Correlation between dysthyroidism and efficacy in patients treated with anti PD-1 or anti PDL-1 agents.

67Background: Immune checkpoints inhibitors have clearly improved patients’outcomes in different tumors, but definitive predictive biomarkers are still missing. Since thyroiditis have been reported, we have evaluated whether clinical responses are more frequent in patients who underwent anti PD-1 or anti PDL-1 agents and experienced dysthyroidism. Methods: We retrospectively evaluated 135 metastatic solid tumor patients, treated at our Institute with anti PD-1/PDL-1 antibodies since 2013. Thyroid toxicity was defined according to CTCAE version 4.0 and disease control (DC: CR+PR+SD) was chosen as efficacy endpoint. Correlation between dysthyroidism and DC rate was assessed by Fisher’s exact test. Results: Of 135 patients, 76 (56.3%) were treated by anti PD-1 and 59 (43.7%) by anti PDL-1 agents. Population was heterogeneous, including patients from the 1st to the 9th line of therapy, affected by the following cancers: 57 (42.2%) NSCLC, 18 (13.3%) melanoma, 13 (9.6%) RCC, 7 (5.2%) bladder and urothelial, 6 (...