Eltrombopag increases platelet numbers in thrombocytopenic patients with HCV infection and cirrhosis, allowing for effective antiviral therapy

Thrombopoietin receptor agonists and risk of portal vein thrombosis in patients with liver disease and thrombocytopenia: A meta-analysis

BACKGROUND

Treatment of thrombocytopenia with thrombopoietin receptor agonists (TPORAs) seems to be associated with portal vein thrombosis (PVT) in patients with chronic liver disease (CLD). We performed a meta-analysis of the trials carried out in this clinical setting to assess if such association is detectable.

METHODS

We performed a meta-analysis with studies that compared the effect of TPORAS vs placebo in patients with CLD and thrombocytopenia.

RESULTS

Four studies, including 1953 patients, reported the incidence of PVT in patients with CLD and thrombocytopenia treated with TPORAs or placebo. No significant difference was found for incidence of PVT in patients treated with TPORAs compared with placebo (O.R.: 2.8; 95% C.I., 0.97-8.16; p = 0.055). A significant association between PVT and TPORAs was observed only in patients treated with eltrombopag (O.R.: 3.8; 95% C.I., 1.14-13.2; p = 0.03). Three studies, including 514 patients who were undergoing an elective invasive procedure, analyzed the incidence of PVT in TPORAs-treated patients with CLD and thrombocytopenia; no significant difference was found for incidence of PVT in patients treated with TPORAs compared with placebo (O.R.: 2.6; 95% C.I., 0.6-11.6; p = 0.212). A significant difference was found for incidence of arterial and venous thrombo-embolic events in CLD patients treated with eltrombopag compared with placebo-treated patients (O.R.: 3.4; 95% C.I., 1.5-7.7; p = 0.003).

CONCLUSION

The results of this meta-analysis show that TPORAs are not associated with PVT in CLD patients even in the case of surgical procedure. PVT risk seems to be associated only with eltrombopag use.

Relationship between response to lusutrombopag and splenic volume

AIM

To assess the correlation between the efficacy of lusutrombopag and clinical characteristics in patients with chronic liver disease.

METHODS

In this retrospective, multicenter study, which conducted at four locations in Japan, 50 thrombocytopenic patients with chronic liver disease were enrolled. All patients received oral lusutrombopag (3.0 mg/d for 7 d) for chronic liver disease. We assessed the increase in platelet count after the trial drug administration. A treatment response was defined as a platelet count ≥ 5 × 104/μL and an increased platelet count ≥ 2 × 104/μL from baseline after drug administration. We evaluated the response to lusutrombopag compared to baseline clinical characteristics in patients with chronic liver disease.

RESULTS

The numbers of responders and non-responders were 40 (80.0%) and 10 (20.0%), respectively. The patients were divided into a responder and non-responder group, and we added factors that may correspond to successful treatment with lusutrombopag. Splenic volume and body weight were lower in the responder group than in the non-responder group. White blood cell count and hemoglobin level were higher in responders compared with non-responders. Using a logistic regression model to assess the relationship between response to lusutrombopag and clinical characteristics, multivariate analysis confirmed that splenic volume was an independent factor that predicted the response of platelet counts (P = 0.025; odds ratio = 11.2; 95% confidence interval: 1.354-103.0). Splenic volume negatively correlated to changes in platelet count (r = -0.524, P = 0.001).

CONCLUSION

Splenic volume influences the change in platelet counts after administration of lusutrombopag in patients with chronic liver disease.

Thrombopoietin level predicts response to treatment with eltrombopag and romiplostim in immune thrombocytopenia

Thrombopoietin receptor agonists (TPO-RAs) are used to treat immune thrombocytopenia (ITP), but predicting clinical response to TPO-RAs before initiation is not possible. To determine whether endogenous TPO levels predict treatment response to TPO-RAs we performed a retrospective analysis of ITP patients with known baseline TPO levels who received TPO-RAs. Data was collected for ITP patients with a baseline TPO level treated with eltrombopag or romiplostim. Multiple logistic regression was used to model the probability of 3 classes of treatment response (overall, moderate, and superior) based on TPO level; receiver operating characteristic (ROC) analysis was performed to identify optimal TPO thresholds for response; correlations between TPO level and various response characteristics were analyzed. A total of 67 patients (37 receiving eltrombopag and 46 receiving romiplostim) were included. Logistic regression models demonstrated a significant predictive relation between TPO level and probability of all classes of response; per 10 pg/mL TPO increase, odds ratio for overall response to eltrombopag was 0.524 (95% CI 0.327, 0.837) and romiplostim was 0.905 (95% CI, 0.844, 0.970). TPO level was inversely correlated with all classes of response; for overall response, r = -0.719 (P < .001) for eltrombopag and r = -0.584 (P < .001) for romiplostim. ROC analysis identified TPO thresholds of ≤136 pg/mL (eltrombopag) and ≤209 pg/mL (romiplostim) as optimally discriminating between responders and nonresponders. Most non-responders had high TPO levels but did respond after addition of low-dose prednisone. In conclusion, TPO levels predict response to eltrombopag and romiplostim in ITP patients, with lower levels predicting improved probability and magnitude of response.

Efficacy and safety of partial splenic embolization for hypersplenism in pre- and post-liver transplant patients: A 16-year comparative analysis

PURPOSE

To report the effect of partial splenic embolization (PSE) on hematological indices and the procedure's safety in pre- and post-liver transplant (LT) patients.

MATERIALS AND METHODS

A single-center retrospective study evaluating all patients who underwent PSE over a 16-year period was performed. Inclusion criteria were splenomegaly confirmed by imaging and at least one of the following cytopenias: hemoglobin ≤10 g/dL, WBC count ≤1500 μL^-1, or platelet count ≤100,000 μL^-1. 38 of 102 patients (37%) met criteria (24 pre- and 14 post-LT) for a total of 40 PSEs.

RESULTS

No effect was seen on median hemoglobin beyond 2 weeks post-PSE. There was a significant and sustained increase in median WBC counts (from 3400 μL^-1 to 5400 μL^-1 at 2 years) and platelet count (from 65,000 μL^-1 to 117,000 μL^-1 at 3.5 years). In 6 out of 40 PSEs (15%) a major complication occurred which included pleural effusion, ascites, spontaneous bacterial peritonitis, pneumonia, and inferior vena cava thrombus. Similar efficacy was observed in pre- and post-LT cohorts, with a trend toward higher complication rate in pre-LT patients.

CONCLUSIONS

PSE is efficacious in increasing WBC count out to 2 years and platelet count out to 3.5 years in patients with hypersplenism. Efficacy and safety appeared independent of pre- or post-LT status. The intervention is associated with major complications and special care should be taken when selecting patients for PSE.

Platelet aggregation response in immune thrombocytopenia patients treated with romiplostim

The thrombopoietin receptor agonist romiplostim is used for the long-term treatment of chronic immune thrombocytopenia (ITP). ITP patients have an increased thrombotic risk, which could be exacerbated if romiplostim increased platelet hyperreactivity or caused spontaneous platelet aggregation. To investigate this possibility, this study examined platelet function in romiplostim-treated ITP patients and healthy subjects. Light transmission platelet aggregometry utilizing arachidonic acid, collagen, epinephrine, ristocetin, ADP, and saline (to assess spontaneous aggregation) was performed for each subject. In addition, the ADP AC₅₀ (ADP concentration that induced half-maximal aggregation) was determined for each patient as a sensitive measurement of altered platelet reactivity. Fifteen ITP patients and 7 healthy subjects entered the study. All ITP patients had active disease and were receiving weekly romiplostim as the sole ITP-directed therapy. Platelet aggregation in response to the strong agonists arachidonic acid, collagen, and ristocetin was not significantly different between ITP patients and healthy subjects (P = 0.2442, P = 0.0548, and P = 0.0879, respectively). Platelet aggregation in response to weak agonists was significantly reduced in ITP patients compared with that in healthy subjects: median (range) aggregation to ADP, 45% (15-84%) versus 89% (70-95%) (P = 0.0010), and epinephrine, 21% (1.6-90%) versus 88% (79-94%) (P = 0.0085). The median AC₅₀ of ADP was threefold higher in ITP patients versus that in healthy subjects (6.3 μM vs 2.1 μM) (P = 0.0049). Significant spontaneous aggregation was not observed in any patient. Platelets from romiplostim-treated ITP patients do not show evidence for spontaneous aggregation or hyperreactivity, but instead have a modestly reduced aggregation response to ADP and epinephrine.

