A Multicenter, Randomized, Double-Blind, Placebo-Controlled Phase III Clinical Study to Evaluate the Efficacy and Safety of RSS0393 Ointment in Adult Patients With Plaque Psoriasis.

Phase III Efficacy and Safety Study of RSS0393 Ointment in Plaque Psoriasis.

Study Overview

• Status: Not yet recruiting
• Conditions: Plaque Psoriasis Subjects
• Intervention / Treatment: Drug: RSS0393 ointment placebo; Drug: RSS0393 ointment 0.03%

• Study Type: Interventional
• Enrollment (Estimated): 600
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Shuang Li; Phone Number: 18604031725; Email: Shuang.li.sl100@hengrui.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100730
      • Peking Union Medical College Hospital (PUMCH)
      • Principal Investigator: Hongzhong Jin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age must be ≥18 years on the day of signing the informed consent form, male or female.
2. Body Mass Index (BMI = weight [kg] / height² [m²]) ≥18.0 kg/m² at screening.
3. A history of plaque psoriasis for ≥6 months.
4. Body Surface Area (BSA) involvement of psoriasis lesions between 2% and 20%, and a Psoriasis Area and Severity Index (PASI) score ≥2, and a Physician's Global Assessment (PGA) score ≥2 at both screening and baseline.

Exclusion Criteria:

1. Presence of any of the following skin abnormalities or conditions:

   The participant is diagnosed with skin diseases or conditions other than plaque psoriasis during the screening period that, in the investigator's opinion, may interfere with the evaluation of study-related endpoints.

2. Use of any of the following medications or participation in clinical studies:

1) Treatment with topical anti-psoriatic medications within 14 days prior to baseline, or systemic anti-psoriatic therapies or phototherapy within 28 days prior to baseline, or biologics for psoriasis within the protocol-specified washout period prior to baseline.

2) Participation in any clinical study (including investigational vaccines) or medical device trial within 3 months prior to baseline or within 5 elimination half-lives of the prior investigational product (whichever is longer).

3.Presence of any significant medical histories or underlying conditions that may affect safety.

4.Any of the following laboratory abnormalities and/or 12-lead ECG findings at screening/baseline:

1. Hemoglobin <100.0 g/L (for males) or <90.0 g/L (for females);
2. White blood cell count <3.0 × 10⁹/L;
3. Neutrophil count <1.5 × 10⁹/L;
4. Platelet count <100 × 10⁹/L;
5. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2.5 × the upper limit of normal (ULN);
6. Total bilirubin (TBIL) >1.5 × ULN;
7. Estimated glomerular filtration rate (eGFR) calculated by the Modification of Diet in Renal Disease (MDRD) study equation <60 mL/min/1.73 m², or serum creatinine outside the normal range, and considered by the investigator as unsuitable for study participation;
8. Positive test for hepatitis B surface antigen (HBsAg), human immunodeficiency virus (HIV) antibody, syphilis antibody, or anti-hepatitis C virus (HCV) antibody; OR a 12-lead ECG showing clinically significant abnormalities that may affect participant safety.

5. General Conditions:

1. Women who are pregnant or breastfeeding.
2. Known hypersensitivity to the investigational product or any of its excipients.
3. History or suspicion of alcohol abuse, drug abuse, or substance abuse, in the investigator's judgment.
4. Administration of a live-attenuated vaccine within 12 weeks prior to randomization, intention to receive a live-attenuated vaccine during the study, or participation in a vaccine clinical trial within 12 weeks prior to randomization.
5. Donation of approximately 500 mL of blood within 8 weeks prior to randomization, or plans to donate blood during the study period.
6. Anticipated use of artificial or natural ultraviolet (UV) light exposure (e.g., phototherapy, tanning beds, extensive sun exposure) on the treatment areas during the study treatment period, which, in the investigator's judgment, could interfere with efficacy evaluations.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment group 1: RSS0393 ointment 0.03%	Drug: RSS0393 ointment 0.03%; RSS0393 ointment 0.03%
Placebo Comparator: Treatment group 2: RSS0393 ointment placebo	Drug: RSS0393 ointment placebo; RSS0393 ointment placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Achieving a Physician's Global Assessment (PGA) response at Week 8	week8

Secondary Outcome Measures

Outcome Measure	Time Frame
The proportion of participants achieving at least a 75% improvement frombaseline in the Psoriasis Area and Severity Index (PASI) score (PASI 75).	week54
The proportion of participants with a baseline Itch Numerical Rating Scale (Itch-NRS) score ≥4 who achieved an Itch-NRS response (defined as a reduction of ≥4 points from baseline).	week54
Achieving an Intertriginous Physician's Global Assessment (I-PGA) response in participants with baseline involvement of intertriginous areas and a baseline I-PGA score ≥ 2.	week54
The proportion of participants achieving a Physician's Global Assessment (PGA) response (score of "clear" or "almost clear") at each of the other scheduled visits.	week 54
Change from baseline in Psoriasis Area and Severity Index (PASI) score (absolute and percentage) at each visit.	week 54
The proportion of participants achieving PASI 50, PASI 90, or PASI 100 at each visit.	week 54
Change from baseline in the Itch Numerical Rating Scale (Itch-NRS) score (absolute and percentage) at each visit.	week 54
Change from baseline in Body Surface Area (BSA) involvement (absolute and percentage) at each visit.	week 54
Change from baseline in the Dermatology Life Quality Index (DLQI) at each visit.	week 54
Adverse Event (AE)	week 54
Local Tolerability Score	week 54

Collaborators and Investigators

• Sponsor: Reistone Biopharma Company Limited

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: April 7, 2026
• First Submitted That Met QC Criteria: April 15, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: RSS0393Oint-301

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No