Drug-Induced Liver Injury Throughout the Drug Development Life Cycle: Where We Have Been, Where We are Now, and Where We are Headed. Perspectives of a Clinical Hepatologist

Clinical Significance of Transient Asymptomatic Elevations in Aminotransferase (TAEAT) in Oncology

Monitoring for liver injury remains an important aspect of drug safety assessment, including for oncotherapeutics. When present, drug-induced liver injury may limit the use or result in the discontinuation of these agents. Drug-induced liver injury can exhibit with a wide spectrum of clinical and biochemical manifestations, ranging from transient asymptomatic elevations in aminotransferases (TAEAT) to acute liver failure. Numerous oncotherapeutics have been associated with TAEAT, with published reports indicating a phenomenon in which patients may be asymptomatic without overt liver injury despite the presence of grade ≥3 aminotransferase elevations. In this review, we discuss the occurrence of TAEAT in the context of oncology clinical trials and clinical practice, as well as the clinical relevance of this phenomenon as an adverse event in response to oncotherapeutics and the related cellular and molecular mechanisms that may underlie its occurrence. We also identify several gaps in knowledge relevant to the diagnosis and the management of TAEAT in patients receiving oncotherapeutics, and identify areas warranting further study to enable the future development of consensus guidelines to support clinical decision-making.

Azithromycin-Induced Liver Injury in an Asthma Exacerbation Patient With Autoimmune Features

Drug-induced liver injury (DILI) is one of the leading causes of acute liver failure in the United States. Antimicrobials are the most common class of drugs implicated in this pathology. Although azithromycin has been documented as a relatively safe drug, one of its rare and potentially fatal side effects is DILI. Diagnosing DILI is difficult because it is a diagnosis of exclusion. Autoimmune hepatitis (AIH) may present similarly to DILI, and a liver biopsy may be needed to differentiate between the two conditions. We present a case of azithromycin-induced liver injury in an asthma exacerbation patient with features of AIH.

Onapristone Extended Release: Safety Evaluation from Phase I-II Studies with an Emphasis on Hepatotoxicity

Introduction

Antiprogestins have demonstrated promising activity against breast and gynecological cancers, but liver-related safety concerns limited the advancement of this therapeutic class. Onapristone is a full progesterone receptor antagonist originally developed as an oral contraceptive and later evaluated in phase II studies for metastatic breast cancer. Because of liver enzyme elevations identified during clinical studies, further development was halted. Evaluation of antiprogestin pharmacology and pharmacokinetic data suggested that liver enzyme elevations might be related to off-target or metabolic effects associated with clinical drug exposure.

Objective

We explored whether the use of a pharmaceutic strategy targeting efficacious systemic dose concentrations, but with diminished peak serum concentrations and/or total drug exposure would mitigate hepatotoxicity. Twice-daily dosing of an extended-release formulation of onapristone was developed and clinically evaluated in light of renewed interest in antiprogestin therapy for treating progesterone receptor-positive breast and gynecologic cancers. The hepatotoxic potential of extended-release onapristone was assessed from two phase I–II studies involving patients with breast, ovarian, endometrial, and prostate cancer.

Results

Among the 88 patients in two phase I–II studies in progesterone receptor-positive malignancies treated with extended-release onapristone, elevated alanine aminotransferase/aspartate aminotransferase levels were found in 20% of patients with liver metastases compared with 6.3% without metastases. Of five patients with grade 3 or higher alanine aminotransferase elevations with or without bilirubin elevations (four with breast cancer and one with endometrial cancer), four were assessed as unrelated to extended-release onapristone by the safety data review committee. Furthermore, while the fifth patient’s liver enzyme elevations were considered possibly drug related by the study investigator, they were adjudicated as unlikely to be related (< 25% likelihood) by a subsequent independent hepatologist.

Conclusions

These results suggest that the extended-release formulation by reducing drug exposure may be associated with a reduced risk of hepatotoxicity, and supports the continued clinical evaluation of extended-release onapristone for treating progesterone receptor-positive cancers.

ACG Clinical Guideline: Diagnosis and Management of Idiosyncratic Drug-Induced Liver Injury

Idiosyncratic drug-induced liver injury (DILI) is common in gastroenterology and hepatology practices, and it can have multiple presentations, ranging from asymptomatic elevations in liver biochemistries to hepatocellular or cholestatic jaundice, liver failure, or chronic hepatitis. Antimicrobials, herbal and dietary supplements, and anticancer therapeutics (e.g., tyrosine kinase inhibitors or immune-checkpoint inhibitors) are the most common classes of agents to cause DILI in the Western world. DILI is a diagnosis of exclusion, and thus, careful assessment for other etiologies of liver disease should be undertaken before establishing a diagnosis of DILI. Model for end-stage liver disease score and comorbidity burden are important determinants of mortality in patients presenting with suspected DILI. DILI carries a mortality rate up to 10% when hepatocellular jaundice is present. Patients with DILI who develop progressive jaundice with or without coagulopathy should be referred to a tertiary care center for specialized care, including consideration for potential liver transplantation. The role of systemic corticosteroids is controversial, but they may be administered when a liver injury event cannot be distinguished between autoimmune hepatitis or DILI or when a DILI event presents with prominent autoimmune hepatitis features.

