Here, we describe the markedly improved and drug‐like pharmacokinetics (PK) and pharmacodynamics (PD) of ORP100S which was found to retain the target selectivity and stress‐protective functions of natural TRX, but unlike rhTRX showed no capacity to stimulate tumor cell proliferation or chemoresistance yet was able to mitigate lethal effects of total body irradiation in rodents and primates. This evidence concerns the gene TXN and neoplasm.