“…Finally, decreased pre-systemic metabolism results in higher a bioavailability of unmetabolized drug, which means a smaller dosage can achieve the same exposure. 20,21 Many studies have already reported several deuterium-labeled entities, [22][23][24][25][26][27][28] and some of these have entered clinical trials including CTP-354, 20 CTP-449, 29 SD-254, and 21 SD-809. 19 The Auspex drug, SD-809, significantly reduced the incidence of uncontrolled movements in patients with Huntington's disease compared with a placebo, according to results from a phase III study announced recently, and it is expected to seek US approval for SD-809 in the middle of this year.…”