Study to Characterise Pharmacokinetics (PK), Pharmacodynamics (PD), and Safety of Anifrolumab Administered Subcutaneously (SC) or Intravenously (IV)

This is a multicentre, randomised, phase I open-label study. The study will comprise of the following: * Screening period: Up to 30 days * Two treatment periods * Part A: Randomised SC vs IV Treatment Period: 5 weeks * Part B: Optional Extended Treatment Period: Up to 47 weeks * Safety follow-up period: 12 weeks after the final dose Part A will include all participants who will be randomised into SC anifrolumab via autoinjector (AI) or IV anifrolumab. Part B is an optional extended treatment period where participants will receive SC anifrolumab via accessorised prefilled syringe (aPFS).