An Open-label, Randomized, Parallel-group, Noninferiority Study to Evaluate the Pharmacokinetics of Bimekizumab Administered Intravenously or as a Subcutaneous Injection in Participants With Active Psoriatic Arthritis and/or Active Axial Spondyloarthritis

Inclusion Criteria: 1. Be 18+ years old and legally able to consent 2. Have active psoriatic arthritis (PsA) or axial spondyloarthritis (axSpA), suitable for bimekizumab treatment 3. Weigh between 45-100 kg (females) or 50-100 kg (males). 4. Be biologic disease-modifying anti-rheumatic drug (bDMARD)-naïve or have stopped bDMARDs ≥3 months or 5 half-lives ago Exclusion Criteria: 1. Serious organ system disorders (e.g., heart, liver, kidney, gastrointestinal, neuro) 2. Severe psychiatric issues or substance abuse in the past year 3. Recent or chronic infections, including tuberculosis (TB) or…