November 14, 2013

Hepatic Medicine: Evidence and Research

DOI: http://dx.doi.org/10.2147/HMER.S90511

Mona H Ismail1, Massimo Pinzani2

1Department of Internal Medicine, Division of Gastroenterology, King Fahad University Hospital, Al-Khobar, Saudi Arabia; 2Dipartimento di Medicina Interna Center for Research, High Education and Transfer, Università degli Studi di Firenze, Florence, Italy

Abstract: Chronic liver injuries of different etiologies eventually lead to fibrosis, a scarring process associated with increased and altered deposition of extracellular matrix in the liver. Progression of fibrosis has a major worldwide clinical impact due to the high number of patients affected by chronic liver disease which can lead to severe complications, expensive treatment, a possible need for liver transplantation, and death. Liver fibrogenesis is characterized by activation of hepatic stellate cells and other extracellular matrix producing cells. Liver fibrosis may regress following specific therapeutic interventions. Other than removing agents causing chronic liver damage, no antifibrotic drug is currently available in clinical practice. The extent of liver fibrosis is variable between individuals, even after controlling for exogenous factors. Thus, host genetic factors are considered to play an important role in the process of liver scarring. Until recently it was believed that this process was irreversible. However, emerging experimental and clinical evidence is starting to show that even cirrhosis in its early stages is potentially reversible.

Keywords: liver fibrosis, cirrhosis, fibrogenesis, antifibrotic agents

Introduction

Chronic liver disease is a major cause of mortality and morbidity worldwide. Most chronic liver diseases progress from mild inflammation to more severe inflammation, leading to fibrosis or cirrhosis. This can result in liver failure and portal hypertension, and is associated with an increased risk of liver cancer.1 The development of advanced fibrosis, and particularly cirrhosis, is associated with significant and life-threatening complications, with liver transplantation being the only available treatment. However, transplantation is not always possible, due to limited organ availability and the presence of contraindicating comorbidities.

Fibrosis is a progressive pathological process in which the body’s wound healing and tissue remodeling mechanisms respond to liver injury by promoting replacement of normal hepatic tissue with a scar-like matrix composed of cross-linked collagen.2 Until recently, it was believed that this process was irreversible.3 However, emerging experimental and clinical evidence is starting to show that even early stages of cirrhosis are potentially reversible.

The cascade of events leading to hepatic fibrosis is complex, and is influenced by how different cell types in the liver interact in response to injury. The main cell type responsible for the development of fibrosis in chronic liver disease is the activated hepatic stellate cell. Chronically activated hepatic stellate cells proliferate and synthesize extracellular matrix proteins to produce the fibrous scar (Figure 1).4

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Figure 1 Schematic presentation of liver fibrogenesis.

Following any type of liver injury, hepatic stellate cells differentiate into myofibroblasts and acquire the typical “myofibroblast- like” phenotype characterized by a multifunctional profibrogenic, proinflammatory, and proangiogenic profile. Reported phenotypic changes garnered from hepatic stellate cell culture studies include increased proliferation, increased expression levels of platelet-derived growth factor-β and smooth muscle α-actin (α-SMA), and enhanced collagen secretion.5–8 More recent evidence implicates a role for leptin in hepatic stellate cell transdifferentiation by activating the hedgehog pathway, and galectin-3 for hepatic stellate cell activation in vivo.9,10

In addition to hepatic stellate cells, other resident liver mesenchymal cells, such as portal fibroblasts and myofibroblasts, contribute to hepatic fibrogenesis, particularly in chronic liver diseases characterized by primary involvement of the portal and periportal areas (ie, chronic viral hepatitis and cholestatic diseases).11

There is some evidence that bone marrow-derived fibrocytes or circulating mesenchymal cells can migrate through the injured liver and become myofibroblasts, which participate in the fibrotic process.12,13 In addition, there is controversial evidence that hepatocytes and cholangiocytes may undergo epithelial–mesenchymal transition to become activated myofibroblasts.14 Likewise, phenotypic agility associated with epithelial–mesenchymal transition allows for the reverse process whereby mesenchymal cells convert into epithelial derivatives.14

Among the three types of proposed epithelial– mesenchymal transitions, type 2 epithelial–mesenchymal transition refers to the process occurring in chronic fibrogenic disorders. In the context of fibrogenesis, synthesis and deposition of type I collagens most appropriately signal myofibroblast function in vivo.14 However, despite in vitro evidence supporting 1α1 gene activation in cultured epithelial cells, including hepatocytes, these cells fail to generate collagen 1α1 transcripts in vivo.14–16 In addition, some cells, particularly macrophages, internalize the collagen fibrillar extracellular matrix that leads to mistaken association of collagen accumulation with collagen synthesis. These contradictions beg the question of whether epithelial cells really play a role in fibrogenesis.14,15,17–19

Many cellular markers have been wrongly defined as myofibroblast-specific based on gene expression patterns. For example, certain hepatocytes and cholangiocytes express “mesenchymal markers” typical of cell motility and survival. Hepatocytes when cultured in vitro and chronically stimulated with transforming growth factor-β1 or serum factors exhibit genetic expression patterns analogous to myof ibroblasts in vivo and connective tissue at the development stage.14,20–24 Some of the genes expressed include α-SMA, Slug, Twist, Snail, vimentin, and fibroblast- specific protein implicated in cell motility in general, although these genes do not mark myofibroblast or epithelial cell lineages specifically.14,15,18,25–28 Oddly, α-SMA, that forms part of the cell’s contractile machinery, constitutes a poor lineage marker for fibrogenesis, although it is the most widely used marker for recognizing myofibroblasts. Activation of this protein expression during disease or as part of an adaptive response to injury, compounded by the fact that it contributes minimally, if at all, to the synthesis and deposition of fibrillar extracellular matrix, explains the ambiguous role of α-SMA in marking myofibroblastic activity.14

A direct contribution of cholangiocytes to fibrosis via an epithelial–mesenchymal transition pathway has been proposed by Omenetti et al who demonstrated that immature cholangiocytes undergo a complete epithelial–mesenchymal transition when treated with activated hepatic stellate cell medium.29 Others have shown coexpression of epithelial and mesenchymal markers in human liver cholangiocytes extracted from patients with cholestatic disease.30,31 However, recent reports have challenged the concept of cholangiocyte epithelial–mesenchymal transition, with conclusions pointing towards an absence of this process in liver fibrosis models.32 Specifically, fluorescently labeled cholangiocytes expressing the bile ductular cell-specific marker, K19, failed to coexpress myofibroblast markers in either bile duct-ligated or CCL4-induced fibrosis mouse models.33 Clearly, further explorations beyond intuitive speculation are needed to unravel the role of epithelial cells and cholangioctyes in fibrogenesis, if any.

The development of significant tissue fibrosis usually requires several years of ongoing insult. However, not all patients exposed to a similar causal agent develop the same degree of liver fibrosis, ie, patients with similar risk factors have some variability in progression of liver fibrosis, which also may reflect host genotypic polymorphisms.33 Evidence of fibrotic regression has now been documented in the entire spectrum of chronic liver diseases, including autoimmune hepatitis, biliary obstruction, iron overload, nonalcoholic steatohepatitis,34 and viral hepatitis B (HBV) and C (HCV).35,36

Patterns of fibrosis progression have been described on the basis of their disease origin. Among the contributors, chronic HCV poses a significant risk for developing fibrotic tissue, but only becomes lethal following cirrhosis onset. Factors affecting the rate of fibrosis progression in HCVinfected patients include duration of infection, age, male gender, consumption of alcohol, human immunodeficiency (HIV) coinfection, and low CD4 count.37–41 Metabolic conditions, including obesity, steatosis, and diabetes, are also surfacing as independent risk factors.42

Both male gender and age strongly influence the speed of disease transition from infection to cirrhosis, with a 300- fold higher progression rate seen in men aged 61–70 years versus those 20–40 years of age.41 In contrast, HCV-infected women progress to cirrhosis at a much slower rate compared with their male counterparts, regardless of age. A multicenter study aimed at evaluating the natural history of liver fibrosis progression in HCV and associated risk factors reported a median 39% higher annual rate of fibrosis progression in men compared with women.43 The significance of this result was partially rationalized by the greater alcohol consumption associated with men in this trial.

