A Phase 2, Double-Blinded, Randomized, Placebo-Controlled, Dose-Ranging Study Evaluating the Efficacy and Safety of GS-5290 in Participants With Moderately to Severely Active Ulcerative Colitis

Inclusion criteria:

• Adults 18 to 75 years of age assigned male at birth, or nonpregnant, nonlactating patients assigned female at birth.
• Patients must have a confirmed Ulcerative Colitis (UC) diagnosis at least 90 days prior to enrolling in the study.
• Patients also must have UC with minimum disease extent of 15 cm from the anal verge.
• Patients have moderately to severely active UC as determined during the screening visit and based on the studies scoring criteria.
• Patients have prior treatment with at least one approved advanced therapy for ulcerative colitis (UC), but the patient must have experienced failure (such as no response or losing response) to no more than three different types of advanced therapies. A surveillance colonoscopy for dysplasia is required prior to enrollment if indicated by regional guidelines for patients with UC.

Exclusion criteria:

• Have a current diagnosis of Crohn's Disease (CD) or a type of colitis that could not be clearly identified, such as one caused by an infection, or specific forms like lymphocytic or collagenous colitis
• Patients with disease limited to the rectum (ulcerative proctitis) during screening endoscopy.
• Have a requirement for ongoing therapy with or prior use of any prohibited medications.
• Have an active clinically significant infection, or any infection requiring hospitalization or treatment with intravenous anti-infectives within 8 weeks of enrollment; or any infection requiring oral anti-infective therapy within 6 weeks of randomization.
• Have a history of opportunistic infection.
• Have a current diagnosis of acute severe colitis, fulminant colitis, or toxic megacolon.

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