Efficacy and Safety of Eltrombopag for Aplastic Anemia: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Eltrombopag seems to be effective in treating patients with aplastic anemia in several clinical trials. This paper aims to perform the first meta-analysis analyzing the efficacy and safety of eltrombopag for aplastic anemia.

METHODS

Literatures were retrieved from PubMed, EMBASE, OVID, Web of Science, Cochrane, Wanfang, http://clinicaltrials.gov and World Health Organization International Clinical Trials Registry Platform search portal from establishment to July 2018. Using Stata statistical software version 12.0, subgroup analyses and sensitivity analyses were conducted.

RESULTS

The overall hematologic response rate is 88% (95% CI 83-94%) for patients treated with eltrombopag plus immunosuppressive therapy, and 47% (95% CI 38-56%) for patients with refractory aplastic anemia using eltrombopag alone. Karyotype abnormality rates include an overall rate of 10% (95% CI 7-14%), a subtotal rate of 8% (95% CI 3-13%) for patients who are treated with eltrombopag plus immunosuppressive therapy without using antithymocyte globulin before, and a subtotal rate of 17% (95% CI 10-24%) for patients with refractory aplastic anemia treated with eltrombopag alone.

CONCLUSIONS

With different treatments and in different conditions eltrombopag showed a distinctive effect for aplastic anemia. However, clone evolution and adverse events were associated with treatment.

Avatrombopag, an oral thrombopoietin receptor agonist: results of two double-blind, dose-rising, placebo-controlled Phase 1 studies

Avatrombopag is an oral thrombopoietin receptor agonist that has been recently approved for treating thrombocytopenia in chronic liver disease patients needing invasive procedures. Clinical trials supporting this new treatment were guided by two double‐blind, dose‐rising, placebo‐controlled Phase 1 studies in healthy adults reported here that assessed safety, tolerability and pharmacokinetic profile of avatrombopag, and its effect on platelet counts. Subjects were randomised (2:1) in the single‐dose study (N = 63) to avatrombopag (1, 3, 10, 20, 50, 75 and 100 mg) or placebo, and in the multiple‐dose study (N = 29) to avatrombopag (3, 10 and 20 mg) or placebo daily for 14 days. There were no serious adverse events (AEs), dose‐limiting toxicities, deaths, AEs causing withdrawal, thromboses or liver function abnormalities. In both studies, avatrombopag peak concentration and exposure increased proportionally relative to dose; half‐life was 18–21 h and independent of dose, supporting once‐daily dosing. Effects on platelet counts depended on dose, concentration and treatment duration. Platelet count increases began 3–5 days post‐administration, with maximum changes of >370 × 10⁹/l over baseline with 20 mg daily after 13–16 days. These data support continued development of avatrombopag for treatment of other thrombocytopenic conditions and provide important guidance for the haematologist in the use of this new thrombopoietin receptor agonist.

Thrombocytopenia in chronic liver disease

Thrombocytopenia is a common haematological disorder in patients with chronic liver disease. It is multifactorial and severity of liver disease is the most influential factor. As a result of the increased risk of bleeding, thrombocytopenia may impact upon medical procedures, such as surgery or liver biopsy. The pathophysiology of thrombocytopenia in chronic liver disease has long been associated with the hypothesis of hypersplenism, where portal hypertension causes pooling and sequestration of all corpuscular elements of the blood, predominantly thrombocytes, in the enlarged and congested spleen. Other mechanisms of importance include bone marrow suppression by toxic substances, such as alcohol or viral infection, and immunological removal of platelets from the circulation. However, insufficient platelet recovery after relief of portal hypertension by shunt procedures or minor and transient recovery after splenic artery embolization have caused many to question the importance and relative contribution of this mechanism to thrombocytopenia. The discovery of the cytokine thrombopoietin has led to the elucidation of a central mechanism. Thrombopoietin is predominantly produced by the liver and is reduced when liver cell mass is severely damaged. This leads to reduced thrombopoiesis in the bone marrow and consequently to thrombocytopenia in the peripheral blood of patients with advanced-stage liver disease. Restoration of adequate thrombopoietin production post-liver transplantation leads to prompt restoration of platelet production. A number of new treatments that substitute thrombopoietin activity are available or in development.

Factors associated with success of telaprevir- and boceprevir-based triple therapy for hepatitis C virus infection

AIM

To evaluate new therapies for hepatitis C virus (HCV), data about real-world outcomes are needed.

METHODS

Outcomes of 223 patients with genotype 1 HCV who started telaprevir- or boceprevir-based triple therapy (May 2011-March 2012) at the Mount Sinai Medical Center were analyzed. Human immunodeficiency virus-positive patients and patients who received a liver transplant were excluded. Factors associated with sustained virological response (SVR24) and relapse were analyzed by univariable and multivariable logistic regression as well as classification and regression trees. Fast virological response (FVR) was defined as undetectable HCV RNA at week-4 (telaprevir) or week-8 (boceprevir).

RESULTS

The median age was 57 years, 18% were black, 44% had advanced fibrosis/cirrhosis (FIB-4 ≥ 3.25). Only 42% (94/223) of patients achieved SVR24 on an intention-to-treat basis. In a model that included platelets, SVR24 was associated with white race [odds ratio (OR) = 5.92, 95% confidence interval (CI): 2.34-14.96], HCV sub-genotype 1b (OR = 2.81, 95%CI: 1.45-5.44), platelet count (OR = 1.10, per x 10⁴ cells/μL, 95%CI: 1.05-1.16), and IL28B CC genotype (OR = 3.54, 95%CI: 1.19-10.53). Platelet counts > 135 x 10³/μL were the strongest predictor of SVR by classification and regression tree. Relapse occurred in 25% (27/104) of patients with an end-of-treatment response and was associated with non-FVR (OR = 4.77, 95%CI: 1.68-13.56), HCV sub-genotype 1a (OR = 5.20; 95%CI: 1.40-18.97), and FIB-4 ≥ 3.25 (OR = 2.77; 95%CI: 1.07-7.22).

CONCLUSION

The SVR rate was 42% with telaprevir- or boceprevir-based triple therapy in real-world practice. Low platelets and advanced fibrosis were associated with treatment failure and relapse.

Thrombopoetin receptor agonist therapy in thrombocytopenia: ITP and beyond

Eltrombopag is well established in treatment of severe immune thrombocytopenia (ITP) and is increasingly commonplace in second-line management. A role is also suggested for both bridging therapy for surgery, as well as treating thrombocytopenia due to non-immune aetiologies. We present the largest single-centre experience with eltrombopag, with our cohort of 62 patients. Patients with severe ITP (n = 34) had 91·2% response, which was sustained over a median of 18·5 months. In 41·4% of ITP cases (n = 14), complete response (CR- platelet count >100 × 10⁹ /l) was achieved and in 2 cases, therapy was stopped and CR maintained. In our bridging group (n = 15) with a higher baseline platelet count, 93·3% achieved a CR. In the non-ITP group (n = 13), a response was achieved in 76·9%. In all groups, side effects were transient, with the drug discontinued in 2 patients due to minor complications (rash, nausea, diarrhoea). We conclude that eltrombopag is both effective and well tolerated as therapy in severe ITP. It is also advantageous in ITP patients who do not normally require therapy, but need a temporary platelet count boost pre-procedure. Furthermore, there are potentially far wider implications for the use of eltrombopag in counteracting thrombocytopenia beyond ITP, which merit further investigation.

