A Clinical Study to Evaluate the Safety and Efficacy of GT801 Injection in the Treatment of Moderate to Severe Refractory Autoimmune Diseases

This study is an open-label, single-arm, dose-escalation and dose-expansion clinical trial designed to evaluate the safety, efficacy and cellular pharmacokinetics of GT801 injection in patients with moderate to severe refractory autoimmune diseases.

Study Overview

• Status: Recruiting
• Conditions: Moderate to Severe Refractory Autoimmune Diseases
• Intervention / Treatment: Biological: GT801 Injection

• Study Type: Interventional
• Enrollment (Estimated): 22
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Hong Cai; Phone Number: +86 18621576622; Email: 18621576622@163.com

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200127
      • Recruiting
      • RenJi Hospital
      • Contact: Hong Cai; Phone Number: +86 18621576622; Email: 18621576622@163.com
      • Principal Investigator: Hong Cai

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• 1.The participant or their legal representative voluntarily signs a written informed consent form and is willing and able to comply with the study procedures.
• 2. Aged 18 to 65 years old (inclusive) at the time of signing the informed consent, regardless of gender.
• 3.subjects should be diagnosed with recurrent or refractory autoimmune diseases, including but not limited to systemic lupus erythematosus (SLE), lupus nephritis (LN), membranous nephropathy (MN), Idiopathic Inflammatory Myopathy (IIM), Systemic Sclerosis (SSc), ANCA-Associated Vasculitis (AAV), Sjogren's Syndrome.
• 4.Organ function meets the corresponding criteria.
• 5.Women of childbearing potential must have a negative serum β-human chorionic gonadotropin (β-hCG) pregnancy test result at screening and agree to avoid breastfeeding during study participation until at least 1 year after GT801 injection or until GT801 cells are no longer detectable by two consecutive flow cytometry tests, whichever is later.

Exclusion Criteria:

