Development for a novel countermeasure, RadioDefender, as a radioprotector for hematopoietic acute radiation syndrome

Acute radiation syndrome (ARS) is a severe illness that occurs when a person is exposed to high levels of ionizing radiation, typically within a relatively short period. The hematopoietic system is most vulnerable for radiation exposure since mild symptoms may occur at the exposure dose of as low as 0.3 Gy, and severe ionizing radiation-induced hematopoietic failure usually results in lethal infections. So far, the United States Food and Drug Administration (US FDA) has approved four post-exposure therapeutics to treat the hematopoietic ARS. Pre-exposure prophylactic (PrEP) radiation medical countermeasures (MCMs) are designed to be administered prior to radiation exposure to prevent harmful impacts of radiation exposure, increase survival, and reduce the recovery time and cost. US military personnel may be exposed to ionizing radiation during military operations in known radiologically contaminated areas, and thus effective, safe PrEP MCMs against hematopoietic ARS are clearly urgent medical demands. Therefore, Zymeron is developing RadioDefender, a safe and easy-to-use PrEP radiation MCM based on amifostine that provides significant radioprotection on the hematopoietic system.