Antifibrotic effects from estrogen may also explain the fibrosis progression disparity seen between the genders. Long-term estrogen exposure reduced liver fibrosis progression in HCV-infected women who had either been pregnant, taken oral contraceptives, or received hormone replacement therapy in one retrospective study conducted across two centers in France.44 Infected postmenopausal women not receiving hormone replacement therapy showed the highest rate of fibrosis progression.44

Some speculative data have emerged demonstrating a correlation between insulin resistance and increased rate of fibrosis progression in nondiabetic individuals infected with chronic HCV, although a longitudinal study is needed to confirm this interesting observation.45

Patients coinfected with HIV and HCV have more rapid progression of cirrhosis that may be partially curbed with highly active antiretroviral therapies.46–50 In a recent study, Berenguer et al examined the effects of exposing coinfected patients to nonnucleoside reverse transcriptase inhibitor and protease inhibitor therapy, and reported a successful outcome in reducing fibrosis progression with nonnucleoside reverse transcriptase inhibitors but not with protease inhibitors.46

Other special populations on the radar for developing fibrosis-related complications include those with hemochromatosis or nonalcoholic steatohepatitis. Cirrhotic patients with nonalcoholic steatohepatitis have a reduced life expectancy and a concomitant 67% 5-year survival rate.51,52 Evaluation of pooled data from histological studies identified inflammation on the initial biopsy and age as independent predictors of progression of fibrosis to advanced nonalcoholic steatohepatitis.52

Individuals suffering from hemochromatosis, characterized by iron deposition within tissues and related end-organ damage, develop cirrhosis, which may or may not present with symptoms or elevated liver enzymes.53–55 Some important risk factors identified for increased rate of progression of fibrosis in this patient population include alcohol consumption, hepatic steatosis, HCV coinfection, male gender, oxidative injury, and genetic polymorphisms, particularly implicating transforming growth factor-β1, tumor necrosis factor-β, and MCP1.53

Although there is no doubt that liver tissue fibrosis can regress, the issue of regression/reversibility of cirrhosis is controversial and requires considerable clarification. This is particularly relevant after several claims of “cirrhosis reversal” in patients with chronic HBV and HCV infection after antiviral treatment.35,56 The concept of cirrhosis reversibility originates from evidence obtained in animal models upon the discontinuation of the cause of liver damage or following treatment with antifibrotic agents. Although cirrhosis tends to be defined as one stage, it is quite evident, both morphologically and clinically, that there are several stages of evolution following the initial morphological evidence of cirrhotic transformation of liver tissue. “Early” cirrhosis is often macronodular, with a limited thickness of fibrotic septa and a scarcity of neoangiogenesis. In addition, at this stage, the fibrotic tissue is still characterized by the presence of profibrogenic cells and an abundant inflammatory infiltrate. The evolution of this picture is characterized by increased thickness of the septa that become progressively acellular and by the development of micronodular cirrhosis. From the biochemical point of view, collagen fibers undergo extensive crosslinking and are wrapped in filaments of elastin. At this advanced stage, fibrosis becomes largely irreversible. Therefore, claims of “cirrhosis reversal” need to be framed in the stage of evolution of a cirrhotic liver and the term “reversal” used to denote a return to near-normal liver structure.

Establishing cirrhosis reversal in humans has been hampered by a lack of supportive evidence, compounded by the fact that few relevant experiments were carried out using animal models.57,58 It should be stressed that in the large majority of the available animal models (mostly in rodents), cirrhosis develops within weeks and is rather different both in morphological and biochemical (ie, composition and three-dimensional arrangement) terms from the cirrhosis observed in chronically ill patients who develop liver disease over several decades.

Mechanisms of fibrosis reversal

The first documented evidence for the reversal of liver fibrosis derived from studies showing a progressive decrease of fibrosis associated with apoptosis of hepatic stellate cells in rat models of chronic intoxication with CCl4 following suspension of toxic and bile duct ligation after recanalization of the bile duct.59,60 Altogether, these studies suggested that apoptosis of hepatic stellate cells plays a critical role in the recovery from biliary as well as toxic-induced liver fibrosis. In addition, hepatic stellate cell survival and apoptosis are regulated by growth factors expressed during fibrotic liver injury. Issa et al58 went further to show that reversal was obtained in a chronic CCl4 model, even when an advanced stage of micronodular cirrhosis was obtained after 12 weeks of administration of CCl4. Indeed, 1 year after the cessation of administration of CCl4, micronodular cirrhosis underwent remodeling to macronodular cirrhosis. In addition, expression of collagen type 1 and tissue inhibitor of metalloproteinases 1 (TIMP-1) mRNA decreased significantly, and active metalloproteinases were shown in liver tissue during fibrosis remodeling. This was paralleled by a significant loss of more recently formed fibrils, decreased perisinusoidal fibrosis, and decreased thickness of fibrotic septa. Once again, resolution was characterized by apoptosis of hepatic stellate cells, predominantly at the edges of fibrotic septa. Residual septa, not remodeled after 1 year, were characterized by transglutaminase-mediated crosslinking and relative hypocellularity. This experimental study highlighted a limited potential for the cirrhotic liver to engage in spontaneous regression of the mature matrix in the absence of a therapeutic intervention.57,58

The relationship between fibrosis reversal and hepatic stellate cell apoptosis highlighted by these studies in animal models suggested that induction of hepatic stellate cell apoptosis could represent a potential antifibrogenic target. This process would necessarily remove the primary hepatic source of newly synthesized collagens as well as TIMP-1.61 Hepatic TIMP-1 inhibits metalloproteinases implicated in matrix degradation, and both collagen and TIMP-1 promote myofibroblast survival.62,63 Reverse differentiation of the myofibroblasts back to their original phenotype occurs in vitro and therefore constitutes an alternative mechanism for fibrosis regression, although as yet there is no in vivo evidence supporting this claim.57,64,65 In fact, Kim et al reported decreases in desmin-positive cells in rats recovering from dimethylnitrosamine-induced fibrosis.66 This result argues for the apoptotic pathway because desmin marks both activated myofibroblasts and their hepatic stellate cell precursors.66

However, the concept of hepatic stellate cell apoptosis in animal models is not likely to be completely reproducible in the human setting. Despite what we have learned about antifibrotic mechanisms from animal studies, the evidence is at best speculative and needs further support particularly with relevance to clinical evidence. Although apoptosis seems to play a role in fibrosis regression, it may simply represent a symptom of extracellular matrix remodeling. This explanation garners validity from experimental evidence showing that expression levels of both collagen 1 and TIMP-1 ramp up during fibrogenesis, but then decrease in the recovering injured liver.57,63,67

Different studies performed in human hepatic stellate cells and in liver tissue obtained from patients with chronic viral hepatitis have suggested that human profibrogenic cells, and particularly hepatic stellate cells, are characterized by a resistance to apoptosis once activated and fully involved in the fibrogenic process.68,69 It is therefore plausible that long-term fibrogenesis is characterized, in addition to biochemical evolution of scar tissue and lack of an appropriate degradation machinery, by the immovability of a critical mass of profibrogenic cells.

An important aspect of macrophage biology in the fibrogenic process is the observation that these cells are required for fibrosis resolution after withdrawal of the damaging agent. Along these lines, selective depletion of macrophages resulted in reduced scarring and a lower number of fibrogenic cells in the active phase of fibrogenesis, as expected based on previous work.70 However, macrophage depletion during fibrosis resolution was associated with delayed matrix degradation. These data indicate the existence of distinct subpopulations of macrophages and the role of these cells in the recovery phase of the fibrogenic process. These data have been recently expanded with the observation that scar-associated macrophages that mediate fibrosis resolution express matrix metallopeptidase 13 allowing them to degrade complex extracellular matrices and remodeling of scar.71 The interaction between the chemokine system and macrophages in the process leading to fibrosis resolution has also been recently investigated. When chronically intoxicated with CCl4, mice lacking chemokine (C-C motif) receptor 2 (CCR2) showed lower levels of fibrosis compared with wild-type animals, and reduced F4/80+, CD11b+, and CD11c+ populations at the sites of injury.72 However, upon discontinuation of toxin administration, fibrosis persisted in CCR2 knockout mice, and was correlated with sustained expression of TIMP-1 and with reduction in matrix metallopeptidase 13 expression. These data suggest that this chemokine system is one of the molecular effectors of both macrophage recruitment during active fibrogenesis and of macrophagedependent fibrosis resolution. Accordingly, because therapies that interfere with chemokines or their receptors are being developed, it may be speculated that a therapy interfering with CCR2 could possibly retard the regression of fibrosis, especially when associated with a strategy that reduces the extent of damage.

Clinical evidence for reversal

Accordingly, when performing an accurate analysis of results of the clinical studies claiming reversal of cirrhosis after antiviral treatment, the only prudent conclusion is that, in most cases, there was a variable degree of fibrosis regression in cirrhosis but not a reversal of cirrhosis.73,74 For example, Poynard et al reported fibrosis reduction among cirrhotic patients with chronic HCV who received pegylatedinterferon (IFN) and ribavirin regimens.75 Of the 153 patients enrolled in their study, 49% showed downstaging of liver fibrosis from stage 4 to stage 3. A separate study looked retrospectively at liver improvements in 113 individuals with confirmed hepatic cirrhosis and receiving immunosuppressive therapies, including IFN-α, or a combination of IFN-α and ribavirin in the case of viral hepatitis infection, or steroids plus azathioprine in autoimmune patients. Among the 113 participants, 14 (12.4%) had biopsy-proven disappearance of cirrhosis.76 One rare report describing spontaneous recovery in two young men who had developed HBV-related cirrhosis as children recently emerged. The investigators attributed their “cure” to cessation of viral replication.77

Although fibrosis seems to be a reversible process accompanied by regression of scar tissue, establishing clear remodeling or an apoptotic mechanism underlying the regression process remains an elusive goal. However, the more challenging goal of reversing cirrhosis must take into account features other than simple regression alone. Additional factors, including what effects rapid clearance of the matrix would have on the highly altered vasculature structure of the cirrhotic liver, warrants special consideration.13,74,78 The availability of improved diagnostic techniques for monitoring disease progression should also enhance the evaluation of potential antifibrotic therapeutics in the clinic.79

In other words, fibrotic deposition related to recent disease and characterized by the presence of thin reticulin fibers, often in the presence of a diffuse inflammatory infiltrate, is likely to be fully reversible, whereas longstanding fibrosis, characterized by extensive collagen crosslinking in a dense acellular/ paucicellular extracellular matrix and decreased expression and/or activity of specific metalloproteinases, is not.58,80

