Ribavirin dose reduction during telaprevir/ribavirin/peg-interferon therapy overcomes the effect of the ITPA gene polymorphism

Predictive factors of anemia during sofosbuvir and ribavirin therapy for genotype 2 chronic hepatitis C patients

AIM

Sofosbuvir (SOF) and ribavirin (RBV) combination therapy has improved the sustained virologic response (SVR) rate and shortened the treatment duration for patients with chronic hepatitis C virus (HCV) genotype 2 infection. Ribavirin-induced hemolytic anemia is one of the most troublesome side-effects of SOF/RBV therapy; however, factors associated with this condition have not been fully elucidated. We aimed to identify a safer way to complete treatment with SOF/RBV therapy by examining factors related to RBV-induced hemolytic anemia and identifying patients who did not develop anemia.

METHODS

Two hundred and one patients with genotype 2 chronic hepatitis C treated with SOF/RBV therapy were studied. Significant factors associated with the decline in hemoglobin (Hb) levels from the baseline were analyzed.

RESULTS

The SVR rate was 96.5% (194 out of 201 patients) based on intent-to-treat analysis. In multivariate analysis, inosine triphosphatase (ITPA) gene variation (P < 0.0001) and estimated glomerular filtration rate (eGFR) (0.001) were significantly associated with a decrease in Hb levels less than 2 g/dL. All patients were divided into four groups by ITPA and eGFR at baseline, and we identified patients with ITPA CA/AA and eGFR >75 as a group that did not develop anemia.

CONCLUSIONS

The results presented here suggest that patients with ITPA CA/AA and eGFR >75 had no reduction in Hb levels during the treatment with SOF/RBV in HCV genotype 2-infected patients. Adding RBV to direct-acting antiviral therapy might not be problematic in certain patients, at least in terms of the occurrence of anemia.

ITPA polymorphism effects on decrease of hemoglobin during sofosbuvir and ribavirin combination treatment for chronic hepatitis C

BACKGROUND

Polymorphisms in the inosine triphosphatase (ITPA) gene is associated with anemia induced by peg-interferon (PEG-IFN) plus ribavirin (RBV) treatment for patients with chronic hepatitis C virus (HCV) infection. However, the effect of ITPA polymorphism on sofosbuvir plus RBV treatment is unknown.

METHODS

Two hundred and forty-four patients with chronic HCV genotype 2 infection without decompensated liver cirrhosis were treated with sofosbuvir plus RBV for 12 weeks. The effects of ITPA polymorphism on hemoglobin levels and RBV dose reduction and treatment response were analyzed. ITPA (rs1127354) was genotyped using the Invader assay. Multivariate regression analysis was performed to identify factors associated with sustained virological response (SVR).

RESULTS

Overall, SVR12 was achieved in 231 (94.7%) patients, based on intention to treat analysis. During the therapy, reduction of hemoglobin levels was significantly greater in ITPA genotype CC patients than CA/AA patients. Therefore, the cumulative proportion of patients with RBV dose reduction was significantly higher and total dose of RBV was significantly lower in patients with CC genotype compared to CA/AA genotypes. SVR12 rates were similar between ITPA genotypes CC and CA/AA (94.7 and 94.4%, respectively, P = 0.933). Multivariate logistic regression analysis identified FIB4 index <3.25 (odds ratio [OR], 9.388 for ≥3.25; P = 0.005) and low body weight (OR, 1.059, for high body weight; P = 0.017) as independent predictors for SVR12.

CONCLUSIONS

ITPA polymorphism influences hemoglobin levels and incidence of RBV dose reduction during sofosbuvir plus RBV therapy. However, ITPA genotype CC patients can expect a curative effect equivalent to CA/AA patients for chronic HCV genotype 2 infection.

