Promising results from a phase II trial published in the journal Gastroenterology suggest adding the new drug danoprevir to the current standard care (peginterferon and ribavirin) for patients with hepatitis C leads to high rates of remission.

The results raise hopes that Roche’s new drug can improve the quality of life for patients with hepatitis C.

Lead author Dr. Patrick Marcellin, professor of hepatology at the University of Paris and head of the Viral Hepatitis Research Unit in Hôpital Beaujon, Clichy, in France, says:

“Despite recent advances, the current hepatitis C treatment regimen is burdensome on the patient and prone to adverse events.”

The purpose of a phase II trial is to find out if the new treatment works well enough to justify a larger, phase III trial. It establishes the best dose to use and seeks to learn more about the side effects and how to manage them.

In the case of this trial, the investigators treated 237 patients who had not yet received any treatment. The patients were randomly assigned to receive either 12 weeks of danoprevir or placebo plus peginterferon alfa-2a and ribavirin, followed by peginterferon alfa-2a and ribavirin.

The patients who received danoprevir were given one of three doses: 300 mg every 8 hours, 600 mg every 12 hours, or 900 mg every 12 hours.

The main outcome measure the investigators were looking for was sustained viral response – that is no detectable traces of hepatitis C virus in the blood – after 6 months.

The results show that the drug was well tolerated and the sustained viral response was higher in patients who took danoprevir.

The highest response was for those patients who had the 600 mg every 12 hour dose (85% sustained viral response), followed by those who had 900 mg every 12 hours (76%) and then the 300 mg every 8 hours (68%). The placebo group’s sustained viral response was 42%.

The investigators also found that even before they had completed 1 week of treatment, the danoprevir group was showing reduced blood levels of hepatitis C virus.

As many as 79% of the patients who had danoprevir added to their treatment achieved an early response and were eligible for a shortened treatment schedule.

Studies using lower doses of danoprevir plus current standard of care are already underway, say the investigators, adding that early effectiveness and safety data from these studies are promising. The point of these studies is to find the optimum balance between effectiveness and minimum exposure to the drug.

Hepatitis C is caused by a virus that spreads through direct contact with the blood of infected persons. Until about 20 years ago, before routine screening was introduced, a common route was through donated blood. This was how Dame Anita Roddick, the British environmental campaigner and founder of Body Shop, contracted the disease.

When Dame Anita announced she had hepatitis C, some 7 months before her death in September 2007, she said she got the virus when she received a blood transfusion in 1971 when her daughter Sam was born.

Chronic hepatitis C can lead to liver damage, cirrhosis, liver failure or liver cancer.

Infections have two stages: acute infection, which is the first 6 months after initial infection, and chronic infection.

During the acute phase very few symptoms are present, and about 20% of people who become infected manage to shed the virus and do not develop chronic infection. But for the remaining 80%, the chronic stage sets in for decades and that is when the serious damage is done.

The timescale for symptoms to emerge is erratic, and some people can go undiagnosed for years. So it can be decades, as in the case of Dame Anita, before they find out the have the disease.

Diagnosis can also be complicated by the fact some of the symptoms, such as fatigue, depression, insomnia, abdominal pains and upsets, skin irritations and rashes, can be mistaken for other illnesses.

The trial was funded by F. Hoffmann-La Roche Ltd.