Thrombocytopenia in Patients with Chronic Hepatitis C Virus Infection

Thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection is a major problem. The pathophysiology is multifactorial, with auto-immunogenicity, direct bone marrow suppression, hypersplenism, decreased production of thrombopoietin and therapeutic adverse effect all contributing to thrombocytopenia in different measures. The greatest challenge in the care of chronic HCV patients with thrombocytopenia is the difficulty in initiating or maintaining IFN containing anti-viral therapy. Although at present, it is possible to avoid this challenge with the use of the sole Direct Antiviral Agents (DAAs) as the primary treatment modality, thrombocytopenia remains of particular interest, especially in cases of advanced liver disease. The increased risk of bleeding with thrombocytopenia may also impede the initiation and maintenance of different invasive diagnostic and therapeutic procedures. While eradication of HCV infection itself is the most practical strategy for the remission of thrombocytopenia, various pharmacological and non-pharmacological therapeutic options, which vary in their effectiveness and adverse effect profiles, are available. Sustained increase in platelet count is seen with splenectomy and splenic artery embolization, in contrast to only transient rise with platelet transfusion. However, their routine use is limited by complications. Different thrombopoietin analogues have been tried. The use of synthetic thrombopoietins, such as recombinant human TPO and pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMDGF), has been hampered by the development of neutralizing antibodies. Thrombopoietin-mimetic agents, in particular, eltrombopag and romiplostim, have been shown to be safe and effective for HCV-related thrombocytopenia in various studies, and they increase platelet count without eliciting any immunogenicity Other treatment modalities including newer TPO analogues-AMG-51, PEG-TPOmp and AKR-501, recombinant human IL-11 (rhIL-11, Oprelvekin), recombinant human erythropoietin (rhEPO), danazol and L-carnitine have shown promising early result with improving thrombocytopenia. Thrombocytopenia in chronic HCV infection remain a major problem, however the recent change in DAAs without IFN, as the frontline therapy for HCV, permit to avoid the dilemmas associated with initiating or maintaining IFN based anti-viral therapy.

From chronic immune thrombocytopenia to severe aplastic anemia: recent insights into the evolution of eltrombopag

Thrombopoietin (TPO) is the most potent cytokine stimulating thrombopoiesis. Therapy with exogenous TPO is limited by the formation of antibodies cross-reacting with endogenous TPO. Mimetics of TPO are compounds with no antigenic similarity to TPO. Eltrombopag is an orally-active nonpeptide small molecule that binds to the transmembrane portion of the TPO receptor MPL. Initial trials of eltrombopag have centered on immune thrombocytopenia (ITP), which is due to both increased destruction and decreased production of platelets. Eltrombopag at 25-75 mg/day has been shown to be highly effective in raising the platelet count in ITP with suboptimal response to immunosuppression and splenectomy. These successful results led to the exploration of eltrombopag in other thrombocytopenic disorders. In hepatitis C viral infection, eltrombopag raises the platelet count sufficiently enough to allow treatment with ribavirin and pegylated interferon. Because MPL is expressed on hematopoietic cells, eltrombopag use in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) might enhance leukemic proliferation. Clinical trials of eltrombopag in MDS and AML, however, have shown amelioration of thrombocytopenia without promoting disease progression. In severe aplastic anemia (SAA) not responding to immunosuppression with anti-thymocyte globulin (ATG) and cyclosporine, eltrombopag as a single agent at 150-300 mg/day results in an overall response rate of 40-70%. At high doses, adverse effects including pigmentation, gastrointestinal upset and hepatic derangement have become evident. Current studies have examined the first-line use of eltrombopag in combination with ATG in SAA. In a recent study, eltrombopag used at 150 mg/day with horse ATG resulted in an overall response rate of 90% in newly diagnosed SAA patients, with a complete response rate of about 50%. Clonal karyotypic aberrations are, however, found in 10-20% of SAA patients treated with eltrombopag. The safety and efficacy of eltrombopag in SAA require further evaluation, particularly when it is used with less intensive immunosuppression.

Thrombocytopenia and infections

INTRODUCTION

Acquired thrombocytopenia recognizes a myriad of causes. Among these, infectious diseases play a relevant role since a low platelet count is commonplace along with other abnormal laboratory data. Areas covered: This narrative review, after a brief presentation of the possible pathogenic mechanisms, is focused on the most prevalent infections associated with thrombocytopenia, namely those attributable to hepatitis C virus (HCV), human immunodeficiency virus (HIV) and Helicobacter pylori. Expert commentary: An underlying HCV or HIV infection should always be suspected in patients at risk who present with isolated thrombocytopenia. The eradication of Helicobacter pylori is advisable in infected patients with secondary immune thrombocytopenia, because this will increase the platelet count in a substantial number of cases, thus avoiding more aggressive and prolonged treatments.

Platelets in liver and renal disease

This review will discuss how 2 common and morbid conditions, renal disease and liver disease, alter platelet number and function. It will review the impact of thrombocytopenia on bleeding complications in patients with these disorders and whether the low platelet count actually correlates with bleeding risk. Emerging data also suggest that platelets are much more than bystanders in both renal and liver disease, but instead play an active role in the pathobiology of these disorders. This review will briefly cover the emerging information on novel roles of platelets in the biology of renal and liver disease.

Alternatives to allogeneic platelet transfusion

Allogeneic platelet transfusions are widely used for the prevention and treatment of bleeding in thrombocytopenia. Recent evidence suggests platelet transfusions have limited efficacy and are associated with uncertain immunomodulatory risks and concerns about viral or bacterial transmission. Alternatives to transfusion are a well-recognised tenet of Patient Blood Management, but there has been less focus on different strategies to reduce bleeding risk by comparison to platelet transfusion. Direct alternatives to platelet transfusion include agents to stimulate endogenous platelet production (thrombopoietin mimetics), optimising platelet adhesion to endothelium by treating anaemia or increasing von Willebrand factor levels (desmopressin), increasing formation of cross-linked fibrinogen (activated recombinant factor VII, fibrinogen concentrate or recombinant factor XIII), decreasing fibrinolysis (tranexamic acid or epsilon aminocaproic acid) or using artificial or modified platelets (cryopreserved platelets, lyophilised platelets, haemostatic particles, liposomes, engineered nanoparticles or infusible platelet membranes). The evidence base to support the use of these alternatives is variable, but an area of active research. Much of the current randomised controlled trial focus is on evaluation of the use of thrombopoietin mimetics and anti-fibrinolytics. It is also recognised that one alternative strategy to platelet transfusion is choosing not to transfuse at all.

Management of Thrombocytopenia in Chronic Liver Disease: Focus on Pharmacotherapeutic Strategies

Thrombocytopenia (platelet count <150 × 10⁹/L) often complicates chronic liver disease, impeding optimal management of these patients. The prevalence of this manifestation ranges from 6 % among non-cirrhotic patients with chronic liver disease to 70 % among patients with liver cirrhosis. It has also been shown that the severity of liver disease is associated with both prevalence and level of thrombocytopenia. Its development is often multifactorial, although thrombopoietin is thought to be a major factor. The discovery of and ability to clone thrombopoietin led to new treatment opportunities for this clinical manifestation. This review discusses data on the three most important thrombopoietin receptor agonists: eltrombopag, avatrombopag, and romiplostim. Currently, only eltrombopag is approved for usage among patients with thrombocytopenia and chronic hepatitis C virus infection in order to initiate and maintain interferon-based antiviral treatment. Nevertheless, the optimal management of hematologic abnormalities among patients with chronic liver disease, and its risk for bleeding complications, is still a matter of discussion. Thrombocytopenia definitely contributes to hemostatic defects but is often counterbalanced by the enhanced presence of procoagulant factors. Therefore, a thorough assessment of the patient’s risk for thrombotic events is essential when the use of thrombopoietin receptor agonists is considered among patients with chronic liver disease and thrombocytopenia.

