 By blocking the isomerisation of retinol, emixustat hydrochloride may decrease the oxygen demand of the retina and therefore liberate large amounts of oxygen for other processes.In a completed Phase 1a study, the drug was "well tolerated" by male and female human participants, and demonstrated dose-dependent modulation of electroretinogram (ERG) signals.A Phase II study, completed in 2015, produced a dose dependent, reversible effect on rod function consistent with emixustat's planned mechanism of action.