Boceprevir

Boceprevir is a potent and selective inhibitor of hepatitis C virus (HCV) protease NS3 with Ki value of 14 nM [1].
HCV is a type of RNA virus and infects about 300 million people worldwide. As a serine protease of HCV, NS3 plays an important role in the replication process of HCV when the virus enters the host cell. NS3 processes the polyprotein translated from the virus RNA genome and promotes the maturation of the virus. NS3 is also found to restore the interferon-sensitive signaling pathway. Due to these features, NS3 is thought to be the appropriate target for the therapy of antivirus. The SAR studies led to the discovery of boceprevir (also named as SCH 503034). Boceprevir has a ketoamide group, it binds NS3 and forms a covalent and reversible adduct with the active site serine [1, 2 and 3].
In the cell-based replicon assay using hepatocytes, boceprevir showed improved potency than other derivatives with IC90 value of 350 nM. The selectivity of boceprevir was tested by binding to human neutrophil elastase which had similar structure with NS3. Boceprevir exerted a great selectivity with a HNE/HCV ratio of 2200. It is approximately 15-fold more selective than the corresponding carbamate derivative. In MTS assay, the compound showed no significant cytotoxicity even when its concentration was up to 50 μM [1].
Boceprevir is an orally bioavailable inhibitor of HCV NS3 protease. In rats, oral administration of boceprevir showed AUC value of 1.5 μM•H and bioavailability of 26%. In dogs, boceprevir demonstrated a 30% bioavailability with AUC value of 3.1μM•H at a dose of 3 mg/kg. Boceprevir was also used as a combination therapy with the pegylated interferon (PEG-IFN-α-2B). It was found that the combination showed at least addictive potency compared with each one alone [1, 2].
References:
1.Venkatraman S, Bogen S L, Arasappan A, et al. Discovery of (1 R, 5 S)-N-[3-Amino-1-(cyclobutylmethyl)-2, 3-dioxopropyl]-3-[2 (S)-[[[(1, 1-dimethylethyl) amino] carbonyl] amino]-3, 3-dimethyl-1-oxobutyl]-6, 6-dimethyl-3-azabicyclo [3.1. 0] hexan-2 (S)-carboxamide (SCH 503034), a Selective, Potent, Orally Bioavailable Hepatitis C Virus NS3 Protease Inhibitor: A Potential Therapeutic Agent for the Treatment of Hepatitis C Infection. Journal of medicinal chemistry, 2006, 49(20): 6074-6086.
2.Sarrazin C, Rouzier R, Wagner F, et al. SCH 503034, a novel hepatitis C virus protease inhibitor, plus pegylated interferon α-2b for genotype 1 nonresponders. Gastroenterology, 2007, 132(4): 1270-1278.
3.Flores M V, Strawbridge J, Ciaramella G, et al. HCV-NS3 inhibitors: determination of their kinetic parameters and mechanism. Biochimica et Biophysica Acta (BBA)-Proteins and Proteomics, 2009, 1794(10): 1441-1448.

Rapid virological response of telaprevir and boceprevir in a Brazilian cohort of HCV genotype 1 patients: a multicenter longitudinal study.[Pubmed:28138248]

Ther Clin Risk Manag. 2017 Jan 10;13:59-64.

BACKGROUND: Chronic hepatitis C is a major public health issue, but there is a gap in the literature regarding the effectiveness and safety of direct-acting antiviral agents in the Brazilian population. The main aim of this study was to describe the effectiveness of Boceprevir and telaprevir in patients treated at public health care institutions in Brazil. MATERIALS AND METHODS: A prospective longitudinal and multicenter study was conducted in five centers in the State of Parana between September 2014 and June 2016. Data regarding effectiveness and safety were collected from medical records of patients treated with Boceprevir or telaprevir. The effectiveness outcome comprised the rapid virological response (RVR). Multivariate analysis was performed to verify the influence of independent variables (ie, age, gender, baseline viral load) on RVR achievement. RESULTS: Data were collected from 117 patients with chronic hepatitis C virus (HCV) genotype 1 infection. Fifteen patients received treatment with Boceprevir and 102 received telaprevir. The mean age was 51.6 years, 64.1% were male, 44.4% were infected with HCV subtype 1a, 62.4% had a high baseline viral load (>/=800,000 IU/mL) and 33% were cirrhotic. Furthermore, 79.5% of patients achieved RVR (26.7% in the Boceprevir group and 87.3% in the telaprevir group). Multivariate analysis demonstrated that the type of protease inhibitor (Boceprevir or telaprevir) and the baseline viral load had an influence on the RVR rate (odds ratio [OR] =0.011; 95% confidence interval [CI]: 0.001-0.119; P<0.001/OR =13.004; 95% CI: 1.522-111.115; P=0.019, respectively). CONCLUSION: In this longitudinal multicenter cohort study conducted from the Brazilian perspective, differences were found in the RVR rates, favoring telaprevir over Boceprevir for genotype 1 HCV-infected patients. In addition, the baseline viral load was associated with RVR achievement in both evaluated groups. As RVR is also reported in the literature as a predictor of the sustained virological response (SVR), further analyses of RVR as predictor of SVR outcomes should be further evaluated in Brazil.