Hemostatic balance in patients with liver cirrhosis: Report of a consensus conference

Patients with cirrhosis present with hemostatic alterations secondary to reduced availability of pro-coagulant and anti-coagulant factors. The net effect of these changes is a rebalanced hemostatic system. The Italian Association of the Study of the Liver (AISF) and the Italian Society of Internal Medicine (SIMI) promoted a consensus conference on the hemostatic balance in patients with cirrhosis. The consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Rome in December 2014. The statements were graded according to quality of evidence and strength of recommendations, and approved by an independent jury. The statements presented here highlight strengths and weaknesses of current laboratory tests to assess bleeding and thrombotic risk in cirrhotic patients, the pathophysiology of hemostatic perturbations in this condition, and outline the optimal management of bleeding and thrombosis in patients with liver cirrhosis.

Economic assessment of eltrombopag in the treatment of thrombocytopenia

OBJECTIVE

This study assesses the cost-effectiveness of eltrombopag in the treatment of hepatitis C virus (HCV)-related thrombocytopenia.

METHODS

A Markov model was constructed on the basis of the clinical trials ENABLE 1 and ENABLE 2. Three alternatives were considered: scenario 1; treatment with eltrombopag in both the enabling phase and during antiviral therapy, as in the ENABLE trial design; scenario 2; no eltrombopag treatment and no antiviral therapy; scenario 3; no eltrombopag treatment and subsequent administration of a reduced dose of peg-IFN.

RESULTS

Base case results demonstrate that scenario 1 is associated with a cost per QALY of €30,020.94 in comparison with scenario 2. The incremental cost-effectiveness ratio reaches a value of €32,752.44 per QALY when scenario 1 is compared with scenario 3.

CONCLUSION

The use of eltrombopag in HCV patients with thrombocytopenia is cost-effective as it leads to a reduction in disease progression and thus a drop in the number of patients with advanced liver disease.

Health-related quality of life in thrombocytopenic patients with chronic hepatitis C with or without cirrhosis in the ENABLE-1 and ENABLE-2 studies

Background

Despite changes in the treatment paradigm towards non-interferon-based therapies, interferon-based treatments are still used in some geographical regions for treating patients with hepatitis C virus (HCV) infection. Use of eltrombopag with interferon-based treatment for patients with thrombocytopenia and HCV was assessed in two similarly designed phase 3 trials (Eltrombopag to Initiate and Maintain Interferon Antiviral Treatment to Benefit Subjects With Hepatitis C-Related Liver Disease [ENABLE-1 and ENABLE-2]). These trials also aimed to determine whether response to antiviral therapy (e.g., sustained virologic response [SVR]) is associated with changes in health-related quality of life (HRQoL). This pooled, post-hoc analysis aimed to (1) determine whether or not specific aspects of clinical response to treatment (i.e., achieving SVR) are associated with a significant change in HRQoL, and (2) to determine the magnitude and direction of the association between important changes in HRQoL, clinical response to interferon-based therapy (e.g., SVR) and treatment (eltrombopag or placebo), and patient and disease attributes.

Methods

The Short-Form 36 Health Survey version 2 and Chronic Liver Disease Questionnaire–Hepatitis C Virus version were administered at various time points during the studies. Results from both trials were pooled for the analyses. Logistic regression analysis was used to assess the influence of 5 clinical factors (SVR, early virologic response [EVR], genotype [2/3 vs. non-2/3], treatment [eltrombopag or placebo], and cumulative interferon dose), plus other factors including ethnicity, model of end-stage liver disease score, and platelets as predictors of meaningful changes in HRQoL.

Results

Between antiviral therapy baseline and the end of the 24-week post-treatment follow-up, declines in HRQoL were smaller in eltrombopag-treated patients than in placebo-treated patients, but the differences were not statistically significant. Mean changes among patients achieving SVR and EVR were small in comparison to thresholds of minimally important changes. Logistic models did not confirm the strength of the 5 clinical factors as predictors of meaningful changes in HRQoL during antiviral therapy, with the exception of the interaction between SVR and EVR (P = 0.0009). Asian ethnicity had a consistent effect on HRQoL, with East Asian patients being more likely to experience deterioration in HRQoL compared with white and/or other non-East Asian patients.

Conclusions

While on active antiviral therapy, declines in HRQoL were not statistically different for eltrombopag-treated patients versus placebo-treated patients, suggesting that eltrombopag neither worsened HRQoL nor mitigated the effects of antiviral therapy on HRQoL.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-016-0447-1) contains supplementary material, which is available to authorized users.

Severe Thrombotic Complication of Eltrombopag in a Cirrhotic Patient

We present a patient with hepatitis C virus (HCV) and cirrhosis who was treated with eltrombopag for idiopathic thrombocytopenic purpura and was incidentally found to have a right atrial thrombus with extension into the left internal jugular vein. Eltrombopag was discontinued and the patient was treated with thrombectomy and anticoagulation. Given the proposed use of eltrombopag in HCV-associated thrombocytopenia, we advise caution when treating cirrhotics who are at higher intrinsic risk of thrombosis.

The Use of Thrombopoietin Receptor Agonists for Correction of Thrombocytopenia prior to Elective Procedures in Chronic Liver Diseases: Review of Current Evidence

Patients with chronic liver diseases (CLD) undergo a range of invasive procedures during their clinical lifetime. Various hemostatic abnormalities are frequently identified during the periprocedural work-up; including thrombocytopenia. Thrombocytopenia of cirrhosis is multifactorial in origin, and decreased activity of thrombopoietin has been identified to be a major cause. Liver is an important site of thrombopoietin production and its levels are decreased in patients with cirrhosis. Severe thrombocytopenia (platelet counts < 60-75,000/µL) is associated with increased risk of bleeding with invasive procedures. In recent years, compounds with thrombopoietin receptor agonist activity have been studied as therapeutic options to raise platelet counts in CLD. We reviewed the use of Eltrombopag, Romiplostim, and Avatrombopag prior to various invasive procedures in patients with CLD. These agents seem promising in raising platelet counts before elective procedures resulting in reduction in platelet transfusions, and they also enabled more patients to undergo the procedures. However, these studies were not primarily aimed at comparing bleeding episodes among groups. Use of these agents had some adverse consequences, importantly being the occurrence of portal vein thrombosis. This review highlights the need of further studies to identify reliable methods of safely reducing the provoked bleeding risk linked to thrombocytopenia in CLD.

Sofosbuvir-based therapy for patients with chronic hepatitis C: Early experience of its efficacy and safety in Korea

Background/Aims

The previous standard treatment for chronic hepatitis C (CHC) patients, comprising a combination of pegylated interferon (IFN) and ribavirin, was associated with suboptimal efficacy and severe adverse reactions. A new era of direct-acting antivirals is now dawning in Korea. Early experience of applying sofosbuvir-based therapy to CHC patients in Korea is reported herein.

Methods

Data on efficacy and safety were collected for CHC patients treated with a combination of sofosbuvir plus ribavirin or sofosbuvir/ledipasvir with or without ribavirin.

