Sofosbuvir for previously untreated chronic hepatitis C infection.

BACKGROUND: In phase 2 trials, the nucleotide polymerase inhibitor sofosbuvir was effective in previously untreated patients with chronic hepatitis C virus (HCV) genotype 1, 2, or 3 infection. METHODS: We conducted two phase 3 studies in previously untreated patients with HCV infection. In a single-group, open-label study, we administered a 12-week regimen of sofosbuvir plus peginterferon alfa-2a and ribavirin in 327 patients with HCV genotype 1, 4, 5, or 6 (of whom 98% had genotype 1 or 4). In a noninferiority trial, 499 patients with HCV genotype 2 or 3 infection were randomly assigned to receive sofosbuvir plus ribavirin for 12 weeks or peginterferon alfa-2a plus ribavirin for 24 weeks. In the two studies, the primary end point was a sustained virologic response at 12 weeks after the end of therapy. RESULTS: In the single-group study, a sustained virologic response was reported in 90% of patients (95% confidence interval, 87 to 93). In the noninferiority trial, a sustained response was reported in 67% of patients in both the sofosbuvir-ribavirin group and the peginterferon-ribavirin group. Response rates in the sofosbuvir-ribavirin group were lower among patients with genotype 3 infection than among those with genotype 2 infection (56% vs. 97%). Adverse events (including fatigue, headache, nausea, and neutropenia) were less common with sofosbuvir than with peginterferon. CONCLUSIONS: In a single-group study of sofosbuvir combined with peginterferon-ribavirin, patients with predominantly genotype 1 or 4 HCV infection had a rate of sustained virologic response of 90% at 12 weeks. In a noninferiority trial, patients with genotype 2 or 3 infection who received either sofosbuvir or peginterferon with ribavirin had nearly identical rates of response (67%). Adverse events were less frequent with sofosbuvir than with peginterferon. (Funded by Gilead Sciences; FISSION and NEUTRINO ClinicalTrials.gov numbers, NCT01497366 and NCT01641640, respectively.).

Sofosbuvir with peginterferon-ribavirin for 12 weeks in previously treated patients with hepatitis C genotype 2 or 3 and cirrhosis.

UNLABELLED: Sofosbuvir (SOF) in combination with ribavirin (RBV) for 12 or 24 weeks is the current standard of care for patients infected with hepatitis C virus (HCV) genotypes 2 and 3, respectively. However, in clinical trials treatment-experienced patients, particularly those with cirrhosis, had suboptimal sustained virological response (SVR) rates. We assessed the efficacy and safety of sofosbuvir plus peginterferon and ribavirin (SOF+Peg-IFN+RBV) administered for 12 weeks to treatment-experienced patients with HCV genotypes 2 and 3, with and without cirrhosis. We enrolled 47 patients in this open-label, nonrandomized, uncontrolled phase 2 study. The primary endpoint was the proportion of patients with SVR at 12 weeks after cessation of study treatment (SVR12). The overall rate of SVR12 was 89% (95% confidence interval [CI]: 77-97). Rates of SVR12 were higher in patients with genotype 2 than in those with genotype 3, 96% (95% CI: 78-100) and 83% (95% CI: 62-95), respectively. Rates of SVR12 were similar in patients with and without cirrhosis: for genotype 2, 93% of patients with cirrhosis and 100% of patients without cirrhosis achieved SVR12, and for genotype 3, the SVR12 rate was 83% in patients both with and without cirrhosis. One patient discontinued study treatment because of an adverse event and four patients experienced serious adverse events. The most common adverse events were influenza-like illness, fatigue, anemia, and neutropenia. CONCLUSION: In treatment-experienced patients with HCV genotypes 2 and 3, 12-week administration of SOF+Peg-IFN+RBV provided high SVR rates, irrespective of cirrhosis status. No safety concerns were identified.

Genetic variation in IL28B predicts hepatitis C treatment-induced viral clearance.

Chronic infection with hepatitis C virus (HCV) affects 170 million people worldwide and is the leading cause of cirrhosis in North America. Although the recommended treatment for chronic infection involves a 48-week course of peginterferon-alpha-2b (PegIFN-alpha-2b) or -alpha-2a (PegIFN-alpha-2a) combined with ribavirin (RBV), it is well known that many patients will not be cured by treatment, and that patients of European ancestry have a significantly higher probability of being cured than patients of African ancestry. In addition to limited efficacy, treatment is often poorly tolerated because of side effects that prevent some patients from completing therapy. For these reasons, identification of the determinants of response to treatment is a high priority. Here we report that a genetic polymorphism near the IL28B gene, encoding interferon-lambda-3 (IFN-lambda-3), is associated with an approximately twofold change in response to treatment, both among patients of European ancestry (P = 1.06 x 10(-25)) and African-Americans (P = 2.06 x 10(-3)). Because the genotype leading to better response is in substantially greater frequency in European than African populations, this genetic polymorphism also explains approximately half of the difference in response rates between African-Americans and patients of European ancestry.

