Liver biopsy findings in patients on immune checkpoint inhibitors

Exploring molecular imaging to investigate immune checkpoint inhibitor-related toxicity

Immune checkpoint inhibitors (ICI) boost the endogenous anticancer immunity, evoking long-lasting anticancer responses in a subset of patients with solid tumors. Simultaneously, ICI are also associated with serious toxicities, impacting treatment duration and the quality of life. The proposed processes underlying ICI-related toxicity include T-cell activation and recruitment to non-tumor tissues, involvement of other immune cells and fibroblasts and the host' microbiome composition. However, the exact mechanisms of these processes remain incompletely understood, hindering clinicians' ability to predict and identify ICI-related toxicity in the early stages of treatment. Molecular imaging may play a role as a non-invasive biomarker, providing a tool to study ICI-related toxicity. This review discusses the applications of molecular imaging to answer questions regarding the mechanisms, detection, and prediction of ICI-related toxicity. Potential targets and the current state of development of suitable imaging techniques are discussed.

IQ DILI Consensus Opinion: Best Practices for Rechallenge Following Suspected Drug-Induced Liver Injury in Clinical Trials

Rechallenge with study drug after suspected drug-induced liver injury (DILI) during drug development requires a comprehensive assessment of risks and benefits. Lack of universal consensus or societal guidelines makes this decision-making process more challenging and difficult to manage in clinical development. The sparse published literature is biased towards reporting cases of positive rechallenge (recurrent DILI), often with adverse outcomes. The heterogeneity of available data and inconsistent approaches to drug rechallenge likely lead to bias in our perception of the risks of rechallenge, ultimately leaving this topic controversial. The IQ DILI Causality Assessment Working Group, in collaboration with academic and regulatory experts, developed this manuscript with the following objectives: (1) understand and describe current practices via literature review and survey of practices and opinions among drug developers, academic experts, and regulators; (2) propose a consistent and structured approach to decision-making and managing the rechallenge process; (3) facilitate better understanding of the risks and benefits of rechallenge via a standardized approach to collecting rechallenge data, including outcomes and the importance of publishing rechallenge data; and (4) the role of obtaining a liver biopsy, guidance on when a biopsy might be considered, and what histologic findings can assist in making the rechallenge decision. Lastly, knowledge gaps in the drug rechallenge paradigm are highlighted alongside the proposal to standardize the collection and publication of rechallenge data to help address these gaps. This consensus expert opinion does not encourage rechallenge but provides guidance for drug developers to apply a consistent approach to rechallenge.

Secondary Sclerosing Cholangitis due to Drugs With a Special Emphasis on Checkpoint Inhibitors

BACKGROUND

Secondary sclerosing cholangitis (SSC), is one of the phenotypes of DILI first described in the 1980s. Check point inhibitors (CPIs) are currently the most frequent cause of SCC.

AIMS

To describe the epidemiology, clinical and biochemical features at presentation, differential diagnoses, pathophysiology, imaging, histological characteristics and management associated with SSC.

MATERIALS AND METHODS

A language and date-unrestricted Medline literature search was conducted to identify case reports and clinical series on SSC with special emphasis on CPIs (2007-2023).

RESULTS

We identified 19 different drugs that have been shown to induce SSC. A total of 64 cases with SSC due to CPIs are presented. This was mostly seen in patients treated with anti-Programmed cell death (PD)-1/PD-L1 inhibitors. The most frequent presenting signs and symptoms were abdominal pain and jaundice. Large-duct cholangitis induced by CPIs is a very rare condition while small-duct cholangitis is more common. Nivolumab and pembrolizumab were the most commonly implicated agents. Biopsies have revealed predominant CD8+ T cell infiltration in biliary strictures. Corticosteroids is linked to a low frequency of success and is the only agent recommended to begin the treatment.

CONCLUSIONS

CPIs-induced SSC seems to affect the entire biliary system. Clinicians should consider and suspect SSC when a probable CPIs-induced hepatitis does not respond to corticosteroids. Additionally, further randomized, controlled trials should prospectively investigate alternative therapies for treatment.

Clinical features and pathological findings by liver biopsy in patients with immune-related sclerosing cholangitis induced by immune checkpoint inhibitors

BACKGROUND

Immune-related sclerosing cholangitis (irSC) induced by immune checkpoint inhibitors (ICIs) is relatively rare, and its clinical and pathological features are not well known.

AIMS

We aimed to compare the clinical course and pathological findings of irSC with those of non-irSC liver injury.

METHODS

Clinical data were retrospectively collected from 2416 patients with advanced malignancies treated with ICIs between September 2014 and October 2023. The data of patients with severe ICI-induced liver injury who underwent liver biopsy were analyzed and compared between patients with irSC and non-irSC.

RESULTS

Ninety-three (3.8 %) patients had severe ICI-induced liver injury, and 38 underwent liver biopsy. Of these, five were diagnosed with irSC. The irSC group had a significantly longer time to onset of ICI-induced liver injury and a lower rate of improvement of liver injury than did the non-irSC group (irSC, 3/5; non-irSC, 32/33). Liver biopsies revealed more moderate-to-severe pathological cholangitis in the irSC group than in the non-irSC group (irSC, n = 5/5; non-irSC, n = 16/33). Other pathological findings were similar between the two groups.

CONCLUSION

Appropriate management of irSC requires an understanding of its characteristics of late onset and steroid resistance, and liver biopsy, in addition to imaging, may be useful for diagnosing irSC.

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 inhibitor-induced diarrhea and colitis: an overview

Immune checkpoint inhibitors (ICIs) have emerged as an integral component of the management of various cancers and have contributed to significant improvements in overall survival. Most available ICIs target anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4), and anti-programmed cell death 1/programmed cell death ligand 1 (anti-PD1/PDL1). Gastrointestinal immune-related adverse events remain a common complication of ICIs. The predominant manifestations include diarrhea and colitis, which often manifest concurrently as immune-mediated diarrhea and colitis (IMDC). Risk factors for developing these side effects include baseline gut microbiota, preexisting autoimmune disorders, such as inflammatory bowel disease, and type of neoplasm. The hallmark symptom of colitis is diarrhea which may be accompanied by mucus or blood in stools. Patients may also experience abdominal pain, fever, vomiting, and nausea. If not treated rapidly, ICI-induced colitis can lead to serious life-threatening complications. Current management is based on corticosteroids as first-line, and immunosuppressants like infliximab or vedolizumab for refractory cases. Microbiota transplantation and specific cytokines and lymphocyte replication inhibitors are being investigated. Optimal patient care requires maintaining a balance between treatment toxicity and efficacy, hence the aim of this review is to enhance readers' comprehension of the gastrointestinal adverse events associated with ICIs, particularly IMDC. In addition to identifying the risk factors, we discuss the incidence, clinical presentation, workup, and management options of IMDC.

