Development of a novel progesterone analog in the treatment of traumatic brain injury. 
Although systemic progesterone (PROG) treatment has been shown to be neuroprotective by many laboratories and in multiple animal models of brain injury including traumatic brain injury (TBI), PROG's poor aqueous solubility limits its potential for use as a therapeutic agent.  The problem of solubility presents challenges for an acute intervention for neural injury, when getting a neuroprotectant to the brain quickly is crucial.  Native PROG (nPROG) is hydrophobic and does not readily dissolve in an aqueous-based medium, so this makes it harder to give under emergency field conditions.  An agent with properties similar to those of PROG but easier to store, transport, formulate, and administer early in emergency trauma situations could lead to better and more consistent clinical outcomes following TBI.  At the same time, the engineering of a new molecule designed to treat a complex systemic injury must anticipate a range of translational issues including solubility and bioavailability.  Here we describe the development of EIDD-1723, a novel, highly stable PROG analog with >104-fold higher aqueous solubility than that of nPROG.  We think that, with further testing, EIDD-1723 could become an attractive candidate use as a field-ready treatment for TBI patients.  This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".