Peg-IFN achieves poor results in HIV-HCV patients even when used with ribavirin

Michael Carter
Estimated reading time 2 minutes
This article is more than 21 years old.

HIV-positive individuals coinfected with hepatitis C virus (HCV) who receive anti-HCV therapy including pegylated-interferon alpha, either as monotherapy or in combination with ribavirin, experience a very poor treatment response and a high rate of side-effects, according to French data presented to the 43rd Interscience Conference on Antimicrobial Agenets and Chemotherapy in Chicago on September 15 th.

The 24 week preliminary analysis of the study involved 74 individuals who were coinfected with HIV and HCV. At baseline mean CD4 cell count was 558 cells3, and mean HIV viral load was 1,334 copies/mL. A little under three-quarters (73.2%) were infected with HCV genotype-1, which is associated with a poor response to anti-HCV treatment. Average age was a little over 39 years and 68% of individuals were men.

A total of 44 patients were randomised to receive 24 weeks of treatment with pegylated interferon with ribavirin, and the remaining 30 individuals were randomised to receive pegylated interferon monotherapy throughout the study. Baseline characteristics were comparable between the two arms of the study.

Glossary

monotherapy

Taking a drug on its own, rather than in combination with other drugs.

pegylated interferon

Pegylated interferon, also known as peginterferon, is a chemically modified form of the standard interferon, sometimes used to treat hepatitis B and C. The difference between interferon and peginterferon is the PEG, which stands for a molecule called polyethylene glycol. The PEG does nothing to fight the virus. But by attaching it to the interferon (which does fight the virus), the interferon will stay in the blood much longer. 

p-value

The result of a statistical test which tells us whether the results of a study are likely to be due to chance and would not be confirmed if the study was repeated. All p-values are between 0 and 1; the most reliable studies have p-values very close to 0. A p-value of 0.001 means that there is a 1 in 1000 probability that the results are due to chance and do not reflect a real difference. A p-value of 0.05 means there is a 1 in 20 probability that the results are due to chance. When a p-value is 0.05 or below, the result is considered to be ‘statistically significant’. Confidence intervals give similar information to p-values but are easier to interpret. 

intent to treat analysis

All participants in a clinical trial are included in the final analysis, in the groups they were originally assigned to, whether or not they actually completed their course of treatment. This method provides a better estimate of the real-world effect of a treatment than an ‘on treatment’ analysis.

pancreatitis

Inflammation of the pancreas.

After 24 weeks of anti-HCV therapy, 42.9% of individuals who received pegylated interferon with ribavirin had a virological response, defined as a negative HCV PCR. This compared to 25% of the monotherapy arm (p=0.166).

There was a very high rate of treatment discontinuation due to side-effects, with 45.3% of patients withdrawing from the study, and 45.9% reporting at least one adverse event. One patient who received pegylated-interferon with ribavirin died from acute pancreatitis.

When the investigators repeated their analysis, using an intent to treat analysis, with failure defined as no treatment response and/or treatment discontinuation due to severe side-effects, and/or loss to follow-up, there was no statistical difference between the two study arms (combination HCV-therapy 62.8% versus 72% monotherapy, p=0.22).

The investigators concluded that a very poor treatment response was seen at week 24, with no significant difference seen between the use of pegylated-interferon in combination or monotherapy.

References

Chaillou S et al. Copere: A randomised open label trial of pegylated-interferon alpha-2b plus ribavirin vs pegylated-interferon monotherapy in hepatitis C coinfected patients. 24 weeks preliminary study. 43rd ICAAC, abstract H-828, Chicago, September 14 – 17th, 2003.

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