Inclusion Criteria:

• A history of Crohn's disease or fistulizing Crohn's disease of at least 3 months' duration, with colitis, ileitis, or ileocolitis, confirmed at any time in the past by radiography, histology, and/or endoscopy.
• Currently receiving subcutaneous 90 mg every 8 weeks (q8w) ustekinumab maintenance therapy and initially responded to ustekinumab induction therapy, administered according to the local label, followed by secondary loss of response (LoR) to ustekinumab. Secondary LoR to ustekinumab is defined as active disease at study baseline, proven by a Crohn's Disease Activity Index (CDAI) score of greater than or equal to (≥) 220 and ≤ 450 with at least one of the following: Elevated C-reactive protein (CRP) (> 3.0 milligram per liter [mg/L]); and/or
• Elevated Fecal calprotectin (FeCa) >250 milligram per kilogram [mg/kg]); and/or endoscopy (performed less than or equal to (≤) 3 months before baseline) with evidence of active Crohn's disease, (defined as one or more ulcerations in the ileum and/or colon).
• Participants receiving either oral 5-aminosalicylic acid (5-ASA) compounds, oral corticosteroids (e.g., prednisone, budesonide) at a prednisone-equivalent dose of ≤ 40 mg/day or ≤ 9 mg/day of budesonide, antibiotics used as the primary treatment of Crohn's disease, or conventional immunomodulators (i.e., azathioprine [AZA], 6-mercaptopurine [6-MP], or methotrexate [MTX]) are permitted providing the doses indicated are stable before baseline or have been discontinued before baseline within the protocol defined durations

Exclusion Criteria:

• Complications of Crohn's disease, such as symptomatic strictures or stenoses, short gut syndrome, or any other manifestation that might be anticipated to require surgery, could preclude the use of the CDAI to assess response to therapy, or would possibly confound the ability to assess the effect of treatment with ustekinumab.
• Currently has or is suspected of having an abscess. Recent cutaneous and perianal abscesses are not exclusionary if drained and adequately treated at least 3 weeks before baseline (or 8 weeks before baseline for intra-abdominal abscesses) provided there is no anticipated need for any further surgery. Participants with active fistulas may be included if there is no anticipation of a need for surgery and there are currently no abscesses identified.
• Any kind of bowel resection within 6 months or any other intra-abdominal surgery within 3 months before baseline.
• A draining (i.e., functioning) stoma or ostomy.
• Received any off-label use of ustekinumab, including additional intravenous (IV) re-induction or shortened frequency of subcutaneous dose administration after the initial weight-tiered based IV induction dose of ustekinumab.