Cancer therapy causes 'avalanche of cell death'

Antibody drugs that stop new vessels forming in tumours have already been developed and marketed — but generally tumours can adapt and rely on back-up mechanisms to get blood flowing again.

A team from Hull University and ETH Zurich have now joined these antibodies to a photosensitive molecule.

The drug is administered intravenously as normal and is localised to the tumour site by the antibody, which attaches to a protein specific to the blood vessels there. The antibody stops the growth of new vessels — but, in addition, light is applied to the tumour, which activates the photosensitive molecule and leads to a cascade that damages existing vessels.

‘The photosensitiser absorbs red wavelength light and it goes into an excited state, so it’s got to get rid of that energy somehow and the way it does that is to interact with oxygen, converting it to something much more cytotoxic — which is bad for any cells in the immediate environment,’ Dr Ross Boyle of Hull told The Engineer.