When KI isn't enough, biotechs race to develop acute radiation drugs

Potassium iodide offers little protection against acute radiation syndrome. Having already tested in people, small biotechs hope to have their ARS therapies on the market soon.
Written by Janet Fang, Contributor on

Since the nuclear crisis at the Fukushima Daiichi power station, people around the world have been stockpiling potassium iodide (KI)… but those provide little protection against the harmful effects of high-dose radiation toxicity.

Luckily, experimental products that combat ‘acute radiation syndrome’ (ARS) have already been tested in people and could be on the cusp of market approval, Nature Medicine reports.

Nearly a quarter-million KI doses (pictured) have been amassed by evacuation centers near the site. But while those guard against the long-term risks of thyroid cancer linked with chronic radiation exposure, they do little for plant workers and emergency personnel in the event of a meltdown.

There is currently no approved treatment for ARS, the extreme radiation sickness associated with exposure to high doses of ionizing radiation over a short period of time. (Chernobyl caused 134 confirmed cases of ARS, almost one-third of the reported incidences worldwide.)

If any workers at Fukushima are diagnosed with ARS, their treatment options are limited to antibiotics, blood transfusions, and fluid supplements to deal with the symptoms of the disease. Doctors also sometimes administer cancer drugs to help the immune system rebound.

Now, however, several small biotech companies are racing to develop the first approved therapy for ARS, using biologics and small molecules to halt radiation’s harmful effects in the field. Some block cell death and protect damaged tissue exposed to radiation; others replace cells lost to exposure.

  1. CBLB502, developed by Cleveland BioLabs, binds an immune protein to activate a cell survival pathway. The company has tested the product in 150 healthy volunteers in two phase 1 safety studies and plans to submit an approval application by the end of next year.
  2. Ex-RAD from Onconova inhibits certain proteins involved in the regulation of cell death. The molecule has been safety tested in more than 50 people, with few adverse effects reported.
  3. CLT-008 from Cellerant Therapeutics replaces blood stem cells lost due to exposure. Those blood progenitor cells form mature infection-fighting and clotting blood cells when infused by intravenous drip.
  4. Prochymal from Osiris Therapeutics is a stem cell therapy derived from adult bone marrow to treat organ damage due to radiation exposure.
  5. AEOL-10150 of Aeolus Pharmaceuticals is a small molecule that reduces inflammation associated with radiation exposure.

All of these drugs are being developed under the FDA’s ‘animal rule,’ which requires extensive efficacy data in animal models, but only demands safety testing in people.

In 2004, Congress passed the Project BioShield Act, and the Pandemic and All-Hazard Preparedness Act (signed into law 2 years later) allotted billions of dollars in funding for research into medical countermeasures to be used in the case of nuclear, chemical, and biological attacks. These government awards include more than $500 million for the treatment and prevention of ARS.

Since many of these drugs have already passed human safety testing, they could be on the market before the next nuclear catastrophe strikes.

Via Nature Medicine.

Image: potassium iodide tablets / Wiki

This post was originally published on Smartplanet.com

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