Results

This retrospective study included 25 consecutive patients who received sofosbuvir-based therapy (19 with genotype 1b and 6 with genotype 2) at Seoul National University Hospital from May 2014 to April 2015. A virologic response was achieved at week 4 by 85.7% and 80% of the patients with genotypes 1b and 2, respectively. The HCV-RNA level decreased more slowly in IFN-experienced than in treatment-naïve patients with genotype 1b. However, the sustained virologic response at week 12 (SVR12) rate did not differ among these patients, and was as high as 100%. The presence of cirrhosis significantly increased the risk of a virologic response failure at week 4 (OR, 11.0; P=0.011) among patients with HCV genotype 1b. Only five patients (20%) experienced minor adverse events, including grade 1 fatigue and headache. The hemoglobin level decreased slightly after sofosbuvir-based therapy, but there was no case of premature discontinuation of this therapy.

Conclusions

In a real clinical practice, sofosbuvir-based therapy for CHC patients in Korea achieved optimal antiviral efficacy with insignificant adverse events. Long-term follow-up data are warranted to ensure the sustained antiviral efficacy and long-term safety of sofosbuvir-based IFN-free therapy.

12 weeks of interferon-based therapy is feasible in patients with hepatitis C-related cirrhosis and thrombocytopenia: A post hoc analysis of eltrombopag studies

BACKGROUND

A 24-48-week course of interferon-based therapy poorly tolerated in hepatitis C virus (HCV) cirrhosis patients with thrombocytopenia. Aim of the study was to identify patients at low-risk of liver-related complications over a 12-week course of interferon-based therapy.

METHODS

We assessed the rate of complications and death during the first 12 weeks of interferon-based therapy in HCV cirrhotics with thrombocytopenia (platelets ≤75×10(9)/L) enrolled in the ENABLE-1 and -2 phase 3 randomised controlled trials.

RESULTS

Overall, among 1441 patients, 89 complications (6.9%) and 10 deaths (0.7%) were observed within the first 12 weeks of therapy. At univariate analysis baseline albumin levels and Model for End Stage Liver Disease (MELD) score (≤35 g /L, p<0.001, and ≥10, p<0.001, respectively) were the only predictors associated with occurrence of complications and death. Of the 1026 patients with serum albumin >35 g/L (71.2%), one patient died (0.1%) and 17 experienced liver-related complications (1.7%). Among 667 patients with serum albumin >35 g/L and MELD score <10, no deaths occurred and 4 experienced liver-related complications (0.6%).

CONCLUSION

Among HCV cirrhotic patients with thrombocytopenia, albumin levels and MELD score can identify patients who may safely receive a 12-week course of interferon-based therapy with a low risk of complications.

Safety and tolerability of eltrombopag versus placebo for treatment of thrombocytopenia in patients with advanced myelodysplastic syndromes or acute myeloid leukaemia: a multicentre, randomised, placebo-controlled, double-blind, phase 1/2 trial

BACKGROUND

Patients with myelodysplastic syndrome or acute myeloid leukaemia who are thrombocytopenic and unable to receive disease-modifying therapy have few treatment options. Platelet transfusions provide transient benefit and are limited by alloimmunisation. Eltrombopag, an oral thrombopoietin receptor agonist, increases platelet counts and has preclinical antileukaemic activity. We aimed to assess the safety and tolerability of eltrombopag for the treatment of thrombocytopenia in adult patients with advanced myelodysplastic syndrome, secondary acute myeloid leukaemia after myelodysplastic syndrome, or de-novo acute myeloid leukaemia.

METHODS

We did this multicentre, randomised, placebo-controlled, double-blind, phase 1/2 trial at 37 centres in ten countries in Europe, east Asia, and the Americas. Patients aged 18 years or older who had relapsed or refractory disease or were ineligible for standard treatments; had platelet counts of less than 30 × 10(9) platelets per L; had 10-50% bone-marrow blasts; or were platelet transfusion dependent were randomly assigned (2:1), via a telephone-based interactive voice-response system (GlaxoSmithKline Registration and Medication Ordering System) with a permuted-block randomisation schedule (block size of three), to receive once-daily eltrombopag or matching placebo dose adjusted from 50 mg to a maximum dose of 300 mg. Randomisation was stratified by presence of poor-prognosis (complex) karyotype (presence of at least three abnormalities, or chromosome 7 abnormalities, vs absence) and bone-marrow blast count (<20% vs ≥20%). Patients and study personnel were masked to treatment allocation. The primary endpoint was safety and tolerability, including adverse events, non-haematological laboratory grade 3-4 toxic effects, and changes in bone-marrow blast counts from baseline. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT00903422.

FINDINGS

Between May 14, 2009, and May 9, 2013, we randomly assigned 98 patients to receive either eltrombopag (n=64) or placebo (n=34). 63 (98%) patients in the eltrombopag group and 32 (94%) patients in the placebo group had adverse events. The most common adverse events were pyrexia (27 [42%] vs 11 [32%]), nausea (20 [31%] vs 7 [21%]), diarrhoea (19 [30%] vs 6 [18%]), fatigue (16 [25%] vs 6 [18%]), decreased appetite (15 [23%] vs 5 [15%]), and pneumonia (14 [22%] vs 8 [24%]). Drug-related adverse events of grade 3 or higher were reported in six (9%) patients in the eltrombopag group and four (12%) patients in the placebo group. Increases in the proportion of peripheral blasts did not differ significantly between groups. Haemorrhage of grade 3 or higher was reported in ten (16%) patients given eltrombopag and nine (26%) patients given placebo. 21 (33%) patients receiving eltrombopag and 16 (47%) patients receiving placebo died while on treatment. No deaths in patients receiving eltrombopag and two deaths in patients receiving placebo were regarded as treatment related. Post-baseline bone-marrow examinations were done in 40 (63%) patients in the eltrombopag group and 17 (50%) patients in the placebo group. The most common reason for no examination was death before the scheduled 3 month assessment. There were no differences between median bone-marrow blast counts or proportions of peripheral blasts between groups.

INTERPRETATION

Eltrombopag doses up to 300 mg daily had an acceptable safety profile in patients with advanced myelodysplastic syndrome or acute myeloid leukaemia. The role of eltrombopag in these patients warrants further investigation.

FUNDING

GlaxoSmithKline.

Multicenter Experience with Boceprevir or Telaprevir to Treat Hepatitis C Recurrence after Liver Transplantation: When Present Becomes Past, What Lessons for Future?

Background and aims

First generation protease inhibitors (PI) with peg-interferon (PEG-IFN) and ribavirin (RBV) have been the only therapy available for hepatitis C virus (HCV) genotype 1 infection in most countries for 3 years. We have investigated the efficacy and tolerance of this triple therapy in transplanted patients experiencing a recurrence of HCV infection on the liver graft.

Patients

This cohort study enrolled 81 liver transplant patients (Male: 76%, mean age: 55.8±9.7 years) with severe HCV recurrence (F3 or F4: n = 34 (42%), treatment experienced: n = 44 (54%)), treated with boceprevir (n = 36; 44%) or telaprevir (n = 45; 56%). We assessed the percentages of patients with sustained virological responses 24 weeks after therapy (SVR24), and safety.

Results

The SVR24 rate was 47% (telaprevir: 42%; boceprevir: 53%, P = ns). At baseline, a normal bilirubin level (p = 0.0145) and albumin level >35g/L (p = 0.0372) and an initial RBV dosage of ≥800 mg/day (p = 0.0033) predicted SVR24. During treatment, achieving an early virological response after 12 weeks was the strongest independent factor to predict SVR24 (p<0.0001). A premature discontinuation of anti-HCV therapy due to a serious adverse event (SAE) was observed in 22 patients (27%). Hematological toxicity, infections and deaths were observed in 95%, 28% and 7% of patients, respectively. A history of post-LT antiviral therapy and thrombocytopenia (<50G/L) during treatment were both independent predictors of the occurrence of infections or SAE (p = 0.0169 and p = 0.011).

