Outcomes of immune checkpoint inhibitor‐induced liver toxicity managed by hepatologists in a multidisciplinary toxicity team

Aim To detect immune‐related adverse events (irAEs) early and treat them appropriately, our institute established an irAE‐focused multidisciplinary toxicity team in cooperation with various departments. This study aimed to evaluate a consultation system involving a team of hepatologists in terms of its utility for the management of severe immune checkpoint inhibitor (ICI)‐induced liver toxicity. Methods To analyze the diagnosis and treatment of severe ICI‐induced liver toxicity (Grade 2 requiring corticosteroid therapy and Grade 3 or higher), we examined patients' clinical courses before and after the hepatologist consultation system was established (pre‐period, September 2014 to February 2019; post‐period, March 2019 to March 2023). Results The median follow‐up period was 392 days. Of the 1247 patients with advanced malignancies treated with ICIs, 66 developed severe ICI‐induced liver toxicity (n = 22 and 44 in the pre‐ and post‐periods, respectively). In the pre‐period, hepatologist consultations were sought for 15/22 patients, whereas in the post‐period, 42/44 patients were referred to and treated by hepatologists. The time from the onset of liver toxicity to the consultation was significantly shorter in the post‐period than in the pre‐period (mean 1.9 vs. 6.5 days, respectively; p = 0.012). The number of patients with a biopsy‐confirmed diagnosis of ICI‐induced liver toxicity was significantly higher in the post‐period than in the pre‐period (n = 22 vs. n = 3, respectively; p = 0.006). Finally, there were no cases of immune‐related cholangitis in the pre‐period, compared to five cases in the post‐period. Conclusion A hepatologist consultation system in an irAE‐focused multidisciplinary toxicity team is useful for managing severe ICI‐induced liver toxicity. This study demonstrated a hepatologist consultation system in an immune‐related adverse events‐focused multidisciplinary toxicity team significantly increases the rate of consultation to hepatologists from the primary physician across the department and accelerates the improvement of liver toxicity. The evaluation of liver toxicity by a hepatologist can assist in identifying severe immune checkpoint inhibitor‐induced liver toxicity, such as immune‐related cholangitis, and in establishing appropriate treatment strategies.