HBsAg loss in patients treated with peginterferon alfa-2a and adefovir is associated with SLC16A9 gene variation and lower plasma carnitine levels.

BACKGROUND & AIMS: Achievement of HBsAg loss remains the hallmark of chronic hepatitis B treatment. In order to identify host factors contributing to treatment-induced HBsAg loss, we performed a genome-wide screen of single nucleotide polymorphisms (SNPs) and studied its immunological consequence. METHODS: Chronic hepatitis B patients (40 HBeAg-positive and 44 HBeAg-negative) treated with peginterferon alfa-2a and adefovir were genotyped for 999,091 SNPs, which were associated with HBsAg loss at week 96 (n = 9). Plasma carnitine levels were measured by tandem-mass spectrometry, and the effect of carnitine on the proliferative capacity of hepatitis B virus (HBV)-specific and non-specific CD8 T cells was studied in vitro. RESULTS: One polymorphism, rs12356193 located in the SLC16A9 gene, was genome-wide significantly associated with HBsAg loss at week 96 (p = 1.84 × 10(-8)). The previously reported association of rs12356193 with lower carnitine levels was confirmed in our cohort, and baseline carnitine levels were lower in patients with HBsAg loss compared to patients with HBsAg persistence (p = 0.02). Furthermore, we demonstrated that carnitine suppressed HBV-specific CD8 T cell proliferation. CONCLUSIONS: In chronic hepatitis B patients treated with peginterferon and adefovir, we identified strong associations of SLC16A9 gene variation and carnitine levels with HBsAg loss. Our results further suggest that a lower baseline plasma carnitine level increases the proliferative capacity of CD8 T cells, making patients more susceptible to the immunological effect of this treatment. These novel findings may provide new insight into factors involved in treatment-induced HBsAg loss, and play a role in the prediction of treatment outcome.

Reduction of HBV replication prolongs the early immunological response to IFNα therapy.

BACKGROUND & AIMS: The interaction between HBV replication and immune modulatory effects mediated by IFNα therapy is not well understood. We characterized the impact of HBV DNA replication on the early IFNα-induced immunomodulatory mechanisms. METHODS: We interrogated the transcriptional, serum cytokine/chemokine and cellular immune profiles of 28 patients with HBeAg+ chronic HBV infection (CHB) randomly assigned to one of 4 treatment cohorts (untreated n=5, weekly dosing of 360 µg Pegasys [PegIFNα] n=11, daily dose of 300 mg Viread [tenofovir disoproxil fumarate, TDF] n=6, or a combination of both n=6). Samples were characterized at multiple early time points through day 14 of therapy, after which all patients were given standard of care (180 µg Pegasys injected subcutaneously, weekly). RESULTS: PegIFNα induced a distinct and rapid up-regulation of IFN signaling pathway that coincided with increase detection of distinct serum cytokines/chemokines (IL-15, IL-6, and CXCL-10) and the up-regulation of the frequency of proliferating NK and activated total CD8+ T cells. IFNα treatment alone did not result in rapid decay of HBV replication and was not able to restore the defective HBV-specific T cell response present in CHB patients. In addition, the IFNα immune-stimulatory effects diminished after the first dose, but this refractory effect was reduced in patients where HBV replication was simultaneously inhibited with TDF. CONCLUSIONS: We present here the first comprehensive description of the early effects of IFNα treatment on immune and viral biomarkers in HBeAg+ CHB patients. Our results show that PegIFNα-induced innate immune activation directly benefits from the suppression of HBV replication.

Oral combination therapy with a nucleoside polymerase inhibitor (RG7128) and danoprevir for chronic hepatitis C genotype 1 infection (INFORM-1): a randomised, double-blind, placebo-controlled, dose-escalation trial.