Assessment of fibrosis regression

Assessment of the fibrotic evolution of chronic liver disease has relied and still largely relies on histopathological scoring of liver tissue obtained by liver biopsy. However, liver biopsy is an invasive procedure limited by issues relating to sampling, cost, and morbidity, and only provides a static measure of fibrosis. It was evident that liver biopsy was an imperfect gold standard when it was used to assess the extent of disease progression in terms of fibrotic transformation of liver tissue, and even more so when the fibrotic stage derived from histopathological evaluation was used as a gold standard to define the diagnostic accuracy of noninvasive methods.81 It is increasingly clear that the diagnostic accuracy of liver biopsy is limited by two major caveats, ie, sampling error and interobserver variation among pathologists, with an average 20% error rate in assessment of fibrosis stage.82,83

Alternative methods to quantify liver tissue, such as computer-aided morphometric image analysis of hepatic collagen,84 can provide an objective measurement of the proportion of liver with fibrous tissue. By comparison, routine histological assessment also takes into account other subjective factors, such as architectural distortion or nodule formation, but is clearly dependent upon the experience of the individual pathologist.85 The coefficient of variation for image analysis compared with standard histological assessment remains unacceptably high, even for 25 mm biopsies. 82 In addition, liver biopsy is not practical for monitoring disease progression or response to therapy in chronic HCV infection.86 Thus, there is a need for noninvasive tests to assess liver fibrosis. Ideally these tests should be simple, readily available, inexpensive, and accurate. Over past years, several noninvasive tests have become available to assess liver fibrosis. In general terms, these are either “direct markers”, ie, proteins derived from the extracellular matrix assembly and remodeling, or “indirect markers” that are in general represented by algorithms, including biochemical tests that are commonly altered in chronic liver disease.87

This decline in the diagnostic relevance of liver biopsy, particularly in chronic HCV, has led to the development of noninvasive methodologies for assessment of liver fibrosis or cirrhosis. There are two critical endpoints, ie, the presence of significant fibrosis, which is an indication for antiviral treatment in chronic HBV and HCV, and the presence of cirrhosis, which is an indication for specific monitoring of complications related to portal hypertension and to the increased risk of developing hepatocellular carcinoma. A summary of the more widely applied diagnostic techniques for evaluating stage of fibrosis are presented in Table 1.

The most commonly used noninvasive methods are measurement of liver stiffness using transient elastography (Fibroscan®, Echosens, Paris, France)88 and serum biomarkers of fibrosis, eg, the patented FibroTest algorithm.36 Various noninvasive markers have been developed to differentiate mild from moderate-to-advanced stage disease, mainly in HCV, but the most widely used and validated with transient elastography88 by far are the aspartate to platelet ratio index (APRI, a free nonpatented index89) and the FibroTest.90

The APRI index has also been validated as a fibrosis predictor in HIV coinfection and chronic HCV, and also in alcoholic liver disease.91,92 A meta-analysis of 22 studies (most in chronic HCV) shows that, at an APRI threshold of 0.5, the sensitivity and specificity for significant fibrosis have been 81% and 50%, respectively, and that, at an APRI threshold of 1.0, the sensitivity and specificity for predicting cirrhosis have been 76% and 71%, respectively.93

Other popular biochemical tests include the Forns’ fibrosis index94 and Enhanced Liver Fibrosis score.95 The diagnostic performance of these indices is generally good, with a receiver-operating characteristic (ROC) curve ranging from 0.77 to 0.88. Comparative studies have noted that the performance characteristics of these biomarker panels are similar.96,97

Imaging techniques are an attractive way of evaluating fibrosis. They have the advantages of being noninvasive and being able to detect structural changes, which serologicalbased tests of fibrosis and inflammation are unable to do. Using the modalities of ultrasound, computed tomography, or magnetic resonance imaging, it is possible to diagnose features of advanced chronic liver disease by recognizing surrogate markers of portal hypertension with a high degree of sensitivity and specificity. However, these techniques do not reliably detect lesser degrees of fibrosis.

Transient elastography has recently become available, which measures liver stiffness or elasticity to assess liver fibrosis.98 The scan was developed on the principle that livers with increasing degrees of scarring or fibrosis have decreasing elasticity and that a shear wave propagating through stiffer material would progress faster than in one with more elastic material.99 Although the reproducibility of transient elastography has been shown to be excellent in terms of interobserver and intraobserver agreement,40 its applicability may not be as good as that of biomarkers.100 The principal reasons are obesity, particularly increased waist circumference, and limited operator experience. The risk of overestimating liver stiffness values has been reported in the case of alanine aminotransferase flares in patients with acute viral hepatitis or chronic HBV,101–103 as well as in cases of extrahepatic cholestasis104 and congestive heart failure.105

Initial studies of noninvasive markers largely consisted of single components, but the field has evolved into combining these single components into panel markers.

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The diagnostic performance of panel markers depends on the stage of fibrosis that is distinguished and disease origin. Although the diagnostic performance of the panel markers is broadly similar, there seems to be a trend of superior performance in alcohol-induced, followed by chronic HCV and nonalcoholic fatty liver disease, and then chronic HBV. In nonalcoholic fatty liver disease, a systematic review by Guha et al106 suggested that the evolution of noninvasive markers lagged behind HCV with fewer panel markers. Variables found to be significant in the detection of fibrosis included the presence of diabetes, age, homeostasis model assessment of insulin resistance, ratio of aspartate to alanine transaminase, decreased platelet count, presence of hyaluronic acid, and increased body mass index. However, it remains difficult to draw any firm conclusions regarding the performance of these markers, given the heterogeneous fibrosis scoring systems and endpoints used in these studies. Transient elastography could be useful as a screening test to exclude advanced fibrosis in patients with nonalcoholic fatty liver disease.

Realistic endpoints for antifibrogenic therapy

The most effective antifibrotic strategy is to cure the underlying disease process before advanced fibrosis has developed. Existing treatments, particularly those that treat the primary cause of tissue injury, can allow extensive resolution.

Advances in our understanding of the pathogenesis of liver fibrosis have identified several potential feasible therapeutic targets, but unfortunately clinical development so far has been disappointing. One major limitation has been the often-prolonged natural history of fibrosis compared with that in experimental models, and difficulties in accurate noninvasive fibrosis assessment, thus making clinical trial design difficult. Furthermore, many patients are asymptomatic even when fibrosis is already advanced, or present with decompensated cirrhosis, which would require not only prevention of evolution in cirrhosis but also reversal of established fibrosis in a cirrhotic liver. Indeed, in broad terms, the two main endpoints of antifibrogenic therapy are reduction of fibrogenesis in the precirrhotic stage, in order to prevent the establishment of cirrhosis, and reduction of fibrosis in a cirrhotic liver, leading to reduction of portal hypertension and expansion of the complication-free period (ie, compensated cirrhosis). Indeed, while the use of antifibrotic drugs in the precirrhotic stage is debatable and priority should be given to agents acting on the primary cause of disease (ie, antivirals), the single use of this class of drugs could be indicated in patients with cirrhosis, especially when not responding to treatments aimed at eliminating the cause of chronic damage. Several drugs with specific “antifibrotic activity” have been studied in human trials but were not shown to be clearly effective. The ideal antifibrotic agent which is safe when used over a long time, specific to the liver and nontoxic to hepatocytes, potent, orally bioavailable, and inexpensive, is not yet available. It is now well established that elimination of the fibrogenic stimulus can lead to regression of accumulated fibrosis, even in the setting of early cirrhosis. Examples include sustained virological clearance in HCV infection,107,108 durable viral suppression in patients with chronic HBV,109–111 venesection for hemochromatosis,112 chelation for Wilson’s disease, immunosuppression for autoimmune hepatitis,113 and weight loss for nonalcoholic steatohepatitis.114 Unfortunately, curative therapy is not possible in many patients either because available diseasespecific therapies have failed or because of late presentation with established cirrhosis. These patients have limited therapeutic options to reduce their risk of developing complications from end-stage liver disease. Fortunately, a number of promising targeted approaches (Table 2) are in development.115 Such therapies have been targeted to any of several different biological targets (eg, inhibition of collagen synthesis, interruption of matrix deposition, stimulation of matrix degradation, modulation of stellate cell activation, induction of stellate cell death, or blocking receptor tyrosine kinases like vascular endothelial growth factor receptor and platelet-derived growth factor receptor).

