A Defined Pathomechanism for Acute Radiation Syndrome Death and a Three Drug Regimen to Prevent It

Death from Acute Radiation Syndrome (ARS) has been a long-standing threat. The current, heightened risk of a nuclear event, e.g., a conflict bomb, terror bomb, reactor core dispersion, or recurrent exposure to medical radiation, would all benefit from a systemic treatment to reduce or eliminate ARS death. This study utilizes a step-wise progression to i) identify why lethally irradiated mice die from ARS, and ii) identify a multidrug regimen, administered before or after irradiation, that prevents or treats ARS pathologies to significantly suppress or eliminate ARS death. Lethal, blood-borne, E. coli septic infection was found in 97% of near-death, irradiated mice; this observation was consistent with the numerous breaches observed in GI histology showing broken and breached GI epithelium and GI muscularis externa. Our study found i) a new and clear explanation of why irradiated mice die from ARS, ii) identified two drugs (PrC-210, ciprofloxacin), which administered minutes pre-radiation conferred 100% survival benefit, or 56% when administered a day after irradiation, and iii) a three drug regimen (PrC-210, ciprofloxacin, GCSF) that conferred 92% survival benefit when administered 1-2 days after radiation. The drug regimens can be “field-deployed” to field staging areas as well as to home medicine chests, to enable simple, widespread use of the regimen in the face of radiation threat.