Infections during peginterferon/ribavirin therapy are associated with the magnitude of decline in absolute lymphocyte count: results of the IDEAL study.

BACKGROUND: Myelosuppression due to pegylated interferon (peg-IFN) is common during treatment for hepatitis C virus. The relationship between infection risk and decreases in leukocyte lines, however, is not well established. The objective of this analysis was to determine the incidence of and risk factors for infections during peg-IFN/ribavirin (RBV) therapy. METHODS: A total of 3070 treatment-naive, chronic hepatitis C genotype 1-infected patients were treated for up to 48 weeks with peg-IFN alfa-2b 1.5 µg/kg/week or 1 µg/kg/week, or peg-IFN alfa-2a 180 µg/week plus RBV. On-treatment leukocyte counts were obtained every 2-6 weeks. Dose reduction was required for a neutrophil count <0.75 × 10(9) cells/L, and treatment discontinuation was required for a neutrophil count <0.5 × 10(9) cells/L. Granulocyte colony-stimulating factor was prohibited. Data on infections were captured at each study visit and categorized according to MedDRA version 13.0. RESULTS: A total of 581 (19%) patients experienced moderate, severe, or life-threatening infections as assessed by the investigator; 648 (21%) patients had at least 1 neutrophil count <0.75 × 10(9) cells/L, but only 242 (8%) sustained an infection and had a neutrophil count <0.75 × 10(9) cells/L at any time while on treatment. Twelve patients had severe or life-threatening infection and grade 3/4 neutropenia, but only 4 had temporally related infections. In a multivariate logistic regression model, nadir lymphocyte count, history of depression, and female sex, but not nadir neutrophil count, were associated with moderate, severe, or life-threatening infection. CONCLUSIONS: Nadir lymphocyte count, not nadir neutrophil count, was independently associated with moderate, severe, or life-threatening infections in the IDEAL study. Clinicians should be aware of their patients' absolute lymphocyte counts during peg-IFN/RBV therapy; peg-IFN dose reductions may be a consideration in patients with significant lymphocytopenia (<0.5 × 10(9) cells/L).

Telaprevir for previously untreated chronic hepatitis C virus infection.

BACKGROUND: In phase 2 trials, telaprevir, a hepatitis C virus (HCV) genotype 1 protease inhibitor, in combination with peginterferon-ribavirin, as compared with peginterferon-ribavirin alone, has shown improved efficacy, with potential for shortening the duration of treatment in a majority of patients. METHODS: In this international, phase 3, randomized, double-blind, placebo-controlled trial, we assigned 1088 patients with HCV genotype 1 infection who had not received previous treatment for the infection to one of three groups: a group receiving telaprevir combined with peginterferon alfa-2a and ribavirin for 12 weeks (T12PR group), followed by peginterferon-ribavirin alone for 12 weeks if HCV RNA was undetectable at weeks 4 and 12 or for 36 weeks if HCV RNA was detectable at either time point; a group receiving telaprevir with peginterferon-ribavirin for 8 weeks and placebo with peginterferon-ribavirin for 4 weeks (T8PR group), followed by 12 or 36 weeks of peginterferon-ribavirin on the basis of the same HCV RNA criteria; or a group receiving placebo with peginterferon-ribavirin for 12 weeks, followed by 36 weeks of peginterferon-ribavirin (PR group). The primary end point was the proportion of patients who had undetectable plasma HCV RNA 24 weeks after the last planned dose of study treatment (sustained virologic response). RESULTS: Significantly more patients in the T12PR or T8PR group than in the PR group had a sustained virologic response (75% and 69%, respectively, vs. 44%; P<0.001 for the comparison of the T12PR or T8PR group with the PR group). A total of 58% of the patients treated with telaprevir were eligible to receive 24 weeks of total treatment. Anemia, gastrointestinal side effects, and skin rashes occurred at a higher incidence among patients receiving telaprevir than among those receiving peginterferon-ribavirin alone. The overall rate of discontinuation of the treatment regimen owing to adverse events was 10% in the T12PR and T8PR groups and 7% in the PR group. CONCLUSIONS: Telaprevir with peginterferon-ribavirin, as compared with peginterferon-ribavirin alone, was associated with significantly improved rates of sustained virologic response in patients with HCV genotype 1 infection who had not received previous treatment, with only 24 weeks of therapy administered in the majority of patients. (Funded by Vertex Pharmaceuticals and Tibotec; ADVANCE ClinicalTrials.gov number, NCT00627926.).

