So far, I do not consider the data proof of concept. Perhaps there will be statistical significance in reducing viral load in combination with interferon.
I'm not sure it's "a good thing" to reduce the ALT levels without a concommitant reduction in viral load.
Well ribavirin doesn't markedly reduce viral load as a monotherapy either:
J Hepatol 1998 Jul;29(1):29-35 Related Articles
Effect of ribavirin on virus load and quasispecies distribution in patients
infected with hepatitis C virus.
Lee JH, von Wagner M, Roth WK, Teuber G, Sarrazin C, Zeuzem S
Medizinische Klinik II, Klinikum der Johann Wolfgang Goethe-Universitat,
Frankfurt a.M., Germany.
BACKGROUND/AIMS: The combination of ribavirin and interferon alfa has potent
synergistic effects in the treatment of chronic hepatitis C. The antiviral
mechanism of ribavirin is unknown. We investigated whether a transient
initial antiviral effect of ribavirin was sufficient to improve the response
to interferon. METHODS: Fifteen HCV-infected patients (ten male, five
female; mean age 45.4+/-11.0 years) treated with ribavirin (1000-1200 mg)
and 17 untreated patients with chronic hepatitis C (11 male, six female;
mean age 45.6+/-9.9 years) were investigated. All patients were either
non-responders to (n=19) or relapsed after (n=13) previous interferon
treatment. Serum HCV-RNA concentrations and HCV quasispecies distribution
were serially measured over 4 weeks by quantitative reverse
transcription-polymerase chain reaction and single-strand conformation
polymorphism analysis, respectively. RESULTS: In six of the 15 patients
treated with ribavirin, but in none of the controls, serum alanine
aminotransferase levels declined by at least 30%. Pretreatment HCV-RNA
levels ranged from 5.0x10(5)-5.0x10(7) copies/ml. After initiation of
ribavirin treatment, minor (0.5-1.0 log) or no changes (<0.5 log) in total
hepatitis C viremia were observed in ten and five patients, respectively. In
HCV-infected patients without treatment 7/17 patients had minor and 10/17 no
changes in viremia. Polymerase chain reaction amplification of the
hypervariable region-1 of HCV was successful in 13/15 treated and in 17/17
untreated patients. Changes in HCV quasispecies according to the
single-strand conformation polymorphism band pattern occurred in only one
patient treated with ribavirin and in three of the untreated patients.
CONCLUSIONS: Ribavirin monotherapy has no initial antiviral effect on total
hepatitis C viremia nor on HCV quasispecies. Unlike the rapid emergence of
antiviral drug-resistant strains in HIV-infected patients, no viral escape
phenomena are observed in HCV-infected patients treated with ribavirin.
Seems to me (as Miljenko said) that VX-497 looks like a potentially better version of ribavirin.
Peter
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