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.

Focus on Immune Checkpoint Inhibitors-related Intestinal Inflammation: From Pathogenesis to Therapeutical Approach

Recently, antitumor immunotherapies have witnessed a breakthrough with the emergence of immune checkpoint inhibitors (ICIs) including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. Unfortunately, the use of ICIs has also led to the advent of a novel class of adverse events that differ from those of classic chemotherapeutics and are more reminiscent of autoimmune diseases, the immune-related adverse events (IRAEs). Herein, we performed an insight of the main IRAEs associated with ICIs, focusing on gastroenterological IRAEs and specifically on checkpoint inhibitor colitis, which represents the most widely reported IRAE to date. We comprehensively dissected the current evidence regarding pathogenesis, diagnosis, and management of ICIs-induced colitis, touching upon also on innovative therapies.

Review article: Contemporary management of gastrointestinal, pancreatic and hepatic toxicities of immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are effective oncologic agents which frequently cause immune-related adverse events (irAEs) which can impact multiple organ systems. Onco-Gastroenterology is a novel and emerging subspecialty within gastroenterology focused on cancer treatment-related complications. Gastroenterologists must be prepared to identify and manage diverse immune-mediated toxicities including enterocolitis, hepatitis, pancreatitis and other ICI-induced toxicities.

AIM

To provide a narrative review of the epidemiology, diagnostic evaluation and management of checkpoint inhibitor-induced gastrointestinal and hepatic toxicities.

METHODS

We searched Cochrane and PubMed databases for articles published through August 2023.

RESULTS

Gastrointestinal and hepatic irAEs include most commonly enterocolitis and hepatitis, but also pancreatitis, oesophagitis, gastritis, motility disorders (gastroparesis) and other rarer toxicities. Guidelines from the National Comprehensive Cancer Network, American Society of Clinical Oncology and European Society for Medical Oncology, in combination with emerging cohort and clinical trial data, offer strategies for management of ICI toxicities. Evaluation of irAEs severity by formal classification and clinical stability, and a thorough workup for alternative etiologies which may clinically mimic irAEs underlie initial management. Treatments include corticosteroids, biologics and other immunosuppressive agents plus supportive care; decisions on dosing, timing and choice of steroid adjuncts and potential for subsequent checkpoint inhibitor dosing are nuanced and toxicity-specific.

CONCLUSIONS

Expanding clinical trial and cohort data have clarified the epidemiology and clinical characteristics of gastrointestinal, pancreatic and hepatic toxicities of ICIs. Guidelines, though valuable, remain based principally on retrospective cohort data. Quality prospective, controlled studies may refine algorithms for treatment and potential immunotherapy rechallenge.

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.

Characteristics and outcomes of immunotherapy-related liver injury in patients with hepatocellular carcinoma versus other advanced solid tumours

BACKGROUND & AIMS

Immune-related liver injury (irLI) is commonly observed in patients with cancer treated with immune checkpoint inhibitors (ICIs). We aimed to compare the incidence, clinical characteristics, and outcomes of irLI between patients receiving ICIs for hepatocellular carcinoma (HCC) vs. other solid tumours.

METHODS

Two separate cohorts were included: 375 patients with advanced/unresectable HCC, Child-Pugh A class treated with first-line atezolizumab+bevacizumab from the AB-real study, and a non-HCC cohort including 459 patients treated with first-line ICI therapy from the INVIDIa-2 multicentre study. IrLI was defined as a treatment-related increase of aminotransferase levels after exclusion of alternative aetiologies of liver injury. The incidence of irLI was adjusted for the duration of treatment exposure.

RESULTS

In patients with HCC, the incidence of any grade irLI was 11.4% over a median treatment exposure of 4.4 months (95% CI 3.7-5.2) vs. 2.6% in the INVIDIa-2 cohort over a median treatment exposure of 12.4 months (95% CI 11.1-14.0). Exposure-adjusted-incidence of any grade irLI was 22.1 per 100-patient-years in patients with HCC and 2.1 per 100-patient-years in patients with other solid tumours (p <0.001), with median time-to-irLI of 1.4 and 4.7 months, respectively. Among patients who developed irLI, systemic corticosteroids were administered in 16.3% of patients with HCC and 75.0% of those without HCC (p <0.001), and irLI resolution was observed in 72.1% and 58.3%, respectively (p = 0.362). In patients with HCC, rates of hepatic decompensation and treatment discontinuation due to irLI were 7%. Grade 1-2 irLI was associated with improved overall survival only in patients with HCC (hazard ratio 0.53, 95% CI 0.29-0.96).

CONCLUSIONS

Despite higher incidence and earlier onset, irLI in patients with HCC is characterised by higher rates of remission and lower requirement for corticosteroid therapy (vs. irLI in other solid tumours), low risk of hepatic decompensation and treatment discontinuation, not negatively affecting oncological outcomes.

IMPACT AND IMPLICATIONS

Immune-related liver injury (irLI) is common in patients with cancer receiving immune checkpoint inhibitors (ICIs), but whether irLI is more frequent or it is associated with a worse clinical course in patients with hepatocellular carcinoma (HCC), compared to other tumours, is not known. Herein, we compared characteristics and outcomes of irLI in two prospective cohorts including patients treated with ICIs for HCC or for other oncological indications. irLI is significantly more common and it occurs earlier in patients with HCC, also after adjustment for duration of treatment exposure. However, outcomes of patients with HCC who developed irLI are not negatively affected in terms of requirement for corticosteroid therapy, hepatic decompensation, treatment discontinuation and overall survival.

HBV reactivation and clinical resolution in an isolated anti-HBc-positive patient during immune checkpoint inhibition

BACKGROUND

Immune checkpoint inhibitor (ICI)-related liver injury is a growing concern as ICIs are increasingly used in cancer treatment regimens. Interestingly, ICIs have exhibited antiviral effects among patients with chronic hepatitis B virus (HBV). However, the underlying mechanisms remain unclear, and clinical data on patients with previous HBV infection/exposure and isolated anti-HBV core antibodies (IAHBcs) are lacking.