In patients infected with HBV or HCV, regression of liver fibrosis usually happens naturally upon achieving a sustained viral response from antiviral therapy. Controlling HBV involves giving the patient nucleotide analogs, such as lamivudine, adefovir, and entecavir, while combined pegylated IFN (+ribavirin) therapy provides the best treatment protocol for eradicating HCV.116 Sustained response with this regimen has now reached 60%. IFN may also regulate promoters of collagen gene expression and reduce hepatic stellate cell proliferation with the help of intracellular signaling molecules, like microRNA-29b.116–118

Therapeutics that target TIMP-1 provide a good strategy for antifibrotic development because TIMP-1 is implicated in extracellular collagen matrix turnover and antiapoptic activity towards myofibroblasts.63,79,119 Of experimental relevance, a recent study showed reduced collagen accumulation in fibrotic liver tissue of rats treated with a TIMP-1- neutralizing antibody.120 Because agents targeting TIMP-1 act extracellularly, drug design does not have to overcome the additional burden of crossing membrane barriers in this case.79 Other agents that degrade the collagen-rich matrix may also offer alternative and viable antifibrotic treatment. As proof of concept, overexpression of matrix metalloproteinase 8 with adenovirus therapy led to fibrosis regression in two models of experimental liver fibrosis (CCl4 and bile duct ligation).121 Adenoviral transfection of matrix metalloproteinase 1 similarly attenuated hepatic fibrosis in rats.122

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Perhaps some of the most interesting drug targets stem from inhibition of transforming growth factor-β1, because this cytokine plays a critical role in the activation of myofibroblasts. Adenoviral constructs involved in transforming growth factor-β1 signaling and other soluble molecules that modulate the expression or function of transforming growth factor-β1 have shown antifibrotic efficacy in vitro and in vivo.123–130 However, the importance of this cytokine in homeostasis and repair, cautions against the long-term use of transforming growth factor-β1 inhibitors, making this class of therapeutics less attractive. Indeed, complete chronic abrogation of the effects of transforming growth factor-β1 on immunomodulation and regulation of epithelial cell apoptosis could result in autoimmunity and the emergence of neoplastic clones.

Angiotensin II accelerates fibrogenesis in response to liver injury. Vasoactive modulators like angiotensin, type 1 receptor antagonists, or angiotensin-converting enzyme inhibitors therefore represent attractive antifibrotic therapies by blocking angiotensin II receptor access, or decreasing its production.125,126,131–134 Such agents have effectively attenuated liver fibrosis in rat models and are suitable for long-term treatment because of their known safety profile.

Targeted antifibrotic therapies that block receptors on hepatic stellate cells have emerged with promising results. Target specificity is achieved by modifying drug protein carriers with molecules that recognize growth factors and collagen type IV receptors,135 or by coupling apoptotic gliotoxin to mannose-6-phosphate-modified human serum albumin.136 Alternatively, Sato et al observed complete resolution of hepatic fibrosis in rats treated with siRNA delivered with high specificity to stellate cells using vitamin A-coupled liposomes.137

Conclusion

Our understanding of the mechanism of liver fibrosis has changed dramatically over the last decade. It is no longer viewed as passive or permanent, but as a dynamic process. Many mechanisms and potential therapies continue to be identified and more research is required. The number of potential therapeutic targets has exploded in recent years, and the realization that fibrosis can regress lends new urgency to their investigation. For the time being, greater emphasis must be placed on early identification of patients with potentially treatable chronic liver disease.

Disclosure

The authors report no conflicts of interest in this work.

View references on pp.9-12 of PDF …..

Canadian Journal of Gastroenterology
November 2013, Volume 27 Issue 11: 639-642

Original Articles

PJ Thuluvath | E Ahn | GC Nguyen

Abstract

OBJECTIVE: A nationwide analysis of alcoholic hepatitis (AH) admissions was conducted to determine the impact of hepatitis C virus (HCV) infection on short-term survival and hospital resource utilization.

METHODS: Using the Nationwide Inpatient Sample, noncirrhotic patients admitted with AH throughout the United States between 1998 and 2006 were identified with diagnostic codes from the International Classification of Diseases, Ninth Revision. The in-hospital mortality rate (primary end point) of AH patients with and without co-existent HCV infection was determined. Hospital resource utilization was assessed as a secondary end point through linear regression analysis.

RESULTS: From 1998 to 2006, there were 112,351 admissions for AH. In-hospital mortality was higher among patients with coexistent HCV infection (41.1% versus 3.2%; P=0.07). The adjusted odds of in-hospital mortality in the presence of HCV was 1.48 (95% CI 1.10 to 1.98). Noncirrhotic patients with AH and HCV also had longer length of stay (5.8 days versus 5.3 days; P<0.007) as well as greater hospital charges (US$25,990 versus US$21,030; P=0.0002).

CONCLUSIONS: Among noncirrhotic patients admitted with AH, HCV infection was associated with higher in-hospital mortality and resource utilization.

Alcoholic hepatitis | Hepatitis C | Mortality

Source

Clin Infect Dis. 2013 Dec;57(11):1618-25. doi: 10.1093/cid/cit550. Epub 2013 Sep 30.

Branch AD, Drye LT, Van Natta ML, Sezgin E, Fishman SL, Dieterich DT, Meinert CL, Jabs DA.

Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York.

Abstract

Background. Both hepatitis C virus (HCV) and human immunodeficiency virus (HIV) penetrate the central nervous system. HIV-associated neuroretinal disorder (HIV-NRD), a visual impairment of reduced contrast sensitivity and reading ability, is associated with cytokine dysregulation and genetic polymorphisms in the anti-inflammatory interleukin 10 (IL-10) signaling pathway. We investigated associations between HCV and HIV-NRD and between HCV and single-nucleotide polymorphisms (SNPs) in the IL-10 receptor 1 (IL10R1) gene.

Methods. Logistic and Cox regression analysis were used to analyze risk factors for HIV-NRD in 1576 HIV-positive patients who did not have an ocular opportunistic infection at enrollment. Median follow-up was 4.9 years (interquartile range, 2.4-8.8 years). Four IL10R1 SNPs were examined in a subset of 902 patients.

Results. The group included 290 patients with chronic HCV infection, 74 with prior infection, and 1212 with no HCV markers. There were 244 prevalent cases of HIV-NRD and 263 incident cases (rate = 3.9/100 person-years). In models adjusted for demographics, HIV treatment and status, liver function, and immune status, both the prevalence and incidence of HIV-NRD were significantly higher in patients with chronic HCV infection (odds ratio = 1.54; 95% confidence interval [CI], 1.03-2.31 and hazard ratio = 1.62; 95% CI, 1.13-2.34, respectively), compared to patients with no HCV markers. Chronic HCV was associated with rs2228055 and 2 additional IL-10R1 SNPs expected to reduce IL-10 signaling. HIV-NRD was not significantly associated with these SNPs.

Conclusions. HCV is a possible risk factor for HIV-NRD. Genetic analysis suggests that alterations in the IL-10 signaling pathway may increase susceptibility to HIV-NRD and HCV infection. Inflammation may link HCV and HIV-NRD.

KEYWORDS: AIDS, HIV-1, HIV-associated neuroretinal disorder, cytomegalovirus retinitis, hepatitis C virus

PMID: 24081683 PubMed - in process] PMCID: PMC3814824  [Available on 2014/12/1]
 
Source

Gut doi:10.1136/gutjnl-2013-305667

Viral hepatitis

Original article

M Colombo1, I Fernández2, D Abdurakhmanov3, P A Ferreira4, S I Strasser5, P Urbanek6C Moreno7, A Streinu-Cercel8, A Verheyen9, W Iraqi10, R DeMasi11, A Hill12, J M Läuffer13I Lonjon-Domanec10, H Wedemeyer14

+ Author Affiliations

Correspondence toProfessor Massimo Colombo, 1st Division of Gastroenterology, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Via F. Sforza 35, Milan 20122, Italy; massimo.colombo@unimi.it

Received 15 July 2013
Revised 3 October 2013
Accepted 15 October 2013
Published Online First 7 November 2013

Abstract

Background and aim Severe adverse events (AEs) compromise the outcome of direct antiviral agent-based treatment in patients with advanced liver fibrosis due to HCV infection. HEP3002 is an ongoing multinational programme to evaluate safety and efficacy of telaprevir (TVR) plus pegylated-interferon-α (PEG-IFNα) and ribavirin (RBV) in patients with advanced liver fibrosis caused by HCV genotype 1 (HCV-1).

Methods 1782 patients with HCV-1 and bridging fibrosis or compensated cirrhosis were prospectively recruited from 16 countries worldwide, and treated with 12 weeks of TVR plus PEG-IFN/RBV, followed by 12 or 36 weeks of PEG-IFN and RBV (PR) alone dependent on virological response to treatment and previous response type.

Results 1587 patients completed 12 weeks of triple therapy and 4 weeks of PR tail (53% cirrhosis, 22% HCV-1a). By week 12, HCV RNA was undetectable in 85% of naives, 88% of relapsers, 80% of partial responders and 72% of null responders. Overall, 931 patients (59%) developed grade 1–4 anaemia (grade 3/4 in 31%), 630 (40%) dose reduced RBV, 332 (21%) received erythropoietin and 157 (10%) were transfused. Age and female gender were the strongest predictors of anaemia. 64 patients (4%) developed a grade 3/4 rash. Discontinuation of TVR due to AEs was necessary in 193 patients (12%). Seven patients died (0.4%, six had cirrhosis).

Conclusions In compensated patients with advanced fibrosis due to HCV-1, triple therapy with TVR led to satisfactory rates of safety, tolerability and on-treatment virological response with adequate managements of AEs.

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Significance of this study

What is already known on this subject?
  • The treatment outcome for patients with chronic hepatitis C due to genotype 1 of HCV has remarkably improved following the addition of the oral HCV protease inhibitors boceprevir (BOC) or telaprevir (TVR) to pegylated interferon+ribavirin (RBV) (PR) therapy.

  • However, advanced hepatic fibrosis may limit both the access as well as the response rates of patients to triple therapy with significant issues of tolerability and safety.

  • A French observational study with TVR- or BOC-based triple therapy in patients with cirrhosis reported high frequency of anaemia and severe adverse events (AEs) particularly in patients with low platelet counts and low serum values of albumin (beyond the selection criteria of registration trials).

