Retreatment With Immune Checkpoint Inhibitors After a Severe Immune-Related Hepatitis: Results From a Prospective Multicenter Study

Immune-Mediated Liver Injury From Checkpoint Inhibitor: An Evolving Frontier With Emerging Challenges

Over the past decade, immune checkpoint inhibitors (ICIs) have transformed the treatment of cancer, though they come with the risk of immune-related adverse (irAEs) events such as hepatotoxicity or Immune-mediated Liver Injury from Checkpoint Inhibitors (ILICI). ILICI is a serious irAE that, when severe, requires cessation of ICI and initiation of immunosuppression. Cytotoxic T Lymphocytes (CTLs) play a central role in ILICI; however, they are just part of the picture as immunotherapy broadly impacts all aspects of the immune microenvironment and can directly and indirectly activate innate and adaptive immune cells. Clinically, as our understanding of this entity grows, we encounter new challenges. The presentation of ILICI is heterogeneous with respect to latency, pattern of injury (hepatitis vs. cholangitis) and severity. This review focuses on our knowledge regarding risk factors, presentation and treatment of ILICI including ILICI refractory to steroids. An emerging topic, the possibility of rechallenge while accepting some risk, in patients who experience ILICI but require immunotherapy, is also discussed. This review provides an update on the current knowns and unknowns in ILICI and highlights several knowledge gaps where studies are needed.

Hepatotoxicity in Cancer Immunotherapy: Diagnosis, Management, and Future Perspectives

Cancer immunotherapy, particularly immune checkpoint inhibitors, has positively impacted oncological treatments. Despite its effectiveness, immunotherapy is associated with immune-related adverse events (irAEs) that can affect any organ, including the liver. Hepatotoxicity primarily manifests as immune-related hepatitis and, less frequently, cholangitis. Several risk factors, such as pre-existing autoimmune and liver diseases, the type of immunotherapy, and combination regimens, play a role in immune-related hepatotoxicity (irH), although reliable predictive markers or models are still lacking. The severity of irH ranges from mild to severe cases, up to, in rare instances, acute liver failure. Management strategies require regular monitoring for early diagnosis and interventions, encompassing strict monitoring for mild cases to the permanent suspension of immunotherapy for severe forms. Corticosteroids are the backbone of treatment in moderate and high-grade damage, alone or in combination with additional immunosuppressive drugs for resistant or refractory cases. Given the relatively low number of events and the lack of dedicated prospective studies, much uncertainty remains about the optimal management of irH, especially in the most severe cases. This review presents the main features of irH, focusing on injury patterns and mechanisms, and provides an overview of the management landscape, from standard care to the latest evidence.

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.

Management and treatment of severe immune-related hepatotoxicity based on clinical and pathological characteristics

BACKGROUND

The management of severe immune-related hepatotoxicity (irH) needs to be further optimized. This study aims to analyze the clinical characteristics of severe irH; improve the therapeutic strategy, especially salvage treatment in steroid-refractory irH; and determine the safety of immune checkpoint inhibitor (ICPi)-rechallenge.

METHODS

This multicenter retrospective study included patients who developed severe irH and those without irH after immunotherapy between May 2019 and June 2023. Propensity score matching was used to match these two cohorts with similar baseline characteristics.

RESULTS

Among 5,326 patients receiving ICPis, 51 patients developed severe irH. irH occurred after a median duration of 36 days and a median of two doses after the first ICPi administration. Patients receiving PD-L1 inhibitors faced a lower risk of developing severe irH. A higher dose of glucocorticoids (GCS) was administered to grade 4 irH than grade 3 irH. For steroid-sensitive patients, grade 4 irH individuals received a higher dosage of GCS than those with grade 3 irH, with no difference in time to resolution. Meanwhile, a significantly higher dose of GCS plus immunosuppression was needed in the steroid-refractory group. Liver biopsy of the steroid-refractory patients exhibited heterogeneous histological features. Twelve patients were retreated with ICPi. No irH reoccurred after a median follow-up of 9.3 months.

CONCLUSION

irH requires multidimensional evaluation. PD-L1 inhibitors correlated with a lower risk of severe irH. Grade 4 irH demands a higher dose of GCS than recommended. Pathology may guide the salvage treatment for steroid-refractory irH. ICPi rechallenge in severe irH is feasible and safe.