Levetiracetam-Induced Hepatic Dysfunction

Although levetiracetam is the antiepileptic of choice in patients after hepatic transplantation and patients with hepatic dysfunction, we report a patient in whom levetiracetam was the most probable cause of hepatic dysfunction. Treatment of this hepatic dysfunction is to have a high degree of suspicion and withdraw the drug at the earliest to prevent morbidity and rarely mortality. Though rare, this is an important unwanted side effect of this highly useful medication.

Computational Models Using Multiple Machine Learning Algorithms for Predicting Drug Hepatotoxicity with the DILIrank Dataset

Drug-induced liver injury (DILI) remains one of the challenges in the safety profile of both authorized and candidate drugs, and predicting hepatotoxicity from the chemical structure of a substance remains a task worth pursuing. Such an approach is coherent with the current tendency for replacing non-clinical tests with in vitro or in silico alternatives. In 2016, a group of researchers from the FDA published an improved annotated list of drugs with respect to their DILI risk, constituting “the largest reference drug list ranked by the risk for developing drug-induced liver injury in humans” (DILIrank). This paper is one of the few attempting to predict liver toxicity using the DILIrank dataset. Molecular descriptors were computed with the Dragon 7.0 software, and a variety of feature selection and machine learning algorithms were implemented in the R computing environment. Nested (double) cross-validation was used to externally validate the models selected. A total of 78 models with reasonable performance were selected and stacked through several approaches, including the building of multiple meta-models. The performance of the stacked models was slightly superior to other models published. The models were applied in a virtual screening exercise on over 100,000 compounds from the ZINC database and about 20% of them were predicted to be non-hepatotoxic.

[Drug Induced Liver Injury by Prophylactic Administration of Albendazole]

Albendazole is used as a typical antiparasitic agent worldwide. The side effects of albendazole may include nausea, vomiting, abdominal pain, dizziness, headache, alopecia, and increased liver enzymes. Mild elevation of the liver enzyme has been reported in more than 10% of cases, but drug induced liver injury was reported to be very rare. A 30-year-old woman visited the Dong-A University Hospital with anorexia, nausea, jaundice, and elevated liver enzyme. For diagnosis, other acute hepatitis etiologies were excluded, but the prophylactic administration of albendazole was verified. This paper introduces a case of drug-induced liver injury through the prophylactic administration of albendazole. Physicians should be aware of severe liver injury as one of the side effects of albendazole.

Safety data and withdrawal of hepatotoxic drugs

BACKGROUND AND AIM

The occurrence of drug induced liver injury (DILI) is the most common reason of post-marketing withdrawals. DILI in humans is difficult to predict using in vitro cytotoxicity screening and animal studies. A review of hepatotoxicity data was performed with the aim of identifying relevant factors that could have predicted the occurrence of serious DILI.

METHODS

The drugs withdrawn from the market due to hepatotoxicity in Europe and/or in USA either by marketing authorization holders or by Regulatory agencies from 1997 to 2016 were selected. The liver safety data and the withdrawal decisions were identified from a search within the European medicine agency (EMA) website, the Food and drug administration (FDA) orange book and PubMed^®.

RESULTS

From 1997 to 2016, eight drugs were withdrawn from the market for hepatotoxicity reason: tolcapone, troglitazone, trovafloxacin, bromfenac, nefazodone, ximelagatran, lumiracoxib and sitaxentan. The safety data suggest that while liver test abnormalities have been detected during clinical trials, other relevant factors leading to the discontinuation of these drugs have been identified: lack of predictability of animal models, inappropriate liver function test, non-compliance with drug treatment, less attention paid to rare adverse drug reactions, unpredictable occurrence and irreversible outcome of liver toxicity.

CONCLUSION

Several relevant factors may contribute to an inadequate risk management leading to the discontinuation of the drugs. Preclinical safety data are not sufficient to allow early prediction of DILI in humans and post-marketing safety monitoring and signal detection still should be used to identify potential serious cases of DILI. However, it seems that changes in Pharmacovigilance legislation with a closer management of drug safety may have contributed to the improvement of the risk minimization.

Drug-induced liver injury: Do we know everything?