Sofosbuvir (GS-7977) plus peginterferon/ribavirin in treatment-naïve patients with HCV genotype 1: a randomized, 28-day, dose-ranging trial.

BACKGROUND & AIMS: Sofosbuvir (formerly GS-7977) is a pyrimidine nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B polymerase. We assessed the safety, tolerability, antiviral activity, and pharmacokinetics of sofosbuvir plus pegylated-interferon (PegIFN)/ribavirin (RBV) in a 28-day, dose-ranging trial in treatment-naïve patients infected with genotype 1 HCV. METHODS: In this double-blind study, 64 patients were randomized (1:1:1:1) to receive one of three once-daily doses of oral sofosbuvir (100, 200, or 400mg) or placebo plus PegIFN/RBV for 28 days, after which all patients continued to receive PegIFN/RBV alone for a further 44 weeks. RESULTS: Patients in the sofosbuvir/PegIFN/RBV groups experienced mean reductions in HCV RNA >5 log10 IU/ml (-5.3 for 100 mg, -5.1 for 200 mg and -5.3 for 400 mg) vs. -2.8 log10 IU/ml for placebo/PegIFN/RBV after 28 days. Rapid virologic response (RVR) rates were markedly higher after sofosbuvir treatment (88-94%) than placebo (21%), as were rates of sustained virologic response (SVR) at post-treatment Week 24 (56%, 83%, and 80% for sofosbuvir 100, 200, and 400 mg, respectively, vs. 43% for placebo). The number of patients experiencing virologic breakthrough and post-treatment relapse was higher in the sofosbuvir 100 mg group than sofosbuvir 200 and 400 mg groups. Sofosbuvir was well tolerated; the most frequent adverse events were fatigue and nausea. CONCLUSIONS: These results support further studies with sofosbuvir at 200 mg and 400 mg to determine the optimal dose and treatment duration of sofosbuvir in HCV genotype 1.

Telaprevir for previously treated chronic HCV infection.

BACKGROUND: Patients with genotype 1 hepatitis C virus (HCV) who do not have a sustained response to therapy with peginterferon alfa and ribavirin have a low likelihood of success with retreatment. METHODS: We randomly assigned patients with HCV genotype 1 who had not had a sustained virologic response after peginterferon alfa-ribavirin therapy to one of four treatment groups: 115 patients to the T12PR24 group, receiving telaprevir (1125-mg loading dose, then 750 mg every 8 hours) for 12 weeks and peginterferon alfa-2a (180 microg per week) and ribavirin (1000 or 1200 mg per day, according to body weight) for 24 weeks; 113 patients to the T24PR48 group, receiving telaprevir for 24 weeks and peginterferon alfa-2a and ribavirin for 48 weeks (at the same doses as in the T12PR24 group); 111 patients to the T24P24 group, receiving telaprevir and peginterferon alfa-2a for 24 weeks (at the same doses as in the T12PR24 group); and 114 patients to the PR48 (or control) group, receiving peginterferon alfa-2a and ribavirin for 48 weeks (at the same doses as in the T12PR24 group). The primary end point was sustained virologic response (undetectable HCV RNA levels 24 weeks after the last dose of study drugs). RESULTS: The rates of sustained virologic response in the three telaprevir groups--51% in the T12PR24 group, 53% in the T24PR48 group, and 24% in the T24P24 group--were significantly higher than the rate in the control group (14%; P<0.001, P<0.001, and P=0.02, respectively). Response rates were higher among patients who had previously had relapses than among nonresponders. One of the most common adverse events in the telaprevir groups was rash (overall, occurring in 51% of patients, with severe rash in 5%). Discontinuation of study drugs because of adverse events was more frequent in the telaprevir groups than in the control group (15% vs. 4%). CONCLUSIONS: In HCV-infected patients in whom initial peginterferon alfa and ribavirin treatment failed, retreatment with telaprevir in combination with peginterferon alfa-2a and ribavirin was more effective than retreatment with peginterferon alfa-2a and ribavirin alone. (ClinicalTrials.gov number, NCT00420784.)

The protease inhibitor, GS-9256, and non-nucleoside polymerase inhibitor tegobuvir alone, with ribavirin, or pegylated interferon plus ribavirin in hepatitis C.