Hepatitis C virus pharmacogenomics in Latin American populations: implications in the era of direct-acting antivirals

In recent years, great progress has been made in the field of new therapeutic options for hepatitis C virus (HCV) infection. The new direct-acting antiviral agents (DAAs) represent a great hope for millions of chronically infected individuals because their use may lead to excellent cure rates with fewer side effects. In Latin America, the high prevalence of HCV genotype 1 infection and the significant association of Native American ancestry with risk predictive single-nucleotide polymorphisms (SNPs) in IFNL4 and ITPA genes highlight the need to implement new treatment regimens in these populations. However, the universal accessibility to DAAs is still not a reality in the region as their high cost is one of the major, although not the only, limiting factors for their broad implementation. Therefore, under these circumstances, could the assessment of host genetic markers be a useful tool to prioritize DAA treatment until global access to these new drugs can be achieved? This review will summarize the scientific evidences and the potential implications of HCV pharmacogenomics in this rapidly evolving era of anti-HCV drug development.

Rapidity and Severity of Hemoglobin Decreasing Associated with Erythrocyte Inosine Triphosphatase Activity and ATP Concentration during Chronic Hepatitis C Treatment

The purpose of this study was to evaluate the association between therapy-induced hemoglobin (Hb) decreasing rapidity and severity with erythrocyte inosine triphosphatase (ITPase) activity and ATP concentration in chronic hepatitis C patients receiving chronic hepatitis C (HCV) treatment. Forty-three Japanese patients were included in the study. Erythrocyte ITPase activity before therapy was determined by HPLC-UV. Erythrocyte ATP concentrations before and during therapy were determined by luciferase assay. Genotyping for ITPA 94C>A (rs1127354) and IVS2+21 A>C (rs7270101) was conducted using TaqMan probes. The median ITPase activity (µmol/h/g hemoglobin) of ITPA 94 CC, CA, and AA genotypes was 136.8 (range, 80.4-289.6), 41.1 (24.3-93.1), and 11.8, respectively. ITPase activity and Hb decreasing showed a significantly inverse relationship at therapeutic weeks 2, 4, and 6 (p<0.01). Erythrocyte ATP concentration was decreased by therapy, and Hb decreasing was significantly and inversely correlated with erythrocyte ATP concentration at week 4 and after week 8 (p<0.001 and 0.05, respectively). ATP concentration for patients with ITPA 94CA was significantly lower than ITPA 94CC at week 4 (p=0.045). We concluded that ITPase activity plays an important function and that ATP concentration changes due to therapy are related to the Hb decreasing mechanism in the early period of therapy with HCV treatment.

Correlation of interferon-lambda 4 ss469415590 with the hepatitis C virus treatment response and its comparison with interleukin 28b polymorphisms in predicting a sustained virological response: a meta-analysis

BACKGROUND

Interferon-lambda 4 (IFNL4) ss469415590 is a newly discovered polymorphism that could predict the treatment response in hepatitis C virus (HCV)-infected patients. This meta-analysis was performed in order to clarify its specific effect on the treatment response and to compare it with interleukin 28b (IL28B).

METHOD

The commonly used literature databases were searched. Meta-analyses were performed with fixed/random-effects models using Stata 12.0. The sustained virological response (SVR) rate was summarized using R software. Publication bias was examined through Egger's test.

RESULTS

A total of seven studies were finally included in this meta-analysis. IFNL4 ss469415590 was demonstrated to be associated with SVR (odds ratio (OR) 3.83, 95% confidence interval (CI) 3.22-4.56, p<0.001). Asians had a higher likelihood of achieving SVR than Caucasians (OR=7.36 vs. 3.54). When stratifying all the patients according to HCV genotype, a significant association was observed in HCV genotype 1 patients (OR 4.5, 95% CI 2.91-6.95, p<0.001). In HCV genotype 2/3 patients, the favorable TT/TT genotype patients tended to have a statistically higher SVR rate than the non-TT/TT genotype patients (84.4% vs. 78.3%, p=0.058). Compared with IL28B rs12979860 (OR 3.45) and rs8099917 (OR 3.50), ss469415590 TT/TT genotype patients showed a slightly higher probability of achieving a SVR (OR 3.61 calculated from studies investigating both IFNL4 and rs12979860; OR 4.86 for studies investigating both IFNL4 and rs8099917). Furthermore, ss469415590 showed a slightly higher predictive value than rs12979860 using the diagnostic test tool (area under the curve=0.71 vs. 0.70). IFNL4 was also correlated with rapid virological response (RVR) (OR 4.35, 95% CI 1.43-13.20, p=0.01), viral clearance (OR 0.31, 95% CI 0.24-0.39, p<0.001), and HCV susceptibility (OR 0.76, 95% CI 0.65-0.89, p=0.001).

