CBLB502

·         In April 2008 US scientists revealed having developed CBLB502 - a drug which may protect the body against damage from radiation

·         CBLB502, so far tested in animals, switches on a biological mechanism that helps healthy cells survive blasts of radiation.

·         Studies in animals suggest CBLB502 protects healthy cells in the bone marrow and digestive tract against radiation but does not seem to protect tumour cells which remain vulnerable to treatment.

·         Mice and monkeys injected with the drug between 45 minutes and 24 hours before being subjected to normally lethal radiation were more likely to survive or live longer than untreated animals

·         Radiation kills cells by causing damage which encourages cell suicide, or apoptosis.

·         But healthy cells may be killed alongside tumour cells in the process which is why radiologists need to target the tumour as specifically as possible.

·         Researchers developed the drug after looking at how some resistant cancer cells are able to withstand radiotherapy.

·         One risk of preventing cell death is that defective cells may be allowed to survive which could then turn cancerous.

·         However, the researchers found no sign of this happening in the laboratory tests on mice.

·         Also, there were no apparent side effects.

·         Protecting healthy cells against the effects of radiation may allow cancer patients to receive higher doses of radiotherapy, or longer courses of treatment.

·         The drug may also be useful in protecting against fall out from a nuclear disaster, such as Chernobyl, or the effects of a terrorist "dirty bomb".