An algorithm based on immunotherapy discontinuation and liver biopsy spares corticosteroids in two thirds of cases of severe checkpoint inhibitor-induced liver injury

Immune-mediated liver injury from checkpoint inhibitors: mechanisms, clinical characteristics and management

Immunotherapy has changed the treatment landscape for patients with cancer in the past decade. Immune checkpoint inhibitor (ICI)-based therapies have proven effective in a range of malignancies, including liver and gastrointestinal cancers, but they can cause diverse off-target organ toxicities. With the increasingly wider application of these drugs, immune-mediated liver injury from ICIs has become a commonly encountered challenge in clinical hepatology and gastroenterology. In this Review, we discuss the evidence from human and animal studies on the immunological mechanisms of immune-mediated liver injury from ICIs and summarize its clinical features and practical considerations for its management.

Immune checkpoint inhibitors and the liver: balancing therapeutic benefit and adverse events

Immune checkpoint inhibitors (ICI) have led to breakthrough improvements in the management of malignancy including hepatocellular (HCC) and biliary tract cancer, improving decades-old standards of care and increasing patient survival. In both liver tumour types, which commonly arise in the context of liver inflammation and underlying functional impairment, the lack of validated predictors of response underscores the need to balance predicted gains in survival with risk of treatment-related hepatoxicity and decompensation of underlying chronic liver disease.In addition, the liver is implicated in the toxicity associated with ICI therapy for non-liver cancers, which exhibits a high degree of variability in presentation and severity. An accurate assessment is mandatory for the diagnosis and management of ICI-induced liver injury.In this Recent Advances article, we provide an overview of the mechanisms of efficacy and toxicity of anticancer immunotherapy in liver tumours and liver toxicity in extrahepatic malignancies.We compare and contrast characteristics, management strategies and outcomes from immune-related liver injury in patients with chronic hepatitis/cirrhosis or with an underlying healthy liver and discuss the latest findings on how toxicity and decompensation may impact the outlook of patients with liver tumours and extrahepatic malignancies offering insights into the future directions of clinical research and practice in the field.

Time to use the right classification to predict the severity of checkpoint inhibitor-induced liver injury, as assessed for causality using the updated RUCAM

BACKGROUND AND AIMS

While immune checkpoint inhibitors (ICIs) are revolutionising cancer therapy, checkpoint inhibitor-induced liver injury is a significant immune-related side effect of this immunotherapy. This study focuses on the severity classifications and characteristics of patients with checkpoint inhibitor-induced hepatitis.

METHODS

A retrospective analysis of patients with severe Checkpoint Inhibitor-induced hepatitis grade 3 and 4 according to the recommended Common Terminology Criteria for Adverse Events (CTCAE) classification was conducted. Data on clinicobiological characteristics, treatment and outcomes were collected from 3 university hospitals, and causality was assessed by using the updated Roussel Uclaf Causality Assessment Method. The severity of hepatitis was assessed using the Model for End-stage Liver Disease score, the Drug-Induced Liver Injury Network, and the Drug-Induced Liver Injury International Expert Working Group classifications.

RESULTS

We retrospectively included 100 patients presenting various hepatitis patterns with a median time to onset of 20 days after checkpoint inhibitors. Severity grading varied significantly among the classifications used. A lower incidence of severe cases was observed when using the Drug-Induced Liver Injury classifications instead of the recommended CCTCAE classification, and this was correlated with outcomes.

CONCLUSIONS

This retrospective study challenges the efficacy of the CTCAE classification in defining the severity of Checkpoint Inhibitor-induced hepatitis and suggests that the traditional hepatology-focused scores may be more relevant. The CTCAE classification is inconsistent and gives equal weight to jaundice and elevated transaminases, which leads to steroid overtreatment and limits the rechallenge of ICIs.

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.

Hepatobiliary complications of immune checkpoint inhibitors in cancer

Immune checkpoint inhibitors (ICIs) have dramatically changed the landscape of cancer therapy. Over the last decade, both their primary focus in trials and clinical application have exponentially risen, with repeated demonstrations of their efficacy in improving survival in various cancer types. The adverse effects of these drugs on various organ systems were recognised in early phase studies. Given their relatively new emergence on the market, there has been increasing interest into short- and long-term effects and management of ICIs in real-world settings. ICI-related hepatobiliary toxicities are often challenging to diagnose and difficult to distinguish from other causes of deranged liver biochemical tests. The aim of this review is to provide an up-to-date and detailed exploration of the hepatobiliary complications of ICIs, including pathogenesis and approaches to diagnosis and management.

Therapeutic inhibition of monocyte recruitment prevents checkpoint inhibitor-induced hepatitis

BACKGROUND

Checkpoint inhibitor-induced hepatitis (CPI-hepatitis) is an emerging problem with the widening use of CPIs in cancer immunotherapy. Here, we developed a mouse model to characterize the mechanism of CPI-hepatitis and to therapeutically target key pathways driving this pathology.

METHODS

C57BL/6 wild-type (WT) mice were dosed with toll-like receptor (TLR)9 agonist (TLR9-L) for hepatic priming combined with anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) plus anti-programmed cell death 1 (PD-1) ("CPI") or phosphate buffered saline (PBS) control for up to 7 days. Flow cytometry, histology/immunofluorescence and messenger RNA sequencing were used to characterize liver myeloid/lymphoid subsets and inflammation. Hepatocyte damage was assessed by plasma alanine transaminase (ALT) and cytokeratin-18 (CK-18) measurements. In vivo investigations of CPI-hepatitis were carried out in Rag2-/- and Ccr2rfp/rfp transgenic mice, as well as following anti-CD4, anti-CD8 or cenicriviroc (CVC; CCR2/CCR5 antagonist) treatment.

RESULTS

Co-administration of combination CPIs with TLR9-L induced liver pathology closely resembling human disease, with increased infiltration and clustering of granzyme B+perforin+CD8+ T cells and CCR2+ monocytes, 7 days post treatment. This was accompanied by apoptotic hepatocytes surrounding these clusters and elevated ALT and CK-18 plasma levels. Liver RNA sequencing identified key signaling pathways (JAK-STAT, NF-ΚB) and cytokine/chemokine networks (Ifnγ, Cxcl9, Ccl2/Ccr2) as drivers of CPI-hepatitis. Using this model, we show that CD8+ T cells mediate hepatocyte damage in experimental CPI-hepatitis. However, their liver recruitment, clustering, and cytotoxic activity is dependent on the presence of CCR2+ monocytes. The absence of hepatic monocyte recruitment in Ccr2rfp/rfp mice and CCR2 inhibition by CVC treatment in WT mice was able to prevent the development and reverse established experimental CPI-hepatitis.

CONCLUSION

This newly established mouse model provides a platform for in vivo mechanistic studies of CPI-hepatitis. Using this model, we demonstrate the central role of liver infiltrating CCR2+ monocyte interaction with tissue-destructive CD8+ T cells in the pathogenesis of CPI-hepatitis and highlight CCR2 inhibition as a novel therapeutic target.

Editorial: Corticosteroids for severe checkpoint inhibitor-induced liver injury-Not one size fits all?

This article is linked to Riveiro‐Barciela et al paper. To view this article, visit https://doi.org/10.1111/apt.17898