Oxford could soon see its first biotechnology drug on the market by 2009 following a £350m deal with pharmaceutical giant Sanofi-aventis.

Alan Kingsman, chief executive and co-founder of Oxford Biomedica, based at the Oxford Science Park, said the deal was being described as the biggest ever for British biotechnology.

Sanofi-aventis has agreed to develop and commercialise Biomedica's cancer treatment, TroVax, which uses a horse virus to introduce genes to boost the body's immune system.

It has been evaluated in clinical trials involving more than 180 patients with various forms of cancer, but has yet to pass final tests.

Prof Kingsman said that across the industry, 30 per cent of drugs failed their final trials.

He added: "Clearly, Trovax needs to work for us to get the big bucks."

He said the company now had money to develop its other treatments for Parkinson's disease and vision loss.

It will earn royalties on global sales if TroVax makes it to market.

Sanofi-aventis will fund all research and development costs, including developing TroVax for bowel cancer. It may also be developed for lung, breast and prostate cancers.

Oxford Biomedica, founded by Prof Kingsman and his wife Sue, employs 90 people in Oxford and in San Diego, US.