A Study of Filgotinib in Korean Participants With Rheumatoid Arthritis

Inclusion Criteria:

1. Participants who voluntarily provided written consent to participate in this study

2. Male or female, aged greater than or equal to (>=) 19 years at the time of writteninformed consent

3. Participants diagnosed with rheumatoid arthritis according to the 2010 ACR/ EuropeanLeague Against Rheumatism (EULAR) classification criteria and who have an ACRfunctional class of I to III

4. Participants who meet the following criteria are eligible for the specifiedtreatment protocol; those who have been treated with two or more type types (including MTX) of Disease-Modifying Antirheumatic Drugs (DMARDs) for at least 6months (at least 3 months each) but have experienced insufficient therapeuticeffects or have had to discontinue treatment due to adverse events of thesemedications (However, in cases where MTX is contraindicated due to conditions suchas liver disease or renal failure, the participant must have been treated with atleast two types of DMARDs, excluding MTX).

• Furthermore, in participants over 65 years of age, those at high risk ofcardiovascular diseases, and those with a potential risk of malignancy, thisprotocol applies if they have not adequately responded to or toleratedconventional therapies, including Tumor Necrosis Factor (TNF) inhibitors orother biologic agents. Eligibility is confirmed if one of the followingcriteria is met:

1. DAS28 score exceeding 5.1.
2. DAS28 score between 3.2 and 5.1, with diagnostic imaging showingprogression of joint damage.

Exclusion Criteria:

1. Participants with hypersensitivity reactions to the active ingredient or othercomponents of the investigational product

2. Participants with serious infections (for example [e.g.], sepsis) or activeinfections including localized infections

3. Participants with active tuberculosis (TB)

4. Participants with severe hepatic impairment (e.g., Child-Pugh C)

5. Participants with end-stage renal disease (<creatinine clearance [CrCl] 15milliliters per minute [mL/min])

6. Participants with absolute neutrophil count (ANC) <1*10^9 cells per liter (/L)

7. Participants with absolute lymphocyte count (ALC) <0.5*10^9 cells/L

8. Participants with hemoglobin <8 grams per deciliter (g/dL)

9. Pregnant or lactating women

10. Women of childbearing potential who are not willing to consent to using effectivecontraception

11. Participants with rare hereditary problems of galactose intolerance, total lactasedeficiency or glucose-galactose malabsorption should not take this medicinal product

12. Participants who received Janus kinase (JAK) inhibitors for the treatment ofrheumatoid arthritis

13. Participants who have participated in other clinical studies for investigationalproduct/medical device within 4 weeks prior to screening

14. Participants in whom the administration of Jyseleca Tablet is contraindicatedaccording to the product label approved in Korea or based on certain medicalconditions that have been identified in previous clinical studies

15. Participants for whom follow-up deems impossible