Multizentrische, randomisierte, doppelblinde, placebokontrollierte Studie zur Beurteilung der Sicherheit und Wirksamkeit von ABT 494 als Induktions- und Erhaltungstherapie bei Teilnehmern mit mittelschwerer bis schwerer aktiver Colitis ulcerosa

Drug: Placebo;Drug: Updacitinib (ABT-494)

Inclusion Criteria:

Note: Adolescent participants at the age of 16 or 17 years old will be eligible to
participate if approved by the country or regulatory/health authority. If approval has not
been granted, only participants >= 18 years old will be enrolled.

Adolescents must weigh >= 40 kilograms and meet the definition of Tanner Stage 5 at
Screening Visit.

- Diagnosis of ulcerative colitis for 90 days or greater prior to Baseline, confirmed by
colonoscopy during the Screening Period, with exclusion of current infection, colonic
dysplasia and/or malignancy. Appropriate documentation of biopsy results consistent
with the diagnosis of UC, in the assessment of the Investigator, must be available.

- Active ulcerative colitis with an Adapted Mayo score of 5 to 9 points and endoscopic
sub score of 2 to 3 (confirmed by central reader).

- Demonstrated an inadequate response to, loss of response to, or intolerance to at
least one of the following treatments including: oral aminosalicylates,
corticosteroids, immunosuppressants, and/or biologic therapies in the opinion of the
investigator.

Note: Participants who have had inadequate response, loss of response to conventional
therapy, but have not failed biologic therapy (Non-bio-IR) and have received a prior
biologic for up to 1 year may be enrolled, however they must have discontinued the biologic
for reasons other than inadequate response or intolerance (e.g., change of insurance, well
controlled disease) and must meet criteria for inadequate response, loss of response or
intolerance to aminosalicylates, corticosteroids, and/or immunosuppressants as defined
above.

- If female, participant must meet the criteria for Contraception Recommendations.

- Female participants of childbearing potential must have a negative serum pregnancy
test at the Screening Visit and a negative urine pregnancy test at the Baseline Visit
prior to study drug dosing.

Exclusion Criteria:

- Participant with current diagnosis of Crohn's disease (CD) or diagnosis of
indeterminate colitis (IC).

- Current diagnosis of fulminant colitis and/or toxic megacolon.

- Participant with disease limited to the rectum (ulcerative proctitis) during the
Screening endoscopy.

- Received cyclosporine, tacrolimus, mycophenolate mofetil, or thalidomide within 30
days prior to Baseline.

- Participant on azathioprine or 6-mercaptopurine within 10 days of baseline.

- Received intravenous corticosteroids within 14 days prior to Screening or during the
Screening Period.

- Participant with previous exposure to Janus Activated Kinase (JAK) inhibitor (e.g.,
tofacitinib, baricitinib, filgotinib, upadacitinib).

- Screening laboratory and other analyses show any abnormal results.