Clinical characteristics of null responders to Peg-IFNα2b/ribavirin therapy for chronic hepatitis C

The Discovery and Early Clinical Evaluation of the HCV NS3/4A Protease Inhibitor Asunaprevir (BMS-650032)

The discovery of asunaprevir (1) began with the concept of engaging the small and well-defined S₁’ pocket of the hepatitis C virus (HCV) NS3/4A protease that was explored in the context of tripeptide carboxylic acid-based inhibitors. A cyclopropyl-acyl sulfonamide moiety was found to be the optimal element at the P₁-P₁’ interface enhancing the potency of carboxylic acid-based prototypes by 10- to >100-fold, dependent upon the specific background. Optimization for oral bioavailability identified a 1-substituted isoquinoline-based P₂* element that conferred a significant exposure advantage in rats compared to the matched 4-substituted quinoline isomer. BMS-605339 (30) was the first cyclopropyl-acyl sulfonamide derivative advanced into clinical trials that demonstrated dose-related reductions in plasma viral RNA in HCV-infected patients. However, 30 was associated with cardiac events observed in a normal healthy volunteer (NHV) and an HCV-infected patient that led to the suspension of the development program. Using a Langendorff rabbit heart model, a limited structure-cardiac liability relationship was quickly established that led to the discovery of 1. This compound, which differs from 30 only by changes in the substitution pattern of the P₂* isoquinoline heterocycle and the addition of a single chlorine atom to the molecular formula, gave a dose-dependent reduction in plasma viral RNA following oral administration to HCV-infected patients without the burden of the cardiac events that had been observed with 30. A small clinical trial of the combination of 1 with the HCV NS5A inhibitor daclatasvir (2) established for the first time that a chronic genotype 1 (GT-1) HCV infection could be cured by therapy with two direct-acting antiviral agents in the absence of exogenous immune-stimulating agents. Development of the combination of 1 and 2 was initially focused on Japan where the patient population is predominantly infected with GT-1b virus, culminating in marketing approval which was granted on July 4, 2014. In order to broaden therapy to include GT-1a infections, a fixed dose triple combination of 1, 2, and the allosteric NS5B inhibitor beclabuvir (3) was developed, approved by the Japanese health authorities for the treatment of HCV GT-1 infection on December 20, 2016 and marketed as Ximency^®.

First Week HCV RNA Level Under the Pegylated Interferon and Ribavirin Treatment Predicts Sustained Virological Response

This study was planned to investigate whether the decrease in the hepatitis C virus (HCV) RNA levels at the first week of combined pegylated interferon and ribavirin treatment of naive genotype 1 patients with HCV was predicting sustained virologic response (SVR). Fifty-two patients were enrolled into the study. HCV RNA levels were measured at the baseline, first, fourth, and 12th weeks of treatment. Thirty-four patients achieved SVR, which basal, first week, and fourth week HCV RNA levels were log 5.57, log 3.65, and log 1.92, respectively. Eighteen patients could not achieve SVR, which basal, first week, and fourth week HCV RNA levels were log 6.22, log 5.45, and log 3.84, respectively (P < 0.05). Patients were distributed in 2 groups according to the amount of decrease in HCV RNA levels at the first week as less or more than 1.5 log. There were 20 patients with ≥1.5 log decrease in the HCV RNA levels at the first week. They were named as patients with very rapid virologic response (VRVR). All patients (100%) with VRVR were achieved SVR. In only 14 (44%) of the 32 patients without VRVR, SVR was achieved. In 16 (84%) of the 19 patients with rapid virologic response and 33 (79%) of the 42 patients with early virologic response, SVR was achieved. A ≥1.5 log decrease (VRVR) in HCV RNA levels of patients with HCV at the first week of combined pegylated interferon and ribavirin treatment predicts SVR very strongly.

Prediction of a null response to pegylated interferon α-2b plus ribavirin in patients with high viral load genotype 1b hepatitis C

Background/Aims

The present study aimed to clarify whether virological response within 2 weeks after therapy initiation can predict a null response to pegylated interferon α-2b plus ribavirin therapy in patients with high viral load genotype 1b hepatitis C.

Methods

The participants consisted of 72 patients with high viral load genotype 1b. The dynamics of viral load within 2 weeks were measured.

