The Induction and Long-Term Extension Periods were completed and analyzed as planned. The Sponsor decided to terminate clinical conduct in the Open-Label Extension Period. The decision to terminate the study was not due to safety concerns.

This is a study to understand if taking VTX002 daily as a tablet orally is safe and effective in participants diagnosed with moderate to severe ulcerative colitis (UC). Approximately 189 participants will take VTX002 Dose A, VTX002 Dose B, or matching placebo, once daily.

The study consists of a 28-day Screening Period (to see if a participant qualifies for the study), a 13-week double-blind period (a participant receives either active Dose A, Dose B or Placebo), a Long-Term Extension (LTE) Treatment Period of up to 39 weeks, an Open-Label Extension (OLE) Treatment Period of up to 143 weeks, and a 2-week Follow-Up Period. The maximal duration of treatment including the Induction Period, LTE and OLE will be 36 months.

This is a multicenter, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of VTX002 in subjects with moderately to severely active UC following daily oral administration of VTX002 as a tablet. Approximately 189 eligible subjects will be randomized in a 1:1:1 ratio to receive VTX002 Dose A, VTX002 Dose B, or matching placebo, once daily (approximately 63 subjects per treatment group).

The study consists of a 28-day Screening Period, a 13-week double-blind Induction Treatment Period (including 7 days of titration followed by 12 weeks of treatment at the assigned dose), a Long-Term Extension (LTE) Treatment Period of up to 39 weeks, an Open-Label Extension (OLE) Treatment Period of up to 143 weeks, and a 2-week Follow-Up Period. The maximal duration of treatment including the Induction Period, LTE and OLE will be 36 months.

Objectives Primary Objective

• Assess the efficacy of VTX002 when administered for 13 weeks on clinical remission

Secondary Objectives

• Assess the efficacy of VTX002 when administered for 13 weeks on endoscopic changes, symptomatic response and remission, histology, and mucosal healing
• Assess the safety and tolerability of VTX002
• Assess the pharmacokinetics (PK) of VTX002

Long-Term and Open-Label Extension Objectives

• Assess the efficacy of VTX002 through the LTE and OLE Treatment Periods on endoscopic changes, symptomatic response and remission, histology, and mucosal healing
• Assess the safety of VTX002 through the LTE and OLE Treatment Periods

Inclusion Criteria:

• Diagnosed with UC ≥ 3 months prior to Screening.
• Active UC confirmed by endoscopy

Exclusion Criteria:

• Severe extensive colitis
• Diagnosis of Crohn's disease (CD) or indeterminate colitis or the presence or history of a fistula consistent with CD
• Diagnosis of microscopic colitis, ischemic colitis, or infectious colitis

The study will employ a double-blind design. Subjects, Investigators, study center staff, persons performing the assessments, central endoscopy readers and the Sponsor are to remain blinded to the identity of the Induction Period treatment from the time of randomization until the interim database lock for the study.