What are the new findings?

  • We gained further insights into the safety and efficacy of TVR+PR treatment in 1587 patients with advanced liver fibrosis or cirrhosis due to HCV-1 who were enrolled in an open label expanded access programme to TVR-based regimen and were selected following registration trials criteria for platelets, neutrophils and albumin levels.

  • During 16 weeks of treatment (12 weeks of triple therapy followed by 4 weeks of PR) anaemia was the main side effect as 59% of patients developed grade 1–4 anaemia (grade 3/4 in 31%), 630 (40%) dose reduced RBV, 332 (21%) received erythropoietin and 157 (10%) were transfused.

  • Treatment was safe as 12% of patients had to discontinue TVR due to AEs and only seven died (0.4%, six with cirrhosis).

  • At the end of triple therapy serum HCV RNA was undetectable in the vast majority of previous untreated patients and importantly in 72% of 436 patients who had had a prior null response to PR. The latter is the most difficult to cure population that was under-represented in a previous field practice study in France.

How might it impact on clinical practice in the foreseeable future?

  • In compensated patients with advanced liver fibrosis due to HCV-1 who fulfilled the selection criteria of registration trials, 16 weeks of TVR triple therapy proved to be safe, tolerated and effective.

Introduction

Chronic infection with HCV is a leading cause of liver-related morbidity and mortality worldwide, for which an effective antiviral treatment with pegylated-interferon (PEG-IFN) and ribavirin (PR) has been available since early 2000.1 ,2 The treatment outcome for difficult to cure patients, such as those chronically infected with HCV genotype 1 (HCV-1), has remarkably improved following the addition of the oral HCV protease inhibitors (PI) boceprevir (BOC) or telaprevir (TVR) to PR therapy.3–5 While eradication of HCV by PI+PR therapy is expected to greatly extend treatment success rates, resulting in a reduced risk of liver-related mortality,6–8 factors that may limit both the access as well as the response rates of patients to triple therapy have been identified. Perhaps the most relevant is the presence of advanced hepatic fibrosis,9–11which affects tolerability and safety of triple therapy. The impact of this factor on treatment access and response rates is driven by an increased rate of myelosuppression-related adverse events (AEs) such as anaemia and infections in patients treated with triple therapy.10–13 In addition, suboptimal dosing due to poor treatment tolerability may impact the outcome of PI+PR therapy in patients with advanced fibrosis, leading to reduced rates of virus eradication and also to unaffordable cost to utility ratios.14 A French observational study with TVR- and BOC-based triple therapy in patients with cirrhosis revealed that 33%–46% of the patients had been ineligible for registration studies with one of these PIs due to their severe level of liver disease. Up to 11.7% of patients had to discontinue therapy until week 16 due to the onset of AEs including anaemia, neutropenia, rash, clinical decompensation and bacterial infections. In addition, more than half of the patients on TVR required treatment with bone marrow stimulating factors and 16.1% received blood transfusions to manage treatment-related anaemia.15 Another real-world study in Germany showed a high frequency of anaemia and SAEs in patients with cirrhosis who were treated with triple therapy, particularly in patients with low platelet counts.16 Therefore, the safety of triple therapy is now being perceived by hepatologists as a potential barrier to its use in patients with the most need, such as those with advanced fibrosis, who are more often vulnerable to myelosuppression-related complications.

To gain further insights into the safety and efficacy of TVR+PR treatment in patients with advanced liver fibrosis or cirrhosis due to HCV-1 infection, an open label expanded access programme (EAP) was launched in late 2011 involving 16 nations worldwide. Cumulatively, the programme enrolled more than 2000 treatment naive or experienced patients with bridging fibrosis or cirrhosis. We report here the analysis of the on-treatment virological response and safety in the first 1587 patients who reached week 16 of therapy.

Patients and methods

Patients

From August 2011 to March 2013, compensated (Child–Pugh A) patients with bridging fibrosis or cirrhosis due to HCV-1 infection were enrolled in the TVR EAP at study centres located in 16 countries across Europe, South America and Australasia. Key inclusion criteria were male and female gender; ages 18–70; infection with HCV-1; quantifiable serum HCV RNA; and documentation of liver fibrosis assessed by liver biopsy or a non-invasive test like Fibrotest or Fibroscan showing severe fibrosis (Metavir F3 or Ishak 3–4 (S3,4)) or cirrhosis (Metavir F4 or Ishak 5–6 (S5,6)). Eligible patients had to have an absolute neutrophil count >1500/mm3, a platelet count >90 000/mm3 and haemoglobin (Hb) >12 g/dL for women and 13 g/dL for men. Patients were excluded if they had history or other evidence of decompensated liver disease, hepatocellular carcinoma, or if they were infected or co-infected with HCV other than genotype 1, HBV, or HIV or had a history of alcohol abuse. Additionally, patients were excluded if they had a history of receiving HCV protease or polymerase inhibitors. The enrolment criteria for the TVR EAP were similar to the REALIZE study.12

The protocol was signed by the principal site investigators and approved by the independent ethics committee at each participating study centre. All patients provided written informed consent prior to the conduct of any procedures for the EAP.

Treatment

During the first 12 weeks of the programme, all patients received oral administration of TVR at a dose of 750 mg every 8 h in combination with PR. The type (α 2a vs α 2b PEG-IFN; copegus vs rebetol) and doses of PR were selected according to local guidelines. After week 12, PR was administered for another 12 or 36 weeks depending on the virological response to treatment and/or previous response type. The concomitant administration of PR followed label recommendations.17 In patients with bridging fibrosis who were treatment naive or prior treatment relapsers, PR was administered for another 12 or 36 weeks based on virological response to treatment as measured by week 4 and 12 plasma HCV RNA levels. Patients with undetectable HCV RNA at weeks 4 and 12 received an additional 12 weeks of PR alone (total treatment duration of 24 weeks); patients with detectable HCV RNA (but not meeting stopping rules) at either week 4 or 12 received an additional 36 weeks of PR alone (total treatment duration of 48 weeks). Patients with bridging fibrosis with prior partial or null response to previous treatment with PR including a viral breakthrough and all patients with cirrhosis were treated for a subsequent 36 weeks. At weeks 4 and 12, patients were assessed as to whether they met the predefined stopping rules based on virological response. If at either time point the HCV RNA levels were greater than 1000 IU/mL, all treatment was permanently discontinued.

Measures of disease severity and treatment efficacy

Liver fibrosis was staged on histological specimens obtained by percutaneous liver biopsy using either the Metavir or Ishak score or by Fibrotest or Fibroscan. Fibroscan cut-off to diagnose bridging fibrosis and cirrhosis was ≥9.5 kPa and ≥12.5 kPa, respectively.18 The Child–Pugh score system was used to define the clinical status of patients, Child–Pugh A stage indicating compensated liver disease.

A range of assays were used to measure HCV RNA levels at local investigational sites. The majority of sites used the Roche COBAS TaqMan or Abbott RealTime assays (96%). Roche COBAS TaqMan (versions 1 and 2) has a lower limit of quantification (LLOQ) of 15–25 IU/mL depending on serum volume and the method of RNA extraction with a lower limit of detection (LLOD) of 10 IU/mL. Abbott RealTime has an LLOQ of 12 IU/mL and an LLOD of 10–12 IU/mL.

In the intent to treat analysis, the number of patients who had HCV RNA levels below LLOD was calculated for the overall population (n=1587) and in subgroups by prior treatment history.

Safety assessments

Throughout the treatment period and follow-up, safety assessments were carried out including laboratory assessments, physical examinations, evaluation of vital signs and the reporting of AEs. Any clinically significant abnormalities persisting at the end of the EAP/early withdrawal were followed by the investigator until a resolution or clinical stable endpoint was reached.

The DAIDS criteria were used to grade AEs19 except for rash which had protocol-specific definitions of severity grades: grade 1 mild, localised to one or several isolated sites; grade 2 moderate, diffuse skin eruption involving up to 50% of the body surface area; grade 3 severe, involving more than 50% of the body surface area or with significant systemic signs or symptoms; and grade 4 life-threatening, diagnosis of generalised bullous eruption, Steven Johnson syndrome or TEN. For patients who experienced grade 1 or 2 rash, medical management was left to the discretion of the investigator. For patients whose grade 2 rash progressed to grade 3, and for those experiencing grade 3 rash, TVR was permanently discontinued. If the rash did not improve, symptomatically or objectively within 7 days following TVR discontinuation, R was also discontinued. Immediate and permanent discontinuation of all study drugs was mandatory for all patients diagnosed with grade 4 rash.

Hb levels were assessed before treatment and at weeks 2, 4, 8 and 12, and as clinically appropriate thereafter; additional visits could be performed at the discretion of the investigator. Anaemia was defined as an AE by the investigator in the case report form, according to the following guidelines: grade 1 Hb values between 10.0 and 10.9 g/dL or any decrease from baseline between 2.5 and 3.4 g/dL; grade 2 Hb values between 9.0 and 9.9 g/dL or any decrease of Hb between 3.5 and 4.4 g/dL; grade 3 Hb values between 7.0 and 8.9 g/dL or any decrease of Hb ≥4.5 g/dL; and grade 4 an Hb value less than 7.0 g/dL. If anaemia developed during treatment, R dose was modified according to label recommendations. TVR was discontinued only if reductions of R dose or discontinuation did not result in an improvement of anaemia. TVR dose reductions were prohibited and TVR could not be reinitiated if treatment was discontinued. Use of blood transfusions, erythropoietin (EPO) or iron-based products were allowed during the trial.

