A Study to Evaluate the Efficacy and Safety of 608 in Adult Subjects With Active Ankylosing Spondylitis(AS)

A Multicenter, Randomized, Double-blind, Placebo-controlled Phase III Clinical Study to Evaluate the Efficacy and Safety of 608 in Adult Subjects With Active Ankylosing Spondylitis (AS)

This study will evaluate the efficacy and safety of 608 in patients with AS.

Study Overview

• Status: Recruiting
• Conditions: Ankylosing Spondylitis
• Intervention / Treatment: Drug: Placebo; Drug: 608 dose

Detailed Description

The purpose of this trial is to demonstrate the clinical efficacy at week 16; and to demonstrate safety and tolerability of 608 compared to placebo in patients with ankylosing spondylitis at week 16 and long term safety up to Week 60.

• Study Type: Interventional
• Enrollment (Estimated): 500
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Qing hong Zhou; Phone Number: +86 18911301578; Email: zhouqinghong@3sbio.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100730
      • Recruiting
      • Site 01
      • Contact: Zeng Xiao feng MD; Phone Number: +86 13501069845; Email: Xiaofeng.zeng@cstar.org.cn

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Able to understand and comply with the protocol requirements, participate and sign the informed consent form (ICF) voluntarily;
2. At least 18 years of age at the time of signing the ICF, with no gender restrictions;
3. Meet the 1984 modified New York criteria for ankylosing spondylitis (AS);
4. Have inadequate response to non-steroidal anti-inflammatory drugs (NSAIDs) or have contraindications/intolerance to NSAIDs treatment;
5. Willing to practice contraception and have no plans for pregnancy, sperm donation, or egg donation from the screening period until at least 6 months after the last dose.

Exclusion Criteria:

1. Patients with other uncontrolled active inflammatory diseases.
2. Clinical laboratory tests and other tests that reveal abnormalities with clinical significance
3. Patients who have active Hepatitis B, Hepatitis C or HIV infections as determined by positive results at Screening.
4. History of cancer.
5. Known or suspected history of immunosuppression.

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
Placebo Comparator: Placebo; Placebo subcutaneous (SC) injection.	Drug: Placebo; Placebo subcutaneous (SC) injection.
Experimental: 608 Dose; 608 subcutaneous (SC) injection.	Drug: 608 dose; 608 subcutaneous (SC) injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Percentage of Participants Who Achieved an Assessment of Spondylo Arthritis International Society (ASAS) 40 Response.	Assessment of SpondyloArthritis International Society criteria (ASAS) consist of 6 domains (4 main and 2 additional assessment domains): 1. Patient's global assessment measured on a NRS; 2. Patient's assessment of back pain, measured on a NRS; 3. Function represented by Bath Ankylosing Spondylitis Functional Index (BASFI) average of 10 questions as measured by NRS; 4. Inflammation represented by mean duration and severity of morning stiffness, on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) as measured by NRS; 5. Spinal mobility represented by the Bath Ankylosing Spondylitis Metrology Index (BASMI) lateral spinal flexion assessment; 6. C-reactive protein (acute phase reactant). ASAS40 response is defined as an improvement of ≥40% and ≥2 units on a scale of 10 in at least three of the four ASAS main domains and no worsening at all in the remaining domain. A higher score on the NRS signifies higher severity.	Week 16.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Percentage of Participants Who Achieved an Assessment of Spondylo Arthritis International Society (ASAS) 20 Response.	Assessment of SpondyloArthritis International Society criteria (ASAS) consist of 6 domains (4 main and 2 additional assessment domains): 1. Patient's global assessment measured on a NRS; 2. Patient's assessment of back pain, measured on a NRS; 3. Function represented by Bath Ankylosing Spondylitis Functional Index (BASFI) average of 10 questions as measured by NRS; 4. Inflammation represented by mean duration and severity of morning stiffness, on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) as measured by NRS; 5. Spinal mobility represented by the Bath Ankylosing Spondylitis Metrology Index (BASMI) lateral spinal flexion assessment; 6. C-reactive protein (acute phase reactant). ASAS 20 response is defined as an improvement of ≥20% and ≥1 unit on a scale of 10 in at least three of the four main domains and no worsening of ≥20% and ≥1 unit on a scale of 10 in the remaining domain. A higher score on the NRS signifies higher severity.	Week 16.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
608 Concentration in Serum.	The concentration of 608 in Serum.	Up to 60 Weeks.

Collaborators and Investigators

• Sponsor: Sunshine Guojian Pharmaceutical (Shanghai) Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): November 7, 2025
• Primary Completion (Estimated): January 14, 2027
• Study Completion (Estimated): November 18, 2027

Study Registration Dates

• First Submitted: November 21, 2025
• First Submitted That Met QC Criteria: November 21, 2025
• First Posted (Estimated): December 3, 2025

Study Record Updates

• Last Update Posted (Actual): December 10, 2025
• Last Update Submitted That Met QC Criteria: December 3, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Axial Spondyloarthritis; Bone Diseases; Musculoskeletal Diseases; Arthritis; Joint Diseases; Spinal Diseases; Spondylarthropathies; Ankylosis; Spondylarthritis; Spondylitis; Spondylitis, Ankylosing
• Other Study ID Numbers: SSGJ-608-AS-III-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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