UNLABELLED: Tegobuvir (GS-9190), a non-nucleoside nonstructural protein (NS)5B polymerase inhibitor, and GS-9256, an NS3 serine protease inhibitor, individually have activity against hepatitis C virus (HCV) genotype 1. The antiviral activity of tegobuvir and GS-9256 as oral combination therapy, or together with ribavirin (RBV) or pegylated interferon (Peg-IFN) alpha-2a and RBV, was assessed in a phase II, randomized, open-label trial. Treatment-naïve patients with genotype 1 HCV were assigned 28 days of tegobuvir 40 mg twice-daily (BID) and GS-9256 75 mg BID (n = 16), tegobuvir and GS-9256 plus RBV 1,000-1,200 mg daily (n = 15), or tegobuvir and GS-9256 plus Peg-IFN alpha-2a (180 µg once-weekly)/RBV (n = 15). The primary efficacy endpoint was rapid virologic response (RVR), with HCV RNA <25 IU/mL at day 28. After 28 days, all patients received Peg-IFN/RBV. All patients with viral rebound or nonresponse, defined as >0.5-log(10) increase in HCV RNA from nadir or <2-log decrease at day 5, initiated Peg-IFN/RBV immediately. Median maximal reductions in HCV RNA were -4.1 log(10) IU/mL for tegobuvir/GS-9256, -5.1 log(10) IU/mL for tegobuvir/GS-9256/RBV, and -5.7 log(10) IU/mL for tegobuvir/9256/Peg-IFN/RBV. RVR was observed in 7% (1 of 15) of patients receiving tegobuvir/GS-9256, 38% (5 of 13) receiving tegobuvir/GS-9256/RBV, and 100% (14 of 14) receiving tegobuvir/9256/PEG-IFN/RBV. The addition of Peg-IFN/RBV at day 28 or earlier resulted in HCV RNA <25 IU/mL at week 24 in 67% (10 of 15), 100% (13 of 13), and 94% (13 of 14) of patients in the three treatment groups. Transient elevations in serum bilirubin occurred in all treatment groups. CONCLUSION: In genotype 1 HCV, adding RBV or RBV with Peg-IFN provides additive antiviral activity to combination therapy with tegobuvir and GS-9256.

Dysregulation of innate immunity in hepatitis C virus genotype 1 IL28B-unfavorable genotype patients: impaired viral kinetics and therapeutic response.

UNLABELLED: Recent studies have shown that a single-nucleotide polymorphism upstream of the interleukin-28B (IL28B) gene plays a major role in predicting therapeutic response in hepatitis C virus (HCV)-infected patients treated with pegylated interferon (PEG-IFN)/ribavirin. We sought to investigate the mechanism of the IL28B polymorphism, specifically as it relates to early HCV viral kinetics, IFN pharmacokinetics, IFN pharmacodynamics, and gene expression profiles. Two prospective cohorts (human immunodeficiency virus [HIV]/HCV-coinfected and HCV-monoinfected) completing treatment with IFN/ribavirin were enrolled. Patients were genotyped at the polymorphic site rs12979860. In the HIV/HCV cohort, frequent serum sampling was completed for HCV RNA and IFN levels. DNA microarray of peripheral blood mononuclear cells and individual expression of IFN-stimulated genes (ISGs) were quantified on IFN therapy. The IL28B-favorable (CC) genotype was associated with improved therapeutic response compared with unfavorable (CT or TT) genotypes. Patients with a favorable genotype had greater first- and second-phase viral kinetics (P = 0.004 and P = 0.036, respectively), IFN maximum antiviral efficiency (P = 0.007) and infected cell death loss (P = 0.009) compared with unfavorable genotypes. Functional annotation analysis of DNA microarray data was consistent with depressed innate immune function, particularly of natural killer cells, from patients with unfavorable genotypes (P <0.004). Induction of innate immunity genes was also lower in unfavorable genotypes. ISG expression at baseline and induction with IFN was independent of IL28B genotype. CONCLUSION: Carriers of the IL28B-favorable genotype were more likely to have superior innate immune response to IFN therapy compared with unfavorable genotypes, suggesting that the unfavorable genotype has aberrant baseline induction of innate immune response pathways resulting in impaired virologic response. IL28B genotype is associated with more rapid viral kinetics and improved treatment response outcomes independent of ISG expression.

Analysis of site performance in academic-based and community-based centers in the IDEAL Study.