Statistical methods

Fisher's exact tests were used to detect differences in the prevalence of AEs between patients who were F3 versus F4 at baseline. Multivariate linear regression was used to identify baseline factors associated with a higher probability of extended rapid virological response (eRVR) (defined as HCV RNA undetectable at both weeks 4 and 12) and development of anaemia (defined as Hb below 10 g/dL at any time on treatment).

Results

Baseline characteristics

Patient demographics and disease severity are shown in table 1A,B. A total of 746 patients (47%) had bridging fibrosis and 835 patients (53%) a cirrhosis (F4 or S5,6).

    Table 1
    Baseline characteristics of the study patients according to disease severity*
    Characteristic Bridging fibrosis (N=752)† Cirrhosis (N=835) Overall (N=1587)
    Panel A
    Age year—mean (range) 52 (22–73) 54 (19–75) 53 (19–75)
    Body mass index (BMI)‡ 26±3.7 27±4.2 27±4.0
    BMI—range 18–42 19–47 18–47
    Males sex—no. (%) 463 (62) 549 (66) 1012 (64)
    Race or ethnic group—no. (%)§
    White 740 (98) 817 (98) 1557 (98)
    Black, Asian or other 12 (2) 18 (2) 30 (2)
    HCV-1 subtype—no. (%)
    1a 168 (22) 189 (23) 357 (22)
    1b 562 (75) 609 (73) 1171 (74)
    Missing or unknown 22 (3) 37 (4) 59 (4)
    HCV RNA log10—IU/mL, mean (SD)¶ 6.2±0.66 6.1±0.74 6.1±0.71
    HCV RNA ≥ 800 000 IU/mL—no. (%) 507 (67) 548 (66) 1055 (66)
    Model for End Stage Liver Disease score 7 (6–8) 7 (7–8) 7 (6–8)
    α-Fetoprotein—µg/L 5.6 (3.5–10.0) 9.0 (5.3–16.9) 7.1 (4.2–13.1)
    Albumin—g/L 44.0 (41.1–46.1) 42.2 (40.0–45.0) 43.0 (40.4–46.0)
    Bilirubin—µmol/L 11.8 (8.2–15.4) 13.5 (10.0–17.5) 12.3 (9.0–16.7)
    Creatine—µmol/L 69.8 (59.2–79.6) 69.0 (60.0–79.0) 69.0 (59.2–79.6)
    Glucose—mmol/L 5.2 (4.7–5.8) 5.4 (4.8–6.3) 5.3 (4.8–6.0)
    Haemoglobin—g/L 151 (141–160) 149 (140–159) 150 (140–159)
    Neutrophils –×109/L 3.2 (2.5–4.0) 3.0 (2.3–3.8) 3.0 (2.4–3.9)
    Platelets –×109/L 182 (149–226) 144 (114–184) 161 (126–205)
    Prothrombin intl. normalised ratio 1.0 (1.0–1.1) 1.1 (1.0–1.1) 1.04 (1.00–1.11)
    Panel B**
    IFNλ-3—no. (%)
    Missing or unknown 577 (77) 620 (74) 1197 (75)
    CC 23 (3) 50 (6) 73 (5)
    CT 117 (16) 121 (14) 238 (15)
    TT 35 (5) 44 (5) 79 (5)
    Previous type of response—no. (%)
    Prior null responder 180 (24) 256 (31) 436 (27)
    Prior partial responder 91 (12) 112 (13) 203 (13)
    Total non-responders†† 291 (39) 394 (47) 685 (43)
    Relapsers 265 (35) 266 (32) 531 (33)
    Treatment naive 169 (22) 152 (18) 321 (20)
    Viral breakthrough 26 (3) 23 (3) 49 (3)
    Unknown 1 (0) 0 (0) 1 (0)
    • *Values are medians and IQR unless otherwise indicated. Percentages may not total 100 because of rounding.
    • †Includes three F1 patients and three F2 patients.
    • ‡BMI is the weight in kilograms divided by the square of the height in metres.
    • §Race or ethnic group was self-reported. Patients of any race could also identify themselves as Hispanic.
    • ¶Log10 values for HCV RNA are means±SE.
    • **Values are means±SD unless otherwise indicated. Percentages may not total 100 because of rounding.
    • ††Includes prior null responders, prior partial responders and non-responders-unspecified.

    Disease stage was assessed by Fibroscan in 1149 patients (72%), biopsy in 308 patients (19%) and fibrosis markers in 130 patients (8%). Fibrosis stage was classified by Metavir in 1412 patients (89%) and Ishak in 175 patients (11%). The mean and SD of the baseline score of Fibroscan was 11.6 kPa (2.8) for patients classified as F3 at baseline, and 25.0 kPa (12.6) for patients classified as F4 at baseline.

    Overall, the mean age of the patients was 53; 1012 patients (64%) were male and 1557 (98%) were white. In all, 357 patients (22%) were infected with HCV-1a and 1055 (66%) had HCV RNA greater than or equal to 800 000 IU/mL. At baseline, 374 patients (24%) had grade 1–3 thrombocytopenia (platelets <125 000/mm3), while 134 patients (8%) had a grade 2–4 thrombocytopenia (platelets <100 000/mm3). A total of 23 patients (1%) had grade 1–3 reductions in serum albumin (<3.5 g/dL).

    Among the 532 out of 835 cirrhotic patients with currently available information, 78 patients (14.7%) had either grade or presence of oesophageal varices reported.

    Overall, 321 patients (20%) were treatment naive, 531 (33%) were prior treatment relapsers, 203 (13%) were prior partial responders, 436 (27%) were prior null responders and 49 (3%) had had a viral breakthrough. In all, 47 patients (3%) had had an unspecified previous non-response. The demographic and clinical characteristics were similar between the bridging fibrosis and cirrhosis study groups.

    Efficacy

    Overall, 82% of patients at week 4 had a serum HCV RNA level less than 25 IU/mL, a rate that increased to 86% at week 12. Furthermore, 60% and 82% of patients had undetectable HCV RNA at weeks 4 and 12, respectively. The percentage of treatment naive patients who had undetectable HCV RNA levels at week 12 was 85% whereas among treatment experienced patients, 88% of treatment relapsers, 80% of partial responders, 72% of null responders and 84% of viral breakthrough patients had undetectable HCV RNA levels at week 12.

    Figure 1 shows the outcome of treatment at weeks 4 and 12 for each subgroup of patients with respect to previous PR treatment. At week 12, null responders had a significantly higher rate of virological failure (14%) than the other groups (treatment naives (4%), prior relapsers (2%) and partial responders (5%)). In all, 37 patients (2%) stopped TVR at week 4 having met the futility rules criteria. Three patients (0.2%) continued triple therapy despite having met the week 4 virological criteria for anticipated TVR interruption. The number of patients discontinuing triple therapy for AEs was similar in all groups (7% for treatment naive, 4% for prior relapsers, 7% for partial responders and 7% for null responders).

    F1.medium

    Figure 1 Outcome of treatment at weeks 4 and 12, by prior treatment. Shown are the week 4 and 12 outcomes of treatment by subgroup: treatment naive (n=321), prior treatment relapsers (n=531), previous partial responders (n=436) and previous null (n=203). Data for patients who had previously experienced viral breakthrough (n=49) and whose prior response to treatment was unspecified (n=47) have not been represented.

    In multivariate analysis, four baseline factors were associated with a higher chance of eRVR: baseline viral load <800 000 IU/mL (OR=1.47, 95% CI 1.18 to 1.85), genotype 1b (OR=1.52, 95% CI 1.16 to 1.96), α-fetoprotein <10 pg/mL (OR=2.36, 95% CI 1.82 to 3.23) and naive, relapser or prior partial response versus prior null response (OR=2.0, 95% CI 1.56 to 2.5). The rates of eRVR were 20/50 (40%), 77/235 (33%), 262/500 (52%), 349/584 (60%) and 173/200 (79%) for patients with 0, 1, 2, 3 or 4 of these predictive factors, respectively. There was no association between eRVR and the type of PEG-IFN used.

    Safety and tolerability

    Through week 16, 1014 (64%) patients experienced grade 2–4 AEs that were considered related to TVR treatment. The most common AEs were anaemia (n=698, 44%), rash (n=201, 13%), thrombocytopenia (n=120, 8%), pruritus (n=95, 6%) and asthenia (n=91, 6%). Patients with cirrhosis developed more AEs than those with bridging fibrosis (67% vs 60%, p=0.01). Overall, 12% of patients experienced AEs that ultimately led to TVR discontinuation (table 2). Of the 1587 patients, seven patients died during the PR tail as a consequence of hepatic failure, pneumonia, haemorrhage, septic shock or ischaemic colitis leading to subsequent multi-organ failure. Detailed results are shown in table 3.

