Liver injury is most commonly due to hepatic metastases rather than drug hepatotoxicity during pembrolizumab immunotherapy

Summary Background Pembrolizumab immunotherapy has been associated with hepatotoxicity in 1%‐10% of oncology patients treated in clinical trials. Aim To describe the incidence, phenotypes and outcomes of liver injury in a large cohort of solid organ tumour patients receiving pembrolizumab Methods Liver injury was defined by serum alanine aminotransferase, alkaline phosphatase, and/or total bilirubin levels exceeding threshold values. The likelihood of drug‐induced liver injury was adjudicated by expert opinion. Results Seventy (14.3%) of the 491 pembrolizumab‐treated patients developed liver injury at a median of 62 days (6‐478) and 71.4% had a cholestatic injury profile at onset. The median age, gender and tumour types of liver injury patients were similar to those without, but hepatic metastases (53% vs 21%, P