METHODS

We report a case illustrating the dual effects of ICIs in a patient experiencing panlobular hepatitis and concurrent HBV reactivation.

FINDINGS

A 68-year-old male patient positive for IAHBcs was admitted with panlobular hepatitis and HBV reactivation after receiving systemic chemotherapy (several months before admission) and ICI treatment (4 weeks before admission) subsequent to metastatic primary lung cancer (NSCLC stage IV). This was followed by a rapid and significant decrease of HBV DNA viral load before and during antiviral treatment.

CONCLUSIONS

This unique case sheds light on the dynamics of ICI therapy in IAHBc-positive patients experiencing HBV reactivation during chemotherapy and underscores the dual impact of ICIs. Moreover, it emphasizes the need for assessment of HBV serology and prophylaxis in IAHBc-positive patients undergoing chemotherapy and ICI treatment.

FUNDING

R.T.C. was supported by the MGH Research Scholars Program.

Morphology of immune-mediated hepatitis: A comparison between immune checkpoint inhibitor therapy and combined immune checkpoint inhibitor/anti-angiogenic therapy

BACKGROUND

The combination of immune checkpoint inhibitors (ICIs) with anti-angiogenic drugs has shown promising anticancer effects. However, ICIs can trigger immune-mediated hepatitis (IMH). We aimed to clarify whether the combined use of anti-angiogenic drugs and ICIs would increase the severity of IMH.

METHODS

One hundred IMH patients (ICI monotherapy vs. ICI plus anti-angiogenic therapy 30 vs. 70) were retrospectively enrolled. Clinicopathological parameters were compared between the two groups.

RESULTS

IMH mainly showed variable degrees of panlobular hepatitis (84 %), while some cases presented mixed cholangio-hepatitic (14 %) or cholangitic (2 %) pattern. The incidence of moderate-severe injury was not significantly different between the two groups (combination vs. monotherapy 38.6 % vs. 20.0 %, p = 0.109). Specifically, the rates of marked lobular injury and portal inflammation were higher in the combination group than in the monotherapy cohort (p < 0.005), while the frequencies of interface hepatitis, bile duct injury, histiocytosis aggregates, and endothelialitis were comparable between the two groups (p > 0.05). Compared to mild IMH cases, severe IMH cases showed higher immunostaining expression levels of PD-L1 (60.7 % vs. 19.4 %, p < 0.0001). Treatments and outcomes of IMH were not significantly different between the two groups (p > 0.05).

CONCLUSIONS

Compared to ICI monotherapy, the administration of anti-angiogenic drugs in combination with ICIs was not associated with increased hepatotoxicity.

PD-1/PD-L1 immune checkpoint therapy demonstrates favorable safety profile in patients with autoimmune and cholestatic liver disease

INTRODUCTION

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many malignancies in recent years. However, immune-related adverse events (irAE) are a frequent concern in clinical practice. The safety profile of ICI for the treatment of malignancies in patients diagnosed with autoimmune and cholestatic liver disease (AILD) remains unclear. Due to this uncertainty, these patients were excluded from ICI clinical trials and ICI are withheld from this patient group. In this retrospective multicenter study, we assessed the safety of ICI in patients with AILD.

METHODS

We contacted tertiary referral hospitals for the identification of AILD patients under ICI treatment in Europe via the European Reference Network on Hepatological Diseases (ERN RARE-LIVER). Fourteen centers contributed data on AILD patients with malignancies being treated with ICI, another three centers did not treat these patients with ICI due to fear of irAEs.

RESULTS

In this study, 22 AILD patients under ICI treatment could be identified. Among these patients, 12 had primary biliary cholangitis (PBC), five had primary sclerosing cholangitis (PSC), four had autoimmune hepatitis (AIH), and one patient had an AIH-PSC variant syndrome. Eleven patients had hepatobiliary cancers and the other 11 patients presented with non-hepatic tumors. The applied ICIs were atezolizumab (n=7), durvalumab (n=5), pembrolizumab (n=4), nivolumab (n=4), spartalizumab (n=1), and in one case combined immunotherapy with nivolumab plus ipilimumab. Among eight patients who presented with grade 1 or 2 irAEs, three demonstrated liver irAEs. Cases with grades ≥ 3 irAEs were not reported. No significant changes in liver tests were observed during the first year after the start of ICI.

DISCUSSION

This European multicenter study demonstrates that PD-1/PD-L1 inhibitors appear to be safe in patients with AILD. Further studies on the safety of more potent dual immune checkpoint therapy are needed. We conclude that immunotherapy should not categorically be withheld from patients with AILD.

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 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.

Capmatinib-Induced Liver Injury as Emerging Toxicity of MET Inhibitors in Patients With NSCLC Pretreated With Immune Checkpoint Inhibitors

Safety data on MET inhibitors in patients with advanced NSCLC harboring MET exon 14 mutation and treated with frontline immune checkpoint inhibitors (ICIs) are still limited. Here, we describe clinical characteristics, liver biopsy features, and management of liver injury of two patients with a diagnosis of MET exon 14-mutant NSCLC receiving capmatinib after ICI failure. On the basis of histologic findings and exclusion of other potential causes, a diagnosis of drug-induced liver injury (DILI) associated with portal fibrosis was made in both cases. The use of hepatoprotective drugs, in addition to oral ursodeoxycholic acid, resulted in liver blood tests normalization. To provide a global safety perspective, we queried the Food and Drug Administration Adverse Event Reporting System and detected a robust disproportionality signal. Out of the 918 total reports with capmatinib from the Food and Drug Administration Adverse Event Reporting System database, DILI was recorded in 43 cases (4.7%), mostly serious (93.0%) with hospitalization and death recorded in 25.6% and 16.3% of the cases, respectively. The median time to onset was 42 days, with discontinuation and positive dechallenge documented in 41.9% and 39.5% of the cases, respectively. Anti-programmed cell death protein-1 agents were coreported in 11 DILI cases. Only two cases of DILI out of 105 reports were found for tepotinib. Our data support a potential association between capmatinib and DILI in patients who have also been previously exposed to immunotherapy. Considering the potential implications for sequence strategy and timing of ICI and MET inhibitor, further investigation is warranted.