Interest in drug-induced liver injury (DILI) has dramatically increased over the past decade, and it has become a hot topic for clinicians, academics, pharmaceutical companies and regulatory bodies. By investigating the current state of the art, the latest scientific findings, controversies, and guidelines, this review will attempt to answer the question: Do we know everything? Since the first descriptions of hepatotoxicity over 70 years ago, more than 1000 drugs have been identified to date, however, much of our knowledge of diagnostic and pathophysiologic principles remains unchanged. Clinically ranging from asymptomatic transaminitis and acute or chronic hepatitis, to acute liver failure, DILI remains a leading causes of emergent liver transplant. The consumption of unregulated herbal and dietary supplements has introduced new challenges in epidemiological assessment and clinician management. As such, numerous registries have been created, including the United States Drug-Induced Liver Injury Network, to further our understanding of all aspects of DILI. The launch of LiverTox and other online hepatotoxicity resources has increased our awareness of DILI. In 2013, the first guidelines for the diagnosis and management of DILI, were offered by the Practice Parameters Committee of the American College of Gastroenterology, and along with the identification of risk factors and predictors of injury, novel mechanisms of injury, refined causality assessment tools, and targeted treatment options have come to define the current state of the art, however, gaps in our knowledge still undoubtedly remain.

Current and future directions in the treatment and prevention of drug-induced liver injury: a systematic review

While the pace of discovery of new agents, mechanisms and risk factors involved in drug-induced liver injury (DILI) remains brisk, advances in the treatment of acute DILI seems slow by comparison. In general, the key to treating suspected DILI is to stop using the drug prior to developing irreversible liver failure. However, predicting when to stop is an inexact science, and commonly used ALT monitoring is an ineffective strategy outside of clinical trials. The only specific antidote for acute DILI remains N-acetylcysteine (NAC) for acetaminophen poisoning, although NAC is proving to be beneficial in some cases of non-acetaminophen DILI in adults. Corticosteroids can be effective for DILI associated with autoimmune or systemic hypersensitivity features. Ursodeoxycholic acid, silymarin and glycyrrhizin have been used to treat DILI for decades, but success remains anecdotal. Bile acid washout regimens using cholestyramine appear to be more evidenced based, in particular for leflunomide toxicity. For drug-induced acute liver failure, the use of liver support systems is still investigational in the United States and emergency liver transplant remains limited by its availability. Primary prevention appears to be the key to avoiding DILI and the need for acute treatment. Pharmacogenomics, including human leukocyte antigen genotyping and the discovery of specific DILI biomarkers offers significant promise for the future. This article describes and summarizes the numerous and diverse treatment and prevention modalities that are currently available to manage DILI.

Enoxaparin-Induced Liver Injury: Case Report and Review of the Literature and FDA Adverse Event Reporting System (FAERS)

Anticoagulants are a well known cause of drug-induced liver injury (DILI). We recently encountered a 45-year-old male who developed DILI during treatment with enoxaparin, a low-molecular-weight heparin (LMWH), for dural venous thrombosis. The man received enoxaparin 80 mg subcutaneously, twice daily. After 4 days, the patient was asymptomatic but he developed liver aminotransferase elevations: AST 340 U/L and ALT 579 U/L. Investigation revealed an R ratio of 19.9 by day 5 and a Roussel Uclaf Causality Assessment Method score of 10, giving a high probable likelihood that enoxaparin was the cause of hepatic injury. Enoxaparin was discontinued on day 7, and 1 week later AST and ALT had decreased to 61 and 273 U/L, respectively. This case prompted a literature search and a review of the FDA Adverse Event Reporting System (FAERS) database for the range of hepatic adverse events (HAEs) associated with this class. A MEDLINE/PubMed search was conducted using DILI terms and cross-referenced with the anticoagulant classes. A Freedom of Information Act (FOIA) request was also made to identify adverse events (AEs) associated with enoxaparin in FAERS. Case type, severity of outcome, and demographic information were analyzed. Five publications have reported DILI with enoxaparin. Trial data found elevations in ALT >3 times the upper limit of normal (ULN) for unfractionated heparins (UFH) and LMWH in 8 and 4-13 % of subjects, respectively. However, liver injury in all cases was mild, self-limited, and asymptomatic. Our FOIA request yielded 8336 adverse events related to enoxaparin over a 14-year period (Jan 2000-Sept 2014). Specific HAEs were found in 4 % of reports, but all were described with other serious adverse events. The reported outcomes of hospitalization (75 %), death (17 %), and life-threatening medical events (5 %) were likely due to other related serious adverse events such as hemorrhage (28 %) and thrombocytopenia (11 %). We conclude that LMWH-related liver injury is uncommon and reversible. The mechanism of liver injury is not known, although an idiosyncratic effect is postulated. Although the FAERS database lists hepatic injury in 4 % of all enoxaparin-related AEs, it appears that serious outcomes are related to non-hepatic events.

