Page 17 - The Flying Publisher Guide to Hepatitis C Treatment

Antiviral Therapy: The Basics
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for patients <75 kg and 1200 mg/day for patients >75 kg. Recent
clinical trials with new antiviral compounds associated with
PegIFN/RBV have demonstrated that maintaining RBV in the
therapeutic regimen has an important additive effect.
Predictors of response before treatment
Experienced providers need to take treatment decisions on a
case-by-case basis. There are a series of virus, host and
treatment characteristics that influence the likelihood of
treatment success and are useful when assessing the benefits and
risks of therapy.
Virus factors
HCV genotype, pretreatment HCV RNA level (viral load-VL) and
the evolution of viral quasispecies (cluster of variant viruses that
arise from mutations over time in viral population) are strong
independent predictors of SVR to SoC therapy, as well as to
triple combination therapy with protease inhibitors.
– HCV Genotype is a major predictor of treatment response.
HCV genotypes can be ranked, in a decreasing order of
susceptibility to IFN-based treatment, as follows: genotypes
2, 3, 4 and 1. Furthermore, subtype 1b rather than 1a and
subtype 2b rather than 2a are likely to respond poorer to
IFN-based therapy. Permanent viral eradication (SVR) can
be achieved in up to 80% of individuals infected with
‘favorable’ or “easy-to-treat” HCV genotypes (G2/3), but
only in approximately 40% of those infected with
‘unfavorable’ or “difficult-to-treat” HCV genotypes
(G1/4).
– High baseline VL (with a cutoff value of 400000 IU/mL)
influences negatively the response rate in patients infected
with HCV G1 (41% versus 56%), but not significantly in those
with HCV G 2/ 3 (74% versus 81%).
– Higher viral quasispecies complexity at baseline has been
observed in nonresponders compared with sustained