The primary objective of this study is to evaluate the testicular safety of filgotinib in adult males with moderately to severely active inflammatory bowel disease. Results of this study may be pooled with the results of a separate study being conducted in participants with rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or non-radiographic axial spondyloarthritis (Protocol GLPG0634-CL-227; NCT03926195) with the same objective. The total planned number of participants in both studies combined will be up to approximately 250 participants.



Eligible Ages
Between 21 Years and 65 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Male participants who are between the ages of 21 and 65 (inclusive) on the day of signing informed consent
  • Documented diagnosis of ulcerative colitis (UC) or Crohn's Disease (CD) of at least 4 months. Endoscopic and histopathologic documentation of UC or CD.
  • Have moderately to severely active UC or CD

Exclusion Criteria

  • Previously or currently documented problems with male reproductive health
  • Current use of sulfasalazine or its use within the 26 weeks leading up to Screening; sulfasalazine is not permitted at any point during the study
  • Current use of corticosteroids at a dosage of > 20 mg/day of prednisone or equivalent at randomization
  • Indeterminate colitis, ischemic colitis, fulminant colitis, isolated ulcerative proctitis, or toxic mega colon
  • Active tuberculosis (TB) or untreated latent tuberculosis
  • Use of concomitant prohibited medications as outlined by protocol

Note: Other protocol defined Inclusion/Exclusion criteria may apply

Study Design

Phase 2
Study Type
Intervention Model
Parallel Assignment
Primary Purpose
Double (Participant, Investigator)

Arm Groups

ArmDescriptionAssigned Intervention
Part A and Part B (Filgotinib or Placebo)
Participants will receive double-blind filgotinib or placebo for 13 weeks in Part A. Based on inflammatory bowel disease response status and sperm parameters, participants will continue on the blinded treatment for up to an additional 13 weeks in Part B or discontinue blinded study drug and commence open-label filgotinib.
  • Drug: Filgotinib
    200 mg tablet administered orally once daily
  • Drug: Placebo
    Tablet administered orally once daily
Open-Label Filgotinib Phase
Participants will receive open-label filgotinib for up to 13 weeks.
  • Drug: Filgotinib
    200 mg tablet administered orally once daily
Monitoring Phase
Participants whose sperm parameters meet a pre- specified decrease threshold at any time during the study, regardless of inflammatory bowel disease response status, will discontinue study drug and receive standard of care therapy in the Monitoring Phase.
  • Drug: Standard of Care
    Standard of care therapy
Long Term Extension Phase
Participants qualifying to enter the Long Term Extension Phase will receive either open-label filgotinib or blinded study drug for up to 195 weeks based on the individual's response criteria.
  • Drug: Filgotinib
    200 mg tablet administered orally once daily
  • Drug: Placebo
    Tablet administered orally once daily

Recruiting Locations

University of Texas Health Science Center at Houston
Houston, Texas 77030

More Details

Gilead Sciences

Study Contact

Gilead Clinical Study Information Center
1-833-445-3230 (GILEAD-0)


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.