Rationale, Design and Methods of the Filgotinib Initial Response Study in Rheumatoid Arthritis (FIRST-RA)

Area of Science:

• Rheumatology
• Pharmacology
• Clinical Trials

Background:

• Filgotinib is an oral JAK1 inhibitor for moderate-to-severe active rheumatoid arthritis (RA).
• Real-world data on early filgotinib treatment effects are limited.
• The FIRST-RA study addresses this gap under routine care.

Purpose of the Study:

• To evaluate very early treatment effects of filgotinib in RA patients.
• To assess improvements in pain, fatigue, and function within 4 weeks.
• To support personalized RA management and clarify filgotinib use.

Main Methods:

• Prospective, multicentre, non-interventional cohort study in Germany and Austria.
• Enrollment of ~300 adult RA patients newly starting filgotinib.
• Follow-up for 24 weeks with clinical assessments and patient-reported outcomes (PROs).

Main Results:

• Primary endpoint: change in RAID pain score from baseline to week 4.
• Secondary endpoints: fatigue, disease activity, morning stiffness, satisfaction, and tolerability.
• Analysis of early symptom changes and effectiveness across advanced therapy (AT) subgroups.

Conclusions:

• FIRST-RA is the first real-world study capturing very early symptomatic responses to filgotinib.
• Integrating PROs with clinical outcomes supports personalized RA management.
• The study aims to clarify filgotinib's role in current clinical practice.