GOALS: To evaluate differences in metrics of quality and site performance in academic and community sites participating in a multicenter study. BACKGROUND: In the Individualized Dosing Efficacy Versus Flat Dosing to Assess Optimal Pegylated Interferon Therapy study, the participation of 76 academic-based and 42 community-based US centers provided an opportunity to evaluate various metrics of quality and site performance. STUDY: A secondary data analysis of the Individualized Dosing Efficacy Versus Flat Dosing to Assess Optimal Pegylated Interferon Therapy study was performed. There were 3070 treatment-naive, hepatitis C virus genotype 1 infected patients were included. We retrospectively evaluated rates of screen failure, completion, and discontinuation of treatment and follow-up, treatment adherence, and virologic response by site type. RESULTS: Of the patients screened, 63% and 37% were in academic and community centers, respectively. Screen failure rates were similar (30% to 32%). End-of-treatment response, relapse, and sustained virologic response (SVR) rates in academic and community centers did not differ. SVR was achieved in 40% of patients at academic sites and 39% at community sites. Adherence to ≥80% of peginterferon-α and ribavirin dosing for ≥80% assigned duration was also similar (46% in academic and 47% in community centers). In both academic and community centers, 54% of patients completed treatment; there were similar discontinuation rates for treatment failure and adverse events. CONCLUSIONS: There were no significant differences in adherence, adverse events, rates of discontinuation, on-treatment virologic response, and SVR when comparing academic and community sites. The performance of academic-based and experienced community-based sites in clinical trials is largely similar for the treatment of chronic hepatitis C.

Viral clearance is associated with improved insulin resistance in genotype 1 chronic hepatitis C but not genotype 2/3.

OBJECTIVES: Genotype-specific associations between hepatitis C virus (HCV) and insulin resistance (IR) have been described, but a causal relationship remains unclear. This study investigated the association between a sustained virological response (SVR) and IR after chronic HCV therapy. METHODS: 2255 treatment-naive patients with chronic HCV genotype 1 or 2/3 were enrolled in two phase 3 trials of albinterferon alpha-2b versus pegylated interferon alpha-2a for 48 or 24 weeks, respectively. IR was measured before treatment and 12 weeks after treatment using homeostasis model assessment (HOMA)-IR. RESULTS: Paired HOMA-IR measurements were available in 1038 non-diabetic patients (497 with genotype 1; 541 with genotype 2/3). At baseline the prevalence of HOMA-IR >3 was greater in patients with genotype 1 than 2/3 (33% vs 27%; p=0.048). There was a significant reduction in the prevalence of IR in patients with genotype 1 achieving SVR (δ 10%; p<0.001), but not in genotype 1 non-responders or those with genotype 2/3. Multivariate analysis indicated that SVR was associated with a significant reduction in mean HOMA-IR in patients with genotype 1 (p=0.004), but not in those with genotype 2/3, which was independent of body mass index, alanine transaminase, γ-glutamyl transpeptidase and lipid level changes. CONCLUSIONS: SVR is associated with a reduction in HOMA-IR in patients with HCV genotype 1 but not in those with genotype 2/3. Genotype 1 may have a direct effect on the development of IR, independent of host metabolic factors, and may be partially reversed by viral eradication.

Single nucleotide polymorphism upstream of interleukin 28B associated with phase 1 and phase 2 of early viral kinetics in patients infected with HCV genotype 1.

BACKGROUND & AIMS: We studied the relationship between IL28B gene-related SNP rs12979860 and early viral kinetics (day 0-28) during peginterferon and ribavirin treatment, in 173 African Americans (AA) and 188 Caucasian Americans (CA) with HCV genotype 1. METHODS: We studied the relationship between IL28B 16 gene-related SNP rs12979860 and early viral kinetics (day 0-28) 17 during peginterferon and ribavirin treatment, in 171 African 18 Americans (AA) and 188 Caucasian Americans (CA) with HCV 19 genotype 1. RESULTS: Compared to non-C/C genotypes, C/C was associated with greater declines in serum HCV RNA during phase 1 (day 0-2), phase 2 (day 7-28), and day 0-28 and higher response (undetected HCV RNA) rates at weeks 4 and 12 in AA and CA. A static phase and increases in HCV RNA from day 2 to 7 were more common in patients with non-C/C genotypes. C/C was also associated with higher week 24, 48, and 72 response rates in CA (p<0.01) but not in AA. At baseline, SNP genotype was the only independent predictor of phase 1; SNP genotype and phase 1 were independent predictors of phase 2 (p<0.001). There were no racial differences in HCV RNA declines during phase 1, day 2-7, phase 2, and day 0-28 with the same SNP genotype. AA with C/C and C/T genotypes had lower week 24, 48, and 72 (SVR) rates than did CA (p=0.03). SNP C/C predicted higher SVR rates in AA and CA with high baseline HCV RNA (≥ 600,000 IU/ml), and in CA with ≥ 1 log(10)IU/ml decrease in HCV RNA from day 0 to 28. CONCLUSIONS: SNP rs12979860 is strongly associated with both phase 1 and phase 2 HCV RNA kinetics in AA and CA with HCV genotype 1.

Genome-wide association study of interferon-related cytopenia in chronic hepatitis C patients.

