Among treatment-naive
patients, half of those taking telaprevir triple therapy had a ribavirin dose
reduction, compared with 18% of those on pegylated interferon/ribavirin alone (45
and 11%, respectively, received < 600 mg/day of ribavirin while on
triple therapy).
Ribavirin dose
reduction did not negatively affect the likelihood of treatment success, with
the following SVR rates:
- 79% with telaprevir triple therapy and 46% with pegylated
interferon/ribavirin among patients who never reduced their ribavirin dose;
- 75 and 54%, respectively, among those who used 800 to 1000mg/day
ribavirin;
- 74 and 42%, respectively, among those who used < 600mg ribavirin.
Turning to the more
challenging treatment-experienced group, 39% of prior relapsers, 31% of prior
partial responders, and 18% of prior null responders taking triple therapy
reduced their ribavirin dose, compared with 19, 26 and 19%, respectively,
taking pegylated interferon/ribavirin alone.
Again, ribavirin dose
reduction did not have a detrimental affect on SVR rates.
- 82% with triple therapy and 20%
with pegylated interferon/ribavirin among patients who never reduced
their ribavirin dose;
- 84 and 29%, respectively,
among those who used 800 to 1000mg/day ribavirin;
- 90% and 33%, respectively,
among those who used < 600mg ribavirin.
- Prior partial responders:
- 62 and 20%, respectively,
among people who never reduced their ribavirin dose;
- 50 and 0%, respectively, among
those who used 800 to 1000mg/day ribavirin;
- 62 and 0%, respectively, among
those who used < 600mg ribavirin.
- Prior null responders:
- 31 and 3%, respectively, among
people who never reduced their ribavirin dose;
- 50 and 0%, respectively, among
those who used 800 to 1000mg/day ribavirin;
- 22 and 25%, respectively,
among those who used < 600mg ribavirin.
"In
treatment-naive and previously treated patients who received telaprevir
combination treatment, ribavirin dose reduction was more frequent than in the
control group," the researchers concluded. "Ribavirin dose reduction,
including dose reduction to < 600mg/day, had no substantial effect
on SVR rates in patients treated with telaprevir combination treatment."
Taken together, these studies indicate that the extra potency of HCV protease
inhibitors helps overcome the tendency to relapse among patients who take
inadequate ribavirin in dual therapy with pegylated interferon.
In his summary
of research highlights on the final day of the conference, Jean-Michel
Pawlotsky from the University of Paris said these findings "validate the
use of ribavirin dose reduction" rather than adding the expense of EPO to
an already costly regimen.