A Study to Evaluate the Efficacy and Safety of DC-806 in Participants With Moderate to Severe Plaque Psoriasis

Study Overview
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Brief Summary
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This is a 12-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study to evaluate the efficacy and safety of DC-806 in participants with moderate to severe plaque psoriasis. This study will evaluate the efficacy, safety, tolerability, and pharmacokinetics (PK) of multiple oral doses of DC-806 in participants with moderate to severe plaque psoriasis.

Official Title
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A Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel-group, Dose-ranging Study to Evaluate the Efficacy and Safety of DC-806 in Participants With Moderate to Severe Plaque Psoriasis

Conditions
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Plaque Psoriasis

Intervention / Treatment
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* Drug: DC-806
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Male or female, 18 to 70 years of age Body mass index (BMI) of 18 to 40 kg/m2 All of the following psoriasis criteria: Clinical diagnosis of plaque psoriasis for ≥6 months before the Baseline visit Stable moderate to severe chronic plaque psoriasis, defined as ≥10% BSA psoriasis involvement, sPGA score of ≥3, and PASI score ≥12 at the Screening and Baseline visits Candidate for phototherapy or systemic therapy, as assessed by the Investigator Women of childbearing potential (WOCBP) and men who are sexually active with WOCBP must be willing to use a highly effective method of contraception during the study and for ≥30 days after the last dose of study drug Willing to discontinue topical and/or systemic therapies for psoriasis before the first dose of study drug Key Exclusion Criteria: Have had a clinically significant flare of psoriasis during the 12 weeks before the Baseline visit, as assessed by the Investigator History of erythrodermic psoriasis, generalized or localized pustular psoriasis, predominantly guttate psoriasis, medication-induced or medication-exacerbated psoriasis History of chronic infections including human immunodeficiency virus (HIV) or viral hepatitis (hepatitis B virus [HBV], hepatitis C virus [HCV]) History of active tuberculosis (TB) History or evidence of active infection (including but not limited to coronavirus disease 2019 [COVID-19] infection) and/or febrile illness within 7 days, serious infections leading to hospitalization and intravenous antibiotic treatment within 90 days, or serious infection requiring antibiotic treatment within 30 days before the first dose of study drug History of malignancy or lymphoproliferative disease within the last 5 years except resected cutaneous squamous cell or basal cell carcinoma that has been treated without recurrence Presence of active suicidal ideation, or positive suicide behavior using the Baseline/Screening version of the Columbia Suicide Severity Rating Scale (C-SSRS) and with either of the following criteria: History of suicide attempt (including an actual attempt, interrupted attempt, or aborted attempt) within 5 years before the Screening visit Suicidal ideation in the past month before the Screening visit as indicated by a positive response (Yes) to either Question 4 or Question 5 of the Baseline/Screening version of the C-SSRS Participant has experienced primary failure (no response at approved doses after ≥3 months of therapy) to one or more therapeutic agents targeted to IL-17 (including but not limited to secukinumab, ixekizumab, brodalumab, bimekizumab) Systemic use of known strong and moderate cytochrome P450 (CYP)3A4 inhibitors or strong CYP3A4 inducers from Screening through the end of the study A 12-lead electrocardiogram (ECG) at Screening that demonstrates clinically significant abnormalities or criteria associated with QT interval abnormalities including prolongation of QT interval corrected for heart rate using Fridericia's formula (QTcF) (>500 msec) Laboratory values meeting the following criteria within the screening period before the first dose of study drug: Serum aspartate transaminase ≥2× upper limit of normal (ULN) Serum alanine transaminase ≥2×ULN Serum total, direct, or indirect bilirubin ≥2.0 mg/dL; except for participants with isolated elevation of indirect bilirubin relating to a confirmed diagnosis of Gilbert syndrome Estimated glomerular filtration rate (GFR) by simplified 4-variable Modification of Diet in Renal Disease (MDRD) formula <45 mL/min/1.73m2 Total white blood cell count <3000/μL Absolute neutrophil count <1500/μL Platelet count <100,000/μL Hemoglobin <9 g/dL In the opinion of the Investigator or Sponsor, have any uncontrolled clinically significant laboratory abnormality that would affect interpretation of study data or the participant's enrollment in the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment Group 1: DC-806 Dose A<br> | Drug: DC-806<br>* DC-806 will be supplied as tablets to be administered orally.<br>|
| Experimental: Treatment Group 2: DC-806 Dose B<br> | Drug: DC-806<br>* DC-806 will be supplied as tablets to be administered orally.<br>|
| Experimental: Treatment Group 3: DC-806 Dose C<br> | Drug: DC-806<br>* DC-806 will be supplied as tablets to be administered orally.<br>|
| Experimental: Treatment Group 4: DC-806 Dose D<br> | Drug: DC-806<br>* DC-806 will be supplied as tablets to be administered orally.<br>|
| Placebo Comparator: Treatment Group 5: Placebo<br> | Other: Placebo<br>* Matching placebo will be supplied as tablets to be administered orally.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of participants achieving ≥75% reduction in Psoriasis Area of Severity Index score (PASI-75) |  | Week 12 | 
| Incidence of treatment-emergent adverse events (TEAEs) |  | 16 weeks | 
| Incidence of serious adverse events (SAEs) |  | 20 weeks | 
| Incidence of TEAEs leading to discontinuation |  | 16 weeks |