Conclusions

The use of first generation PI after liver transplantation enabled an SVR24 rate of 47% in genotype 1 patients, but induced a high rate of SAE. The identification of predictive factors for a response to treatment, and the occurrence of SAE, have enabled us to establish limits for the use of this anti-HCV therapy in the transplant setting.

Novel insights into the development of portal vein thrombosis in cirrhosis patients

The prognostic impact of portal vein thrombosis (PVT) in liver cirrhosis remains controversial among studies, primarily because the risk stratification of PVT is often lacking. A definition of clinically significant PVT should be proposed and actively improved. Moreover, the risk factors for the development of PVT in liver cirrhosis should be fully recognized to screen and identify high-risk patients. Currently, well-recognized risk factors include a reduced portal vein flow velocity, a worse liver function, splenectomy, liver transplantation, and factor V Leiden and prothrombin G20210A mutations. Novel risk factors include an increased flow volume of portosystemic collateral vessel, thrombopoietin receptor agnonists, and non-selective beta-blockers. In contrast to the traditional perspectives, the abnormalities of procoagulant and anticoagulant factors may not contribute to the development of PVT in liver cirrhosis. Further studies should explore the role of other risk factors, such as antiphospholipid antibodies, methylenetetrahydrofolate reductase C677T gene mutation, hyperhomocysteinemia, and myeloproliferative neoplasms.

Eltrombopag: a review of its use in the treatment of thrombocytopenia in patients with chronic hepatitis C

Eltrombopag (Revolade(®); Promacta(®)) is an orally bioavailable, small-molecule, thrombopoietin receptor agonist that selectively binds to thrombopoietin receptors on megakaryocyte precursors and megakaryocytes leading to increased platelet production. It is approved in a number of countries for the treatment of thrombocytopenia, including adult patients with chronic hepatitis C virus (HCV) infection to allow for the initiation and maintenance of peginterferon-based therapy, which is the focus of this review. In two, well-designed, randomized controlled trials in adults with chronic HCV infection and thrombocytopenia (ENABLE-1 and ENABLE-2), eltrombopag increased platelet counts to sufficient levels to allow for the initiation of peginterferon-based antiviral therapy in 95 % of patients whose baseline platelet counts would have made them ineligible or marginal candidates for peginterferon therapy. Moreover, a significantly higher proportion of eltrombopag recipients than placebo recipients achieved a sustained virological response (primary endpoint) 24 weeks after the completion of antiviral therapy. Of note, the additional benefit over placebo was relatively small (<10 %). Compared with placebo, eltrombopag was associated with fewer patients discontinuing antiviral therapy early and a numerically greater proportion of patients not requiring antiviral dose reduction. Oral eltrombopag had an acceptable tolerability profile; however, there is an increased risk of adverse events, including potentially fatal hepatic decompensation and thromboembolic events. Eltrombopag provides a new treatment option for thrombocytopenia in patients with chronic HCV infection to allow for optimal antiviral therapy.

Non-cirrhotic thrombocytopenic patients with hepatitis C virus: Characteristics and outcome of antiviral therapy

BACKGROUND AND AIM

Thrombocytopenia is frequently observed in patients with chronic hepatitis C virus (HCV) infection and cirrhosis, although it can also be observed in patients without cirrhosis by a virus-mediated phenomenon. This study assessed the prevalence, characteristics, and outcomes of antiviral therapy in patients with chronic HCV infection and thrombocytopenia not associated with cirrhosis.

METHODS

The study included 1268 patients with HCV infection and thrombocytopenia enrolled in the phase 3 ENABLE studies that assessed the impact of eltrombopag on achieving a sustained virologic response to pegylated interferon and ribavirin. The study population was subdivided according to baseline FibroSURE test results into patients with non-cirrhosis (FibroSURE < 0.4) and cirrhosis-related (FibroSURE ≥ 0.75) thrombocytopenia.

RESULTS

Compared with patients with cirrhosis-related thrombocytopenia (n = 995; 78.5%), non-cirrhotic patients with thrombocytopenia (n = 59; 4.6%) were younger (mean age [95% confidence interval (CI)]: 43.9 [40.7-47.2] vs 52.7 [52.2-53.3] years; P < 0.0001), predominantly female (64% [51-76] vs 30% [27-33]; P < 0.0001), and less frequently had a Model for End-Stage Liver Disease score ≥ 10 (24% [14-37] vs 45% [42-49]; P = 0.0012), low albumin levels (≤ 35 g/L; 2% [0-9] vs 32% [29-35]; P < 0.0001), and prevalence of diabetes mellitus (3% [0-12] vs 21% [19-24]; P = 0.0005). The sustained virologic response rate was higher in non-cirrhotic patients with thrombocytopenia (46% [95% CI, 33-59] vs 16% [14-18]; P < 0.0001).

CONCLUSIONS

Patients with thrombocytopenia associated with HCV who have lower FibroSURE test results may have better preserved liver function and higher sustained virologic response rates than patients with cirrhosis.

Changing common sense: Anti-platelet/coagulation therapy against cirrhosis

Until recently, anti-platelet/coagulation therapy had not been recommended for patients with cirrhosis. Although venous thrombosis is one of the representative complications of cirrhosis and ischemic disorders associated with atherosclerosis are not infrequent in cirrhotic patients, many clinicians have tended to hesitate to introduce anti-platelet/coagulation therapy to their patients. Undoubtedly, this is due to the increased risk of hemorrhagic diathesis in cirrhotic patients. However, accumulating evidence has revealed the benefits of anti-platelet/coagulation therapy for cirrhotic patients. In addition to the safety of the therapy carried out against cardiovascular diseases in cirrhotic patients, some clinical data have indicated its preventive effect on venous thrombosis. Moreover, the efficacy of anti-platelet/coagulation therapy against cirrhosis itself has been demonstrated both clinically and experimentally. The conceptual basis for application of anti-platelet/coagulation therapy against cirrhosis was constructed through two pathologic studies on intrahepatic thrombosis in cirrhotic livers. It may be better to use thrombopoietin-receptor agonists, which have been tested as a treatment for cirrhosis-related thrombocytopenia, in combination with anti-platelet drugs to reduce the risk of venous thrombosis. During the last decade, the World Journal of Gastroenterology, a sister journal of World Journal of Hepatology, has been one of the main platforms of active discussion of this theme.

Efficacy of and risk of bleeding during pegylated interferon plus ribavirin treatment in HIV/HCV-coinfected patients with pretreatment thrombocytopenia

The aim of this study was to assess the efficacy of and the risk of major bleeding during pegylated interferon (peg-IFN)/ribavirin (RBV) treatment among human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients according to the pretreatment platelet count. Two hundred and seventy-four HCV/HIV-coinfected, previously naïve individuals with compensated cirrhosis enrolled in one Spanish prospective cohort who received peg-IFN/RBV were included in this study. The frequency of severe bleeding and sustained virological response (SVR) rate were compared between patients with a pretreatment platelet count ≤70,000/mm(3) and >70,000/mm(3), respectively. Sixty-one (22 %) patients had a baseline platelet count ≤70,000/mm(3). The median (Q1-Q3) pretreatment platelet count was 58,000 (49,000-65,000) cells/mm(3) in the platelet ≤70,000 group and 129,000 (102,500-166,000) cells/mm(3) in the platelet >70,000 group (p < 0.0001). Seventeen (28 %) subjects of the platelet ≤70,000 group and 71 (33 %) patients of the platelet >70,000 group achieved SVR (p = 0.4). Only 2 (3.2 %) patients in the platelet ≤70,000 group developed a severe hemorrhagic event, specifically esophageal variceal bleeding. The efficacy of therapy with peg-IFN/RBV in HIV/HCV-coinfected patients with low pretreatment platelet counts is comparable to that found in the overall subset of subjects with compensated cirrhosis. The frequency of severe hemorrhagic events related with this therapy is low in this population.