Results

Significant differences between null responders and nonnull responders were noted for interleukin (IL)-28B genotype, amino acid 70 substitution, α-fetoprotein, low-density lipoprotein cholesterol, hyaluronic acid, and viral response. The area under the curve (AUC) for the receiver operating characteristic curve of the hepatitis C virus (HCV) RNA level decline at 2 weeks (AUC=0.993) was the highest among the factors predicting the null response. When the cutoff value for the HCV RNA level decline at 2 weeks was set at 0.80 log, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in predicting a null response were 82%, 96%, 82%, 96%, and 94%, respectively. In comparison, values for the non-TT and mutant type of amino acid 70 substitution were similar to those for HCV RNA level decline at 2 weeks.

Conclusions

Virological response at 2 weeks or the combination of IL-28B and amino acid 70 substitution are accurate predictors of a null response.

Differences in HCV viral decline between low and standard-dose pegylated-interferon-alpha-2a with ribavirin in HIV/HCV genotype 3 patients

Background

The aim of the study was to analyze the different impact of standard and low-dose Peg-IFN-α2a/RBV therapies on HCV viral decline in HIV/HCV genotype 3 co-infected patients during the first weeks of treatment.

Methods

Plasma HCV viral decline was analyzed between baseline and weeks 1, 2 and 4 in two groups of treatment-naïve HCV genotype 3 patients with HIV co-infection. The Standard Dose Group (SDG) included patients who received Peg-IFN at 180 µg/per week with a weight-adjusted dose of ribavirin; Low-Dose Group (LDG) patients received Peg-IFN at 135 µg/per week with 800 mg/day ribavirin. The effect of IL28B genotype on HCV viral decline was evaluated in both groups. HCV viral decline was analyzed using a multivariate linear regression model.

Results

One hundred and six patients were included: 48 patients in the SDG and 58 in the LDG. HCV viral decline for patients in the LDG was less than for those in the SDG (week 1∶1.72±0.74 log₁₀ IU/mL versus 1.78±0.67 log₁₀ IU/mL, p = 0.827; week 2∶2.3±0.89 log₁₀ IU/mL versus 3.01±1.02 log₁₀ IU/mL, p = 0.013; week 4∶3.52±1.2 log₁₀ IU/mL versus 4.09±1.1 log₁₀ IU/mL, p = 0.005). The linear regression model identified the Peg-IFN/RBV dose as an independent factor for HCV viral decline at week 4.

Conclusions

Our results showed that HCV viral decline was less for patients in the low-dose group compared to those receiving the standard dose. Until a randomized clinical trial is conducted, clinicians should be cautious about using lower doses of Peg-IFN/RBV in HIV/HCV genotype 3 co-infected patients.

Optimal follow-up time to determine the sustained virological response in patients with chronic hepatitis C receiving pegylated-interferon and ribavirin

BACKGROUND AND AIM

This study evaluated whether the assessment of hepatitis C virus (HCV)-RNA at 12 weeks (FW+12) post-treatment follow-up was as applicable as FW+24 to evaluate sustained virological response (SVR) using the highly sensitive real-time polymerase chain reaction (PCR) HCV assay.

METHODS AND RESULTS

Two hundred and twenty-two patients with chronic hepatitis C were included in this study. Pegylated interferon (Peg-IFN) and ribavirin were administered for 24-72 weeks based on the genotype and viral load. Serum HCV-RNA was measured using real-time PCR at pretreatment, the end of treatment, FW+4, FW+8, FW+12, FW+16, FW+20 and FW+24. Two hundred patients had a virological response at the end of treatment. One hundred and forty-eight of 200 (74.0%) patients with a virological response at the end of treatment had an SVR at the FW+24. The positive predictive value (PPV) to identify patients with SVR at FW+4, FW+8, FW+12 was 87.1, 96.1, 98.0%, respectively. The viral load showed a reversion to the basal level as early as 8 weeks in relapse patients. There were only three patients who relapsed after FW+12 and all three of these patients were females with genotype Ib and a high viral load.

CONCLUSION

The assessment of serum HCV-RNA FW+12, using the highly sensitive real-time PCR assay, is almost as effective as FW+24 to predict SVR. However, there are false negatives in female patients with a high viral load of genotype Ib when the SVR is predicted by FW+12. The current standard with FW+24 is reasonable, but the assessment of serum HCV-RNA FW+12 may be effective in most patients.