Outcomes of immunotherapy-related hepatotoxicity from a multi-disciplinary toxicity team

Background Despite the efficacy of immune checkpoint inhibitors (ICIs), adverse events including hepatotoxicity limit their ongoing use. We investigated the outcomes and management of patients with immune-mediated hepatitis (IMH) and clinical predictors of toxicity resolution. Methods Patients referred to our multidisciplinary immunotherapy-related toxicity group from August 2017 to December 2020 for IMH were evaluated. Toxicity was defined according to CTCAEv4.0. IMH resolution was defined as liver enzyme normalization after steroid initiation. Results Thirty-three patients were included in the study, 62% female, and 71% Caucasian. The most common ICI used was PD-1/PD-L1 (76%). Peak IMH occurred at a median of 89 [45,193] days, for which most patients received 1-2 mg/kg/day prednisone equivalent with 35% requiring MMF. Median follow-up was 123 [33,472] days with IMH resolution seen in 48% of patients at a median of 111 [41,214] days. While high-dose steroid use was not associated with IMH resolution, liver enzyme improvement one week after steroids predicted resolution in univariate analysis (p = 0.041). All 11 patients without IMH resolution died from cancer progression or complications with three patients having acute liver failure. Available liver biopsies showed bile duct injury, with varying degrees of portal and lobular inflammation. Conclusion IMH improvement one week after steroid initiation may predict ultimate IMH resolution.