Risk of thromboembolism with thrombopoietin receptor agonists in adult patients with thrombocytopenia: Systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Romiplostim and eltrombopag are thrombopoietin receptor (TPOr) agonists that promote megakaryocyte differentiation, proliferation and platelet production. In 2012, a systematic review and meta-analysis reported a non-statistically significant increased risk of thromboembolic events for these drugs, but analyses were limited by lack of statistical power. Our objective was to update the 2012 meta-analysis examining whether TPOr agonists affect thromboembolism occurrence in adult thrombocytopenic patients.

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). Updated searches were conduced on PubMed, Cochrane Central, and publicly available registries (up to December 2014). RCTs using romiplostim or eltrombopag in at least one group were included. Relative risks (RR), absolute risk ratios (ARR) and number needed to harm (NNH) were estimated. Heterogeneity was analyzed using Cochran's Q test and I(2) statistic.

RESULTS

Fifteen studies with 3026 adult thrombocytopenic patients were included. Estimated frequency of thromboembolism was 3.69% (95% CI: 2.95-4.61%) for TPOr agonists and 1.46% (95% CI: 0.89-2.40%) for controls. TPOr agonists were associated with a RR of thromboembolism of 1.81 (95% CI: 1.04-3.14) and an ARR of 2.10% (95% CI: 0.03-3.90%) meaning a NNH of 48. Overall, we did not find evidence of statistical heterogeneity (p=0.43; I(2)=1.60%).

CONCLUSIONS

Our updated meta-analysis suggested that TPOr agonists are associated with a higher risk of thromboemboembolic events compared with controls, and supports the current recommendations included in the European product information on this respect.

Modeling and simulation support eltrombopag dosing in thrombocytopenic patients with chronic HCV infection

PURPOSE

The pharmacokinetics of eltrombopag and its stimulation of platelet production were characterized in patients with chronic hepatitis C virus (HCV) infection to optimize an eltrombopag dosing regimen for treatment of HCV-related thrombocytopenia before and throughout peginterferon (pegIFN)-based antiviral therapy.

METHODS

Population pharmacokinetic analysis for eltrombopag included 663 individuals (healthy subjects, n = 28; patients with HCV, n = 635). Population pharmacokinetic/pharmacodynamic analysis for platelet response involved patients with HCV only. Simulations were conducted using various dosing scenarios in the same patient population.

RESULTS

Eltrombopag pharmacokinetics were described by a two-compartment model with dual sequential first-order absorption and elimination. Age, race, sex, and severity of hepatic impairment were predictors of eltrombopag clearance. The effect of eltrombopag on platelet counts was adequately described by a model with four transit compartments in which eltrombopag concentrations stimulated the production rate of platelet precursors in an Emax manner.

CONCLUSIONS

Modeling and simulation results support once-daily eltrombopag 25 mg as an appropriate starting dosing regimen followed by biweekly dose escalation (in 25-mg increments) up to once-daily eltrombopag 100 mg to raise platelet counts sufficiently for initiation of pegIFN-based antiviral therapy in patients with HCV. Biweekly dose adjustment allows patients to stay on the lowest possible eltrombopag dose during antiviral therapy.

Are risk evaluation and mitigation strategies associated with less off-label use of medications? The case of immune thrombocytopenia

Using data from a large commercial health insurer, we studied prescribing of romiplostim (Nplate) and eltrombopag (Promacta), two drugs for primary immune thrombocytopenia (ITP) for which risk evaluation and mitigation strategies (REMS) with elements to assure safe use were initially imposed and then removed. We identified 103 and 117 new users of romiplostim and eltrombopag, respectively. Use was almost exclusively for FDA-approved indications ("on-label") while the REMS with elements to assure safe use were in place. After these elements were lifted, off-label use of eltrombopag among patients with hepatitis C virus (HCV), a subsequently approved indication, increased. The ratio of incidence rate ratios of off-label/HCV to on-label initiation of eltrombopag between the two time periods was significant (13.41; P < 0.001). Our finding of an association with reduced off-label prescribing suggests that REMS with elements to assure safe use can help promote patient safety but may also prevent promising off-label drug uses.

Use of eltrombopag in thrombocytopenia of liver disease

Second generation thrombopoietin agonists including eltrombopag and romiplostim act on the thrombopoietin receptor to increase the megakaryocyte production. These agents were needed as use of first generation recombinant products was associated with formation of autoantibodies. Eltrombopag is an oral thrombopoietin agonist found effective in raising platelet counts in patients with immune thrombocytopenia. The drug has now been found to be useful in raising platelet counts in thrombocytopenia related to liver disease including cirrhosis and chronic viral hepatitis. Although the drug may help enable adequate interferon therapy in patients with HCV infection and help carry out invasive procedures in patients with cirrhosis, concerns have been raised of possible thrombotic complications including portal vein thrombosis. Randomized trials have shown that use of eltrombopag concomitant with pegylated interferon and ribavirin increased the chances of sustained virologic response while decreasing the dose reductions of interferon. The data on use of romiplostim in these clinical indications is also emerging. However, in the future, availability of interferon free regimens is likely to decrease the use of eltrombopag for enabling antiviral therapy. The review discusses the role of eltrombopag in management of liver disease related thrombocytopenia in wake of recent data as also the dosage, precautions and adverse effects associated with its use.

Thrombosis Associated with Viral Hepatitis

Viral hepatitis may promote the development of venous thromboembolism (VTE) and, more specifically, portal vein thrombosis (PVT). In this narrative review, we summarize the clinical data and discuss the possible pathogenetic roles of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and hepatitis A, B, and C viruses (HAV, HBV, HCV) in the occurrence of VTE. CMV is the first qualified candidate to enter the list of VTE minor risk factors, and in the rare case of fulminant infection, both EBV and CMV, like any severe infection or inflammatory disease, increase risk for thrombosis. In chronic hepatitis B and C, it remains controversial whether antiphospholipid antibodies are important for thrombotic complications or merely an epiphenomenon. Retinal vein occlusion described in chronic hepatitis C is usually attributed to the treatment with interferon. Eltrombopag, used for HCV-related thrombocytopenia, has been associated with increased thrombotic risk. The imbalance between procoagulant and anticoagulant factors associated with chronic liver disease may have clinical implications. This may help to explain why these patients are not protected from clinical events such as VTE, PVT, and the progression of liver fibrosis.

Management of thrombocytopenia in advanced liver disease

Thrombocytopenia (defined as a platelet count <150×10(9)) is a well-known complication in patients with liver cirrhosis and has been observed in 76% to 85% of patients. Significant thrombocytopenia (platelet count <50×10(9) to 75×10(9)) occurs in approximately 13% of patients with cirrhosis. Thrombocytopenia can negatively impact the care of patients with severe liver disease by potentially interfering with diagnostic and therapeutic procedures. Multiple factors can contribute to the development of thrombocytopenia including splenic platelet sequestration, immunological processes, bone marrow suppression by chronic viral infection, and reduced levels or activity of the hematopoietic growth factor thrombopoietin. The present review focuses on the etiologies and management options for severe thrombocytopenia in the setting of advanced liver disease.

Hospital-acquired thrombocytopenia

The development of thrombocytopenia is common in hospitalized patients and is associated with increased mortality. Frequent and important causes of thrombocytopenia in hospitalized patients include etiologies related to the underlying illness for which the patient is admitted, such as infection and disseminated intravascular coagulation, and iatrogenic etiologies such as drug-induced immune thrombocytopenia, heparin-induced thrombocytopenia, posttransfusion purpura, hemodilution, major surgery, and extracorporeal circuitry. This review presents a brief discussion of the pathophysiology, distinguishing clinical features, and management of these etiologies, and provides a diagnostic approach to hospital-acquired thrombocytopenia that considers the timing and severity of the platelet count fall, the presence of hemorrhage or thrombosis, the clinical context, and the peripheral blood smear. This approach may offer guidance to clinicians in distinguishing among the various causes of hospital-acquired thrombocytopenia and providing management appropriate to the etiology.

