Use of an adaptive study design in single ascending-dose pharmacokinetics of A0001 (α-tocopherylquinone) in healthy male subjects.

A0001 (α-tocopherylquinone) is a potent antioxidant currently in development for the treatment of symptoms associated with inherited mitochondrial disorders. A0001 pharmacokinetics were studied in a single-blind, adaptive design study following a single daily oral dose of placebo (n = 2) or ascending doses of A0001 (n = 8) at 0.25 and 0.5 g under a fasted state or a 0.5- to 6-g dose with a high-fat meal. Dose escalation was based on safety assessment, and proceeding dose levels were selected based on interim pharmacokinetic analyses. A0001 plasma concentration-time profiles were similar across doses, reaching peak concentration within 4 to 6 hours, with concentrations returning to baseline within 24 hours. Exposure was highly dependent on food and dosing frequency. Exposure was nearly 60-fold higher with food but increased subproportionally above 1-g dose; however, the nonproportionality was offset by administering A0001 in divided doses (0.735 g, 3 times per day). The potential for an A0001:vitamin E interaction was also explored, as vitamin E use is prevalent in this patient population, and suggested that a clinically significant pharmacokinetic interaction is not likely. A0001 was well tolerated with no serious adverse events or dose-limiting toxicities. These findings suggest that A0001 has a favorable pharmacokinetic profile when administered orally with food.