• 1. History of severe hypersensitivity reactions or allergies.
• 2. Contraindications to or hypersensitivity reactions to any component of the investigational product.
• 3. History of the following cardiac diseases:
• a. New York Heart Association (NYHA) Class III or IV congestive heart failure.
• b. Myocardial infarction or coronary artery bypass grafting within 6 months prior to screening.
• c. History of clinically significant ventricular arrhythmia or unexplained syncope not caused by vasovagal response or dehydration; or corrected QT interval (QTc) > 480 ms at screening; history of severe non-ischemic cardiomyopathy.
• 4. History of any active malignancy or malignant tumor within 5 years prior to screening, except for the following conditions: early-stage tumors treated with curative intent (carcinoma in situ or Stage I tumors, non-ulcerative primary melanoma with depth < 1 mm and no lymph node involvement), basal cell carcinoma of the skin, squamous cell carcinoma of the skin, cervical carcinoma in situ, or ductal carcinoma in situ of the breast that has undergone potentially curative treatment.
• 5. Any other known autoimmune diseases besides the study disease.
• 6. Long-term use of anticoagulant drugs that affect coagulation function.
• 7. Clinically significant bleeding symptoms or confirmed bleeding tendency within 6 months prior to screening (e.g., gastrointestinal bleeding, hemorrhagic gastric ulcer, etc.); hereditary or acquired bleeding and thrombotic tendencies (e.g., hemophilia, coagulation disorders, hypersplenism, etc.); arterial or venous thrombotic events within 6 months prior to screening (e.g., cerebrovascular diseases including cerebral hemorrhage and cerebral infarction, deep vein thrombosis, and/or pulmonary embolism).
• 8. Subjects with active virus infection including Human Immunodeficiency Virus (HIV), hepatitis B virus (HBV), Hepatitis C virus (HCV), cytomegalovirus (CMV), syphilis and tuberculosis etc.
• 9. Receipt of other investigational drugs within 4 weeks prior to signing the informed consent form (ICF); or the interval between the ICF signing date and the last dose of the previous clinical trial participation is still within 5 half-lives of the drug, whichever is longer.
• 10. Receipt of plasma exchange therapy or immunoadsorption therapy within 4 weeks prior to investigational product administration.
• 11. Prior treatment with B-cell targeted therapies within 3 months prior to study drug administration (the investigator may make appropriate adjustments according to the participant's condition), including but not limited to rituximab, belimumab, telitacicept, etc.
• 12. Receipt of biologic therapy such as anti-TNF-α antibodies within 12 weeks prior to investigational product administration.
• 13. Use of tacrolimus, cyclosporine, azathioprine, mycophenolate mofetil, mycophenolic acid, methotrexate, etc., within 2 weeks prior to investigational product administration.
• 14. Receipt of neonatal Fc receptor (FcRn) antagonist therapy (e.g., efgartigimod, etc.) within 3 weeks prior to investigational product administration.
• 15. Receipt of complement inhibition therapy (e.g., eculizumab, etc.) within 3 weeks prior to investigational product administration.
• 16. Vaccination with live attenuated vaccines or mRNA vaccines within 8 weeks prior to enrollment; or inactivated vaccines within 4 weeks prior to enrollment.
• 17. Major surgery within 8 weeks prior to screening, or planned surgery during the study period.
• 18. History of organ transplantation.
• 19. Prior receipt of chimeric antigen receptor T-cell (CAR-T) therapy targeting any antigen.
• 20. Presence of any conditions that, in the investigator's judgment, would prevent the participant from completing the entire trial, confound trial results, or make trial participation not in the participant's best interest.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: GT801 Injection treatment group; GT801 Injection	Biological: GT801 Injection; GT801 Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of participants experiencing dose limiting toxicity	The proportion of participants with dose-limiting toxicity (DLT) occurring within 28 days after infusion	28 days
Adverse Events (AEs) occurring after infusion and their proportions	Adverse Events (AEs) occurring after infusion and their proportions	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Efficacy outcomes for Systemic Lupus Erythematosus (SLE)	SLE Response index 4(SRI-4) response: Min/Max Value: Not specified; a decrease in score indicates improvment, higher scores indicate worse outcome	1, 2, 3 and 6 Months post GT801 infusion
Efficacy outcomes for Idiopathic Inflammatory Myopathies (IIM)	Total lmprovement Score (TlS): Min/Max Value: Not specified; an increase in score indicates improvement, higher scores indicate better outcome.	1, 2, 3 and 6 Months post GT801 infusion
Efficacy outcomes for Systemic Sclerosis (SSc)	Combined Response Index in Systemic Sclerosis (CRISS): the score ranges from 0 to 1 point; a score ≥ 0.6 indicates treatment improvement, while a score < 0.6 indicates no disease improvement.	1, 2, 3 and 6 Months post GT801 infusion
Efficacy Outcomes for ANCA-Associated Vasculitis (AAV)	The proportion of subjects achieving complete remission and partial remission	6 and 12 Months post GT801 infusion
Cellular Kinetics of All Participants: Time to Peak Expansion of GT801 Cells After Infusion (Tmax)	Time to Peak Expansion (Tmax) refers to the time point at which the infused target cells proliferate to the peak quantity in the participants' bodies.	From infusion to 12 months
Cellular Kinetics of All Participants: Expansion Peak of GT801 Cells After Infusion (Cmax)	Expansion Peak (Cmax) refers to the maximum quantity of infused GT801 cells achieved during their proliferation in the participants' bodies.	From infusion to 12 months
Cellular Kinetics of All Participants: Area Under the Curve (AUC) of GT801 Cells After Infusion	Area Under the Curve (AUC) refers to the area enclosed by the curve of GT801 cell quantity change over time after infusion and the time axis.	From infusion to 12 months
Cellular Kinetics of All Participants: Duration of Detectable Concentration of GT801 Cells After Infusion (Tlast)	Duration of Detectable Concentration (Tlast) refers to the time period from the infusion of GT801 cells to the last time point at which the target cells can be detected in the peripheral blood or target tissues.	From infusion to 12 months
Pharmacodynamic characteristics in participants for all participants	Monitor serum cytokine levels after infusion	From infusion to 2 months
Efficacy outcomes for lupus nephritis (LN)	Renal response rate	1, 2, 3 and 6 Months post GT801 infusion
Efficacy outcomes for membranous nephropathy (MN)	Renal response rate	1, 2, 3 and 6 Months post GT801 infusion
Efficacy Outcomes for Participants with Sjogren's Syndrome	EULAR Sjögren's Syndrome Disease Activity Index （ESSDAI）response rates	6 and 12 Months post GT801 infusion
Efficacy Outcomes for Participants with Sjogren's Syndrome	EULAR Sjögren's Syndrome Patient-Reported Index （ESSPRI）response rates	6 and 12 Months post GT801 infusion

Collaborators and Investigators

• Sponsor: Vivacta Biotechnology (Shanghai) Co., Ltd.
• Collaborators: RenJi Hospital

Study record dates

Study Major Dates

• Study Start (Actual): May 25, 2026
• Primary Completion (Estimated): December 30, 2031
• Study Completion (Estimated): December 30, 2031

Study Registration Dates

• First Submitted: May 13, 2026
• First Submitted That Met QC Criteria: May 21, 2026
• First Posted (Actual): May 29, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: GRIT-CD-CHN-801-005

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