Effects of immune-related adverse events (irAEs) and their treatment on antitumor immune responses

Immune checkpoint inhibitors (ICIs) are potentially life-saving cancer therapies that can trigger immune-related adverse events (irAEs). irAEs can impact any organ and range in their presentation from mild side effects to life-threatening complications. The relationship between irAEs and antitumor immune responses is nuanced and may depend on the irAE organ, the tumor histology, and the patient. While some irAEs likely represent an immune response against antigens shared between tumor cells and healthy tissues, other irAEs may be entirely unrelated to antitumor immune responses. Clinical observations suggest that low-grade irAEs have a positive association with responses to ICIs, but the correlation between severe irAEs and clinical benefit is less clear. Currently, severe irAEs are typically treated by interrupting or permanently discontinuing ICI treatment and administering empirically selected systemic immunosuppressive agents. However, these interventions could potentially diminish the antitumor effects of ICIs. Efforts to understand the mechanistic relationship between irAEs and the tumor microenvironment have yielded meaningful insights and nominated therapeutic targets for irAE management that may preserve or even boost ICI efficacy. We explore the clinical and molecular relationship between irAEs and antitumor immunity as well as the role that irAE treatments may play in shaping antitumor immune responses.

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.

Gastrointestinal and Hepatobiliary Immune-related Adverse Events: A Histopathologic Review

Immune checkpoint inhibitors have been increasingly used to treat various malignant neoplasms. Despite their superior efficacy in treating certain ones, their global immune-activation effect leads to systemic side effects, referred to as immune-related adverse events. Immune-related adverse events affect a variety of organs, including the skin, gastrointestinal, hepatobiliary, and endocrine organs. Gastrointestinal tract immune-related adverse events present with a wide range of symptoms with variable severity, which may lead to treatment interruption and administration of immunosuppression therapy in many cases. Histopathologic changes are diverse, overlapping with many other conditions. Therefore, recognizing these changes is crucial in diagnosing immune-related adverse events. This review discusses the pathologic manifestations of gastrointestinal immune-related adverse events and discusses the primary differential diagnoses.

Drug-Induced Liver Injury due to Biologics and Immune Check Point Inhibitors

Biological agents have in the last two decades become very important therapeutic agents, particularly for the treatment of various autoimmune disorders. The most widely used biologics are the tumor necrosis factor-α (TNF-α) receptor antagonists: infliximab, adalimumab, and etanercept. Other commonly used biological agents are interleukin (IL)-1 receptor antagonist (Anakinra), interleukin (IL)-6 receptor antagonist (tocilizumab), and CD20 surface antigen antagonist (rituximab). The current review will however focus on TNF-α receptor antagonists.

Effectiveness of immunosuppressant use for the treatment of immune checkpoint inhibitor-induced liver injury: A systematic review and meta-analysis

Background

Immune-mediated liver injury caused by checkpoint inhibitors (ILICI) is a challenging clinical management issue. Although immunosuppressants are widely used to manage ILICI, no large-scale studies have proved definitive evidence for the most effective form of patient management.

Aim

Analysis of the effectiveness of immunosuppression for immune-related liver injury.

Methods

We performed a systematic review and meta-analysis of the clinical outcomes of immunosuppressive treatment of ILICI patients. A literature search of PubMed, Ovid, and Cochrane Library was completed for dates from 2000 to January 1, 2022. The primary outcome was the response rate to immunosuppressive therapy for ILICI, with subgroup analysis based on the type of cancer, immune checkpoint inhibitor regimen, and severity of liver injury. The secondary outcome was the median time to recovery from ILICI with immunosuppressive therapy.

Results

A total of 30 studies that included 1120 patients were collected. The pooled ILICI response rate was 79% (95% CI 0.73-0.84) for treatment with corticosteroids and 93% (95% CI 0.79-1.0) for treatment with mycophenolate mofetil. For ILICI treated with corticosteroids, the median recovery time was 47.59 (95% CI 39.79-55.40) days compared to 37.74 (95% CI 31.12-44.35) days for all forms of immunosuppression.

Conclusion

Findings support the effectiveness of corticosteroids and mycophenolate mofetil for the treatment of ILICI. The identified median time to recovery is a beneficial guide for patients and physicians, allowing for realistic expectations and appropriate treatment management. Future prospective randomized controlled trials are required to define a standardized management approach to immunosuppressive therapy of ILICI.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022313454.

Incidence rate and treatment strategy of immune checkpoint inhibitor mediated hepatotoxicity: A systematic review

Background

A hepatic adverse event (HAE) is defined as a liver injury that occurs following immune checkpoint inhibitor (ICI) administration in oncology Patients. Immune-mediated hepatotoxicity (IMH) is a type of HAE directly caused by ICI and is associated with immune system hyperactivation. HAE incidence varies across different clinical studies. This study aimed to explore the risk factors of HAE and establish a personalized IMH treatment strategy.

Methods

Randomized controlled trials (RCTs) on ICIs and case reports related to IMH were collected and summarized separately. Meta-analysis was performed using Review Manager (version 5.0), whereas correlation analysis and linear regression were performed using SPSS (version 24.0) to evaluate any correlations between the two variables.

Results

Overall, 36 RCTs containing 18,515 patients and 39 case reports met our inclusion criteria. The ICI administration increased the HAE risk (risk ratio [RR] ​= ​1.40) as well as severe HAE (RR ​= ​2.55). The overall HAE incidence and severe incidence were about 15.3% and 4.3%, respectively. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors have a higher incidence of HAE than programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors. Finally, we found a positive correlation between the onset time of IMH and the recovery time of liver injury.

Conclusions

ICI administration increased the incidence risk of HAE, especially in patients treated with CTLA-4 inhibitors. Regarding IMH treatment, the glucocorticoid dosage must be individually reduced according to the severity and onset time of HAE.

Immunotherapy-induced Hepatotoxicity: A Review

Immune checkpoint inhibitors (ICIs) suppress the function of immune checkpoints, which are involved in downregulating immune responses. These lead to an increased activation of the function of T cells, increased release of cytokines, and decreased activity of regulatory T cells. This allows for a more significant and less regulated immune response and subsequent enhanced cytotoxic activity against cancer cells. A number of cancers are now being treated with these agents and this increased use has resulted in more reports of toxicity. While almost every organ can be affected, the skin, gastrointestinal tract, liver, and endocrine glands are most commonly involved. It is necessary that gastroenterologists and hepatologists familiarize themselves with diagnostic steps and management plan in patients with these undesirable outcomes. When assessing for possible ICIs induced hepatotoxicity, it is of utmost importance to use a formal scoring system such as the Roussel Uclaf causality assessment method (RUCAM) to assess for risk factors, alternative causes, and response to cessation and re-exposure of a given drug. While this review is based on studies with and without RUCAM, the conclusions were carefully established mainly from studies that used RUCAM. The aim of this review is to provide information on the epidemiology, risk factors, clinical presentation, diagnostic tools, and management plan based on the most recent studies of immunotherapy-induced hepatotoxicity.

