Multizentrische, randomisierte, doppelblinde, placebokontrollierte Induktionsstudie zur Beurteilung der Wirksamkeit und Sicherheit von Upadacitinib (ABT-494) bei Patienten mit mittelschwerem bis schwerem aktivem Morbus Crohn, die auf konventionelle Therapien nur unzureichend angesprochen oder diese nicht vertragen haben und, falls erhalten, auf eine Biologikatherapie angesprochen haben

Drug: Upadacitinib;Drug: Placebo for Upadacitinib

Inclusion Criteria:

- Confirmed diagnosis of CD for at least 3 months prior to Baseline.

- Confirmed diagnosis of moderate to severe CD as assessed by stool frequency (SF),
abdominal pain (AP) score.

- Evidence of mucosal inflammation based on the Simplified Endoscopic Score for Crohn's
disease (SES-CD) on an endoscopy confirmed by a central reader.

- Demonstrated an inadequate response or intolerance to one or more conventional and/or
biologic therapies (Oral locally acting steroids, Intravenous or oral corticosteroids,
Immunosuppressants), in the opinion of the investigator.

Note: Participants who have had inadequate response or intolerance to conventional therapy
who have received prior biologic may be enrolled; however, participants must have
discontinued the biologic for reasons other than inadequate response or intolerance (e.g.,
change of insurance, well controlled disease).

- If female, participant must meet the contraception recommendations.

Exclusion Criteria:

- Participant with a current diagnosis of ulcerative colitis or indeterminate colitis.

- Participant not on stable doses of CD related antibiotics, oral aminosalicylates,
corticosteroids or methotrexate (MTX).

- Participant with the following ongoing known complications of CD: abscess (abdominal
or peri-anal), symptomatic bowel strictures, fulminant colitis, toxic megacolon, or
any other manifestation that might require surgery while enrolled in the study.

- Participant with ostomy or ileoanal pouch.

- Participant diagnosed with conditions that could interfere with drug absorption
including but not limited to short gut or short bowel syndrome.

- Screening laboratory and other analyses show abnormal results.