Randomized comparison of daclatasvir + asunaprevir versus telaprevir + peginterferon/ribavirin in Japanese hepatitis C virus patients.

BACKGROUND AND AIM: Daclatasvir combined with asunaprevir is the first all-oral, ribavirin-free treatment of hepatitis C virus genotype 1b infection in Japan. This study compared the efficacy and safety of daclatasvir plus asunaprevir versus telaprevir plus peginterferon/ribavirin in Japanese treatment-naive patients infected with hepatitis C virus genotype 1b. METHODS: Treatment-naive patients (20-70 years; baseline viral load, ≥ 100,000 IU/mL) were randomly assigned (stratified by IL28B rs8099917 TT/non-TT status) to receive either daclatasvir 60 mg tablets once daily and asunaprevir 100 mg softgel capsules twice daily for 24 weeks or telaprevir 750 mg (3 × 250 mg tablets) three times daily for 12 weeks and peginterferon/ribavirin per Japanese prescribing information for 24 weeks. A cohort of prior relapsers to peginterferon/ribavirin (20-75 years; baseline viral load, ≥ 100,000 IU/mL) received daclatasvir plus asunaprevir. RESULTS: In treatment-naive patients, sustained virologic response at post-treatment week 12 in daclatasvir plus asunaprevir recipients was non-inferior (treatment difference, +25.8% in favor of daclatasvir plus asunaprevir) and higher (89.1%, 106/119) than telaprevir plus peginterferon/ribavirin recipients (62.2%, 69/111); sustained viral response was achieved in 95.5% (n = 21/22) of relapsers. Numerically, fewer patients receiving daclatasvir plus asunaprevir compared with telaprevir plus peginterferon/ribavirin experienced serious adverse events (4.2% vs. 5.4%), adverse events leading to discontinuation of any drug (5.0% vs. 62.2%), grade 3/4 treatment-related adverse events (14.3% vs. 72.1%), rash-related events (0% vs. 13.5%), or anemia (0% vs. 47.7%). CONCLUSION: Marked differences were observed in the efficacy and safety profile of daclatasvir in combination with asunaprevir, compared with telaprevir plus peginterferon/ribavirin.

Daclatasvir combined with peginterferon alfa-2a and ribavirin in Japanese patients infected with hepatitis C genotype 1.

BACKGROUND: New direct-acting antiviral agents are currently being developed to treat chronic HCV. The efficacy and safety of daclatasvir combined with peginterferon alfa-2a (alfa-2a) and ribavirin were assessed in a randomized, double-blind Phase IIa study of Japanese patients with chronic HCV genotype-1 infection. METHODS: Japanese patients who were treatment-naive (n=25) or prior null (n=12) or partial (n=5) responders received once-daily daclatasvir 10 mg or 60 mg or placebo in combination with alfa-2a and ribavirin. Daclatasvir recipients with a protocol-defined response (HCV RNA<15 IU/ml at week 4 and undetectable at week 12) were treated for 24 weeks; placebo recipients and patients without a protocol-defined response were treated for 48 weeks. RESULTS: Sustained virological response at 24 weeks post-treatment (SVR24) was achieved by 89% and 100% of treatment-naive patients receiving daclatasvir 10 mg and 60 mg, respectively, versus 75% in placebo recipients. Virological failure was more frequent in prior non-responder patients, with 50% and 78% achieving SVR24 in daclatasvir 10 mg and 60 mg groups, respectively. Adverse events occurred with similar frequency among treatment groups and were consistent with the adverse event profile of alfa-2a/ribavirin alone. The most commonly reported adverse events included pyrexia, alopecia, anaemia, lymphopenia, neutropenia, pruritus and diarrhoea. Three patients discontinued treatment due to anaemia. CONCLUSIONS: Daclatasvir combined with alfa-2a/ribavirin in treatment-naive patients showed greater efficacy than alfa-2a/ribavirin alone and was generally well tolerated. The 60-mg dose of daclatasvir achieved the highest rates of SVR24 in both treatment-naive and non-responder populations and will be evaluated in a Phase III clinical trial.

Structural and enzymatic characterization of physarolisin (formerly physaropepsin) proves that it is a unique serine-carboxyl proteinase.

Previously, we purified and partially characterized physarolisin, a lysosomal acid proteinase from Physarum polycephalum, which had been suggested to be concerned with the morphological changes of the mold. In this study, a cDNA for the enzyme was cloned and sequenced, and the structural and enzymatic features were investigated. The enzyme shows a sequence similarity to the serine-carboxyl proteinase family (MEROPS S53). Indeed, diisopropylfluorophosphate (DFP) was shown to strongly inhibit the activity of the enzyme. However, the enzyme possesses several unique features distinct from the other members of the family, such as the two-chain structure and inhibition by diazoacetyl-D,L-norleucine methyl ester (DAN). The sites and mode of processing of the precursor to the mature enzyme were deduced, and the major DAN-reactive residue in the enzyme was identified to be Asp529. These features were suggested to be due to the unique local tertiary structure of the enzyme by molecular modeling. We now propose the name physarolisin for the enzyme.