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

Participants who were in clinical remission on 200 milligram (mg) filgotinib once daily for at least 2 consecutive quarterly visits in the ongoing SELECTION-LTE study (GS-US-418-3899, NCT02914535), were planned to be rolled over and randomized in this study. The primary objective of this study was to evaluate the efficacy of filgotinib in participants in stable clinical remission on 200 mg filgotinib once daily for whom the dose was decreased to 100 mg once daily compared to participants remaining on 200 mg once daily.

Participants were planned to receive the blinded treatment until primary analysis time point. After unblinding at the study primary analysis time point, participants would have received unblinded treatment. The clinical trial was originally designed with the primary endpoint to be assessed at Week 48. Due to early termination of the study, none of the participants completed 48 weeks of treatment. All participants participated in blinded treatment period only and the study was unblinded globally after study completion.

Eligibility Criteria:
Key Inclusion Criteria:

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

  * partial Mayo Clinical Score remission over a period of at least 2 consecutive quarterly visits in the SELECTION-LTE study (GS-US-418-3899) prior to screening of 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 observation within 6 months prior to screening or FCP ≤250 μg/g during the screening of the present study.
  * sigmoidoscopy ES of 0 or 1 (local score) at screening.
* Willing to refrain from live attenuated vaccines during the study and for 12 weeks after the last dose of filgotinib in the study.
* Female participants of childbearing potential must have had a negative highly sensitive (serum beta human chorionic gonadotropin) pregnancy test during screening and must have agreed to continued monthly urine dipstick pregnancy testing during filgotinib treatment.
* Female participants of childbearing potential must have agreed to use highly effective contraception measures as defined in the protocol.

Key Exclusion Criteria:

* Any chronic medical condition (including but not limited to, cardiac or pulmonary disease, alcohol, or drug abuse) that, in the opinion of the investigator or sponsor, would make the participant unsuitable for the study or would prevent compliance with the study protocol.
* Participant had a known hypersensitivity to filgotinib ingredients or history of a significant allergic reaction to filgotinib ingredients as determined by the investigator.
* Female participant who was pregnant or breastfeeding, or intended to become pregnant or breastfeed, and/or plans to undergo egg donation or egg harvesting for the purpose of current or future fertilization, during the study and until the end of the study.
* Participant was unable or unwilling to comply with restrictions regarding prior and concomitant medication as described in the protocol.
* Participant had a positive QuantiFERON® tuberculosis (TB) test at screening or had 2 indeterminate QuantiFERON® TB test results that required Investigational product (IP) treatment interruption, or participant had sign and symptoms of TB reactivation at screening.
* History of malignancy during or in the last 5 years prior to participation in the UC parent studies, except for participants who had been successfully treated for nonmelanoma 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.