BACKGROUND & AIMS: Interferon-alfa (IFN)-related cytopenias are common and may be dose-limiting. We performed a genome wide association study on a well-characterized genotype 1 HCV cohort to identify genetic determinants of peginterferon-α (pegIFN)-related thrombocytopenia, neutropenia, and leukopenia. METHODS: 1604/3070 patients in the IDEAL study consented to genetic testing. Trial inclusion criteria included a platelet (Pl) count ≥80×10(9)/L and an absolute neutrophil count (ANC) ≥1500/mm(3). Samples were genotyped using the Illumina Human610-quad BeadChip. The primary analyses focused on the genetic determinants of quantitative change in cell counts (Pl, ANC, lymphocytes, monocytes, eosinophils, and basophils) at week 4 in patients >80% adherent to therapy (n=1294). RESULTS: 6 SNPs on chromosome 20 were positively associated with Pl reduction (top SNP rs965469, p=10(-10)). These tag SNPs are in high linkage disequilibrium with 2 functional variants in the ITPA gene, rs1127354 and rs7270101, that cause ITPase deficiency and protect against ribavirin (RBV)-induced hemolytic anemia (HA). rs1127354 and rs7270101 showed strong independent associations with Pl reduction (p=10(-12), p=10(-7)) and entirely explained the genome-wide significant associations. We believe this is an example of an indirect genetic association due to a reactive thrombocytosis to RBV-induced anemia: Hb decline was inversely correlated with Pl reduction (r=-0.28, p=10(-17)) and Hb change largely attenuated the association between the ITPA variants and Pl reduction in regression models. No common genetic variants were associated with pegIFN-induced neutropenia or leucopenia. CONCLUSIONS: Two ITPA variants were associated with thrombocytopenia; this was largely explained by a thrombocytotic response to RBV-induced HA attenuating IFN-related thrombocytopenia. No genetic determinants of pegIFN-induced neutropenia were identified.

Telaprevir with peginterferon and ribavirin for chronic HCV genotype 1 infection.

BACKGROUND: Current therapy for chronic hepatitis C virus (HCV) infection is effective in less than 50% of patients infected with HCV genotype 1. Telaprevir, a protease inhibitor specific to the HCV nonstructural 3/4A serine protease, rapidly reduced HCV RNA levels in early studies. METHODS: We randomly assigned patients infected with HCV genotype 1 to one of three telaprevir groups or to the control group. The control group (called the PR48 group) received peginterferon alfa-2a (180 microg per week) and ribavirin (1000 or 1200 mg per day, according to body weight) for 48 weeks, plus telaprevir-matched placebo for the first 12 weeks (75 patients). The telaprevir groups received telaprevir (1250 mg on day 1 and 750 mg every 8 hours thereafter) for 12 weeks, as well as peginterferon alfa-2a and ribavirin (at the same doses as in the PR48 group) for the same 12 weeks (the T12PR12 group, 17 patients) or for a total of 24 weeks (the T12PR24 group, 79 patients) or 48 weeks (the T12PR48 group, 79 patients). The primary outcome was a sustained virologic response (an undetectable HCV RNA level 24 weeks after the end of therapy). RESULTS: The rate of sustained virologic response was 41% (31 of 75 patients) in the PR48 group, as compared with 61% (48 of 79 patients) in the T12PR24 group (P=0.02), 67% (53 of 79 patients) in the T12PR48 group (P=0.002), and 35% (6 of 17 patients) in the T12PR12 group (this group was exploratory and not compared with the control group). Viral breakthrough occurred in 7% of patients receiving telaprevir. The rate of discontinuation because of adverse events was higher in the three telaprevir-based groups (21%, vs. 11% in the PR48 group), with rash the most common reason for discontinuation. CONCLUSIONS: Treatment with a telaprevir-based regimen significantly improved sustained virologic response rates in patients with genotype 1 HCV, albeit with higher rates of discontinuation because of adverse events. (ClinicalTrials.gov number, NCT00336479.)

Optimum ribavirin exposure overcomes racial disparity in efficacy of peginterferon and ribavirin treatment for hepatitis C genotype 1.

