A possible new treatment for bowel cancer developed by an Oxford company has been approved by the UK Gene Therapy Advisory Committee for trial on patients, writes Maggie Hartford.

The trials of the therapeutic vaccine developed by Oxford Biomedica, of Oxford Science Park, should start at the end of the year.

The vaccine, Trovax, is designed to stimulate patients' immune system to recognise and destroy cancer cells. They receive a gene which instructs their cells to make a protein associated with cancer, which in turn induces a powerful anti-tumour response.

Cells and antibodies of the immune system seek out the tumour cells carrying the protein, and destroy them.

Oxford Biomedica chief executive Alan Kingsman said: "We are delighted with this decision by GTAC. This is the third Biomedica protocol that has been approved by the committee and we are pleased to be establishing a good track record of approvable products.

"The preclinical data with Trovax are very promising, suggesting that the product may be useful in a wide range of tumour types."

The company has for some time been keen to move on to the main index of the London Stock Exchange, with its listing in 1996 on the Alternative Investment Market having been affected by a crash in biotech shares.

Finance director Andrew Wood said the latest trial approval meant that Biomedica satisfied the rules for admission, by having two products in clinical trials.

The other is MetXia-P450, a possible breast cancer treatment which also delivers a gene to the tumour.