Study to Evaluate the Pressor Effect of Oral Tyramine During Ozanimod Treatment in Healthy Adult Participants

This is a Phase 1, randomized, double-blind, placebo-controlled, active-controlled, comparator controlled, multi-dose, parallel-group study divided into three treatment periods and a follow-up period with five treatment groups. This study will be conducted at 1 clinical research unit (CRU) in the United States (US). Period 1 will consist of daily escalating doses of tyramine administered until tyramine pressor response (defined as the tyramine dose required to increase systolic blood pressure by at least 30 mm Hg from the daily defined baseline in 3 consecutive measurements within 4 hours after tyramine dosing) is achieved or Day 7. Participants who achieve tyramine pressor response at tyramine doses \>/= 200mg and \</= 700mg are eligible for continuation into Period 2 and will be randomized accordingly. Depending on the group to which a participant is randomized, participants will receive rasagiline, phenelzine, ozanimod (therapeutic dose), ozanimod (supra-therapeutic dose), or placebo in Period 2. The duration of dosing depends on the group to which a participant is randomized. In Period 3, all participants will undergo a sham tyramine challenge and receive a single dose of tyramine placebo. Participants who do not achieve tyramine pressor response following the sham challenge will continue with the tyramine challenge (ie, tyramine pressor tests) for up to 12 additional days. Participants who receive at least one dose of study drug in Period 2 will participate in a follow-up phase during which 2 follow-up telephone calls will be performed, the last of which will occur approximately 80 to 100 days after the last dose of study drug.