Immune checkpoint inhibitors rechallenge in non-small cell lung cancer: Current evidence and future directions

Immunotherapy, remarkably immune checkpoint inhibitors (ICIs), has significantly altered the treatment landscape for non-small cell lung cancer (NSCLC). Despite their success, the discontinuation of ICIs therapy may occur due to factors such as prior treatment completion, disease progression during ICIs treatment, or immune-related adverse events (irAEs). As numerous studies highlight the dynamic nature of immune responses and the sustained benefits of ICIs, ICIs rechallenge has become an attractive and feasible option. However, the decision-making process for ICIs rechallenge in clinical settings is complicated by numerous uncertainties. This review systematically analyses existing clinical research evidence, classifying ICIs rechallenge into distinct clinical scenarios, exploring methods to overcome ICIs resistance in rechallenge instances, and identifying biomarkers to select patients likely to benefit from rechallenge. By integrating recent studies and new technologies, we offer crucial recommendations for future clinical trial design and provide a practical guideline to maximize the therapeutic benefits of immunotherapy for NSCLC patients.

Steroid-refractory immune checkpoint inhibitor (ICI) hepatitis and ICI rechallenge: A systematic review and meta-analysis

BACKGROUND

In recent years, the use of immune checkpoint inhibitors (ICIs) has become a cornerstone in cancer treatment. However, this has also resulted in the emergence of immune-related adverse events, notably ICI hepatitis, posing a significant clinical challenge. While steroids are the primary treatment, there are increasing cases of steroid-refractory ICI hepatitis. Our objective is to investigate the management of ICI hepatitis and its response to steroid treatment.

METHODS

PubMed/MEDLINE, EMBASE, and CENTRAL databases were searched in July 2023 based on keywords including ICIs (anti-Programmed cell death protein 1/Programmed Death-Ligand 1, anti-CTLA-4, and anti-LAG3) and hepatitis.

RESULTS

A total of 4358 studies were screened, and 44 studies were included in this systematic review. One thousand eight hundred fifty-six patients with ICI hepatitis were included (grade 1-2: 31.7%, grade 3-4: 56.0%, and unknown: 12.3%) with 1184 patients who received corticosteroid treatment. The duration of treatment and dosage varied considerably across the studies. Mycophenolate mofetil was the predominant agent used in 68 out of 82 cases (82.9%), followed by infliximab and azathioprine. A summary estimate of the proportion of steroid-refractory hepatitis in a random effects model was 16% (95% CI: 11%-23%). An estimated 40% (95% CI: 30%-51%) of patients of all patients with ICI hepatitis were rechallenged with an ICI, and of those rechallenged, there was an estimated 22% (95% CI: 15%-30%) recurrence.

CONCLUSIONS

Corticosteroids are the primary treatment for ICI hepatitis, with mycophenolate mofetil used as a secondary option for steroids-refractory cases. Current practices mostly rely on expert consensus, highlighting the need for further research to validate and optimize these treatments, particularly for steroid-resistant cases.

Genetic variants associated with immune-mediated liver injury from checkpoint inhibitors

BACKGROUND

The clinical features, liver histology, and genetic variants in 57 patients with moderate to severe immune-mediated liver injury from checkpoint inhibitors (ILICI) are presented.

METHODS

Between 2010 and 2022, 57 high-causality ILICI cases were enrolled in the Drug-Induced Liver Injury Network. HLA and selected candidate gene variants were tested for association with ILICI risk compared to the general population and other DILI controls.

RESULTS

The 57 high-causality cases were attributed to pembrolizumab (16), ipilimumab (15), ipilimumab and nivolumab (13), and other immune checkpoint inhibitors (13) and occurred at a median of 72 days after the first infusion. Median age was 57.8 years, 66% male, and 89% were non-Hispanic Whites. At DILI onset, 53% had hepatocellular, 35% mixed, and 15% cholestatic, with younger patients more likely to have hepatocellular injury. The incidence of ANA, smooth muscle antibody, and elevated IgG levels was low (17%, 23%, and 0%), but corticosteroids were given to 86%. Microgranulomas and hepatic steatosis were seen in 54% and 46% of the 26 liver biopsies, respectively. The HLA alleles associated with autoimmune hepatitis were not over-represented, but 2 host immune response genes (EDIL3 and SAMA5A) and 3 other genes (GABRP, SMAD3, and SLCO1B1) were associated with ILICI (OR: 2.08-2.4, p<0.01).

