A Study of the Efficacy and Safety of Risankizumab in Participants With Crohn's Disease

Inclusion Criteria:

• Participants who have entered and completed Study M16-006 or Study M15-991 or otherAbbVie risankizumab Crohn's disease study.

• Participants have completed the study M16-006 or M15-991 and have achieved clinicalresponse.

• Sub-Study 4:

• Participants receiving maintenance treatment in Sub-study 3 and willing tocomply with the requirements of Sub-study 4, including self-administration ofsub-cutaneous injections using the on-body injector (OBI).

• Participant has received at least 16 weeks of stable dosing with risankizumabin Sub-study 3 (i.e., no rescue within 16 weeks and participant has surpassedthe 72-week mark).

Exclusion Criteria:

• Participants should not be enrolled in Study M16-000 with high grade colonicdysplasia or colon cancer identified during Study M15-991, Study M16-006 or anotherAbbVie risankizumab Crohn's disease study if the final endoscopy was performed priorto enter Study M16-000 OR is considered by the Investigator, for any reason, to bean unsuitable candidate for the study.

• Participant who has a known hypersensitivity to risankizumab or the excipients ofany of the study drugs or the ingredients of Chinese hamster ovary (CHO), OR had anadverse event (AE) during Studies M16-006, M15-991 or another AbbVie risankizumabCrohn's disease study that in the Investigator's judgment makes the participantunsuitable for this study.

• Participant is not in compliance with prior and concomitant medication requirementsthroughout Studies M16-006, M15-991 or another AbbVie risankizumab Crohn's diseasestudy.

• Confirmed positive urine pregnancy test at the Final Visit of Study M16-006, StudyM15-991 or another AbbVie risankizumab Crohn's disease study.

• Have a known history of lymphoproliferative disease, including lymphoma, or signsand symptoms suggestive of possible lymphoproliferative disease, such aslymphadenopathy and/or splenomegaly.

• Any active or chronic recurring infections based on the Investigator's assessmentmakes the participant an unsuitable candidate for the study.