HCV
in Corrections: Frontline or Backwater?
(continued)
Expect
Delays
Length
of Treatment
Expected
Outcome
Liver
Biopsy
Expect
Delays
Currently, PEG-Intron (Schering
Plough) is not available immediately to all patients who are prescribed
treatment. Because demand has exceeded supply, the company has developed
the "Access Assurance" program to ensure that all patients who begin PEG-Intron
treatment can successfully complete it.18 A second pegylated interferon
alfa (Pegasys, Roche), is expected to be approved by the FDA in the second
half of 2002. This product will also require once-weekly injections. Roche
is expected to release its own ribavirin along with Pegasys.
Length
of treatment
Recommendations related
to the duration of combination therapy depend on viral genotype. Genotypes
1a, 1b, 2, and 3 are the most common in the United States; 70% to 80% of
patients are infected with genotype 1. 8 Recommendations are:
(1) HCV genotype 1: A 48-week
(12-month) course of therapy.
(2) HCV genotype 2 or 3:
A 24-week (6-month) course of therapy.
Interferon monotherapy is
no longer the standard of care for initial therapy.
Expected
Outcome
The goal of HCV therapy
is to obtain a sustained virologic response (SVR), which implies that HCV
RNA remains undetectable for 6 months or more after therapy stops. This
correlates with a viral response lasting >4 years and with a histologic
response of regression or arrested progression of fibrosis or inflammation.8
In a randomized trial of patients with chronic HCV infection, 42% of genotype
1 patients and 82% of genotype 2 or 3 patients on the pegylated regimen
experienced SVR in a study of combination therapy (Table 1).16 Additionally,
early HCV viral clearance is a predictor of SVR. Patients on pegylated
interferon therapy show an increased phase I HCV viral clearance in comparison
to patients on standard therapy. This may directly inhibit viral replication
and release, resulting in a more rapid complete viral clearance as predicted
by viral kinetics.19
Adherence is also a key
component to a favorable outcome: patients who receive >80% of their doses
have significantly more favorable outcome than patients who do not.14,15
In addition, other factors, including combination therapy, careful dosing
by weight (see HCV101), age <45, female gender, and mild (rather than
advanced) chronic inflammation on liver biopsy also contribute to improved
treatment outcomes.
Liver
Biopsy
Liver biopsy is necessary
to assess fibrotic damage because neither HCV viral load nor ALT level
correlates well with the degree of liver damage.17 There are three main
indications for liver biopsy: 1) to rule out unsuspected diagnoses that
may influence patient management, 2) to assess the severity of liver damage
and 3) to assess response to therapy. However, the need for biopsy is a
matter of debate in corrections since biopsies are both expensive and logistically
complicated. Some state protocols do not require liver biopsies prior to
starting treatment. Some facilities have liver biopsies provided on-site.
An alternative for correctional settings is to carefully monitor response
to therapy over the initial days and weeks of treatment since patients
who respond immediately are believed to be likely to continue to benefit
from treatment and those who do not are unlikely to benefit and might have
treatment discontinued (see HEPP News, April 2001).20,21
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