How Does Abacavir (Ziagen) Affect Virological Response to Pegylated Interferon plus Ribavirin in HIV-HCV Coinfected Patients?

Abacavir (Ziagen)

The current standard of care for treatment of chronic hepatitis C in HIV-HCV coinfected patients is pegylated interferon plus ribavirin. In 2007, antiretroviral therapy containing abacavir (Ziagen; also in the Epzicom and Trizivir combination pills) was reported to be associated with early virological failure during anti-HCV treatment.

The aim of the present study, published in Antiviral Therapy, was to evaluate the effect of abacavir on the rate of response to anti-HCV therapy.

Spanish investigators undertook a retrospective analysis of 244 HIV-HCV coinfected patients treated with pegylated interferon and weight-adjusted ribavirin at 4 hospitals. Overall, 85% of patients were on highly active antiretroviral therapy; of these, 24% received abacavir-containing regimens. The most frequent HCV genotypes were 1 and 3. Most patients (97%) received a ribavirin dose of 213.2 mg/kg/day.

The investigators conducted an analysis of baseline descriptive variables. Logistic regression models were used to test possible associations between non-response and pre-treatment characteristics, including use if specific antiretroviral drugs.

Results

In a global intent-to-treat analysis, 46.3% of patients achieved sustained virological response (SVR).

SVR rates were 46.2% in the abacavir group versus 46.7% in patients taking non-abacavir regimens, not a statistically significant difference.

In a multivariate analysis, the only 2 factors that were significantly associated with an increased risk of failure to achieve SVR were HCV genotypes 1 or 4 and older patient age.

The use of abacavir was not associated with failure to achieve SVR at any of the time points evaluated.

Based on these findings, the study authors concluded, "Our data suggest that the use of abacavir-based regimens in the context of HCV therapy does not negatively affect the outcome of this treatment."

Infectious Diseases Unit, Hospital Clinic, Barcelona, Spain.

2/03/09

Reference
N Laufer, M Laguno, I Perez, and others. Abacavir does not influence the rate of virological response in HIV-HCV-coinfected patients treated with pegylated interferon and weight-adjusted ribavirin. Antiviral Therapy 13(7): 953-957. 2008.