    Table 2
    Reasons for discontinuation of telaprevir and the incidence of the most common grade 2–4 drug-related AEs and serious AEs
    Variable Bridging fibrosis (F3)* (N=752) Cirrhosis (F4) (N=835) Overall (N=1587) p Value
    Grade 2–4 drug-related AE†—no. (%)
    Patients with one or more AE 453 (60) 561 (67) 1014 (64) <0 .01="" td=""></0>
    Anaemia‡ 307 (41) 391 (47) 698 (44) 0.02
    Rash‡ 90 (12) 111 (13) 201 (13) NS
    Thrombocytopenia‡ 37 (5) 83 (10) 120 (8) <0 .01="" td=""></0>
    Pruritus‡ 37 (5) 58 (7) 95 (6) NS
    Asthenia 44 (6) 47 (6) 91 (6) NS
    Nausea 24 (3) 36 (4) 60 (4) NS
    Anorectal‡ 26 (3) 35 (4) 61 (4) NS
    Serious AEs§—no. (%)
    Patients with one or more serious AEs 76 (10) 110 (13) 186 (12) NS
    Anaemia‡ 32 (4) 43 (5) 75 (5) NS
    Rash‡ 12 (2) 16 (2) 28 (2) NS
    Infection 6 (1) 20 (2) 26 (2) NS
    Pyrexia 4 (1) 8 (1) 12 (1) NS
    Reason for discontinuation¶—no. (%)
    Any AE 80 (11) 113 (14) 193 (12) NS
    Rash‡ 36 (5) 36 (4) 72 (5) NS
    Anaemia‡ 14 (2) 31 (4) 45 (3) 0.01
    Vomiting 8 (1) 9 (1) 17 (1) NS
    Asthenia 6 (1) 10 (1) 16 (1) NS
    Nausea 7 (1) 9 (1) 16 (1) NS
    Pruritus‡ 3 (0) 10 (1) 13 (1) NS
    Abdominal pain 1 (0) 8 (1) 9 (1) NS
    • *Includes three F1 patients and three F2 patients.
    • †Listed are grade 2–4 drug-related AEs that occurred in at least 4% of the overall population.
    • ‡Included in this category are all related events that were described with a variety of descriptive terms.
    • §Listed are serious AEs that occurred in at least 0.5% of the overall population.
    • ¶Listed are discontinuations that occurred in at least 1% of the overall population. These figures are the number of patients who discontinued telaprevir; patients may have continued treatment with pegylated interferon plus ribavirin.
    • AE, adverse event.


    Table 3
    Adverse events with fatal outcome (n=1587)
    Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 Patient 6 Patient 7
    Age 52 51 50 55 60 66 56
    Gender Male Female Female Male Male Male Male
    Fibrosis stage F4 F4 F4 F3 F4 F4 F4
    BSL VL 1 200 000 2 387 203 389 340 3 180 000 1 430 000 977 100 2 502 935
    Last obs. VL Undetectable Undetectable 20 570 Undetectable
    Dates of TVR treatment July 2011 to September 2011 December 2011 to February 2012 January 2012 to April 2012 September 2011 to December 2011 November 2011 to February 2012 May 2012 to July 2012 April 2012 to July 2012
    Date of death 4 weeks after TVR d/c 2 weeks after TVR d/c 4 weeks after TVR d/c 30 weeks after TVR d/c 4 weeks after TVR d/c 24 weeks after TVR d/c 8 weeks after TVR d/c
    Adverse event Anaemia, dehydration, hepatic failure, hepatorenal syndrome, hyper-catabolism, keto-acidosis, multi-organ failure Ischaemic colitis, septic shock, multi-organ failure Hepatic failure, bone marrow failure, multi-organ failure Anaemia, hepatic neoplasm malignant, intra-abdominal haemorrhage, pneumonia Anaemia, oesophageal variceal haemorrhage Diarrhoea, vomit, hypotension, septic shock, coma Anaemia, fatigue, pneumonia
    Causality Possibly related Related Unlikely related Unlikely/not related Unlikely related Not related Unlikely related
    Medical history Diabetes Low platelets (74 000) Neutropenia (830 cells/mm3)  
    • BSL, baseline; d/c, discontinued; TVR, telaprevir; VR, viral load.

    By week 16, 931 patients (59%) developed any grade anaemia (table 4). Among patients with bridging fibrosis and cirrhosis, 55% and 62%, respectively, had any grade anaemia, with 25% and 29% of the patients developing grade 3 anaemia and 3% and 4% developing grade 4 anaemia, respectively. As expected, grade 2–4 anaemia judged to be related to TVR treatment occurred more frequently in patients with cirrhosis than in those with bridging fibrosis (41% vs 47%, p<0.01, table 2). For treatment of anaemia, 630 patients (40%) underwent R dose reduction, 332 (21%) received EPO and 157 (10%) received a blood transfusion. There was combined use of EPO and blood transfusion in 74 patients (5%), EPO and R dose reduction in 234 patients (15%) and combined use of transfusion and R dose reduction in 141 patients (9%).

    Table 4
    Week 16: Prevalence and management of anaemia by fibrosis stage
    Characteristic Bridging fibrosis (F3)* (N=752) Cirrhosis (F4) (N=835) Overall (N=1587)
    Grade 1–4 anaemia† (all cause)—no. (%) 413 (55) 518 (62) 931 (59)
    Grade 3 anaemia† (all cause)—no. (%) 189 (25) 238 (29) 427 (27)
    Grade 4 anaemia† (all cause)—no. (%) 26 (3) 35 (4) 61 (4)
    d/c TVR due to anaemia†—no. (%) 14 (2) 31 (4) 45 (3)
    Initial RBV dose (mg/day)—mean 1106 1120 1114
    Initial RBV dose (mg/kg/day)—mean 14.6 14.3 14.4
    RBV dose reductions—no. (%) 270 (36) 356 (43) 630 (40)
    EPO use—no. (%) 138 (19) 194 (23) 332 (21)
    Blood transfusion—no. (%) 60 (8) 96 (12) 157 (10)
    RBV dose reduction+other intervention (EPO or blood transfusion)—no. (%) 126 (17) 182 (22) 309 (20)
    • *Includes three F1 patients and three F2 patients.
    • †Included in this category are all related events that were described with a variety of descriptive terms.
    • d/c, discontinued; EPO, erythropoietin; RBV, ribavirin; TVR, telaprevir.

    Figure 2 shows the incidence and prevalence rate of any grade TVR-related anaemia over the 16-week period of study. In all, 68% of cases of anaemia occurred within the first 8 weeks of treatment, and 83% of patients who developed anaemia throughout treatment were still considered anaemic at week 16. Table 4 shows the different levels of anaemia recorded during the first 16 weeks of treatment, by baseline fibrosis stage. Overall, 45 patients (3%; 31 cirrhosis and 14 bridging fibrosis) discontinued TVR for anaemia, while 27 patients (2%) discontinued R for anaemia.

    F2.medium

    Figure 2  Incidence and prevalence of any grade telaprevir (TVR)-related anaemia (A) and rash (B). Shown are the incidence and prevalence rates of the Intent to Treat population by month from start of TVR treatment.

    There were reductions in Hb below 10 g/dL in 48% of patients. In a multivariate analysis, the four strongest predictors of Hb <10 g/dL at any time on treatment were female sex (OR=1.69, 95% CI 1.27 to 2.27, p=0.0004), age>65 years (OR=2.31, 95% CI 1.46 to 3.65, p=0.0003), low baseline Hb (OR=1.08, 95% CI 1.06 to 1.09, p<0.0001) and higher weight-based dosing of R (OR=1.13, 95% CI 1.05 to 1.21, p=0.0005). Baseline Fibroscan test results were not a significant predictor of anaemia. There was no association between anaemia and the type of PEG-IFN.

    By week 16, 201 patients (13%) had developed a grade 2–4 cutaneous rash that was considered drug-related; these figures were similar between patients with bridging fibrosis and those with cirrhosis (90; 12% vs 111; 13%). Of these, 64 (4%) were grade 3/4, and 28 cases (2%) were considered serious AEs including one patient who developed Stevens–Johnson syndrome, which resolved after stopping treatment. Overall, 72 patients (5%) discontinued drug treatment for rash of whom 36 had bridging fibrosis and 36 had cirrhosis at baseline (table 2).Figure 2 shows the incidence and prevalence of any grade TVR-related rash which, like anaemia, occurred more frequently during the first 8 weeks of therapy (73% of cases). Of patients who developed rash throughout treatment, 47% of cases were not resolved by week 16.

    While the incidence of grade 2–4 infections considered treatment-related was low (n=14, 1%), 26 patients (2%) developed an infection as a serious AE, including seven cases of pneumonia, two cases of erysipelas, and one case each of sepsis and septic shock. Only four patients (<1%) discontinued TVR for infection.

    Discussion

    The week 16 interim analysis of this EAP provided meaningful insights on the safety profile and on treatment efficacy of triple therapy with TVR in patients with histologically advanced hepatitis C, a category of patients who are more likely to suffer treatment-related AEs and to respond less satisfactorily to IFN-based regimens. Indeed, 12% of the 1587 patients with either bridging fibrosis or cirrhosis had to prematurely discontinue treatment owing to the onset of AEs, whereas grade 2–4 treatment-related anaemia or a cutaneous rash occurred in 44% and 13% of the patients, respectively, in the face of 82% of the overall cohort achieving on treatment clearance of serum HCV-RNA. Cirrhotic patients experienced slightly more grade 2–4 AEs than did patients with bridging fibrosis.

