A group of 24 volunteers has joined trials of a new treatment for the killer liver disease hepatitis B.

Powderject Pharmaceuticals, based at Oxford Science Park, said the clinical trial, sponsored by pharmaceutical giant GlaxoSmithKline, was designed to evaluate a DNA vaccine to treat the disease, one of the world's top ten killers.

DNA vaccines work by introducing new genes that encourage the body's immune system to fight disease.

The volunteers will each receive three doses of vaccine. They will be administered via the needle-free Powderject system, under two different immunisation schedules. They will undergo tests to show whether they have developed immunity and created antibodies against the chronic viral infection. In an earlier clinical trial, all volunteers developed antibodies to the disease.

Hepatitis B, one of the most common infectious diseases in the world, is a potentially fatal liver disease and is the world's ninth biggest killer. Globally there are more than 350 million long-term carriers of the virus, of whom about a third are expected to develop serious progressive liver disease, leading to liver cirrhosis and cancer.

Powderject chairman and chief executive Paul Drayson said: "We are extremely pleased that GlaxoSmithKline has initiated this study, which will provide a clinical foundation for the second development programme in our collaboration.

"Our collaboration with GlaxoSmithKline is advancing extremely well. The start of this study, which marks the beginning of our programme to develop a further effective treatment for hepatitis B, in addition to the clinical success we have achieved to date, clearly demonstrates the progress we are making.' Powderject and Glaxo Wellcome, now part of GlaxoSmithKline, entered a strategic alliance in March 1998. The collaboration covers up to 11 DNA vaccines for hepatitis, HIV and genital warts.

Powderject was set up in 1993 to commercialise research by Prof Brian Bellhouse at Oxford University.