Targeting Tumours with Bacteria

The Challenge

Common cancer treatments such as chemotherapy and radiotherapy are can be very unpleasant as they affect both the tumour and also healthy tissue, causing nasty side-effects to the patient. Newer immunotherapies, although expensive, target molecules presented on the outside of a tumour cell and can offer more precision. But they often fail when the tumour evolves and the cells change so that the surface molecule is no longer presented. A treatment that exploits specific unchanging properties of tumour cells and which can get inside them could be an answer.

The method

Certain bacteria will only grow in a tumour, not in healthy tissue. This is because a tumour cell’s metabolism is different to that of healthy cells. The bacteria use the nutrients provided by the tumour to grow. In addition, the tumour evades the host immune system by supressing it. So the bacteria not only hijack a tumour’s nutrients, but they also use the tumour to hide from the immune system.

The impact

• We use these tumour-targeting cell-invasive bacteria to deliver therapeutic payloads directly into tumour cells. Consequently, only tumour cells stop multiplying, not healthy cells.
• Results from ongoing preclinical trials, supported by Cancer Research UK, are very encouraging, indicating that tumours stop growing and there are no significant side-effects.
• Our next steps are to optimise the therapeutic payloads and progress to clinical trials. The technology opens the door for personalised medicine: as every tumour has its own genetic identity, the therapy can be tailored to match that.