Hep C combinations show promise in HIV/HCV patients

This article is more than 23 years old.

London School of Hygine and Tropical Medicine

Selected Studies of HIV/HCV Co-infection from the 52nd Annual Meeting of the American

Association for the Study of Liver Disease (AASLD,)Dallas, Texas, USA

Glossary

ribonucleic acid (RNA)

The chemical structure that carries genetic instructions for protein synthesis. Although DNA is the primary genetic material of cells, RNA is the genetic material for some viruses like HIV.

 

efficacy

How well something works (in a research study). See also ‘effectiveness’.

log

Short for logarithm, a scale of measurement often used when describing viral load. A one log change is a ten-fold change, such as from 100 to 10. A two-log change is a one hundred-fold change, such as from 1,000 to 10.

cirrhosis

Severe fibrosis, or scarring of organs. The structure of the organs is altered, and their function diminished. The term cirrhosis is often used in relation to the liver. 

statistical significance

Statistical tests are used to judge whether the results of a study could be due to chance and would not be confirmed if the study was repeated. If result is probably not due to chance, the results are ‘statistically significant’. 

The

52nd annual meeting of the AASLD centered along two main lines with

regard to issues concerning co-infection of HIV with HCV: Studies of the

natural history of co-infection and studies concerning the treatment of HCV in

individuals who also have HIV.

Treatment and Survival

One

of the central questions addressed at this meeting was “When should anti-HCV

therapies begin for individuals also infected with HIV?”. In a study by Tarek

Hassanein from the University of California at San Diego, individuals with

HIV+HCV co-infection who were deemed “compliant” in their medical care were

compared to those with similar co-infection who were not “compliant”, and also

to those with HIV mono-infection. The study found significant differences in

survival rates between the groups, and found that those who were adherent to

therapy and who actively sought specialized care for their co-infection had

better survival rates than coinfected individuals who did not. In a study from

France, it was observed that those with HIV+/HCV co-infection got liver

cirrhosis earlier and tended to suffer more problems related to liver failure

when compared to those with HCV alone. The authors concluded that treatment for

HCV should be initiated as soon as possible and that liver transplantation for

those who do not respond should be discussed as well. Taken together, these

studies suggest individuals with co-infection should be encouraged to seek

specialist medical care as early as possible.

With

respect to therapy, a central topic of this year’s meeting was whether drugs

used to treat hepatitis C were well-tolerated and as efficacious in individuals

co-infected with HIV. Preliminary data were presented on treatment of

150 individuals with HIV+HCV co-infection with Roche’s Pegasys (a type of

pegylated interferon, which is a longer lasting form of interferon that is

currently going through trials).

In the treatment of HCV, anti-HCV drugs are typically

given for 12 weeks, and if they achieve a virologic response (undetectable

viral levels, which is typically

genotype of virus an individual is infected with. Genotype 1 viruses are

treated for a longer period of time than others. The virus levels at the end of

the treatment period are assessed at this point. Then, 6 months after

discontinuation of therapy, viral levels are assessed again. If viral levels

are still undetectable at this point, an individual is considered a “sustained

responder.”

The

Pegasys study found that the drug appeared to be well-tolerated and that

no unexpected adverse events were seen. It is worth noting that these are

preliminary data based on week 12 of treatment and that the trial has not been

completed yet. In this study, participants received monotherapy with Pegasys for 12 weeks and then intensified treatment with ribavirin. 19% had undetectable HCV RNA at week 12, and a further 33% had experienced an HCV RNA reduction of more than 2 log (from a mean baseline HCV RNA of 6 log IU/ml).

Another

study, by Edmund Bini, found no significant differences with respect to end of

treatment response in those with HIV+HCV and HCV alone with the use of

interferon + ribavirin on 32 individuals with HCV+/HIV and 64 with HCV

alone.  In the entire group studied,

26.6% with HCV alone and 21.9% with co-infection achieved sustained response.

These differences are not statistically significant. Subgroup analysis

suggested that infection with HCV genotype 1 or genotypes 2 and 3 made no

difference to response either. There was no significant reduction in CD4 cell count in the HIV/HCV group as a result of ribavirin treatment. No serious adverse events or deaths in either

group were observed. The authors concluded that “combination therapy with

interferon and ribavirin is safe and efficacious for the treatment of HCV in

patients co-infected with HIV. Co-infected patients have a sustained virologic

response rate that is no different from patients who are not infected with

HIV.”

In

contrast, a study comparing daily induction dosing of interferon and ribavirin

to standard three times weekly interferon and ribavirin for 6 months showed

differences in response rates between HCV genotype 1 and non-1 infection.

Individuals infected with genotype 1 were less likely to achieve a sustained

response. This may be due to the fact that these patients received only 6

months of therapy (individuals infected with genotype 1 viruses normally

receive 1 year of therapy). Overall, however, they found interferon/ribavirin

to be well-tolerated in individuals co-infected with HCV and HIV.

References:

Hassanein

TI, et al. Survival in HCV/HIV co-infected patients. AASLD, Dallas,

Abstract 234, 2001.

Di

Martino V, et al. Impact of HIV co-infection on the age and the cause of

death in patients with HCV cirrhosis. AASLD, Dallas, Abstract 1095, 2001.

Bini

EJ, et al. Safety and efficacy of interferon alpha-2b and ribavirin combinations

therapy for the treatment of hepatitis C in patients co-infected with HIV.

AASLD, Dallas, Abstract 653, 2001.

Juarez

A. et al. Randomized trial of interferon A plus ribavirin versus

peg-interferon and ribavirin in HIV HCV co-infected patients: interim report on

safety data. AALSD, Dallas, Abstract 985, 2001.