Janssen Research & Development, LLC
The purpose of this study is to assess how well JNJ-78934804 works (efficacy) and how safe it is (safety) as compared to guselkumab at Week 48 in participants with moderately to severely active Crohn's disease (a long-term, progressive \[worsens with time\] and life-threatening disease of the intestine).
Inclusion criteria: * Have a diagnosis of Crohn's disease (CD) or fistulizing CD established greater than or equal to (\>=) 12 weeks before screening including both endoscopic evidence and a histopathology report consistent with a diagnosis of CD * Have moderately to severely active CD based on crohn's disease activity index (CDAI) criteria defined as a baseline CDAI score \>= 220 but less than or equal to (\<=) 450 and either: a. Mean daily stool frequency (SF) count \>= 4.0, based on the unweighted CDAI component of the number of liquid or very soft stools or b. Mean daily AP score \>= 2.0,…
JNJ-78934804 will be administered subcutaneously.
Guselkumab will be administered subcutaneously.