CONCLUSIONS

IFNL4 ss469415590 is significantly associated with SVR in HCV genotype 1 patients, irrespective of race; there is a tendency towards an association in HCV genotype 2/3 patients. Comparable to IL28B, IFNL4 is correlated with natural viral clearance and HCV susceptibility, additionally IFNL4 ss469415590 has a slightly higher predictive performance over IL28B polymorphisms in regard to SVR.

Effects of ITPA polymorphism on decrease of hemoglobin during simeprevir, peg-interferon, and ribavirin combination treatment for chronic hepatitis C

AIM

Polymorphisms in the ITPA gene influence anemia during peg-interferon (PEG-IFN) and ribavirin (RBV) therapy, but their effects during triple therapy with simeprevir, PEG-IFN, and RBV are not sufficiently known.

METHODS

We analyzed 212 patients with genotype 1 chronic hepatitis C, who were treated with simeprevir plus PEG-IFN/RBV triple therapy, and assessed the effect of the ITPA polymorphism on hemoglobin levels and RBV dose reduction. ITPA (rs1127354) and IFNL4 (ss469415590) polymorphisms were genotyped using the Invader assay. A stepwise multivariate regression analysis was carried out to identify factors associated with outcome of the therapy.

RESULTS

Reduction of hemoglobin levels was similar between patients treated with simeprevir plus PEG-IFN/RBV and those treated with PEG-IFN/RBV therapy. In simeprevir plus PEG-IFN/RBV-treated patients, decreases in hemoglobin levels were faster and greater, and the cumulative proportion of patients with ribavirin dose reduction was significantly greater in ITPA genotype CC patients than in CA/AA patients. The total dose of simeprevir and PEG-IFN was similar between ITPA genotype CC and CA/AA patients. In contrast, the total dose of RBV was lower in patients with the CC genotype. Multivariate analysis showed that the IFNL4 TT/TT genotype, but not the ITPA SNP genotype, treatment history (treatment-naive or relapse during prior treatment), and treatment completion were significantly associated with outcome of therapy.

CONCLUSION

ITPA polymorphism influences hemoglobin levels and incidence of RVB dose reduction during simeprevir triple therapy, indicating the importance of monitoring anemia during treatment, particularly for ITPA genotype CC patients.

Recent advances in management of the HIV/HCV coinfected patient

Chronic hepatitis C virus (HCV) is a global epidemic, affecting approximately 150 million individuals throughout the world. The implications of HCV infection have been magnified in those who are infected with both HCV and the HIV as liver disease progression, liver failure and liver-related death are increased, particularly in those without well-controlled HIV disease. The development of direct-acting antiviral agents for HCV that allow shorter treatment periods with increased efficacy and decreased adverse events have greatly changed the outlook for HCV-infected individuals. With these advancements, growing treatment options for the coinfected population have also come. This review will address pharmacotherapy issues in the HIV/HCV coinfected population.

Interferon Lambda 4 Polymorphism Predicts Sustained Viral Response in Hepatitis C Virus Patients Irrespective of Hepatitis C Virus Genotypes, Ethnicity or Treatment Regimen: Results From a Meta-Analysis

CONTEXT

There is growing evidence that interferon lambda 4 (IFNL4) polymorphism is related to sustained virological response (SVR) in hepatitis C virus (HCV) infection. We analyzed the relationship between IFNL4 (rs368234815) polymorphism and SVR in dual- and triple- therapy in HCV genotype 1, 2, 3 and 4 infected Asian, Caucasian and African patients.