CONCLUSIONS

ILICI typically arises within 12 weeks of initiating immunotherapy and is self-limited in most cases. Genetic variants involved in host T-cell regulation and drug disposition were identified, implicating these pathways in the pathogenesis of ILICI. If validated, these findings could lead to improved diagnostic instruments and possible treatments for ILICI.

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.

Nivolumab Rechallenge After Prior Nivolumab Therapy in Advanced Gastric Cancer: A Single-Center Case Series and Literature Review

BACKGROUND AND AIMS

Pivotal phase III trials indicated that the anti-PD-1 inhibitor nivolumab prolongs overall survival in patients with advanced gastric cancer. Nivolumab is currently used in the first- or later-line treatment of patients with advanced gastric cancer in Japan. The efficacy of immune check inhibitor rechallenge after progression has been reported in other cancers. Therefore, this study investigated the clinical outcome of nivolumab rechallenge in patients with advanced gastric cancer who received nivolumab in a previous systemic line.

METHODS

We retrospectively reviewed the medical records of six patients with advanced or recurrent gastric cancer who received nivolumab rechallenge.

RESULTS

During initial nivolumab therapy, three patients experienced partial responses, and one patient achieved stable disease. The reasons for discontinuing initial nivolumab therapy were progressive disease in five patients and immune-related adverse events in one patient. The median interval duration of treatment for patients receiving both nivolumab regimens was 13.7 (range: 5.1-17.8) months. During nivolumab rechallenge, no patients achieved partial responses, whereas two patients had stable disease. Median progression-free survival was 2.5 (95% confidence interval [CI] = 1.6-not available [NA]) months, and median overall survival was 7.4 (95% CI = 2.3-NA) months. Although one patient had discontinued prior nivolumab therapy because of immune-related adverse events, there were no immune-related adverse events associated with nivolumab rechallenge.

CONCLUSIONS

The benefit of nivolumab rechallenge in patients with advanced gastric cancer was limited. Rechallenge with the same immune check inhibitor might be ineffective in patients with advanced gastric cancer.

Diagnosis and management of immune mediated liver injury from checkpoint inhibitors

PURPOSE OF REVIEW

The aim is to summarize the latest data on the incidence, clinical manifestations, and management of immune- mediated liver injury from checkpoint inhibitors (ILICI).

RECENT FINDINGS

ILICI develops in 10-15% of oncology patients receiving immunotherapy with most having asymptomatic serum aminotransferase and/or alkaline phosphatase elevations. Most grade 1-2 ILICI patients improve with drug discontinuation and/or short-term oral corticosteroids. In contrast, the 2-3% with grade 3/4 hepatotoxicity frequently require oral or intravenous corticosteroids and some are hospitalized to initiate further immunosuppression with mycophenolate mofetil or azathioprine. Liver biopsy is generally reserved for patients with atypical features or those with severe hepatotoxicity who fail to respond to treatment. Up to 3% of ILICI patients with a cholestatic profile have MRI evidence of intra or extrahepatic cholangitis that responds poorly to immunosuppression. Most ILICI patients improve during follow-up and liver-related death is very uncommon (<1%). Up to 30% of rechallenged ILICI patients develop recurrent hepatotoxicity with a shorter latency.

SUMMARY

ILICI is increasingly encountered by gastroenterologists evaluating oncology patients with abnormal liver biochemistries. A stepwise approach to exclude viral hepatitis, alcohol, hepatic metastases, and pancreaticobiliary disease is recommended. The majority of ILICI patients fully recover with ICI discontinuation and short-term corticosteroids or a second line immunosuppressant.

Rechallenge in idiosyncratic drug-induced liver injury: An analysis of cases in two large prospective registries according to existing definitions

INTRODUCTION

Data on positive rechallenge in idiosyncratic drug-induced liver injury (DILI) are scarce. We aim to analyse the clinical presentation, outcome and drugs associated with positive rechallenge in two DILI registries.

