Accessorized Pre-Filled Syringe to Autoinjector Pharmacokinetic Bridging Study in Anifrolumab

This will be a multicenter, randomized, open-label, parallel group Phase 1 study. After meeting the eligibility criteria, all eligible participants will be randomized 1:1:1:1:1:1 to a device group (APFS or AI) for an anatomical injection site as defined in the protocol. Randomization will be stratified by protocol defined body weight categories and clinical unit. The study will comprise: * A Screening Period up to 28 days. * One treatment period during which eligible participants will be admitted to the Clinical Unit on Day -1 to reassess their eligibility. Participants who meet eligibility criteria will be randomized to receive a single subcutaneous (SC) dose of anifrolumab by either APFS or AI device on Day 1. Participants will be discharged on Day 3. * The participants will return to the center for Follow-up Visits on Days 6, 8, 12, 15, 22, 29, and 43. * A final Follow-up Visit on Day 57.