EVIDENCE ACQUISITION

We performed a systematic search of PubMed, Medline, Embase, EBSCO and Web of Science databases up to July 2015. Data of qualified studies were analyzed using the meta-analysis method in Stata 12.0 software.

RESULTS

Ten studies involving 4765 patients were included in the analysis. Of overall studies, SVR was more frequent in TT/TT genotype compared to TT /ΔG+ΔG /ΔG (OR = 4.439, 95% CI: 3.410 - 5.778). Genotype stratification analyses revealed rs368234815 TT/ TT was associated with higher SVR in G1, G2/3 and G4 HCV patients (ORG1 = 4.661, 95% CI: 3.937 - 5.518; ORG2/3 = 1.896, 95% CI: 1.265 - 2.841; ORG4 = 6.074; 95% CI: 3.129 - 11.788). Ethnicity stratification analyses of G1 patients showed that SVR was more frequent with TT/ TT genotype in Asians (OR= 8.245, 95% CI: 5.475 - 12.416), Caucasians (OR = 4.166, 95% CI: 3.441 - 5.042) and Africans (SVR: 37.5% vs 17.0%, P = 0.017). Moreover, similar results presented in therapy stratification analyses both in patients with dual-therapy (OR = 3.857; 95% CI: 3.288 - 4.524) or triple-therapy (OR = 8.119; 95% CI: 4.942 - 13.340).

CONCLUSIONS

Favorable IFNL4 rs368234815 genotype is a strong predictor of SVR in HCV patients, irrespective of HCV genotypes, ethnicity or treatment regimen. Thus, detection for IFNL4 rs368234815 polymorphism may be beneficial to guide the clinician in the individualization of therapy and design.

ITPA Polymorphisms Are Associated with Hematological Side Effects during Antiviral Therapy for Chronic HCV Infection

Background/Objective

Genetic polymorphisms in the inosine triphosphatase (ITPA) gene have been associated with the protection from early ribavirin(RBV)-induced hemolytic anemia among patients with chronic hepatitis C virus (HCV) infection. The aim of the present study was to investigate the association between the functional ITPA variants and hematological side effects during antiviral therapy with pegylated interferon (PegIFN) and RBV.

Patients and Methods

This cohort study included all consecutive Caucasian patients treated for chronic HCV infection with PegIFN and RBV between 2000 and 2009 for whom a serum sample was available for genetic testing. The predicted inosine triphosphate pyrophosphatase (ITPase) activity was based on the genotypes of the SNPs rs1127354 and rs7270101. Decline in hemoglobin (Hb) during antiviral therapy, as well as dose reductions, blood transfusions and use of erythropoietin were assessed.

Results

In total, 213 patients were included. The predicted ITPase activity was normal among 152 (71%) patients; 61 (29%) patients had ITPase deficiency. By multivariable linear regression, RBV dose in mg per kilogram (Beta 0.09, 95%CI 0.04–0.13, p<0.001) and normal ITPase activity (Beta 0.89, 95%CI 0.64–1.14, p<0.001) were associated with more Hb decline at week 4 of treatment. Patients with normal ITPase activity underwent more dose adjustments of RBV than patients with ITPase deficiency (19(13%) vs 1(2%),p = 0.014) and received erythropoietin more frequently (12 (8%) vs 0 (0%),p = 0.024).

Conclusion

Genetic variants in the ITPA gene protected against RBV treatment-induced anemia among Caucasian patients with chronic HCV infection. Patients with normal ITPase activity underwent more dose reductions of RBV and received erythropoietin more frequently.