METHODS

Cases from the Spanish and Latin American DILI registries were included. Demographics, clinical characteristics and outcome of cases with positive rechallenge according to CIOMS/RUCAM and current definitions were analysed.

RESULTS

Of 1418 patients with idiosyncratic DILI, 58 cases had positive rechallenge (4.1%). Patients with positive rechallenge had shorter duration of therapy (p=0.001) and latency (p=0.003). In patients with rechallenge, aspartate transaminase levels were increased (p=0.026) and showed a prolonged time to recovery (p=0.020), albeit no differences were seen in terms of fatal outcomes. The main drug implicated in rechallenge was amoxicillin-clavulanate (17%). The majority of re-exposure events were unintentional (71%). Using both existing definitions of positive rechallenge, there were four cases which exclusively fulfilled the current criteria and five which only meet the historical definition. All cases of positive rechallenge, irrespective of the pattern of damage, fulfilled the criteria of either alanine transaminase (ALT) ≥3 times the upper limit of normal (ULN) and/or alkaline phosphatase (ALP) ≥2 times ULN.

CONCLUSIONS

Episodes of rechallenge were characterised by shorter duration of therapy and latency, and longer time to resolution, but did not show an increased incidence of fatal outcome. Based on our findings, ALT ≥3 times ULN and/or ALP ≥2 times ULN, regardless of the pattern of damage, is proposed as a new definition of rechallenge in DILI.

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

BACKGROUND

There are few data on corticosteroids (CS)-sparing strategies for checkpoint inhibitor (ICI)-induced liver injury (ChILI).

AIM

We aimed to assess the performance of a 2-step algorithm for severe ChILI, based on ICI temporary discontinuation (step-1) and, if lack of biochemical improvement, CS based on the degree of necroinflammation at biopsy (step-2).

METHODS

Prospective study that included all subjects with grade 3/4 ChILI. Peripheral extended immunophenotyping was performed. Indication for CS: severe necroinflammation; mild or moderate necroinflammation with later biochemical worsening.

RESULTS

From 111 subjects with increased transaminases (January 2020 to August 2023), 44 were diagnosed with grade 3 (N = 35) or grade 4 (N = 9) ChILI. Main reason for exclusion was alternative diagnosis. Lung cancer (13) and melanoma (12) were the most common malignancies. ICI: 23(52.3%) anti-PD1, 8(18.2%) anti-PD-L1, 3(6.8%) anti-CTLA-4, 10(22.7%) combined ICI. Liver injury pattern: hepatocellular (23,52.3%) mixed (12,27.3%) and cholestatic (9,20.5%). 14(32%) presented bilirubin >1.2 mg/dL. Overall, 30(68.2%) patients did not require CS: 22(50.0%) due to ICI discontinuation (step-1) and 8/22 (36.4%) based on the degree of necroinflammation (step-2). Biopsy mainly impacted on grade 3 ChILI, sparing CS in 8 out of 15 (53.3%) non-improvement patients after ICI discontinuation. CD8+ HLA-DR expression (p = 0.028), central memory (p = 0.046) were lower in CS-free managed subjects, but effector-memory cells (p = 0.002) were higher. Time to transaminases normalisation was shorter in those CS-free managed (overall: p < 0.001, grade 3: p < 0.001). Considering our results, a strategy based on ICI discontinuation and biopsy for grade 3 ChILI is proposed.

CONCLUSIONS

An algorithm based on temporary immunotherapy discontinuation and biopsy allows CS avoidance in two thirds of cases of severe ChILI.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2% to 40%, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Updates in the pathogenesis and management of immune-related enterocolitis, hepatitis and cardiovascular toxicities

