Alkeus Pharma is evaluating the potential of deuterated vitamin A as the drug ALK-001. The hope is that the deuterated vitamin A will reduce the build-up of toxic vitamin A metabolites in the retina and therefore slow rate of visual deterioration. To create deuterated vitamin A some of the hydrogen atoms are replaced with the isotope deuterium which has an extra neutron and is therefore twice the standard atomic weight of hydrogen. A Phase II clinical trial is taking place using ALK-001 that should report in January 2019.