OBJECTIVES: Peginterferon and ribavirin treatment is less effective for hepatitis C virus (HCV) genotype 1 infections in African Americans (AA) compared with Caucasian Americans (CA). Host genetic variability near the interleukin-28B (IL28B) gene locus is partly responsible. We investigated the relationship between ribavirin drug exposure and week 24 and 72 (sustained virologic response, SVR) responses (undetected serum HCV RNA) in 71 AA and 74 CA with HCV genotype 1 who received >90% of the prescribed peginterferon and weight-based ribavirin (1,000 or 1,200 mg per day) from week 1 to 24. METHODS: Ribavirin plasma levels were measured at weeks 1, 2, 4, 8, 12 and 24; ribavirin area under the concentration vs. time curve (AUC) was calculated using the linear trapezoidal rule. RESULTS: Compared with CA, AA had lower week 24 (WK24VR) (57.8 vs. 78.1; P<0.05) and week 72 (SVR) (36.6% vs 54.8%; P<0.05) response rates. AA also had significantly lower ribavirin exposure (AUC) from week 1 to 12 (P<0.05). Ribavirin exposures ≥4,065 and ≥4,480 ng/ml/day in the first week (AUC(0-7)) were thresholds for WK24VR and SVR in receiver-operating characteristic curve analyses. AA were less likely to have a threshold ribavirin AUC(0-7) level than CA (P<0.05). There were no significant racial differences in WK24VR (AA: 77 vs. CA: 84%) and SVR (AA: 52 vs. CA: 60%) rates in patients who met the ribavirin AUC(0-7) thresholds. Ribavirin AUC(0-7) predicted WK24VR and SVR independently of IL28B single-nucleotide polymorphism rs12979860 genotype. Yet, achieving threshold AUC(0-7) levels increased response rates primarily in AA with the less favorable non-C/C genotypes. CONCLUSIONS: Standard weight-based dosing leads to suboptimal ribavirin exposure in AA and contributes to the racial disparity in peginterferon and ribavirin treatment efficacy for HCV genotype 1.

Hepatitis C pharmacogenetics: state of the art in 2010.

In 2009, a correlated set of polymorphisms in the region of the interleukin-28B (IL28B) gene were associated with clearance of genotype 1 hepatitis C virus (HCV) in patients treated with pegylated interferon-alfa and ribavirin. The same polymorphisms were subsequently associated with spontaneous clearance of HCV in untreated patients. The link between IL28B genotype and HCV clearance may impact decisions regarding initiation of current therapy, the design and interpretation of clinical studies, the economics of treatment, and the process of regulatory approval for new anti-HCV therapeutic agents.

Inosine triphosphatase genetic variants are protective against anemia during antiviral therapy for HCV2/3 but do not decrease dose reductions of RBV or increase SVR.

UNLABELLED: Two functional variants in the inosine triphosphatase (ITPA) gene causing inosine triphosphatase (ITPase) deficiency protect against ribavirin (RBV)-induced hemolytic anemia and the need for RBV dose reduction in patients with genotype 1 hepatitis C virus (HCV). No data are available for genotype 2/3 HCV. We evaluated the association between the casual ITPA variants and on-treatment anemia in a well-characterized cohort of genotype 2/3 patients treated with variable-duration pegylated interferon alfa-2b (PEG-IFN-α2b) and RBV. Two hundred thirty-eight Caucasian patients were included in this retrospective study [185 (78%) with genotype 2 and 53 (22%) with genotype 3]. Patients were treated with PEG-IFN-α2b plus weight-based RBV (1000/1200 mg) for 12 (n = 109) or 24 weeks (n = 129). The ITPA polymorphisms rs1127354 and rs7270101 were genotyped, and an ITPase deficiency variable was defined that combined both ITPA variants according to their effect on ITPase activity. The primary endpoint was hemoglobin (Hb) reduction in week 4. We also considered Hb reduction over the course of therapy, the need for RBV dose modification, and the rate of sustained virological response (SVR). The ITPA variants were strongly and independently associated with protection from week 4 anemia (P = 10(-6) for rs1127354 and P = 10(-7) for rs7270101). Combining the variants into the ITPase deficiency variable increased the strength of association (P = 10(-11) ). ITPase deficiency protected against anemia throughout treatment. ITPase deficiency was associated with a delayed time to an Hb level < 10 g/dL (hazard ratio = 0.25, 95% confidence interval = 0.08-0.84, P = 0.025) but not with the rate of RBV dose modification (required per protocol at Hb < 9.5 g/dL). There was no association between the ITPA variants and SVR. CONCLUSION: Two ITPA variants were strongly associated with protection against treatment-related anemia in patients with genotype 2/3 HCV, but they did not decrease the need for RBV dose reduction or increase the rate of SVR.

Quantitation of pretreatment serum interferon-γ-inducible protein-10 improves the predictive value of an IL28B gene polymorphism for hepatitis C treatment response.