Immune checkpoint inhibitors (ICIs) have become a cornerstone of treatment for many solid organ malignancies. Alongside increasing use, the occurrence of immune-related adverse events (irAEs) has also increased and remains a significant challenge when treating patients with ICI. The underlying pathophysiology of irAE development for many organ systems is yet to be elucidated, but may involve unmasking of latent autoimmunity, increased T-cell recognition of shared antigens on cancer and normal tissue and ICI-triggered immune dysregulation with overactivation of proinflammatory pathways and suppression of immune control pathways. Management strategies for irAEs have historically been borrowed from paradigms for conventional autoimmune conditions such as inflammatory bowel disease and autoimmune hepatitis; however, recent translational efforts have clearly demonstrated key differences in underlying immune signalling pathways. As we begin to understand these differences, we must adapt a more targeted approach to immunosuppression and exercise a more nuanced approach with the multiple biologic agents available to mitigate ICI-related toxicity without reversing the antitumour effect of ICI. In this review, we focus on three key immune-related toxicities where recent clinical and translational work has provided nuanced insights into pathogenesis and treatment strategies: enterocolitis, hepatitis and cardiovascular toxicity including myocarditis.

Clinical Management of Gastrointestinal and Liver Toxicities of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have transformed the treatment paradigm for various types of cancer. Nonetheless, with the utilization of these groundbreaking treatments, immune-related adverse events (irAEs) are increasingly encountered. Colonic and hepatic involvement are among the most frequently encountered irAEs. Drug-induced side effects, infectious causes, and tumor-related symptoms are the key differentials for irAE complications. Potential risk factors for the development of irAEs include combination use of immune checkpoint inhibitors, past development of irAEs with other immunotherapy treatments, certain concomitant drugs, and a pre-existing personal or family history of autoimmune illness such as inflammatory bowel disease. The importance of early recognition, timely and proper management cannot be understated, as there are profound clinical implications on the overall cancer treatment plan and prognosis once these adverse events occur. Herein, we cover the clinical management of the well-established gastrointestinal irAEs of enterocolitis and hepatitis, and also provide an overview of several other emerging entities.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2 % to 40 %, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Checkpoint inhibitor hepatotoxicity: pathogenesis and management

Immunotherapy, including immune checkpoint inhibitor (ICI) therapy, has been a paradigm shift in cancer therapeutics, producing durable cancer responses across a range of primary malignancies. ICI drugs increase immune activity against tumor cells, but may also reduce immune tolerance to self-antigens, resulting in immune-mediated tissue damage. ICI-associated hepatotoxicity usually manifests as hepatocellular enzyme elevation and may occur in 2%-25% of ICI-treated patients. Although ICI-associated hepatotoxicity is clinically and pathologically distinct from idiopathic autoimmune hepatitis, our understanding of its pathogenesis continues to evolve. Pending greater understanding of the pathophysiology, mainstay of management remains through treatment with high-dose corticosteroids. This approach works for many patients, but up to 30% of patients with high-grade hepatotoxicity may not respond to corticosteroids alone. Furthermore, atypical cholestatic presentations are increasingly recognized, and rare cases of fulminant hepatitis due to ICI hepatotoxicity have been reported. Optimal management for these challenging patients remains uncertain. Herein, we review the current understanding of pathogenesis of ICI-associated toxicities, with a focus on hepatotoxicity. Based on the existing literature, we propose evolving management approaches to incorporate strategies to limit excess corticosteroid exposure, and address rare but important presentations of cholestatic hepatitis and fulminant liver failure. Finally, as ICI hepatotoxicity frequently occurs in the context of treatment for advanced malignancy, we review the impact of hepatotoxicity and its treatment on cancer outcomes, and the overall safety of re-challenge with ICI, for patients who may have limited treatment options.

Immune-mediated hepatitis: Basic concepts and treatment

Immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized advanced cancer management. Nevertheless, the generalized use of these medications has led to an increase in the incidence of adverse immune-mediated events and the liver is one of the most frequently affected organs. Liver involvement associated with the administration of immunotherapy is known as immune-mediated hepatitis (IMH), whose incidence and clinical characteristics have been described by different authors. It often presents as mild elevations of amino transferase levels, seen in routine blood tests, that spontaneously return to normal, but it can also manifest as severe transaminitis, possibly leading to the permanent discontinuation of treatment. The aim of the following review was to describe the most up-to-date concepts regarding the epidemiology, diagnosis, risk factors, and progression of IMH, as well as its incidence in different types of common cancers, including hepatocellular carcinoma. Treatment recommendations according to the most current guidelines are also provided.

