Long-term Follow-up Study of GLPG0634 in Active Rheumatoid Arthritis Participants

Key Inclusion Criteria:

• Participants who completed one of the qualifying core studies GLPG0634-CL-203 orGLPG0634-CL-204 and may benefit from filgotinib long-term treatment according to theInvestigator's judgment

• Females of childbearing potential and sexually active men must agree to use highlyeffective method of birth control as specified in the protocol, during the study andfor at least 12 weeks after the last dose of filgotinib

Key Exclusion Criteria:

• Participants who prematurely withdrew from one of the 2 core studies (GLPG0634-CL-203 or GLPG0634-CL-204), for any reason

• Persistent abnormal lab values during one of the 2 core studies (GLPG0634-CL-203 orGLPG0634-CL-204), according to the Investigator's judgment

• Diagnosis of rheumatic autoimmune disease or inflammatory joint disease other thanrheumatoid arthritis, except for secondary Sjogren's syndrome

• Any condition or circumstances which, in the opinion of the Investigator, may make aparticipant unlikely or unable to complete the study or comply with study proceduresand requirements

Note: Other protocol defined Inclusion/Exclusion criteria may apply.