Ultradeep sequencing study of chronic hepatitis C virus genotype 1 infection in patients treated with daclatasvir, peginterferon, and ribavirin.

Direct-acting antivirals (DAAs) are either part of the current standard of care or are in advanced clinical development for the treatment of patients chronically infected with hepatitis C virus (HCV) genotype 1, but concern exists with respect to the patients who fail these regimens with emergent drug-resistant variants. In the present study, ultradeep sequencing was performed to analyze resistance to daclatasvir (DCV), which is a highly selective nonstructural protein 5A (NS5A) inhibitor. Eight patients with HCV genotype 1b, who were either treatment naive or prior nonresponders to pegylated interferon plus ribavirin (Rebetol; Schering-Plough) (PEG-IFN/RBV) therapy, were treated with DCV combined with PEG-IFN alpha-2b (Pegintron; Schering-Plough, Kenilworth, NJ) and RBV. To identify the cause of viral breakthrough, the preexistence and emergence of DCV-resistant variants at NS5A amino acids were analyzed by ultradeep sequencing. Sustained virological response (SVR) was achieved in 6 of 8 patients (75%), with viral breakthrough occurring in the other 2 patients (25%). DCV-resistant variant Y93H preexisted as a minor population at higher frequencies (0.1% to 0.5%) in patients who achieved SVR. In patients with viral breakthrough, DCV-resistant variant mixtures emerged at NS5A-31 over time that persisted posttreatment with Y93H. Although enrichment of DCV-resistant variants was detected, the preexistence of a minor population of the variant did not appear to be associated with virologic response in patients treated with DCV/PEG-IFN/RBV. Ultradeep sequencing results shed light on the complexity of DCV-resistant quasispecies emerging over time, suggesting that multiple resistance pathways are possible within a patient who does not rapidly respond to a DCV-containing regimen. (This study has been registered at ClinicalTrials.gov under registration no. NCT01016912.).

Bifunctional inhibition of HIV-1 reverse transcriptase: a first step in designing a bifunctional triphosphate.

The onset of resistance to approved anti-AIDS drugs by HIV necessitates the search for novel inhibitors of HIV-1 reverse transcriptase (RT). Developing single molecular agents concurrently occupying the nucleoside and nonnucleoside binding sites in RT is an intriguing idea but the proof of concept has so far been elusive. As a first step, we describe molecular modeling to guide focused chemical syntheses of conjugates having nucleoside (d4T) and nonnucleoside (TIBO) moieties tethered by a flexible polyethylene glycol (PEG) linker. A triphosphate of d4T-6PEG-TIBO conjugate was successfully synthesized that is recognized as a substrate by HIV-1 RT and incorporated into a double-stranded DNA.

Reduction of hepatitis B surface antigen in sequential versus add-on pegylated interferon to nucleoside/nucleotide analogue therapy in HBe-antigen-negative chronic hepatitis B patients: a pilot study.

BACKGROUND: Although pegylated interferon (PEG-IFN) and nucleotide/nucleoside analogue (NA) combination therapy is considered to be optimal for accelerating serum hepatitis B surface antigen (HBsAg) reduction, the effect is limited, and the best approach to PEG-IFN treatment for chronic hepatitis B patients during long-term NA therapy has yet to be determined. METHODS: A total of 21 hepatitis B e antigen-negative chronic hepatitis B patients whose HBV DNA levels were suppressed to undetectable levels by NA therapy were administrated PEG-IFN-α2a for 48 weeks (sequential therapy: 10, add-on therapy: 11). Factors associated with HBsAg reduction by PEG-IFN therapy were analysed. RESULTS: During PEG-IFN treatment, HBsAg levels were reduced by 0.48 log IU/ml. More than 1 log IU/ml of HBsAg reduction was observed in eight patients (sequential therapy: six, add-on therapy: two), and one patient with sequential therapy achieved HBsAg loss. By univariate analysis, sequential therapy was marginally associated with more than 1 log IU/ml HBsAg reduction during PEG-IFN treatment (P=0.060). After PEG-IFN treatment, only five patients, including the patient with HBsAg loss, achieved more than 0.5 log IU/ml of HBsAg reduction by 1 year after PEG-IFN treatment. By univariate analysis, sequential therapy was significantly associated with HBsAg reduction after PEG-IFN treatment (P=0.012). In addition, alanine aminotransferase elevation during PEG-IFN therapy and lower serum interleukin-8 level at the end of PEG-IFN treatment were also significantly associated with HBsAg reduction by 1 year after PEG-IFN treatment (P=0.038, P=0.044, respectively). CONCLUSIONS: Sequential therapy may be superior to add-on therapy in reducing HBsAg levels during long-term NA therapy in chronic hepatitis B patients.

Predictive value of the IFNL4 polymorphism on outcome of telaprevir, peginterferon, and ribavirin therapy for older patients with genotype 1b chronic hepatitis C.

BACKGROUND: Older patients with chronic hepatitis C have a lower virological response to interferon (IFN) treatment compared to younger patients. The efficacy of telaprevir (TVR) and PEG-IFN plus ribavirin combination therapy and the predictive value of recently identified IFN lambda (IFNL) 4 polymorphisms on the outcome of therapy for older patients have not been addressed. METHODS: We assessed predictive factors for sustained virological response (SVR) to triple therapy in 226 younger (≤65 years) and 87 older (>65 years) Japanese patients with chronic genotype 1 hepatitis C. IFNL4 polymorphism ss469415590 was analyzed by Invader assay. RESULTS: The SVR rate for older patients was slightly lower than for younger patients (69 vs. 82%, P = 0.043). In the older group, the SVR rate for patients with the IFNL4 TT/TT genotype was significantly higher than patients with TT/ΔG or ΔG/ΔG genotypes (81.8 and 42.9%, P = 0.003). In multivariate regression analysis, rapid virological response (OR 36.601, P = 0.002) and IFNL4 TT/TT genotype (OR 19.502, P = 0.009) were identified as significant independent predictors for SVR in older patients. Treatment-related decreases in hemoglobin and increases in serum creatinine were higher in older patients than younger patients. Reduction of initial TVR dose to 1,500 mg per day alleviated these adverse events without compromising SVR rate in older patients. CONCLUSIONS: Analysis of IFNL4 polymorphisms is a valuable predictor in older patients receiving TVR triple therapy. 1,500 mg per day is a suitable initial TVR dose for older Japanese patients.