Burden of grade 3 or 4 liver injury associated with immune checkpoint inhibitors

BACKGROUND & AIMS

There is concern about the burden of liver injury in patients with cancer exposed to immune checkpoints inhibitors (ICIs).

METHODS

In a retrospective cohort study, we evaluated the likelihood of grade 3/4 liver injury, of grade 3/4 cholestatic liver injury, and of liver failure, as per the Common Terminology Criteria for Adverse Events (CTCAE) version 5, following treatment with ICIs. We compared these occurrences with a group of cancer patients who were propensity-matched and treated with conventional chemotherapy. For all ICI patients experiencing grade 3/4 liver injury, we conducted a causality assessment using the RUCAM method and examined patient outcomes.

RESULTS

Among 952 patients (median [IQR] age 66 [57-73] years, 64% males) who were treated with ICI between January 1, 2015, and December 31, 2019, a total of 86 (9%) progressed to grade 3/4 liver injury, and liver failure was not observed. Anti-PD-(L)1/anti-CTLA-4 antibodies combinations (adjusted hazard ratio 3.36 [95% CI: 1.67-6.79]; p <0.001), and chronic hepatitis B (adjusted hazard ratio 5.48 [95% CI: 1.62-18.5]; p = 0.006], were independent risk factors. Liver injury was attributed to ICI treatment in 19 (2.0%) patients. Patients with ICI toxicity typically presented with granulomatous hepatitis or cholangiocyte inflammation. ICI withdrawal was associated with cancer progression and mortality. Re-introduction of ICI was not associated with recurrent grade 3/4 liver injury. Compared with matched patients treated with conventional, non-ICI-based chemotherapy, anti-PD-(L)1/anti-CTLA-4 combinations (p <0.001) and anti-PD-(L)1 monotherapies (p = 0.053) increased the risk of grade 3/4 liver injury and of grade 3/4 cholestatic liver injury, respectively.

CONCLUSIONS

An increased risk of grade 3/4 liver injury under anti-PD-(L)1/anti-CTLA-4 antibodies was observed, whereas no substantial increase in the likelihood of liver failure occurred even after treatment reintroduction.

IMPACT AND IMPLICATIONS

There is concern about liver injury in patients with cancer exposed to immune checkpoints inhibitors (ICIs). We investigated the burden of grade 3/4 liver injury after treatment with ICIs in a multicentric cohort of patients with cancer. Overall, a 9% incidence of grade 3/4 liver injury was detected after ICIs, and direct ICI hepatotoxicity was demonstrated in 2% of patients. Anti-PD-(L)1/Anti-CTLA-4 antibody combinations, and chronic HBV infection were independent risk factors. ICI withdrawal for grade 3/4 liver injury was associated with cancer progression. Re-introduction of ICI treatment was not associated with recurrent grade 3/4 liver injury.

Immune Checkpoint Inhibitor-Induced Liver Injury

In recent years cancer treatment has been revolutionized by the development and wide application of checkpoint inhibitor (CPI) drugs, which are a form of immunotherapy. CPI treatment is associated with immune-related adverse events, off-target tissue destructive inflammatory complications, which may affect a range of organs, with liver inflammation (hepatitis) being one of the more commonly noted events. This is a novel form of drug-induced liver injury and a rapidly evolving field, as our understanding of both the basic immunopathology of CPI hepatitis (CPI-H) and optimal clinical management, races to catch up with the increasing application of this form of immunotherapy in clinical practice. In this review, we summarize current evidence and understanding of CPI-H, from fundamental immunology to practical patient management.

Clinical pattern of checkpoint inhibitor-induced liver injury in a multicentre cohort

Background & Aims

Immune checkpoint inhibitors (ICIs) have changed the landscape of cancer therapy. Liver toxicity occurs in up to 25% of patients treated with ICIs. The aim of our study was to describe the different clinical patterns of ICI-induced hepatitis and to assess their outcome.

