HIV-HCV co-infected patients have poorer response to HCV therapy

Hepatitis coinfection, and in particular hepatitis C virus (HCV), have become significant causes of morbidity and mortality among HIV-infected patients. Unfortunately, response rates to interferon and ribavirin, the primary treatment for HCV, appear to be lower in HIV/HCV coinfected than in HCV monoinfected patients.

In an open label, uncontrolled, multicentre study presented at the 2nd IAS Conference (July 14-16, 2003, Paris, France), investigators analysed factors related to sustained virologic response (SVR) or nonresponse (NR) in a cohort of 128 coinfected patients receiving Peg-Intron (pegylated interferon alfa-2b, 1.5 microgram/kg/week) plus Rebetol (ribavirin, 800 mg/day). In this study, patients with HCV genotypes 1 and 4 were treated for 48 weeks and genotypes 2 and 3 were treated for 24 weeks.

Seventy-two patients had completed 24 weeks post-treatment follow-up at the time of the report. The mean viral load and CD4 count in these patients was 2.5 log10 copies/mL and 425 cells/mm3, respectively.

The overall SVR rate (ie, an undetectable HCV RNA at week 24 of follow up) was 26.4%. The SVR rate was higher for patients with HCV genotypes 2 and 3 (47.6%) than for those with HCV genotypes 1 and 4 (19.5%).

With regard to treatment outcome, there were no significant differences in response rates regarding gender, median age or median CD4 cell count at baseline.

Finally, patients who showed an early treatment response with undetectable HCV RNA at week 12, were significantly more likely to achieve SVR.

The authors conclude: “Overall sustained response rates in HIV/HCV coinfected patients treated with [pegylated interferon and ribavirin] are lower compared with historical data from HCV monoinfected patients. However, several factors affect treatment outcome. Genotypes 2 and 3 favour sustained treatment response. Moreover, early response appears to be a predictive factor in coinfected as well as in HCV monoinfected patients.”

Ref: Voigt E et al. Factors related to outcome of treatment with pegylated interferon alpha 2b (PEG INF) plus ribavirin (RBV) in HCV-HIV coinfected patients. Abstract 976. The 2nd IAS Conference on HIV Pathogenesis and Treatment. July 13-16, 2003. Paris, France.

Comment

The predictive value of early response is no surprise, as it has been shown multiple times in HCV-monoinfected patients. The poorer response to treatment is one of the obstacles in treatment of coinfected patients unfortunately extending to pegylated formulations of interferon, shown for example in the French RIBAVIC trial.