New Drug Reduces Harmful Effects of Radiation Exposure

Researchers in New York have demonstrated that an experimental drug protected monkeys and mice from the damaging effects of radiation. The drug protected the animals’ bone marrow and gastrointestinal cells from being destroyed by radiation without reducing the radiation’s ability to fight cancer, researchers reported Thursday.The finding could someday lead to better emergency treatments for radiation exposure and less toxic cancer treatments. "These tissues fail because these cells choose to commit suicide. Our idea was to block these suicidal intentions," said Andrei Gudkov of the Roswell Park Cancer Institute in Buffalo, New York. Gudkov also serves as chief scientific officer at Cleveland BioLabs Inc., the company developing the drug. He explained that radiation triggers cells to undergo a type of programmed cell death know as apoptosis, the body’s way of ridding itself of defective cells. However, tumors have figured out how to block this suicide function .

"Tumors simply throw it out by causing mutations," said Gudkov during a Reuter’s telephone interview.He and his team wanted to study this mechanism to find a way to protect cells from radiation damage. Using a salmonella protein that naturally makes cells resistant to apoptosis, they developed a compound known as CBLB502. A single dose of the compound given to the animals prior to radiation therapy significantly reduced damage to bone marrow and gastrointestinal cells, and prolonged their survival. The drug also improved survival of mice when given an hour after the radiation therapy."We can temporarily and reversibly convert normal cells into something which is resistant to radiation -- but only for a couple of hours," said Gudkov.

That is crucial, Gudkov explained, because otherwise the cells would develop into tumors. So far the compound has caused very few toxic side effects, Gudkov said."We are basically developing this thing for two applications. One is for general protection from emergency situations -- dirty bombs or Chernobyl-type disasters," he added."For that we would want people to have a loaded syringe with this compound for intramuscular injection.”

The other application is to provide more effective radiation therapy treatments for cancer patients, with fewer side effects.Gudkov’s company is seeking U.S. regulatory approval to begin testing the drug in healthy adults, something that could begin as early as this summer.Last week, Cleveland BioLabs was awarded a $9 million contract from the U.S. Department of Defense to develop the treatment for radiation exposure.

Source : www.redorbit.com