A Phase 1, single-dose, placebo-controlled, double-blind for LY3154207 and placebo, open-label for assay control (modafinil), randomized, 4-period, incomplete crossover study in sleep-deprived healthy male subjects. All subjects were randomized to receive 4 out of 5 available single dose treatments (15, 30, 75 mg LY3154207, placebo or modafanil 200 mg) with all subjects receiving placebo.  The washout period was at least 7 days. MSLT was the primary assessment of wakefulness. Secondary outcomes included Karolinska Sleepines Scale (KSS), EEG and a simple reaction performance task. Blood samples were collected to measure plasma concentrations of LY3154207 and modafinil.

Seventeen subjects enrolled and received at least one dose of study drug with sixteen subjects completing all 4 periods of the trial. There was a dose dependent increase in MSLT with least square means (95% CI) difference compared to placebo of 5.2 minutes (3.3,7.1) for 75 mg, 3.2 minutes (1.4, 5.1) for 30 mg, 1.3 minutes (-0.6, 3.2) for 15 mg. These findings were supported by a dose dependent increase in alertness on the KSS. PK was linear with a Cmax and t1/2 of approximately 3 and 9 hours across the dose range.