Th purpose of the study is to evaluate the dose response of WD-890 in efficacy at Week 16 in participants with moderate-to-severe plaque psoriasis.

The total duration of this study is up to 24 weeks which includes a screening period of less than or equal to (<=) 4 weeks, a 16-week treatment period, and a 4-week safety follow-up period. Aged 18 to 70 years (inclusive) were enrolled in this study. Participants were randomized to receive WD-890 or placebo.

Inclusion Criteria:

• Male or female participant aged 18 to 70 years(inclusive)at the time of informed consent.

• Diagnosis of plaque psoriasis for at least 6 months prior to the screening visit.

  ≥10% of BSA involvement at screening visit and randomization;

• Psoriasis Area and Severity Index (PASI) score ≥12 and static Physician's Global Assessment (sPGA) ≥3 at screening visit and randomization

Exclusion Criteria:

• Participant has a nonplaque form of psoriasis (for example, erythrodermic, guttate, inverse, pustular,or drug induced psoriasis.)
• Has uncontrolled arterial hypertension characterized by a systolic blood pressure (BP) ≥160 mm Hg or diastolic BP ≥100 mm Hg Note: Determined by 2 consecutive elevated readings. If an initial BP reading exceeds this limit, the BP may be repeated once after the subject has rested sitting for ≥10 minutes. If the repeat value is less than the criterion limits, the second value may be accepted
• Class III or IV congestive heart failure by New York Heart Association Criteria
• Participant with a history of chronic bacterial infections (e.g., chronic pyelonephritis, chronic bronchiectasis, or chronic osteomyelitis).