Boceprevir plus pegylated interferon/ribavirin to re-treat hepatitis C virus genotype 1 in HIV-HCV co-infected patients: final results of the Spanish BOC HIV-HCV Study.[Pubmed:27815225]

Int J Infect Dis. 2016 Dec;53:46-51.

INTRODUCTION: Boceprevir (BOC) was one of the first oral inhibitors of hepatitis C virus (HCV) NS3 protease to be developed. This study assessed the safety and efficacy of BOC+pegylated interferon-alpha2a/ribavirin (PEG-IFN/RBV) in the retreatment of HIV-HCV co-infected patients with HCV genotype 1. METHODS: This was a phase III prospective trial. HIV-HCV (genotype 1) co-infected patients from 16 hospitals in Spain were included. These patients received 4 weeks of PEG-IFN/RBV (lead-in), followed by response-guided therapy with PEG-IFN/RBV plus BOC (a fixed 44 weeks was indicated in the case of cirrhosis). The primary endpoint was the sustained virological response (SVR) rate at 24 weeks post-treatment. Efficacy and safety were evaluated in all patients who received at least one dose of the study drug. RESULTS: From June 2013 to April 2014, 102 patients were enrolled, 98 of whom received at least one treatment dose. Seventy-three percent were male, 34% were cirrhotic, 23% had IL28b CC, 65% had genotype 1a, and 41% were previous null responders. The overall SVR rate was 67%. Previous null-responders and cirrhotic patients had lower SVR rates (57% and 51%, respectively). Seventy-six patients (78%) completed the therapy scheme; the most common reasons for discontinuation were lack of response at week 12 (12 patients) and adverse events (six patients). CONCLUSIONS: Response-guided therapy with BOC in combination with PEG-IFN/RBV led to an overall SVR rate of 67%, but an SVR rate of only 51% in patients with cirrhosis. The therapy was generally well tolerated. Although the current standards of care do not include BOC+PEG-IFN/RBV, the authors believe that this combination can be beneficial in situations where new HCV direct antiviral agent interferon-free therapies are not available yet.

Aplastic Anemia and Severe Myelosuppression with Boceprevir or Simeprevir-Containing Hepatitis C Virus Treatment.[Pubmed:28233734]

Ann Hepatol. 2017 March-April;16(2):312-317.

The addition of the new protease inhibitors (PIs) to peg-interferon (IFN) and ribavirin (RBV), approved for chronic hepatitis C, has clearly improved sustained virological response (SVR) rates although several adverse events have been reported with this regimens, including mild hematological toxicity. Moreover, severe pancytopenia and aplastic anemia during triple therapy with telaprevir has recently been described in seven patients. We report here two cases of severe agranulocytosis/aplastic anemia using Boceprevir or simeprevir in interferon-based combination and 2 additional cases of severe myelosupression in IFN-free therapy with sofosbuvir and simeprevir plus RBV. Our observations suggest that PIs could have a sort of class-effect in developing severe hematologic toxicity or, at least, an additive interaction with other potentially myelotoxic agents such as IFN or RBV that are used in the classical regimens against HCV. Unfortunately, the mechanisms behind this phenomenon are currently unknown. In conclusion, given the lifethreatening character of these complications, close monitoring is mandatory in patients under PIs based therapy to promptly detect serious hematological toxicities and to carefully evaluate treatment discontinuation. Prospective studies assessing the usefulness of RBV in the era of new IFN-free combinations are needed.

Boceprevir is a novel, potent, highly selective, orally bioavailable HCV NS3 protease inhibitor with Ki of 14 nM in both enzyme assay and EC90 of 350 nM in cell-based replicon assay.

Boceprevir,394730-60-0,EBP 520; SCH 503034,Natural Products,HCV Protease, buy Boceprevir , Boceprevir supplier , purchase Boceprevir , Boceprevir cost , Boceprevir manufacturer , order Boceprevir , high purity Boceprevir