SLC29A1 polymorphism and prediction of anaemia severity in patients with chronic hepatitis C receiving triple therapy with telaprevir

OBJECTIVES

The equilibrative nucleoside transporter 1 (ENT1) is the main protein involved in ribavirin cellular uptake. Polymorphisms at the SLC29A1 gene, encoding ENT1, may influence ribavirin-associated anaemia, which is observed at a higher incidence with telaprevir in combination with pegylated-IFNα and ribavirin than with pegylated-IFNα and ribavirin alone. In this study, we investigated the role of the rs760370 SLC29A1 variant in ribavirin-induced anaemia in chronic hepatitis C patients treated with telaprevir-based triple therapy.

METHODS

Forty patients infected with hepatitis C virus (HCV) genotype 1 and starting anti-HCV therapy with telaprevir in combination with pegylated-IFN/ribavirin were prospectively evaluated for SNPs at the SLC29A1 gene and inosine triphosphatase (ITPA) genes using a real-time PCR system.

RESULTS

40% of patients developed severe anaemia with a haemoglobin (Hb) decline ≥ 5 g/dL from the pretreatment value. The SLC29A1 rs760370 GG genotype was associated with the severity of Hb decrease as expressed by the median (IQR) Hb nadir change from baseline [-5.4 (-5.6; -5.0) g/dL in GG versus -4.2 (-5.1; -3.4) in AA/AG genotype; P=0.05] and by the Hb decrease ≥ 5 g/dL by week 12 (77.8% of GG carriers versus 24% of AA/AG; P<0.01). In multivariate analysis, older age (P=0.03), lower baseline Hb concentration (P=0.02) and SLC29A1 rs760370 GG (P=0.02) were associated with the development of severe anaemia during treatment, whereas no association was found with ITPA SNPs in our population receiving telaprevir-based therapy.

CONCLUSIONS

In patients with chronic hepatitis C receiving telaprevir-based therapy, SNP rs760370A>G at the SLC29A1 gene influences the severity of ribavirin-induced anaemia, possibly mirroring the erythrocyte uptake of ribavirin.

Telaprevir enhances ribavirin-induced anaemia through renal function impairment

BACKGROUND

Alterations in renal function have been described with telaprevir (TVR). We examined the relationship between ribavirin (RBV) trough concentration (C), estimated glomerular filtration rate (eGFR) and severe anaemia, before and after TVR introduction in HIV-HCV-coinfected patients included in ANRS HC26 TelapreVIH study.

METHODS

69 HIV-HCV genotype-1 coinfected patients received 4 weeks of pegylated interferon (PEG-IFN)-α2a/RBV, followed by 12 weeks of TVR/PEG-IFN/RBV, then 32 to 56 weeks of PEG-IFN/RBV. RBV C was determined at week (W)4, W8 and W20/24. eGFR was estimated by the Modification of the Diet in Renal Disease (MDRD) equation. Severe anaemia was defined as haemoglobin <70 g/l, RBV dose reduction, prescription of erythropoietin or blood transfusion.

RESULTS

67 patients were analysed. eGFR remained normal between baseline (97.9 ml/min) and W4 (103.4 ml/min), declined to 86.3 ml/min at W8 (P<0.0001), stabilized until W16 and increased back to baseline level at W20 (98.4 ml/min). RBV C increased from 1.88 mg/l at W4 to 2.88 mg/l at W8 (P<0.0001), then decreased to 2.73 mg/l at week 20/24 (P=0.015). An inverse correlation was observed between W8 eGFR and W8 RBV C (r2=0.429; P=0.0005). RBV C≥3 mg/l was observed in 12% of patients at W4, 45% at W8 (P<0.0001) and 38% at W20/24 (P=0.0005). Severe anaemia was observed in 23.9% of patients at W4 and 45.3% at W8. RBV C≥3 mg/l at W8 (OR 7.7 [95% CI 2.2, 27.4]) and baseline haemoglobin <150 g/l (OR 6.4 [1.7, 23.8]) were independently associated with W8 severe anaemia.

CONCLUSIONS

Association of TVR to PEG-IFN/RBV was associated with a decrease in eGFR and increase in RBV C, leading to severe anaemia in 45% of patients.