Safety, Tolerability, PK and PD of SSS55 in Healthy Subjects
A Randomized, Double-blind, Placebo-controlled Phase I Clinical Study to Evaluate the Safety, Tolerability, Pharmacokinetic and Pharmacodynamic Characteristics of SSS55 Injection in Healthy Subjects in China
1 other identifier
interventional
26
1 country
1
Brief Summary
This study was a single-dose, randomized, double-blind, placebo-controlled study of SSS55 injection to evaluate the safety, tolerability, PK characteristics, immunogenicity and preliminary efficacy characteristics of single-dose SSS55 injection in healthy individuals.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for phase_1
Started Aug 2025
Typical duration for phase_1
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
May 26, 2025
CompletedFirst Posted
Study publicly available on registry
July 10, 2025
CompletedStudy Start
First participant enrolled
August 4, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 1, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
December 1, 2027
March 2, 2026
February 1, 2026
1.3 years
May 26, 2025
February 26, 2026
Conditions
Outcome Measures
Primary Outcomes (1)
To evaluate the safety and tolerability of a single intravenous infusion of SSS55 injection in healthy adult subjects in China
Number of participants with treatment-related adverse events as assessed by CTCAE v4.0
22days
Secondary Outcomes (3)
To evaluate the pharmacokinetic (PK) characteristics of SSS55 injection after a single intravenous infusion in healthy adult subjects in China
22days
To evaluate the pharmacodynamic characteristics of SSS55 injection after a single intravenous infusion in healthy adult subjects in China
22 days
To evaluate the ADA of SSS55 injection after a single intravenous infusion in healthy adult subjects in China
22days
Study Arms (4)
Low-dose group
EXPERIMENTALdose1
middle-dose group
EXPERIMENTALdose 2
high-dose group
EXPERIMENTALdose 3
Higher-dose group
EXPERIMENTALdose 4
Interventions
SSS55 is an injection targeting complement C3b
Eligibility Criteria
You may qualify if:
- Healthy subjects aged 18 to 45 years old (including the boundary value), regardless of gender;
- The subjects voluntarily participated in the clinical trial and signed the informed consent form;
- Men with a weight of ≥50 kg, women with a weight of ≥45 kg, and those with a body mass index (BMI) ranging from 19 to 28 kg/m2 (including the critical value);
- Those who underwent vital sign assessment, physical examination, blood routine, urine routine, blood biochemistry, coagulation function, pregnancy examination (for women of childbearing age), 12-lead ECG, chest X-ray/lung CT during screening, and the results showed no abnormalities or the abnormalities had no clinical significance;
- Be willing to receive the MV-ACYW meningococcal vaccine and pneumococcal vaccine 14 days or more before randomization.
You may not qualify if:
- \) Those with a clear history of drug or food allergies, or a known history of hypersensitivity reactions that are clinically significant to the research intervention measures or related compounds or commonly used antibacterial agents;
- \) Those with a history of any serious clinical diseases in the past or present, including but not limited to those in the digestive system, cardiovascular system, respiratory system, urinary system, musculoskeletal system, endocrine system, immune system, neuropsychiatric system, hematological system, etc. (except those deemed eligible for enrollment by the researcher);
- \) First-degree relatives with a known history of meningococcal infection or a history of meningococcal infection;
- \) Those with contraindications to meningococcal vaccination (with a history of epilepsy or other brain diseases, etc.);
- \) There was or suspected active viral, bacterial, fungal or parasitic infection within 14 days prior to screening, including herpes, shingles or cold sores;
- \) A history of recurrent infections of unknown cause; Or systemic antibiotics (intravenous antibiotics, oral antibiotics, etc., excluding topical application antibiotics) have been used within 90 days before administration;
- \) There is a history of Gilbert syndrome or the researcher assesses that it meets the diagnostic criteria for the disease;
- \) Received treatment with blood products within 6 months prior to administration;
- \) Those who have undergone major surgical operations within 4 weeks prior to administration or have not fully recovered from any previous invasive procedures;
- \) Suffering from syphilis (Treponema pallidum antibody positive) or AIDS (HIV antibody positive), or active hepatitis C (hepatitis C virus antibody positive), or active hepatitis B (hepatitis B surface antigen positive);
- \) A history of malignant tumors in the past or present;
- \) Any drugs (including prescription drugs, over-the-counter drugs, Chinese herbal medicines, etc.) or health supplements have been used within 2 weeks before administration (if determined by the investigator, the time interval from the start of administration of the drug in this trial \> Five half-lives, and the corresponding subjects can also be enrolled.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Shanghai General Hospital
Shanghai, Shanghai Municipality, China
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 1
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- OTHER
- Intervention Model
- SEQUENTIAL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
May 26, 2025
First Posted
July 10, 2025
Study Start
August 4, 2025
Primary Completion (Estimated)
December 1, 2026
Study Completion (Estimated)
December 1, 2027
Last Updated
March 2, 2026
Record last verified: 2026-02