This is a randomized, open-label, 2-sequence, 2-period crossover study that will be conducted at a single site in the United States to characterize the PK profile, safety and tolerability of peginterferon beta-1a delivered by autoinjector or PFS. Participants will be randomized in a 1:1 ratio to receive a single dose of peginterferon beta-1a at Day 1 delivered by either autoinjector or PFS, followed by a single dose of peginterferon beta 1a delivered by the other device at Day 22. The total duration of study participation is up to 3 months for each participant. Participants will complete a follow-up visit at Day 50 after the end of treatment period.