Drug induced liver injury by immunotherapy

Immunotherapy has become the cornerstone of treatment of many malignancies. Check point inhibitors (CPIs) have been shown to be able to halt the progression of several types of advanced malignancies such as malignant melanoma and even keep patients in longstanding clinical remission (1-2). Thus, the use of CPIs has shown a substantial therapeutic benefit marked by signficant improvement in patient survival. However, this efficacy comes with a cost of several immune associated adverse effects due to the corollary reduction of immune self-tolerance. These adverse can be manifested as gastrointestinal symptoms (colitis), dermatological (dermatitis), lung symptoms (pneumonitis), endocrine manifestations (hypophysitis), apart from drug-induced liver injury (DILI), which is the focus of this editorial. Among 100 DILI patients due to CPIs of whom 53% had advanced melanoma, 45% had concomitant immune-mediated adverse effects, with dermatological (14%) and colitis (9%) being the most common (3).

Systematic comparison with autoimmune liver disease identifies specific histological features of immune checkpoint inhibitor-related adverse events

BACKGROUND

Immune checkpoint inhibitors (ICIs) have become a mainstay of cancer treatment. Their immune-boosting quality has one major drawback, their proclivity to induce a broad array of immune-related adverse events (irAEs) affecting, among others, the liver and sharing some similarities with classic autoimmune liver diseases (AILD).We aimed to compare clinical, laboratory and histological features of patients with liver-related irAEs and AILD.

METHODS

We systematically compared liver irAEs with AILD, namely autoimmune hepatitis (AIH) and primary biliary cholangitis, regarding their clinical, laboratory, and histological features.

RESULTS

Twenty-seven patients with liver irAEs (ICI group) and 14 patients with AILD were identified. We observed three distinct ICI-induced histological liver injury patterns: hepatitic (52%), cholangitic (19%), and mixed (29%). When comparing the ICI and AILD groups, centrilobular injury as well as granuloma formation were more prevalent in the former (p=0.067 and 0.002, respectively). CD4+/CD8+ T cell ratios were heterogeneous between the two groups, without statistically significant difference but with a trend toward increased CD8+ T cells among hepatitic irAEs as compared with AIH. Pattern of liver function test alteration was predictive for the type of irAEs but did not correlate with histological severity.

CONCLUSIONS

Liver irAEs have broad clinical, laboratory and histological presentations. Histological features of irAEs and AILD are distinct, likely underpinning their different immunological mechanisms.

Immune Checkpoint Inhibitor-Induced Hepatic Injury: A Clinicopathologic Review

Although immune checkpoint inhibitors (ICIs) have been a revolutionary milestone in immuno-oncology, immune-related adverse events (irAEs) may occur due to enhanced T cell activation and immune dysregulation. The irAEs can occur as early as within days to reportedly as late as up to 26 weeks. They may affect any organ system in the body, most commonly the luminal gastrointestinal tract, liver, skin, endocrine system, and lungs. The mechanisms of irAEs are complex and have not been fully understood. A breach of self-tolerance, which leads to autoantigen reactivity due to the enhanced activation and infiltration of T cells or the production of autoantibodies, and a non-specific autoinflammatory mechanism have been proposed. Limited data is available on the clinical and pathologic features of ICI-induced liver injury. This review presents an overview of the clinical and common histopathologic features and patterns of ICI-induced liver injury, the differential diagnoses, and the clinical management. Available data suggest that the histopathologic findings of ICI-induced hepatic injury are often non-specific and overlap with other challenging differential diagnoses. Therefore, a good knowledge of the histopathologic spectrum of ICI-induced hepatic injury and their differential diagnoses combined with the serological test results, clinical correlation, and communication with the clinical team is necessary to make an accurate and timely diagnosis.

Checkpoint inhibitor-induced hepatotoxicity: Role of liver biopsy and management approach

Immunological checkpoint inhibitors (ICIs) have revolutionized therapy of many different malignanices. Concomitant immune-mediated adverse effects are common and can affect many organs such as the skin, lungs, gastrointestinal and endocrine organs as well as the liver. Liver injury has been reported in 3%-8% of patients with grade III-IV hepatitis in retrospective studies. The liver injury is characterized by hepatocellular injury resembling autoimmune hepatitis biochemically but not immunologically as patients with ICI induced hepatoxicity rarely have auto-antibodies or IgG elevation. The role for liver biopsy (LB) in patients with suspected liver injury due to ICIs is controversial and it is not clear whether results of a LB will change clinical management. LB can be helpful when there is diagnostic uncertainty and pre-existing liver disease is suspected. Although there are no distinctive histological features, the finding of granulomas and endothelitis may suggest a specific type of hepatitis induced by ICIs. The natural history of hepatotoxicity of ICI therapy is not well known. Recent studies have demonstrated that 33%-50% of patients improve spontaneously with discontinuation of ICIs. In patients with jaundice and/or coagulopathy corticosteroids are used. The high doses of corticosteroids with 1-2 mg/kg/d of methylprednisolone recommended by the oncological societies are controversial. Recently it has shown that initial treatment with 1 mg/kg/d provided similar liver tests improvement which was also associated with a reduced risk of steroid-induced adverse effects in comparison with higher-dose regimens. Secondary immunosuppression mostly with mycophenolate mofetil has been reported to be helpful.

Gastrointestinal and Hepatobiliary Immune-related Adverse Events: A Histopathologic Review

Immune checkpoint inhibitors have been increasingly used to treat various malignant neoplasms. Despite their superior efficacy in treating certain ones, their global immune-activation effect leads to systemic side effects, referred to as immune-related adverse events. Immune-related adverse events affect a variety of organs, including the skin, gastrointestinal, hepatobiliary, and endocrine organs. Gastrointestinal tract immune-related adverse events present with a wide range of symptoms with variable severity, which may lead to treatment interruption and administration of immunosuppression therapy in many cases. Histopathologic changes are diverse, overlapping with many other conditions. Therefore, recognizing these changes is crucial in diagnosing immune-related adverse events. This review discusses the pathologic manifestations of gastrointestinal immune-related adverse events and discusses the primary differential diagnoses.

