YOUR LIFESTYLE:The developers of a new drug claim it can protect humans against the lethal effects of nuclear radiation, reports DEREK SCALLYin Berlin
SOMEONE TELL Joe Jacob we won’t be needing the iodine tablets after all.
Seven years ago, in a legendary radio appearance, the former junior minister entertained the nation with details of Ireland’s shaky strategy to deal with the consequences of nuclear war.
His infamous iodine tablets, which many Irish households never received, may now be redundant thanks to CBLB502, a new drug its developers say protects humans against the lethal effects of nuclear radiation.
Military analysts are calling it the best medical answer yet to the growing threat of localised, mobile nuclear threats such as so-called “dirty” bombs.
With one injection, even after a nuclear attack, creators of the new drug say it could protect people from the worst side effects of ionising radiation.
The drug has an important medical application, too. Preliminary tests show that it may help cancer patients by allowing them to be treated with higher doses of radiation to fight the disease.
With two such exciting uses, the arrival of the drug is already highly anticipated in the defence and medical worlds and is projected to achieve its final licence in the next two to three years.
The breakthrough is the work of Prof Andrei Gudkov, chief scientific officer of Cleveland BioLabs, a Nasdaq-quoted pharmaceuticals company based in Buffalo, New York.
What makes the drug so clever is how, in its basic function, it employs the same tricks that cancer cells use to survive in the body, despite their pathological mutations.
CBLB502 is a synthesised, modified version of the flagellin protein produced by bacteria naturally residing in the human digestive tract.
When injected, the synthesised protein binds to cell receptors which activate the immune system and trigger a “cell suicide mechanism” known as apoptosis – the major cause of cell death after irradiation.
“Radiation sickness predominantly develops because too many cells commit suicide, leading to massive cell loss in the immune system and the digestive tract,” says Prof Gudkov.
By halting this process, the drug gives the cells a chance to start a repair procedure, and the body a better chance of survival.
The first test, using the bacteria flagellin, exposed two groups of lab mice to normally lethal radiation. The control group died shortly afterwards, the treated group survived.
A second round of tests followed, with rhesus monkeys exposed to the radiation equivalent of the highest doses sustained by firefighters at the Chernobyl nuclear plant in 1986.
Without little or no protection, the Ukrainian firefighters were exposed to devastating ionising radiation that caused 32 fatalities.
To date, the only, albeit limited, medical answer to radiation sickness has been iodine tablets, which prevent radioactive iodine from accumulating in the thyroid gland.
CBLB502 could change all that. Of the monkeys in the untreated control group, 70 per cent died, while survivors suffered typical side effects of nuclear sickness.
Almost all of the monkeys treated with CBLB502 survived, mostly without side effects – a hopeful sign for its final use on humans on whom preliminary testing has already begun.
Thanks to a foreshortened regime for certain bio-defence drugs in the US, testing for military use is expected to be completed by late 2010 and Prof Gudkov is hopeful that a licence from the Federal Food and Drug Administration (FDA) will follow.
The research project has received $40 million (€28 million)in developmental funding from the US department of defence and department of health.
What has the military so excited about the drug is the fact that it may be effective even when injected after exposure to radiation.
A round of lab tests revealed that monkeys given the injection after exposure to Chernobyl-level rates of radiation achieved similar survival rates to those treated before exposure.
Animals injected even 48 hours later had an 80 per cent survival rate. Some 40 days after, the majority of survivors displayed no signs of radiation damage.
Administered up to two days after exposure to radiation, it’s too late to avert apoptosis; instead the drug induces regeneration of damaged cells.
This important detail could potentially allow governments to stockpile the drug for use in nuclear emergencies – it is projected to remain stable and active for at least two years – in a spending spree that could generate more than $500 million (€350 million) for Cleveland BioLabs in worldwide sales.
Prof Gudkov is anxious to point out that the drug is not 100 per cent effective against all radiation exposure – anyone at the epicentre of a nuclear blast still has no chance of survival.
He warns against seeing the drug as some kind of “magic shield” that somehow eliminates the concept of a nuclear deterrent.
“With this development, we can expect the mortality rate statistics to be significantly less, but we’re still talking about probability, not complete protection,” he says. “My hope is that it will never be used in reality for this application.”
For him, the real promise of the drug lies in hospitals. Extra research teams have been employed to examine its possible application in bone marrow transplant or in the post-chemotherapy recovery phase.
Currently, though, the most exciting treatment for CBLB502 is in reducing the side effects of radiotherapy to allow a more effective treatment of cancer. In traditional radiotherapy, the treatment itself can have side effects on the patient so severe as to force the therapy to be abandoned.
Tests with CBLB502 in animal models of radiotherapy of head and neck cancer show that the drug protects healthy cells by blocking the receptor that, after being blasted with therapeutic radiation doses, would normally cause adverse effects.
The cancerous tumours have no protection from the full dose of radiation. In their transformation to a malignant state, they have acquired their own resistance to apoptosis and are thus untouched by the drug.
Prof Gudkov is hopeful this will open the door to use of stronger doses of radiation and more effective cancer therapy.
“We’re using the inventiveness of the cancer cells against them,” he said. “Lack of protection for tumour cells is the key for the safe medical application of the drug.”