A Clinical Study to Evaluate the Safety and Efficacy of GT802 Injection in the Treatment of Relapsing/Refractory Multiple Sclerosis

This is a single-arm, open-label, dose-escalation clinical trial intended to evaluate the safety, efficacy and cellular pharmacokinetics of GT802 for the treatment of relapsing/refractory multiple sclerosis.

Inclusion Criteria: * 1\. The participant or their legally authorized representative voluntarily signs a written informed consent form and is willing and able to comply with all study procedures specified in this protocol. * 2\. Aged between 18 and 65 years old inclusive at the time of informed consent signature, with no restriction on gender. * 3\. For any prior systemic therapy administered for the indication, a washout period of at least 4 weeks or 5 half-lives (whichever is shorter) must have elapsed prior to the participant's scheduled administration of study treatment. * 4\. Toxicities resulting from prior therapies must have stabilized and resolved to Grade ≤1, excluding clinically insignificant toxicities such as alopecia. * 5\. Confirmed diagnosis of relapsed/refractory multiple sclerosis with limited effective therapeutic options at present based on specified diagnostic criteria. * 6\. Screening laboratory test results shall meet the corresponding criteria (no corrective treatment with any blood products or cellular growth factors administered within 7 days prior to laboratory testing). * 7\. Pregnancy-related requirements: * a. Serum beta human chorionic gonadotropin (β-hCG) pregnancy test result is negative as confirmed by the investigator at screening. * b. Agree to refrain from breastfeeding throughout study participation for at least 1 year after infusion of GT802 Injection, or until two consecutive flow cytometry assays confirm the absence of GT802 cells (whichever occurs later). * c. Male participants with sexual partners and female participants of childbearing potential must agree to use highly effective contraceptive methods (e.g., oral contraceptives, intrauterine devices, condoms) starting at screening and continuing for at least 1 year after infusion of GT802 Injection, or until two consecutive flow cytometry assays confirm the absence of GT802 cells (whichever occurs later). Male participants must agree to use condoms during sexual intercourse with pregnant females or females of childbearing potential for a minimum of 1 year after GT802 Injection infusion, even following successful vasectomy. Exclusion Criteria: * 1\. Contraindication or hypersensitivity reaction to any component of the investigational product. * 2\. Presence of any of the following conditions within 6 months prior to signing the informed consent form (ICF): uncontrolled congestive heart failure (New York Heart Association \[NYHA\] Class III-IV), angina pectoris, myocardial infarction, cardiomyopathy, stroke (lacunar infarction excluded), coronary/peripheral artery bypass graft surgery, clinically significant arrhythmias including but not limited to ventricular arrhythmias, markedly prolonged QT interval (QTc ≥ 500 ms corrected by Bazett's formula, to be judged by the investigator), poorly controlled hypertension (systolic blood pressure \>160 mmHg or diastolic blood pressure \>100 mmHg), uncontrolled diabetes mellitus, diffuse pulmonary lesions, pulmonary insufficiency, or other clinically significant cardiac disorders. * 3\. History of active malignant tumor or any malignancy within 5 years prior to screening. The following are exceptions: early-stage malignancies treated with curative intent (carcinoma in situ or Stage I tumors, non-ulcerated primary melanoma with depth \