A Safety and Tolerability Study of Belumosudil (KD025) Treatment in Subjects With Moderately Severe Psoriasis Vulgaris

Inclusion Criteria: * Diagnosis of moderately severe plaque psoriasis that has been stable for 6 months and has failed at least one line of systemic therapy and is a candidate for additional systemic therapy. * Had a PASI of ≥12 * At least 10% of body surface area that is affected by plaque psoriasis. * Willing to avoid tanning devices or sun bathing. * Willing to forgo systemic and topical treatments for psoriasis during the course of the study. * Adequate bone marrow function * Negative urine pregnancy test (for women of childbearing potential) * Agree to use a highly effective method of birth control (\< 1% per year failure rate) during the study and for 1 month after the termination of the study. * Willing to complete all study measurements and assessments in compliance with the protocol. Exclusion Criteria: * Non-plaque or drug-induced psoriasis * Currently using corticosteroid or immunosuppressive therapy except for Class 5 or weaker topical corticosteroids to the face, groin, or scalp * Using any topical therapy except for the following: 1. Class 5 or weaker steroids and phototherapy for 4 weeks prior to study entry 2. Immunosuppressive therapies for 4 weeks prior to study entry 3. Methotrexate, acitretin, or cyclosporine for 4 weeks prior to study entry 4. Biologic therapies for 3 months prior to study entry. * Concomitant condition requiring treatment with moderate to high dose steroids in the 12 weeks prior to screening. * Viral, fungal, or bacterial skin infection. * Pregnant or lactating woman. * Currently participating in another study with an investigational drug or within 28 days of study entry * 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 * History or presence of any of the following: 1. Hepatic disease and or alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \> 1.5 × the upper limit of normal (ULN) at screening 2. Renal disease and/or serum creatinine \> 1.5xULN at screening * Has QTc(f) intervals of \> 450 msec at the screening or pre-dose ECG * Subject is receiving any drugs known to prolong the QTc interval, including any anti-arrhythmic medications within 2 weeks prior to screening * Subject is receiving any drug that is a strong CYP enzyme inhibitor * Subject is receiving any concomitant systemic drug that is metabolized by CYP enzyme * Previous exposure to KD025 or known allergy/sensitivity to KD025 or any other ROCK-2 inhibitor.