Rationale, Design and Methods of the Filgotinib Initial Response Study in Rheumatoid Arthritis (FIRST-RA). - Pongratz, Georg; Alten, Rieke; Witte, Torsten; Pausch, Christine; Reinhold, Robert; Pittrow, David; Burmester, Gerd R. (Rheumatology & Therapy, 2026)