The Minnesota based company have received approval from the US Food and Drug Administration (FDA) to begin Phase I clinical trials of Bio 300, a tyrosine kinase inhibitor that could prevent and protect against acute radiation syndrome (ARS). There are no drugs currently approved by the FDA for the prevention and treatment of the bone marrow damage seen in ARS. Bio 300 is touted as a 'next generation' oral therapy. As Ronald Zenk, CEO of Humanetics Corporation said: "Based on our preclinical work on BIO, we are confident it will be a safe and practical countermeasure for ARS." "Our research shows multiple benefits of BIO 300 over existing therapies, including enhanced safety, lower risk of side effects and the ability for large populations to stockpile the agent and self-administer in the event of an accidental or terrorist nuclear incident." This is especially important because medical infrastructure often can't be relied on in the wake of such a tragedy. It is estimated that the detonation of a nuclear bomb in a densely populated area could kill 50,000 people instantly with 200,000 more dying from the effects of the fallout. ARS is categorised by damage to the bone marrow, which causes lower production of key elements of the blood such as platelets, used in blood clotting, infection-fighting white blood cells and oxygen carrying red blood cells. Bio 300 could help reduce these effects through stimulating cell growth and differentiation and preventing radiation-induced cell death, which is triggered by tyrosine kinase. The drug also has potentially significant antioxidant effects that could prevent the cell damage caused by oxidative free radicals during and after exposure to ionising radiation. Humanetics has received over $3m (€2.3m) in federal grants for their drug development programme for ARS as part of a US government project. Project BioShield has set aside $5.6bn to improve medical protection against a biological, chemical, radiological or nuclear attack. Another candidate for stockpiling under the same project is Neumune (HE2100). Developed by Hollis-Eden Pharmaceuticals and currently in Phase I/II clinical trials, the drug could ameliorate the effects of ARS through stimulation of the immune system. RX100 is developed by RxBio and has been shown, in animal studies, to protect against lethal, whole-body radiation even when administered up to several hours after exposure. Humanetics obtained the licence to develop and commercialise BIO 300 from the Henry M. Jackson Foundation for the Advancement of Military Medicine (HJF) and the Armed Forces Radiobiology Research Institute (AFRRI), which is part of the US Department of Defence (DOD). It was this latter group which discovered Bio 300. In preclinical studies in mice subjected to radiation, survival rates increased from six to 81 per cent with Bio 300 compared with placebo.