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.

Anti-nuclear antibody and a granuloma could be biomarkers for iCIs-related hepatitis by anti-PD-1 treatment

It has been reported that various kinds of immune checkpoint inhibitors (iCIs) could induce immune-related liver damage. We should focus on the programmed cell death-receptor-1 (PD-1) antibody and non-small cell lung cancer (NSCLC) to analyze the characteristics of hepatitis related to iCIs and find factors that could be useful biomarkers for the diagnosis. A single-center retrospective study of 252 NSCLC patients who received PD-1 antibody (nivolumab or pembrolizumab). Some of the biochemical markers and immunological markers were analyzed during PD-1-antibody treatment with or without ALT elevation. Histopathological features were reviewed by a single expert of hepatic pathology focusing on the following features: fibrosis, portal inflammation, lobular inflammation, lobular necrosis. The formation of macro- and micro-granulomas was also evaluated. The frequency of liver damage induced by nivolumab including grade 1 to 4 (ALT) was 41.9% (78/186 patients). The positive rate of anti-nuclear antibody in the nivolumab group with iCIs-related hepatitis was significantly higher than that in the nivolumab group without iCIs-related hepatitis (p = 0.00112). Granulomatous changes were significantly increased in patients with iCIs-related hepatitis compared with DILI and AIH patients (p < 0.05). The ratios of inflammatory cells CD4/CD8, and CD138/CD3 in ICIs-related hepatitis were significantly lower than those in AIH or DILI patients (p < 0.05). We demonstrated that the pre-existing ANA and characteristic liver histology including CD8+ cells dominancy and granulomatous hepatitis could be biomarkers for the diagnosis of iCIs-related hepatitis in the NSCLC with anti-PD-1 therapy.

Infrequent liver injury from cemiplimab in patients with advanced cutaneous squamous cell carcinoma

Aim: To describe the incidence and outcomes of liver injury in patients with advanced cutaneous squamous cell carcinoma (cSCC) receiving cemiplimab. Methods: Charts of cSCC patients receiving cemiplimab between 28 September 2018 and 14 July 2020 were reviewed. Liver injury was determined using laboratory criteria, and causality assessment was completed. Results: Of 39 cemiplimab-treated patients, four (10.3%) developed liver injury. Two cases of hepatotoxicity were attributed to immune-mediated liver injury caused by cemiplimab and the two other cases were attributed to other causes. The four patients with liver injury had tumor responses and survival similar to those of the patients without liver injury. Conclusion: Liver injury arising during cemiplimab therapy is mild and infrequent in cSCC patients. Due to its favorable safety profile, cemiplimab should be considered in patients with cSCC and pre-existing liver disease.

Drug-induced bile duct injury: new agents, new mechanisms

PURPOSE OF REVIEW

Drug-induced bile duct injury can be caused by a long list of agents. In most cases, damage is because of T-cell-mediated idiosyncratic reactions. Recently, a number of new agents, including not only drugs but also herbal supplements, have been incriminated and new mechanisms of bile duct injury have emerged. This review will focus on these new data.

RECENT FINDINGS

New members of drug families already known to be responsible for bile duct injury have been incriminated. New players have been identified, such as herbal supplements, like kratom, and recreational drugs, such as ketamine used outside the medical setting. Anticytokine monoclonal antibodies are rarely involved. In contrast, antineoplastic treatments are of growing concern, especially immune checkpoint inhibitors, which induce immune-related adverse effects because of the excessive stimulation of the immune system and its lack of regulation.

SUMMARY

Two patterns of bile duct injury are recognized. Drug-induced small-duct cholangiopathies target the smaller bile ducts; acute injuries eventually progress to chronic disease in the form of the vanishing bile duct syndrome. Drug-induced sclerosing cholangitis target large bile ducts, with a protracted chronic course; the onset of symptoms may be delayed after drug discontinuation; potentially severe, life-threatening complications can occur.

Hepatobiliary and Pancreatic Adverse Events

The expanded approval of immune checkpoint inhibitors (ICIs) for the treatment of multiple cancer types has offered patients more opportunities in treatment selection and survival.Hepatotoxicity is a well-recognized immune-related adverse event (irAE) associated with treatment with ICI. It is considered a type of drug-induced liver injury (DILI). Depending on the specific ICI and whether the patient receives single- or dual-drug therapy, the incidence of hepatotoxicity in general could be as high as 30%. As more patients receive treatment with ICI, more cases of hepatotoxicity are expected to occur. Clinicians must exercise close pharmacovigilance to recognize liver-related irAEs early.ICI-mediated hepatobiliary toxicity (or "IMH") generally presents as asymptomatic elevations of alanine transaminase and aspartate transaminase, with or without alkaline phosphatase elevation. Some patients may present with jaundice, fever, or malaise. Rarely, it may cause liver failure and death. The diagnosis of IMH is made after careful exclusion of other causes of acute hepatitis based on medical history, laboratory evaluation, imaging, and liver histological findings. In clinically significant cases of IMH, the management involves discontinuation of ICI followed by close monitoring and the initiation of immunosuppression. Current society guidelines, which are not based on robust evidence, specify treatment recommendations depending on the grade of liver injury, according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. However, our clinical experience suggests possible alternatives, including lower corticosteroid dosing with adjunct therapies. Whereas current guidelines endorse permanent cessation of future ICI treatment in patients diagnosed with grades 3-4 IMH, published clinical experience suggests potential for flexibility when assessing for candidacy of resuming ICI.Because histologic bile duct injury has been observed in cases ascribed to IMH, ICI-mediated cholangiopathic disease probably exists on a spectrum within IMH. Even extrahepatic bile duct involvement has been observed. This phenotype warrants special considerations in treatment and surveillance.ICI-related cholecystitis has been rarely reported in the literature. Management follows current standards of care for typical cases of cholecystitis. No relationship with ICI-mediated cholangiopathic disease has been observed.Assessing for and managing ICI-associated pancreatic injury remain challenging to the clinician. Many cases of asymptomatic serum lipase elevation are detected on routine labs without clinical signs or symptoms of typical acute pancreatitis. However, symptomatic patients should be initially managed like traditional cases of acute pancreatitis requiring hospitalization for evaluation and inpatient management.

