A Study to Evaluate the Relative Bioavailability of Two Formulations of BIIB104 and Assess the Effect of Food on the Pharmacokinetics of BIIB104 Following Administration of a Single, Fixed, Oral Dose of BIIB104 in Healthy Participants

A Phase 1, Randomized, Open-Label, Parallel-Arm Study to Evaluate the Relative Bioavailability of Two Formulations of BIIB104 and Assess the Effect of Food on the Pharmacokinetics of BIIB104 Following Administration of a Single, Fixed, Oral Dose of BIIB104 in Healthy Participants

The primary objectives of this study are to evaluate the relative bioavailability of the BIIB104 test formulation compared with the reference formulation in healthy Caucasian male adult participants in the fasted state and to assess the impact of food on BIIB104 pharmacokinetic (PK) parameters for the test formulation in healthy Caucasian male adult participants.

The secondary objective of the study is to assess the safety and tolerability of BIIB104 0.5 milligrams (mg) test formulation in the fasted and fed states following single-dose administration.

Key Inclusion Criteria:

• Has a body mass index (BMI) between 18 and 30 kilogram per square meter (kg/m^2), inclusive and a total body weight >50 kilograms [110 pound (lb)].

Key Exclusion Criteria:

• Participates in other studies involving treatment with an investigational drug within 30 days or 5 half-lives (whichever is longer) prior to randomization and/or during study participation.
• Previously participated in this study or previous studies with BIIB104.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.