The primary objective of this study is to evaluate the effect of BIIB091 and its metabolite M23 following multiple therapeutic and supratherapeutic doses of BIIB091 on QTc intervals in healthy participants. The secondary objectives of this study are: to evaluate the effect of BIIB091 and its metabolite M23 following multiple therapeutic and supratherapeutic doses of BIIB091 on other electrocardiogram (ECG) parameters (heart rate \[HR\], pulse rate \[PR\] and QRS intervals, and ECG morphology); to demonstrate assay sensitivity of the study to detect a QTc effect using moxifloxacin as a positive control; to assess the pharmacokinetics (PK) of BIIB091 and its metabolite M23, following multiple oral dose administrations in healthy participants; to evaluate the safety and tolerability of BIIB091 in healthy participants.
