Add Telaprevir

Introduction

To the 2-drug team to combat the virus deadlier than HIV

THE Hepatitis C virus has infected over 170 million people worldwide which is four times the number of hiv infected people. India, alone, has three million cases. The existing treatment is a combination of two drugs: interferon and ribavirin, which together prevent the virus from replicating. But the success rate of the prevailing two-drug combination is less than 50 per cent because it does not completely cure. It only slows the progression of liver damage; the combinations’ effects last only a year.

A team, led by John McHutchison, division of gastroenterology, Duke University, usa, developed a new drug called telaprevir. In half the time normally needed for treatment, it was found to be effective in inhibiting the formation of essential structural proteins needed by the virus. The team used telaprevir in combination with the other two drugs and organized a drug trial.

The Hepatitis C patients were divided into four groups. This included a control group, which received only interferon and ribavirin for a year. Of the other three groups, the first received all three drugs for three months, the second received telaprevir for three and interferon and ribavirin for six months. The last group was administered telaprevir for three months and the other two were continued for a year. The study, reported in the April 30 edition of The New England Journal of Medicine, found that within six months of treatment, viral levels were suppressed 67 per cent in the groups that received telaprevir.

As compared to the control group, those being administered telaprevir showed an increased rate of anaemia, nausea, diarrhoea and rashes. “Side-effects of combination therapy are a real problem. Managing them needs close monitoring,” said Sanjoy Pal, from the Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow.

Side-effects notwithstanding, the three drug-combination can attack the virus in each step of its replication, said Pal. “Interferon indirectly attacks the virus by modulating the immune system activities. Ribavirin interferes with duplication of the virus and telaprevir inhibits formation of structural proteins. All put together, they can rapidly reduce levels of the Hepatitis virus in the body,” he explained.

Source: Down To Earth, June 2009