This is a single-center, non-randomized, open-label Phase 1 study to determine the absorption, metabolism, and excretion (AME) of BIIB122 (DNL151) following administration of a single oral dose of [14C] BIIB122 ([14C] DNL151) following a fast. The mass balance, excretion, and PK of BIIB122 (DNL151) will be used to evaluate AME.

This clinical trial information was submitted voluntarily under the applicable law and, therefore, certain submission deadlines may not apply. (That is, clinical trial information for this applicable clinical trial was submitted under section 402(j)(4)(A) of the Public Health Service Act and 42 CFR 11.60 and is not subject to the deadlines established by sections 402(j)(2) and (3) of the Public Health Service Act or 42 CFR 11.24 and 11.44.).

key Inclusion Criteria:

• For men who choose to have sex with women, either: vasectomy, use of condoms, or sex with a woman who is of non-childbearing potential
• Body mass index ≥18.0 kg/m2 and ≤32.0 kg/m2
• Body weight ≥5.0 kg and ≤100.0 kg
• Considered to be in good health
• Non-smoker

Key Exclusion Criteria:

• History or presence of any condition or prior surgery that, in the opinion of the investigator, poses a significant risk to subject safety and/or achievement of study objectives