A Study to Investigate ABP 654 for the Treatment of Participants With Moderate to Severe Plaque Psoriasis

This is a multicenter study and will enroll approximately 542 participants. The total duration of study participation for each participant will be 56 weeks, with up to 4 weeks for screening, and for 52 weeks after the first administration of either ABP 654 or ustekinumab. After confirmation of eligibility, all participants will be randomized in a 1:1 ratio into 2 treatment groups (Group A will receive ABP 654, and Group B will receive ustekinumab) stratified by prior biologic use for psoriasis (yes versus \[vs\] no), geographic region, and baseline body weight (BW). Based on the psoriasis area and severity index (PASI) score (to determine better improvement or partial improvement) at week 28, the participants in the study will proceed as follows: 1. Participants who do not achieve PASI 50 response or better improvement at Week 28 will be considered to have completed the study and will complete end of study procedures (ie, week 52 procedures), and those unable to complete week 28 visit, or did not have a PASI assessment completed, will be discontinued from the study. 2. Participants who achieve PASI 75 response or better improvement will continue on the study and will be re-randomized in a blinded fashion such that participants initially randomized to Group A (ABP 654) will continue to receive ABP 654 and those in Group B (ustekinumab) will re-randomized, to either continue on ustekinumab (Treatment Group B1) or switch to ABP 654 (Treatment Group B2). 3. Participants with PASI 50 response or better but less than PASI 75 response and on the Investigator's decision, participants will continue on the originally assigned treatment with dose intensification and will not be re-randomized. However, participants that do not dose intensify will be re-randomized.