BACKGROUND: Present interferon-based standard of care treatment for chronic hepatitis C virus (HCV) infection is limited by both efficacy and tolerability. We assessed the safety, tolerability, and antiviral activity of an all-oral combination treatment with two experimental anti-HCV drugs-RG7128, a nucleoside polymerase inhibitor; and danoprevir, an NS3/4A protease inhibitor-in patients with chronic HCV infection. METHODS: Patients from six centres in New Zealand and Australia who were chronically infected with HCV genotype 1 received up to 13 days oral combination treatment with RG7128 (500 mg or 1000 mg twice daily) and danoprevir (100 mg or 200 mg every 8 h or 600 mg or 900 mg twice daily) or placebo. Eligible patients were sequentially enrolled into one of seven treatment cohorts and were randomly assigned by interactive voice or web response system to either active treatment or placebo. Patients were separately randomly assigned within each cohort with a block size that reflected the number of patients in the cohort and the ratio of treatment to placebo. The random allocation schedule was computer generated. Dose escalation was started in HCV treatment-naive patients; standard of care treatment-experienced patients, including previous null responders, were enrolled in higher-dose danoprevir cohorts. Investigators, personnel at the study centre, and patients were masked to treatment allocation. However, the pharmacist who prepared the doses, personnel involved in pharmacokinetic sample analyses, statisticians who prepared data summaries, and the clinical pharmacologists who reviewed the data before deciding to initiate dosing in the next cohort were not masked to treatment allocation. The primary outcome was change in HCV RNA concentration from baseline to day 14 in patients who received 13 days of combination treatment. All patients who completed treatment with the study drugs were included in the analyses. This study is registered with ClinicalTrials.gov, NCT00801255. FINDINGS: 88 patients were randomly assigned to a study drug treatment regimen (n=74 over seven treatment groups; 73 received at least one dose of study drug) or to placebo (n=14, all of whom received at least one dose). The median change in HCV RNA concentration from baseline to day 14 ranged from -3·7 to -5·2 log(10) IU/mL in the cohorts that received 13 days of combination treatment. At the highest combination doses tested (1000 mg RG7128 and 900 mg danoprevir twice daily), the median change in HCV RNA concentration from baseline to day 14 was -5·1 log(10) IU/mL (IQR -5·6 to -4·7) in treatment-naive patients and -4·9 log(10) IU/mL in previous standard of care null responders (-5·2 to -4·5) compared with an increase of 0·1 log(10) IU/mL in the placebo group. The combination of RG7128 and danoprevir was well tolerated with no treatment-related serious or severe adverse events, no grade 3 or 4 changes in laboratory parameters, and no safety-related treatment discontinuations. INTERPRETATION: This oral combination of a nucleoside analogue polymerase inhibitor and protease inhibitor holds promise as an interferon-free treatment for chronic HCV. FUNDING: Roche Palo Alto.

Viral minority variants in the core promoter and precore region identified by deep sequencing are associated with response to peginterferon and adefovir in HBeAg negative chronic hepatitis B patients.

BACKGROUND AND AIM: Precore (PC) and basal core promoter (BCP) mutations are associated with responses to interferon-based treatment in HBeAg-positive chronic hepatitis B (CHB) patients. Here, we identify viral minority variants in these regions and assess association with response to peginterferon-alfa (Peg-IFN) and adefovir combination therapy. PATIENTS AND METHODS: Ultra-deep pyrosequencing analysis of the BCP and PC region was performed for 89 CHB patients (42 HBeAg-positive; 47 HBeAg-negative), at baseline and during treatment. Specifically, associations of individual positions with the HBeAg-negative phenotype were studied, as well as the association of the most prevalent mutations with combined response in HBeAg-positive and -negative patients at week 72 (HBeAg negativity, HBV-DNA <2000 IU/mL and ALT normalization at 24 weeks of treatment-free follow-up). RESULTS: The mutations most strongly correlated with the HBeAg-negative phenotype were at positions 1762/1764 and 1896/1899 in the BCP and PC region, respectively. No major changes in nucleotide composition of these positions were observed during treatment. In HBeAg-negative patients, a combined presence of 1764A and 1896A was correlated with lower ALT levels (p = 0.004), whereas the presence of 1899A was correlated with higher age (p = 0.030), lower HBV-DNA level (p = 0.036), and previous IFN therapy (p = 0.032). The presence of 1764A/1896A or the absence of 1899A at baseline, was associated with lower response rates, after adjustment for HBV genotype (p = 0.031 and p = 0.017) and HBsAg level (p = 0.035 and p = 0.022). CONCLUSION: We identified novel correlations between common BCP and PC variants with response to Peg-IFN and adefovir in HBeAg-negative patients. Ultimately, this may guide the selection of those patients most likely to benefit from Peg-IFN-based treatment.