The maximum tolerated dose has not been established in humans. Toxicology studies have been performed in monkeys at doses up to 30 times the human dose with no evidence of dose-limiting toxicities. No dose-limiting toxicities have been observed during clinical trials of Etarfion. Single intravenous doses up to 60 mg/m2 (approximately twice the recommended dose) have been administered to healthy volunteers in an endotoxaemia study without evidence of dose-limiting toxicities.