A Study of the Efficacy and Safety of Risankizumab in Subjects With Crohn's Disease Who Responded to Induction Treatment in M16-006 or M15-991; or Completed M15-989

Inclusion Criteria:

- Subjects who have entered and completed Study M16-006 or Study M15-991 or Study
M15-989.

- Subjects have completed the study M16-006 or M15-991 and have achieved clinical
response.

Exclusion Criteria:

- Subject is considered by the Investigator, for any reason, to be an unsuitable
candidate for the study .

- Subject who has a known hypersensitivity to risankizumab or the excipients of any of
the study drugs or the ingredients of CHO, or had an AE during Studies M16-006,
M15-991 or M15-989 that in the Investigator's judgment makes the subject unsuitable
for this study.

- Subject is not in compliance with prior and concomitant medication requirements
throughout Studies M16-006, M15-991 or M15-989.

- Confirmed positive urine pregnancy test at the Final Visit of Study M16-006, Study
M15-991 or Study M15-989.

- Have a known history of lymphoproliferative disease, including lymphoma, or signs and
symptoms suggestive of possible lymphoproliferative disease, such as lymphadenopathy
and/or splenomegaly.