Methods

We conducted a retrospective observational study of patients with checkpoint inhibitor-induced liver injury (CHILI) discussed in multidisciplinary meetings between December 2018 and March 2022 in three French centres specialised in ICI toxicity management (Montpellier, Toulouse, Lyon). The hepatitis clinical pattern was analysed by the ratio of serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) (R value = (ALT/ULN)/(ALP/ULN)) for characterisation as cholestatic (R ≤2), hepatocellular (R ≥5), or mixed (2 <R <5).

Results

We included 117 patients with CHILI. The clinical pattern was hepatocellular in 38.5%, cholestatic in 36.8%, and mixed in 24.8% of patients. High-grade hepatitis severity (grade ≥3 according to the Common Terminology Criteria for Adverse Events system) was significantly associated with the hepatocellular hepatitis (p <0.05). No cases of severe acute hepatitis were reported. Liver biopsy was performed in 41.9% of patients: granulomatous lesions, endothelitis, or lymphocytic cholangitis were described. Biliary stenosis occurred in eight patients (6.8%) and was significantly more frequent in the cholestatic clinical pattern (p < 0.001). Steroids alone were mainly administered to patients with a hepatocellular clinical pattern (26.5%), and ursodeoxycholic acid was more frequently used in the cholestatic pattern (19.7%) than in the hepatocellular or mixed clinical pattern (p <0.001). Seventeen patients improved without any treatment. Among the 51 patients (43.6%) rechallenged with ICIs, 12 (23.5%) developed CHILI recurrence.

Conclusions

This large cohort indicates the different clinical patterns of ICI-induced liver injury and highlights that the cholestatic and hepatocellular patterns are the most frequent with different outcomes.

Impact and Implications

ICIs can induce hepatitis. In this retrospective series, we report 117 cases of ICI-induced hepatitis, mostly grades 3 and 4. We find a similar distribution of the different patterns of hepatitis. ICI could be resumed without systematic recurrence of hepatitis.

Immune-mediated hepatitis induced by immune checkpoint inhibitors: Current updates and future perspectives

In recent years, cancer immunotherapy has made remarkable achievements. Immune checkpoint inhibitors (ICIs) have been used successfully in several types of cancer in the past decade. However, expanded indication and increased use of Immune checkpoint inhibitors have resulted in increased reports of toxicity called immune-related adverse events (irAEs). Due to the unique immunological characteristics of the liver, a hepatic immune-related adverse events has also been reported, which is usually termed Immune-mediated hepatitis (IMH). So far, it is generally considered that the mechanism of IMH induced by Immune checkpoint inhibitors is mainly the overactivation of T cells. It has been reported that the incidence of IMH ranges from 1% to 15%. Because of the lack of specific markers, a diagnosis of exclusion of IMH is critical. Although most IMH is mild and recoverable, several death cases have been reported, which has been increasingly concerned. This review summarizes the current understanding of the pathophysiology, epidemiology, diagnosis, management and prognosis of IMH caused by Immune checkpoint inhibitors. It also discusses the controversial issues in IMH, such as the role of liver biopsy, grading criteria, risk factors, rational treatment strategies with steroids, and the timing of Immune checkpoint inhibitors rechallenging, which may provide helpful information for IMH in future clinical practice.

Immune-Mediated Hepatitis During Immune Checkpoint Inhibitor cancer Immunotherapy: Lessons From Autoimmune Hepatitis and Liver Immunology

Immune checkpoint inhibitors (ICI) are being increasingly used to successfully treat several types of cancer. However, due to their mode of action, these treatments are associated with several immune-related adverse events (irAEs), including immune-mediated autoimmune-like hepatitis in 5 to 10% of cases. The specific immune mechanism responsible for the development of immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI) is currently unknown. This review summarizes the current knowledge on hepatic irAEs during cancer immunotherapy. It also addresses the clinical management of ILICI and how it is becoming an increasingly important clinical issue. Clinical, histological, and laboratory features of autoimmune hepatitis (AIH) and ILICI are compared, and their shared and distinctive traits are discussed in an effort to better understand the development of hepatic irAEs. Finally, based on the current knowledge of liver immunology and AIH pathogenesis, we propose a series of events that could trigger the observed liver injury in ICI-treated patients. This model could be useful in the design of future studies aiming to identify the specific immune mechanism(s) at play in ILICI and improve immune checkpoint inhibitor cancer immunotherapy.