Pneumonitis in non-small cell lung cancer (NSCLC) patients treated with programmed death 1 (PD1) axis inhibitors.

9030Background: Pneumonitis (P) has been reported in up to 6% of patients (pts) with advanced NSCLC receiving anti- PD1 or PD ligand 1 (PDL1) antibodies (Ab), with potential for fatality if not recognized and treated expeditiously. Methods: Pts with advanced NSCLC who developed P while receiving an anti- PD1 or PDL1 Ab on clinical trial were identified. Serial imaging studies/ pathology were reviewed with a thoracic radiologist/ pathologist. Results: 24 pts were identified with P, 21 with bronchoscopic sampling. 16 pts received anti-PD1, 2 anti-PDL1, 1 anti-PDL1 + chemotherapy, and 5 anti-PD1 or anti-PDL1 + anti-CTLA4 Ab; objective response rate (RECIST) was 50%. Median age, 75 years (range, 47-89); female/ male, 9/ 15; squamous/ non-squamous histology, 6/ 18; never smoker/ smoker, 3/ 21. All pts were Caucasian. Median onset of P was 75 days (range, 8-549). 19 pts were treated with steroids; P resolved to grade 1 or 0 in all cases. 6 pts were re-challenged with anti- PD1/ PDL1 after steroid taper, 4 devel...