A Study Evaluating the Effect of Filgotinib Dose De-escalation in Participants With Ulcerative Colitis (UC) in Remission

Key Inclusion Criteria:

• Participants must have participated in the SELECTION-LTE study (GS-US-418-3899), whowere on 200 mg filgotinib once daily and fulfilled the following conditions:

• partial Mayo Clinical Score remission over a period of at least 2 consecutivequarterly visits in the SELECTION-LTE study (GS-US-418-3899) prior to screeningof the present study;

• free of corticosteroids for at least 12 weeks prior to and including baseline;

• fecal calprotectin (FCP) ≤250 microgram per gram (μg/g) at last observationwithin 6 months prior to screening or FCP ≤250 μg/g during the screening of thepresent study.

• sigmoidoscopy ES of 0 or 1 (local score) at screening.

• Willing to refrain from live attenuated vaccines during the study and for 12 weeksafter the last dose of filgotinib in the study.

• Female participants of childbearing potential must have had a negative highlysensitive (serum beta human chorionic gonadotropin) pregnancy test during screeningand must have agreed to continued monthly urine dipstick pregnancy testing duringfilgotinib treatment.

• Female participants of childbearing potential must have agreed to use highlyeffective contraception measures as defined in the protocol.

Key Exclusion Criteria:

• Any chronic medical condition (including but not limited to, cardiac or pulmonarydisease, alcohol, or drug abuse) that, in the opinion of the investigator orsponsor, would make the participant unsuitable for the study or would preventcompliance with the study protocol.

• Participant had a known hypersensitivity to filgotinib ingredients or history of asignificant allergic reaction to filgotinib ingredients as determined by theinvestigator.

• Female participant who was pregnant or breastfeeding, or intended to become pregnantor breastfeed, and/or plans to undergo egg donation or egg harvesting for thepurpose of current or future fertilization, during the study and until the end ofthe study.

• Participant was unable or unwilling to comply with restrictions regarding prior andconcomitant medication as described in the protocol.

• Participant had a positive QuantiFERON® tuberculosis (TB) test at screening or had 2indeterminate QuantiFERON® TB test results that required Investigational product (IP) treatment interruption, or participant had sign and symptoms of TB reactivationat screening.

• History of malignancy during or in the last 5 years prior to participation in the UCparent studies, except for participants who had been successfully treated fornonmelanoma skin cancer or cervical carcinoma in situ.

• Participant met discontinuation criteria of the SELECTION-LTE study (GS-US-418-3899).

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