Immune-related adverse events in cancer patients treated with immune checkpoint inhibitors: A single-center experience.

Immune checkpoint inhibitors (ICIs) like cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4) and programmed death cell protein 1 (anti-PD1) have revolutionized cancer treatment. As ICI use becomes widespread, more immune-related adverse events (irAE's) are being reported. Our aim was to investigate the frequency and nature of new irAE's as well as report the frequency of flare-ups of pre-existing autoimmune conditions occurring after ICI therapy.We performed a retrospective chart review of all patients treated for cancer with anti-PD1 or anti-CTLA4 or combination therapy at our tertiary care center from January 2014 to April 2016. Demographic data, cancer type and stage, irAE's (new immune disorders and disease flares of pre-existing autoimmune disorders on ICI therapy), and drug treatment information were extracted.We identified 220 patients treated with ICI therapy during the study period out of which 27% (60/220) developed irAE's. 11% in anti-CTLA4 group and 16% among anti-PD1 treated patients developed irAE's. IrAE's resulted in discontinuation of cancer therapy in 28% of those who developed irAE's. 21.4% had a flare of their autoimmune disease but only 1 required discontinuation of immunotherapy.IrAE's are an important emerging clinical disease entity for specialists to be aware of. Our study shows that ICI's can be safely used in patients with pre-existing autoimmune conditions with close monitoring. However, there is still a large unmet need to have a better understanding of how to systematically evaluate and manage patients with irAE's as well as for identifying the predictors of irAE's.