.2%) developed ir pneumonitis. Four (21%) patients had recurrent pneumonitis during tapering corticoesteroid dose after an initial improvement and finally died. Patient characteristics are summarized in Table 1. Median time to pneumonitis was 4 months (m) (range 1m to 9m). Twelve patients (9.6% %) had grade 3-5 and 7 patients (5.6 %) grade 1-2 pneumonitis. Nine (7.2 %) patients died from ir pneumonitis, including 4 patients with no tumor progression (1 had received only one cycle, and 3 patients had ongoing tumor response at 10m+, 12m+ and 30m+). Ir pneumonitis was more frequent with nivolumab (any grade 21.8 %, grade 3 or higher 18.2 %, including 7 fatal cases-12.7%-), while no patient treated with atezolizumab developed pneumonitis (Table 2).Table 1Total19Gender Women, n (%)7 (36,8%)Age Median (range)63,4 (51-82)Cancer type, n (rate) NSCLC Adenoca NSCLC Squamous SCLC Mesothelioma13 (68,4 %) 4 (21%) 1 (5,3%) 1 (5,3%)Line of therapy, n (rate) Adjuvant First line Second or further line1 (5,2 %) 8 (42,1%) 10 (52,6%)Tumor Response, n (rate) CR PR SD PD NE2 (10,5%) 8 (42,1%) 5 (26,3%) 3 (15,8%) 1 (5,2%) Open table in a new tab Table 2Drug,n patients treatedAny Grade, n (%)Grade 3-5, n (%)Grade 5, n (%)Nivolumab, 5512 (21,8%)10 (18,2%)7 (12,7%)Pembrolizumab, 273 (11,1%)1 (3,7%)1 (3,7%)Atezolizumab, 33000Durvalumab, 42 (50%)00Avelumab, 62 (33,3%)1 (16,7%)1 (16,7%)Total, 12519 (15,2%)12 (9,6%)9 (7,2%) Open table in a new tab In our experience, ir pneumonitis rate with anti PD-1/PD-L1 antibodies in lung cancer patients was 15.2%, including 7.2% of fatal complications. It suggests that previous clinical trials could have under diagnosed this serious complication. Further studies must be performed in order to specifically assess the rate of pneumonitis in patients treated with anti PD-1 and anti PD-L1 antibodies in lung cancer patients.