Immune-related cholangitis induced by immune checkpoint inhibitors: a systematic review of clinical features and management

BACKGROUND AIMS

Immune checkpoint inhibitors (ICIs) improve the survival of patients with advanced tumors. However, immune-related adverse events limit the use of ICIs. Although liver toxicity has been concerned gradually, little is known about bile duct injury associated with ICIs. Hence, this review aims to describe clinicopathological features, imaging, and management of immune-mediated cholangitis (IMC) induced by ICIs.

METHODS

We retrieved the literature from the PubMed database for case reports and series of IMC induced by ICIs. IMC was then classified as small-ducts type, large-ducts type and mixed type. Biochemical parameters, pathological characteristics, imaging features, treatment and response were evaluated and compared among three patterns.

RESULTS

Fifty-three cases of IMC were enrolled. The median values of alkaline phosphatase and alanine transaminase of IMC were 1328 and 156 IU/L. The ALP level of the large-ducts type was higher than that of the small-ducts type (P = 0.021). The main pathological characteristics of small-ducts cholangitis were portal inflammation, bile duct injury and ductular reaction. The imaging features of large-duct cholangitis were bile duct dilatation, stenosis and bile duct wall thickening and irregularity. Forty-eight (90%) cases received immunosuppression therapy. Biliary enzymes reduced in 79% of cases receiving immunosuppression therapy, but only 8.5% of cases returned to normal. It took a long time for biliary enzymes to recover.

CONCLUSIONS

The clinicians should be aware of the possibility of IMC if the biliary enzymes increase significantly after the use of ICIs. The liver function can be improved partially by immunosuppressive therapy in the majority of IMC.

Steatosis, Steatohepatitis and Cancer Immunotherapy: An Intricate Story

Immune checkpoint inhibitors represent one of the most significant recent advances in clinical oncology, since they dramatically improved the prognosis of deadly cancers such as melanomas and lung cancer. Treatment with these drugs may be complicated by the occurrence of clinically-relevant adverse drug reactions, most of which are immune-mediated, such as pneumonitis, colitis, endocrinopathies, nephritis, Stevens Johnson syndrome and toxic epidermal necrolysis. Drug-induced steatosis and steatohepatitis are not included among the typical forms of cancer immunotherapy-induced liver toxicity, which, instead, usually occurs as a panlobular hepatitis with prominent lymphocytic infiltrates. Nonetheless, non-alcoholic fatty liver disease is a risk factor for immunotherapy-induced hepatitis, and steatosis and steatohepatitis are frequently observed in this condition. In the present review we discuss how these pathology findings could be explained in the context of current models suggesting immune-mediated pathogenesis for steatohepatitis. We also review evidence suggesting that in patients with hepatocellular carcinoma, the presence of steatosis or steatohepatitis could predict a poor therapeutic response to these agents. How these findings could fit with immune-mediated mechanisms of these liver diseases will also be discussed.

Clinical course of liver injury induced by immune checkpoint inhibitors in patients with advanced malignancies

BACKGROUND

The clinical course of liver injury induced by immune checkpoint inhibitors (ICIs) varies among individuals, and there were few reports on the therapeutic effects of corticosteroids based on the patterns of liver injury.

METHODS

We evaluated the characteristics and clinical course of immune-related liver injury in 1214 patients treated with ICIs for advanced malignancies except for hepatocellular carcinoma between August 2014 and May 2021.

RESULTS

During the follow-up period (median, 252 days), 58 patients (4.8%) had an immune-related liver injury (≥ Grade 3). The liver-injury patterns were hepatocellular (n = 26, 44.8%), mixed (n = 11, 19.0%), or cholestatic (n = 21, 36.2%), and the median time to onset of liver injury was 39, 81, and 53 days, respectively; the hepatocellular pattern occurred earlier than the other types (p = 0.047). Corticosteroids were administered to 30 (51.7%) patients; while liver injury was improved in almost all patients with the hepatocellular pattern (n = 13/14, 92.9%), that failed to show improvement in over half of the patients with the non-hepatocellular patterns, and three patients with mixed patterns needed secondary immunosuppression with mycophenolate mofetil. Liver biopsies performed in 13 patients mainly showed lobular injury, endothelialitis, and spotty necrosis with infiltration of T cells positive for CD3 and CD8, but not CD4 or CD20.

CONCLUSION

The incidence pattern and therapeutic response to corticosteroids in immune-related liver injury differ according to the injury type. Although corticosteroids were effective for the hepatocellular pattern, an additional strategy for refractory non-hepatocellular patterns is needed.

Deciphering the Dynamic Complexities of the Liver Microenvironment - Toward a Better Understanding of Immune-Mediated liver Injury Caused by Immune Checkpoint Inhibitors (ILICI)

Immune checkpoint inhibitors (ICIs) represent a promising therapy for many types of cancer. However, only a portion of patients respond to this therapy and some patients develop clinically significant immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI), an immune-related adverse event (irAE) that may require the interruption or termination of treatment and administration of systemic corticosteroids or other immunosuppressive agents. Although the incidence of ILICI is lower with monotherapy, the surge in combining ICIs with chemotherapy, targeted therapy, and combination of different ICIs has led to an increase in the incidence and severity of ILICI - a major challenge for development of effective and safe ICI therapy. In this review, we highlight the importance and contribution of the liver microenvironment to ILICI by focusing on the emerging roles of resident liver cells in modulating immune homeostasis and hepatocyte regeneration, two important decisive factors that dictate the initiation, progression, and recovery from ILICI. Based on the proposed contribution of the liver microenvironment on ICILI, we discuss the clinical characteristics of ILICI in patients with preexisting liver diseases, as well as the challenges of identifying prognostic biomarkers to guide the clinical management of severe ILICI. A better understanding of the liver microenvironment may lead to novel strategies and identification of novel biomarkers for effective management of ILICI.

Evaluation of liver enzyme elevations and hepatotoxicity in patients treated with checkpoint inhibitor immunotherapy

BACKGROUND AND AIMS

Immune checkpoint inhibitors (ICI) are increasingly used in cancer therapy. Elevated liver enzymes frequently occur in patients treated with ICI but evaluation is poorly described. We sought to better understand causes of liver enzyme elevation, investigation and management.

METHODS

Patients treated with anti-PD-1, PDL-1 or CTLA-4 therapy in Phase I/II clinical trials between August 2012 and December 2018 were included. Clinical records of patients with significant liver enzyme elevations were retrospectively reviewed.