The Art and Science of Diagnosing and Managing Drug-induced Liver Injury in 2015 and Beyond

Drug-induced liver injury (DILI) remains a leading reason why new compounds are dropped from further study or are the subject of product warnings and regulatory actions. Hy's Law of drug-induced hepatocellular jaundice causing a case-fatality rate or need for transplant of 10% or higher has been validated in several large national registries, including the ongoing, prospective U.S. Drug-Induced Liver Injury Network. It serves as the basis for stopping rules in clinical trials and in clinical practice. Because DILI can mimic all known causes of acute and chronic liver disease, establishing causality can be difficult. Histopathologic findings are often nonspecific and rarely, if ever, considered pathognomonic. A daily drug dose >50-100 mg is more likely to be hepatotoxic than does <10 mg, especially if the compound is highly lipophilic or undergoes extensive hepatic metabolism. The quest for a predictive biomarker to replace alanine aminotransferase is ongoing. Markers of necrosis and apoptosis such as microRNA-122 and keratin 18 may prove useful in identifying patients at risk for severe injury when they initially present with a suspected acetaminophen overdose. Although a number of drugs causing idiosyncratic DILI have HLA associations that may allow for pre-prescription testing to prevent hepatotoxicity, the cost and relatively low frequency of injury among affected patients limit the current usefulness of such genome-wide association studies. Alanine aminotransferase monitoring is often recommended but has rarely been shown to be an effective method to prevent serious DILI. Guidelines on the diagnosis and management of DILI have recently been published, although specific therapies remain limited. The LiverTox Web site has been introduced as an interactive online virtual textbook that makes the latest information on more than 650 agents available to clinicians, regulators, and drug developers alike.

Hepatic decompensation likely attributable to simeprevir in patients with advanced cirrhosis

BACKGROUND

Hyperbilirubinemia is a common side effect of protease inhibitors used to treat chronic hepatitis C (HCV), and most patients do not experience without clinically overt hepatotoxicity. The safety of second-wave protease inhibitors, including simeprevir, has not been well studied in patients with advanced cirrhosis.

MATERIALS & METHODS

We report two cases of suspected drug-induced liver injury leading to hepatic decompensation in patients with advanced HCV cirrhosis treated with the combination of simeprevir and sofosbuvir on a compassionate basis. Both patients developed marked hyperbilirubinemia out of proportion to their aminotransferases, despite clearance of hepatitis C RNA. RUCAM scoring was probable and possible, respectively. While other factors may have contributed to the liver injury, including infection and concurrent administration of other medications, we believe that the potentially deleterious hepatic effects of simeprevir on transporters or other key functional components were the main reason for their decompensation.

CONCLUSIONS

Protease inhibitors should be used with caution, if at all, in patients with cirrhosis, especially in those with the most advanced disease. We await newer, safer, direct-acting antiviral therapies for such patients, especially those on our transplant list.

ACG Clinical Guideline: the diagnosis and management of idiosyncratic drug-induced liver injury

Idiosyncratic drug-induced liver injury (DILI) is a rare adverse drug reaction and it can lead to jaundice, liver failure, or even death. Antimicrobials and herbal and dietary supplements are among the most common therapeutic classes to cause DILI in the Western world. DILI is a diagnosis of exclusion and thus careful history taking and thorough work-up for competing etiologies are essential for its timely diagnosis. In this ACG Clinical Guideline, the authors present an evidence-based approach to diagnosis and management of DILI with special emphasis on DILI due to herbal and dietary supplements and DILI occurring in individuals with underlying liver disease.

Drug-induced liver injury: what was new in 2013?

INTRODUCTION

The year 2013 continued to highlight numerous aspects of drug-induced liver injury (DILI), with new information communicated via > 1500 publications. New reports of DILI were described and FDA warnings and alerts were issued for a number of products, emphasizing the risks related to hepatotoxicity.

AREAS COVERED

We provide a summary of the year's published reports of new causes of DILI, along with reviews and reports of established hepatotoxins, new and expanded DILI registries and the continuing emphasis placed on genetic and other risk factors. Several new analyses of data generated from the US DILI Network are included.

EXPERT OPINION

The clinical usefulness of pharmacogenetic testing remains to be determined; the number of patients who must be tested is large and the overall risk of DILI is quite small. The role that dose and hepatic metabolism play in causing idiosyncratic DILI was reviewed; daily doses > 50 - 100 mg of medications with high lipophilicity appear to be most predictive of severe DILI, but not in all cases. Restricting access to paracetamol in certain parts of the UK continues to demonstrate a successful reduction in the number of acute liver failure cases and patients listed for liver transplant.