Phase 1, open-label, 2-part, single-dose pharmacokinetic and safety study of STS101 in healthy subjects. Part 1 was designed to identify a dose level of STS101 for administration in Part 2. Subjects in Part 1 received 3 ascending doses of STS101 in a 3-period crossover manner. During Part 2, subjects received the dose of STS101 selected from Part 1, 1.0 mg DHE mesylate IM injection, and 2 mg DHE mesylate nasal spray in a randomized, 3 period crossover manner.