RESULTS

Of 470 ICI-treated patients, liver enzyme elevation occurred in 102 (21.6%), attributed to disease progression (56; 54.9%), other drugs/toxins (7; 6.9%), other causes (22; 21.6%) and ICI immunotoxicity (17; 16.7%; 3.6% of total cohort). Immunotoxicity was associated with higher peak ALT than other causes of enzyme elevation (N = 17; M = 217, 95% CI 145-324 for immunotoxicity, N = 103; M = 74, 95% CI 59-92 for other causes; ratio of means 0.34, 95% CI 0.19-0.60, p = <0.001) and higher ALT:AST ratio (M = 1.27, 95% CI 0.78-2.06 for immunotoxicity, M = 0.69, 95% CI 0.59-0.80 for other causes, ratio of means 0.54, 95% CI 0.36-0.82, p = 0.004). Immunotoxicity was more often seen in patients with prior CPI exposure (41.2% of immunotoxicity vs 15.9% of patients without, p = 0.01), anti-CTLA-4 -containing ICI treatments (29.4% of immunotoxicity vs 6.8% of patients without, p = <0.001) and other organ immunotoxicity (76.5% of immunotoxicity vs 19.2% of patients without, p = <0.001). Cause for enzyme elevation was established in most patients after non-invasive investigation. Liver biopsy was reserved for four patients with atypical treatment response.

CONCLUSIONS

Liver enzyme elevation is common in patients receiving ICI, but often has a cause other than immunotoxicity. A biochemical signature with higher ALT and ALT/AST ratio, a history of prior ICI exposure and other organ immunotoxicities may help to identify patients at a higher likelihood of immunotoxicity. Liver biopsy can be safely deferred in most patients. We propose an approach to diagnostic evaluation in patients with liver enzyme elevations following ICI exposure.

Histopathology of Gastrointestinal Immune-related Adverse Events: A Practical Review for the Practicing Pathologist

Immune checkpoint inhibitors target checkpoint proteins with the goal of reinvigorating the host immune system and thus restoring antitumor response. With the dramatic increase in the use of checkpoint inhibitors for cancer treatment, surgical pathologists have assumed a major role in predicting the therapeutic efficacy (score based on programmed cell death ligand 1 immunohistochemistry and mismatch repair protein loss) as well as diagnosing the complications associated with these medications. Immune-related adverse events (irAEs) manifest as histologic changes seen in both the upper and lower gastrointestinal tract, and when viewed in isolation, may be morphologically indistinguishable from a wide range of diseases including infections, celiac disease, and inflammatory bowel disease, among others. Evaluation of biopsies from both the upper and lower gastrointestinal tract can aid in the distinction of gastrointestinal irAEs from their mimics. In the liver, the histologic changes of hepatic irAEs overlap with de novo diseases associated with hepatitic and cholangitic patterns of injury. The diagnosis of irAEs requires communication and collaboration from the pathologist, oncologist, and gastroenterologist. This review provides a background framework and illustrates the histologic features and differential diagnosis of gastrointestinal and hepatic irAEs.

Clinicopathological analysis of hepatic immune-related adverse events in comparison with autoimmune hepatitis and graft-versus host disease

Immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) are widely used to treat advanced metastatic cancers. Neutralisation of PD-1 or CTLA-4 by ICIs results in immune-related adverse events (irAEs). The clinicopathological features of twelve patients with hepatic irAEs were evaluated and compared to those of ten patients with autoimmune hepatitis (AIH) or graft-versus-host disease (GVHD). No significant difference was seen in serum levels of transaminases, whereas serum levels of IgG and anti-nuclear antibody were higher in patients with AIH than in those with GVHD or hepatic irAEs. Inflammation was limited to the liver lobes in patients with GVHD or hepatic irAEs, whereas patients with AIH exhibited both portal and lobular inflammation. Immunohistochemical analyses revealed a predominant infiltration of CD8⁺ T cells and defective accumulation of regulatory T cells (Tregs) expressing forkhead box p3 (FOXP3) in the lobular areas of patients with hepatic irAEs and GVHD. In contrast, periportal lesions of patients with AIH were characterised by an infiltration of CD4⁺ T cells, CD8⁺ T cells, CD20⁺ B cells, and FOXP3⁺ Tregs. Overall, the activation of CD8⁺ T cells in the absence of activation of Tregs potentially underlies the immunopathogenesis of hepatic irAEs.

When steroids are not enough in immune-related hepatitis: current clinical challenges discussed on the basis of a case report

Immune-related hepatitis (IRH) is a frequent but poorly understood immune-related adverse event and its frequency increases since the use of combination therapy in several cancer types. Therefore, there is an urgent need to develop adapted guidelines to manage IRH. In the present letter, based on Ziogas et al report entitled ‘When steroids are not enough in immune-related hepatitis: current clinical challenges discussed on the basis of a case report’, several points are discussed: assessment of IRH severity and liver biopsy indication, immune-related cholangitis as a differential diagnosis for some IRH presentation, the need of steroids for IRH management or the indication for second line immunosuppressive treatment and finally, the possibility of immunotherapy resumption.

Understanding and treating the inflammatory adverse events of cancer immunotherapy

During the past decade, immunotherapies have made a major impact on the treatment of diverse types of cancer. Inflammatory toxicities are not only a major concern for Food and Drug Administration (FDA)-approved checkpoint blockade and chimeric antigen receptor (CAR) T cell therapies, but also limit the development and use of combination therapies. Fundamentally, these adverse events highlight the intricate balance of pro- and anti-inflammatory pathways that regulate protective immune responses. Here, we discuss the cellular and molecular mechanisms of inflammatory adverse events, current approaches to treatment, as well as opportunities for the design of immunotherapies that limit such inflammatory toxicities while preserving anti-tumor efficacy.

Extending the conversation over the immune-related hepatotoxicity: author response to Dr. Gauci et al

Immune-related hepatotoxicity (IRH) remains the subject of many immune-oncology debates due to its challenging diagnosis and management. Although it is currently defined by the restrictive Common Terminology Criteria for Adverse Events (CTCAE), the term of IRH covers a wide range of liver pathologies, including hepatitic, cholangitic, mixed, steatotic and nonspecific patterns of injury. Even when liver biopsy is performed, the recognized histopathological findings cannot predict the response to steroids or the need for secondary immunosuppression, and usually do not significantly modify the suggested empirical treatment of IRH. Beyond the CTCAE grading, a more comprehensive assessment of IRH severity, including laboratory biomarkers and clinical features, should be developed and a more patient-oriented management should be established by additional randomized evidence, incorporating hepatology and immune-oncology experience.