Eltrombopag in chronic hepatitis C

Chronic hepatitis C is a public health problem worldwide. Unfortunately, not all patients may benefit from antiviral therapy due to thrombocytopenia. Its causes are represented by portal hypertension and platelet sequestration in the spleen, decreased serum levels or activity of thrombopoietin, the bone marrow suppression induced by hepatitis C virus and a possible adverse effect of interferon. Thrombopoietin receptor analogs may contribute to increase platelet counts in these patients. Eltrombopag binds to another region of the thrombopoietin receptor compared to endogenous thrombopoietin and stimulates the proliferation and maturation of megakaryocytes and the platelet production in a dose-dependent manner. Eltrombopag has proven its effectiveness for the treatment of patients with primary immune thrombocytopenia. Its indication for other hemopathies or situations (like thrombocytopenia secondary to chemo- or radiotherapy, acute leukemia, myelodysplastic syndroms, acquired and hereditary bone marrow failure, and platelet donors) is under study. Eltrombopag may be particularly useful in patients with advanced chronic hepatitis or liver cirrhosis who require antiviral treatment. We present a minireview on the results of treatment with eltrombopag in patients chronically infected with hepatitis C virus, highlighting the benefits and mentioning possible adverse effects. In some studies eltrombopag increased the number of virological responses after clasical antiviral treatment of patients with chronic hepatitis C and reduced the transfusional requirements of those who had to be subjected to invasive surgery. Eltrombopag is a solution for many of these patients, which allows them receiving antiviral therapy and sometimes getting a sustained virological response, but they must be well monitored to prevent possible thromboembolic or bone marrow complications or liver failure occurrence.

Efficacy and safety of splenectomy in telaprevir-based triple therapy for chronic hepatitis C patients with thrombocytopenia and advanced fibrosis

BACKGROUND AND AIM

Thrombocytopenia (TCP) of chronic hepatitis C patients with cirrhosis has a negative impact on the management of interferon-based treatment. The aim of this study is to evaluate the efficacy and safety of telaprevir-based triple therapy for patients who have undergone splenectomy (Spx).

METHODS

This prospective, multicenter study consisted of 80 patients, including 32 Spx and 48 non-Spx/TCP (platelet count: 60-99 × 10(9) /L) patients with advanced fibrosis infected with hepatitis C virus genotype 1b. All received 12 weeks of telaprevir in combination with 24 weeks of pegylated interferon (PEG-IFN) α2b and ribavirin.

RESULTS

The sustained virological response (SVR) rate of the Spx group (75.0%) was significantly higher than that of the non-Spx/TCP group (52.1%) (P < 0.05). Under favorable conditions such as treatment-naïve/prior relapse and interleukin-28B (IL28B) TT allele (rs8099917), the SVR rates of the Spx group were significantly higher than those of the non-Spx/moderate TCP (60-79 × 10(9) /L) groups (91.3% vs 50.0% and 93.8% vs 37.5%, respectively; both P < 0.05). Adequate PEG-IFNα2b adherence was associated with SVR. However, the percentage of patients who achieved 80% adherence to PEG-IFNα2b in the non-Spx/moderate TCP (42.9%) group was significantly lower than that of the Spx (79.3%) and non-Spx/mild TCP (80-99 × 10(9) /L) (80.0%) groups. Treatment discontinuation due to adverse effects and the development of bacterial infection did not differ between the Spx and non-Spx/TCP groups.

CONCLUSION

The increase of platelet count after Spx contributed to treatment success, especially for moderate to severe TCP patients who are treatment-naïve/prior relapse or IL28B TT allele.

Eltrombopag with gemcitabine-based chemotherapy in patients with advanced solid tumors: a randomized phase I study

Preventing chemotherapy-induced thrombocytopenia could avoid chemotherapy dose reductions and delays. The safety and maximum tolerated dose of eltrombopag, an oral thrombopoietin receptor agonist, with gemcitabine-based therapy was evaluated. Patients with advanced solid tumors and platelets ≤300 × 10⁹/L receiving gemcitabine plus cisplatin or carboplatin (Group A) or gemcitabine monotherapy (Group B) were randomized 3:1 to receive eltrombopag or placebo at a starting dose of 100 mg daily administered on days −5 to −1 and days 2–6 starting from cycle 2 of treatment. Nineteen patients (Group A, n = 9; Group B, n = 10) received eltrombopag 100 mg and seven (Group A, n = 3; Group B, n = 4) received matching placebo. Nine eltrombopag patients in Group A and eight in Group B had 38 and 54 occurrences of platelet counts ≥400 × 10⁹/L, respectively. Mean platelet nadirs across cycles 2–6 were 115 × 10⁹/L and 143 × 10⁹/L for eltrombopag-treated patients versus 53 × 10⁹/L and 103 × 10⁹/L for placebo-treated patients in Groups A and B, respectively. No dose-limiting toxicities were reported for eltrombopag; however, due to several occurrences of thrombocytosis, a decision was made not to dose-escalate eltrombopag to >100 mg daily. In Groups A and B, 14% of eltrombopag versus 50% of placebo patients required chemotherapy dose reductions and/or delays for any reason across cycles 3–6. Eltrombopag 100 mg once daily administered 5 days before and after day 1 of chemotherapy was well tolerated with an acceptable safety profile, and will be further tested in a phase II trial. Fewer patients receiving eltrombopag required chemotherapy dose delays and/or reductions compared with those receiving placebo.

Lack of clinically significant pharmacokinetic interaction between the thrombopoietin receptor agonist eltrombopag and hepatitis C virus protease inhibitors boceprevir and telaprevir

Eltrombopag is an orally bioavailable thrombopoietin receptor agonist approved for the treatment of thrombocytopenia associated with chronic immune (idiopathic) thrombocytopenic purpura and chronic hepatitis C virus (HCV) infection. This study evaluated the potential drug-drug interactions between eltrombopag and the HCV protease inhibitors boceprevir and telaprevir. In this open-label, 3-period, single-sequence, and crossover study, 56 healthy adult subjects were randomized 1:1 to cohort 1 (boceprevir) or 2 (telaprevir). The dosing was as follows: period 1, single 200-mg dose of eltrombopag; period 2, 800 mg boceprevir or 750 mg telaprevir every 8 hours (q8h) for 10 days; and period 3, single 200-mg dose of eltrombopag with either 800 mg boceprevir or 750 mg telaprevir q8h (3 doses). All doses were administered with food, and eltrombopag was administered specifically with low-calcium food. There was a 3-day washout between periods 1 and 2 and no washout between periods 2 and 3. Serial pharmacokinetic samples were collected for 72 h in periods 1 and 3 and for 8 h in period 2. The coadministration of eltrombopag increased the rate of boceprevir absorption, resulting in a 20% increase in the maximum concentration in plasma (Cmax), a 1-h-earlier time to Cmax (Tmax) for boceprevir, a 32% decrease in the concentration at the end of the dosing interval (Cτ), and no change in the area under the concentration-time curve over the dosing interval (AUC0-τ). The coadministration of eltrombopag did not alter telaprevir pharmacokinetics, and the coadministration of boceprevir or telaprevir did not alter eltrombopag pharmacokinetics. Dysgeusia, headache, and somnolence occurred in ≥2 subjects. One subject withdrew because of nausea, headache, dizziness, sinus pressure, and vomiting. There were no severe or serious adverse events. Dose adjustment is not required when eltrombopag is coadministered with boceprevir or telaprevir given the lack of clinically significant pharmacokinetic interaction.