This Study is Being Conducted to Evaluate the Safety, Tolerability, and Efficacy of KD025 Administered Orally for 16 Weeks to Subjects With Moderate to Severe Plaque Psoriasis Who Are Candidates for Systemic Therapy or Phototherapy.

Inclusion Criteria:

• Adult subjects between the ages of 18 and 65 years
• Able to provide written ICF prior to the performance of any study specific procedures
• Has a diagnosis of moderate to severe chronic plaque psoriasis and is a candidate for systemic therapy or phototherapy
• Has a PASI of ≥ 12 at screening and prior to the first dose of study drug, confirmed at Week 1 (Day 1)
• >/= 10% PASI body surface area involvement at screening and prior to the first dose of study drug, confirmed at Week 1 (Day 1)
• Willing to avoid tanning devices

• Have adequate bone marrow function:

  • Absolute neutrophil count (ANC) > 1500/mm3
  • Hemoglobin > 9.0 g/dL
  • Platelets > 100,000/mm3

• Have adequate safety laboratory values:

  • Serum total bilirubin within normal limits (WNL)
  • AST and ALT < 2 × upper limit of normal (ULN)
  • Serum creatinine < 1.5 × ULN

• Female subjects of childbearing potential have a negative pregnancy test at screening. Females of childbearing potential are defined as sexually mature women without prior hysterectomy or who have had any evidence of menses in the past 12 months. However, women who have been amenorrheic for 12 or more months are still considered to be of childbearing potential if the amenorrhea is possibly due to prior chemotherapy, antiestrogens, or ovarian suppression

  • Women of childbearing potential (i.e., menstruating women) must have a negative urine pregnancy test (positive urine tests are to be confirmed by serum test) documented within the 24-hour period prior to the first dose of study drug
  • Sexually active women of childbearing potential enrolled in the study must agree to use two forms of accepted methods of contraception during the course of the study and for 3 months after their last dose of study drug. Effective birth control includes (a) IUD plus one barrier method; (b) on stable doses of hormonal contraception for at least 3 months (e.g., oral, injectable, implant, transdermal) plus one barrier method; (c) 2 barrier methods. Effective barrier methods are male or female condoms, diaphragms, and spermicides (creams or gels that contain a chemical to kill sperm); or (d) a vasectomized partner
• For male patients who are sexually active and who are partners of premenopausal women: agreement to use two forms of contraception as in criterion 5 above during the treatment period and for at least 3 months after the last dose of study drug
• Willing to complete all study measurements and assessments in compliance with the protocol

Exclusion Criteria:

• Has non-plaque or drug-induced (antimalarials, lithium) psoriasis (If subject is taking angiotensin II receptor blockers or beta blockers doses must be stable for 6 months prior to study entry)
• Use of systemic corticosteroids within 12 weeks prior to study entry
• Use topical corticosteroids except to the face, groin, or scalp
• Use of methotrexate, retinoids (such as acitretin), or calcineurin inhibitors (such as cyclosporine) within 4 weeks prior to study entry
• Using phototherapy within 4 weeks prior to study entry
• Using biologic therapies, including antibodies to IL-17, anti-TNFα, anti-IL-12 & -23, within 3 months prior to study entry
• Current use of an inhibitor or inducer of CYP3A4
• Has an active viral, fungal, or bacterial skin infection (other than nail fungal infection).
• Is a pregnant or lactating woman
• Has a history of GI surgery including any bariatric surgery, or any gastrointestinal condition that might interfere with drug absorption
• Currently participating in another study with an investigational drug or within 28 days or 5 half-lives of the investigational drug (whichever is longer) of study entry
• Has a history or other evidence of severe illness or any other conditions that would make the subject, in the opinion of the investigator, unsuitable for the study
• Regular and/or excessive use of alcohol within the 2 years prior to study entry defined as alcohol intake > 14 drinks per week in a man or > 7 drinks per week in a woman. Approximately 10 g of alcohol equals one "drink" unit. One unit equals 1 ounce of distilled spirits, one 12-ounce beer, or one 4-ounce glass of wine
• Has QTc(F) interval (QT interval data corrected using Fridericia's formula) of > 450 msec (average of 3 readings) during screening
• Has had exposure to KD025 or known allergy/sensitivity to KD025 within the last 6 months prior to study entry or any other ROCK-2 inhibitor

• History or presence of any of the following:

  • ALT or AST > 2.0 × ULN at screening. (Subjects with an isolated AST elevation of any magnitude, or a ratio of AST: ALT > 1.5 should be interviewed regarding use of alcohol, have levels repeated and participation in the study should be discussed with the medical monitor.)
  • Renal disease and/or serum creatinine > 1.5 × ULN at screening