A Study About How Well TAK-279 Works and Its Safety in Participants With Moderate-to-severe Plaque Psoriasis During 52 Weeks of Treatment

The main aim of this study is to show how well TAK-279 reduces the skin plaques compared to placebo, in participants with moderate-to-severe plaque psoriasis. Participants will be assigned to one of the 3 study treatments (TAK-279, apremilast (an approved treatment), or a placebo). Participants will be in the study for up to 61 weeks.

The drug being tested in this study is called TAK-279. TAK-279 is being tested to treat people with moderate to severe plaque psoriasis.

The study will enroll approximately 600 patients. Participants will be randomly assigned (by chance, like flipping a coin) to one of the following treatment groups in a ratio of 3:1:1 to receive TAK-279, placebo, or apremilast which will remain undisclosed to the participant and study doctor during the study (unless there is an urgent medical need):

1. TAK-279
2. Placebo
3. Apremilast

This multi-center trial will be conducted worldwide. Participants will go through a screening process to make sure they meet the rules for taking part in the study. This will take up to 35 days. If participants meet the study rules, they will be treated for up to 52 weeks (1 year). There will be a safety follow-up visit 4 weeks after their last day of treatment.