Page 59 - The Flying Publisher Guide to Hepatitis C Treatment

Searching for new antiviral therapies | 59

with unfavorable pre-treatment characteristics (high VL,
advanced fibrosis, IL28B unfavorable genotypes CT or TT), as
well as other “difficult-to-treat” populations detailed in
chapter 3.
– Relapsers and nonresponders of all genotypes.

Different treatment options that can either augment the
efficacy of current therapy or potentially result in PegIFN-
and/or ribavirin (RBV)-sparing regimens are being extensively
studied. New emerging therapies include
– improved interferon (IFN) alfa formulations (to enhance
efficacy and ease of administration)
– alternative RBV-like molecules (to reduce toxicity)
– direct-acting antivirals (DAAs) that target specific key steps
of the viral life cycle

New IFN formulations
New interferons are currently being developed to offer
enhanced activity, improved AE profiles and, hopefully, better
tolerability compared with currently available ones (Table 4.1).
Given the dependence of treatment success on patients
adherence, the development of longer-acting IFN formulations,
with improved pharmacokinetic profiles, is an important focus
of HCV therapy. Their main advantages consist in maintenance
of viral suppression across a longer dosing interval, avoidance of
inter-dose trough, and reduced dosing frequencies (twice or
even once per month compared to once per week for the current
pegylated interferons (PegIFNs). Although studies about
improved formulations of interferons have been focused on HCV
genotype 1, their administration can be also valuable for
genotype 2 or 3 infected patients. In easy-to-treat patients
(infected with genotype 2 or 3), the duration of treatment can be
reduced to 12 weeks if a rapid virologic response (RVR) is
obtained. This can translate into a very convenient therapeutic
regimen of only 3 injections, if longer-acting IFNs, with monthly
dosing, are going to be used.