UNLABELLED: Polymorphisms of the IL28B gene are highly associated with sustained virological response (SVR) in patients with chronic hepatitis C treated with peginterferon and ribavirin. Quantitation of interferon-γ-inducible protein-10 (IP-10) may also differentiate antiviral response. We evaluated IP-10 levels in pretreatment serum from 115 nonresponders and 157 sustained responders in the Study of Viral Resistance to Antiviral Therapy of Chronic Hepatitis C cohort, including African American (AA) and Caucasian American (CA) patients. Mean IP-10 was lower in sustained responders compared with nonresponders (437 ± 31 vs 704 ± 44 pg/mL, P < 0.001), both in AA and CA patients. The positive predictive value of low IP-10 levels (<600 pg/mL) for SVR was 69%, whereas the negative predictive value of high IP-10 levels (>600 pg/mL) was 67%. We assessed the combination of pretreatment IP-10 levels with IL28B genotype as predictors of treatment response. The IL28B polymorphism rs12979860 was tested in 210 participants. The CC, CT, and TT genotypes were found in 30%, 49%, and 21% of patients, respectively, with corresponding SVR rates of 87%, 50%, and 39% (P < 0.0001). Serum IP-10 levels within the IL28B genotype groups provided additional information regarding the likelihood of SVR (P < 0.0001). CT carriers with low IP-10 had 64% SVR versus 24% with high IP-10. Similarly, a higher SVR rate was identified for TT and CC carriers with low versus high IP-10 (TT, 48% versus 20%; CC, 89% versus 79%). IL28B genotype and baseline IP-10 levels were additive but independent when predicting SVR in both AA and CA patients. CONCLUSION: When IL28B genotype is combined with pretreatment serum IP-10 measurement, the predictive value for discrimination between SVR and nonresponse is significantly improved, especially in non-CC genotypes. This relationship warrants further investigation to elucidate the mechanisms of antiviral response and prospective validation.

Retreatment with telaprevir combination therapy in hepatitis C patients with well-characterized prior treatment response.

UNLABELLED: Retreatment with peginterferon alpha and ribavirin (PR) offers a limited chance of sustained virologic response (SVR) in patients who did not achieve SVR with prior PR treatment. This study evaluated the safety and efficacy of telaprevir-based treatment in combination with PR in well-characterized patients who did not achieve SVR in the control arms of three Phase II clinical trials. Patients eligible to enroll in this open-label nonrandomized study either met on-treatment criteria for nonresponse or relapsed after 48 weeks of treatment in the control arm of the three Phase II PROVE studies. The initial protocol was a 24-week regimen: 12 weeks of telaprevir and PR followed by an additional 12 weeks of PR. During the study the protocol was amended to extend PR to 48 weeks for patients with previous null response. All other patients with undetectable hepatitis C virus (HCV) RNA at weeks 4 and 12 received 24 weeks of therapy. Those with detectable HCV RNA at weeks 4 or 12 received a total of 48 weeks of therapy. The overall SVR rate was 59% (69/117). SVR rates with T12PR were 37% (19/51) in prior null responders, 55% (16/29) in prior partial responders, 75% (6/8) in prior breakthroughs, and 97% (28/29) in prior relapsers. The overall relapse rate was 16% (13/83). Adverse events were similar to those in previous trials with telaprevir, with 9% of patients discontinuing due to an adverse event (most commonly rash and anemia). CONCLUSION: This study demonstrated the benefit of retreatment with a telaprevir-based regimen for patients with well-characterized nonresponse (null and partial) or relapse to a prior course of PR treatment.

Racial differences in hepatitis C treatment eligibility.

UNLABELLED: Black Americans are disproportionally infected with hepatitis C virus (HCV) and are less likely than whites to respond to treatment with peginterferon (PEG-IFN) plus ribavirin (RBV). The impact of race on HCV treatment eligibility is unknown. We therefore performed a retrospective analysis of a phase 3B multicenter clinical trial conducted at 118 United States community and academic medical centers to evaluate the rates of and reasons for HCV treatment ineligibility according to self-reported race. In all, 4,469 patients were screened, of whom 1,038 (23.2%) were treatment ineligible. Although blacks represented 19% of treated patients, they were more likely not to be treated due to ineligibility and/or failure to complete required evaluations (40.2%) than were nonblack patients (28.5%; P < 0.001). After the exclusion of persons not treated due to undetectable HCV RNA or nongenotype 1 infection, blacks were 65% less likely than nonblacks to be eligible for treatment (28.1% > 17.0%; relative risk, 1.65; 95% confidence interval, 1.46-1.87; P < 0.001). Blacks were more likely to be ineligible due to neutropenia (14% versus 3%, P < 0.001), anemia (7% versus 4%, P = 0.02), elevated glucose (8% versus 3%, P < 0.001), and elevated creatinine (5% versus 1%, P < 0.001). CONCLUSION: Largely due to a higher prevalence of neutropenia and uncontrolled medical conditions, blacks were significantly less likely to be eligible for HCV treatment. Increased access to treatment may be facilitated by less conservative neutrophil requirements and more effective care for chronic diseases, namely, diabetes and renal insufficiency.