    Owing to the multifactorial origin of anaemia in patients with advanced liver fibrosis including age, myelosuppression and impaired renal function, higher rates of grade 3 or 4 anaemia were observed in EAP patients than those observed in phase II/III studies (31% in the EAP compared with 4%–18% previously reported).11 ,12 ,15 ,20 ,21 These discrepancies can be accounted for by the fewer number of patients enrolled in clinical development studies who had either bridging fibrosis or cirrhosis (ie, an advanced liver disease entailing a significant risk of developing myelosuppression-related AEs). Additionally, our choice of defining anaemia as either Hb below given threshold levels or any decrease of Hb following triple therapy could have increased the estimate of anaemia in some patients. In all, 40% of the overall cohort had anaemia managed with R dose reduction and blood transfusion was used in 10%. In contrast to the registration trial protocols where the use of EPO to correct anaemia was not permitted,11,12 332 patients (21%) received EPO. In addition, a significant proportion of patients had their anaemia treated through a combination of R dose reduction/interruption and either EPO or blood transfusion. It is possible that R dose reduction to manage anaemia was avoided because of concerns that treatment effectiveness may be compromised; however, it is now appreciated from both a retrospective and prospective study with TVR and BOC, respectively, that R dose reduction may not affect sustained virological response (SVR) rates.22 ,23 Overall, the strategies of anaemia management in this study resulted in only 3% of patients discontinuing TVR because of anaemia. This compares with 2% of patients in the REALIZE study who discontinued TVR for anaemia.12

    Similar rates of anaemia were reported in patients with compensated cirrhosis who were enrolled in the field practice study CUPIC in France, where 29% had grade 3 anaemia (defined as Hb <9 g/dL);15 this was despite a higher number of CUPIC patients (33%) with severe liver impairment exceeding the enrolment criteria adopted in REALIZE than in the EAP (9%).12 The clinical burden of anaemia in CUPIC was higher than in the EAP, with EPO use in more than half of the patients (57%) or the need for blood transfusion in 15% possibly reflecting slightly more advanced liver disease in CUPIC patients.

    Not unexpectedly, anaemia defined as a Hb drop below 10 g/dL following PR+TVR therapy more often occurred in >65-year-old patients, women and patients with low pretreatment Hb values or those with higher weight-based dosing of R. While age is a well-recognised risk factor for anaemia in patients with advanced liver disease, likely reflecting an increased susceptibility to treatment-related bone marrow and renal toxicity, female gender and low pretreatment Hb values have long been recognised as risk factors for anaemia also in patients exposed to dual therapy with PR.24 ,25

    One reassuring finding of the TVR EAP was the low rate of cutaneous rash (13% grade 2–4 treatment-related), and in particular of grade 3–4 rash affecting 4% of the population only. This may reflect the improved standard of care based on interventions and counselling to prevent cutaneous toxicity of TVR. This is not unprecedented since the rates of any grade rash were already reduced in phase III registration trials compared with the phase II trials where rash was a leading AE causing a shortened period of TVR administration.15 ,26 Similarly, rather low rates (4.8%) of grade 3/4 rash were also observed in the CUPIC study.15

    In the EAP, a number of patients developed AEs other than anaemia or rash, including infections, thrombocytopenia, pruritus, weakness, nausea and anorectal discomfort. Similar to the cutaneous rash, anorectal discomfort was reported for a lower proportion of patients than in registration trials,11 ,12 ,20 ,21 ,26 again possibly reflecting improved standard of care based on the use of prophylactic and therapeutic remedies. Ultimately, only 12% of patients experienced SAEs including anaemia (5%), rash (2%), infection (2%) and pyrexia (1%). Thus, enrolment of patients fulfilling the selection criteria to the registration trials and well compensated liver status resulted in a satisfactory safety record of TVR-based regimens in patients with advanced liver fibrosis. This explains also the low mortality rates (n=7, 0.4%) in the EAP cohort up to week 16. Deaths were the consequence of multi-organ failure caused by infection in two patients, pneumonia in two patients, and septic shock, ischaemic colitis, and haemorrhage in one patient each. Notably, one of these patients suffered from diabetes, a disease known to increase the risk of infection, and six of the seven patients had cirrhosis. PR-related deaths were reported also in patients with cirrhosis due to HCV (2%) who were enrolled in a trial aiming to evaluate the safety and efficacy of elthrombopag,27 a synthetic compound able to increase the level of circulating platelets. Slightly higher rates (2.8%) of TVR treatment-related deaths were reported in patients with cirrhosis who were enrolled in the CUPIC study15where mortality was almost invariably associated with liver failure and predicted by signs of impaired liver function including a baseline platelet count less than 100 000/mm3 and serum albumin lower than 3.5 g/dL. In this study, TVR-based regimens were also associated with a significant rate of infection (6.5%). With respect to the TVR EAP, the greater burden of AEs and serious complications (29 among 429 patients) observed in the CUPIC study during the first 16 weeks of triple therapy underscore the enrolment of a significant number of patients with deteriorated liver function. In the French study, 20% of patients had <100 000 platelets and 12% <3.5 g albumin compared with TVR EAP where these figures were 8% and 1%, respectively. Poor safety signals in patients with more profound liver derangement were reported in two studies in Germany16 and Austria28 where the prevalence of patients with severe liver impairment was intermediate between CUPIC and TVR EAP.

    The finding that 85% of previously untreated patients had undetectable HCV RNA at week 12 with minor differences between patients with bridging fibrosis and those with cirrhosis (87% vs 83%) is similar to the antiviral efficacy of TVR regimens seen in registration trials. Based on previous phase III trial results, one may therefore predict that a significant proportion of previously untreated patients with advanced fibrosis will ultimately achieve an SVR upon completion of the treatment schedule.11 ,21 Still, the SVR results need to be confirmed in long-term follow-up. In most countries, treatment naive patients with advanced fibrosis have been prioritised to receive triple therapy with TVR. The EAP study also provides encouraging though preliminary data of the efficacy of TVR triple therapy in treatment experienced patients with bridging fibrosis and cirrhosis. These findings were particularly rewarding for those individuals with a previous relapse or partial response to PR, reaching very high HCV RNA undetectability rates of 88% and 80% at week 12. A preliminary report of the CUPIC study is in line with our observation and predictions of SVR in experienced patients with advanced fibrosis/cirrhosis, with 46% of 107 patients enrolled in the study achieving an SVR at week 12 post-treatment.22One important limit of the CUPIC study, however, is the under-representation of null responders, who are most difficult to cure, as a consequence of their poor IFN sensitivity, leading to a high risk of virological breakthroughs and post-treatment relapse of hepatitis. By enrolling 436 patients who had had a prior null response (180 bridging fibrotic and 256 cirrhotic patients), the EAP is the largest study of prior null responders.

    In conclusion, the 16-week interim analysis of the TVR EAP in 1587 patients provided encouraging insights on the safety, tolerability and preliminary efficacy of TVR triple therapy in difficult to cure categories of hepatitis C patients with advanced fibrosis.

    Acknowledgments

    We would like thanks the patients, investigators and staff who worked on this study.

    Footnotes

    Contributors Analysis and interpretation of data, drafting the article and revising it critically for important intellectual content: MC and HW. Conception and design: AV, WI, RD, AH, JML and IL-D. Statistical analysis: AH. Final approval of the version to be published: MC, IF, DA, PAF, SIS, PU, CM, AS-C, AV, WI, RD, AH, JML, IL-D and HW.

    Funding This study was funded by Janssen Pharmaceutics.

    Competing interests MC—Grant and research support: Merck, Roche, BMS, Gilead Science. Advisory committees: Merck, Roche, Novartis, Bayer, BMS, Gilead Science, Tibotec, Vertex, Janssen Cilag, Achillion, Lundbeck, Abbott, Boehringer Ingelheim. Speaking and teaching: Tibotec, Roche, Novartis, Bayer, BMS, Gilead Science, Vertex. IF—Janssen: Speakeŕs bureau; Gilead, MSD, Roche: Speakeŕs bureau. DA—Speaker and had grants for lectures and clinical trials from Merk, Jannsen, Roche, Novartis, BMS. PAF—Speaker and Clinical Investigator to Roche, Abbvie, Janssen, BMS. SIS—Received honoraria from Janssen for speaking and teaching and participating in Advisory Boards. PU—No conflicts of interest regarding the topic of manuscript. CM—Speaker or adviser from MSD, Janssen, Bristol-Myers Squibb and Gilead Sciences pharmaceutical companies. He is investigator for Novartis, Roche, MSD, Gilead Sciences, Bristol-Myers Squibb, Boehringer, Glaxo-Smith-Kline, Abbott, Astellas and Janssen pharmaceuticals. He received research Grant from MSD, Janssen, Astellas, Novartis and Roche pharmaceutical companies. AS-C—PI for the Telaprevir EAP-CT for subjects with Chronic Hepatitis C VX-950HEP3002; speaker for Janssen on different occasions. HW—Honoraria for consulting and/or lectures: Abbvie, Abbott, Achillion, BMS, Gilead, Janssen, MSD, Novartis, Roche, Roche Diagnostics, Siemens, Transgene. Grant support: Roche, BMS, MSD. AV, WI, RD, AH, JML and IL-D—Are Janssen employees.

    Patient consent Obtained.

    Ethics approval Local ethic committee.

    Provenance and peer review Not commissioned; externally peer reviewed.

    Data sharing The principal investigator had full access to the results of the trial.

    This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:http://creativecommons.org/licenses/by-nc/3.0/

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