In 2025, a novel meningoencephalomyelitis associated with Vimentin IgG in cerebrospinal fluid (CSF) has been identified. Most patients exhibited progressive or recurrent episodes, characterized by prominent cerebellar ataxia, cranial nerve palsies, and pyramidal signs. The characteristic features included bilateral magnetic resonance imaging (MRI) lesions of the corticospinal tract, elevated CSF protein levels, and increased CSF cell counts. Despite receiving immunotherapy, these patients experienced significant disability.

This study employed a single-center, open-label, single-arm design to investigate the clinical efficacy and safety of rituximab (RTX) treatment in 40 patients with vimentin antibody (VIMA)-related diseases.

Inclusion Criteria:

1. Age ≥ 18 years, no gender restrictions;
2. Patients with positive CSF anti-Vimentin antibodies（VIMA）, clinically consistent with the clinical features of VIMA-related diseases reported in JAMA Neurology 2024; 3. EDSS ≥ 3.5 points or evidence of disease activity as defined by the protocol within 1 year prior to screening.

Evidence of disease activity as defined by the protocol: One of the following manifestations within 6 months of the screening period: 1. Enlargement of lesions on brain or spinal cord MRI T2 sequence; 2. △EDSS > 0; 3. At least two FS scores increase by 1 point or at least 1 FS increases by 2 points (excluding rectal/bladder and brain); 4. Symptoms lasting for more than 24 hours without fever and more than 30 days since the last episode. 4. Sign informed consent.

Exclusion Criteria:

1. Allergy to the study drug;

2. Known active infections during the screening period (excluding nail bed fungal infections or dental caries);

3. Underwent any surgical procedure within 4 weeks prior to screening, has evidence of other demyelinating diseases or progressive multifocal leukoencephalopathy (PML);

4. Positive serology for HIV or syphilis treponema or RPR during the screening period (if syphilis antibodies are negative, further serological testing for syphilis is not required);

5. Chronic hepatitis B virus or hepatitis C virus infection that meets the following criteria: • HBsAg positive; • If HBsAg negative, HbcAb positive, further HBV DNA testing (result ≥1000 IU/mL); • If HCV antibody testing is positive, further HCV RNA testing (result above the upper limit of normal range at the research site);

6. Evidence of active tuberculosis (excluding patients receiving medication for latent TB infection);

7. Received any live vaccine or attenuated live vaccine within 6 weeks prior to the medication;

8. History of malignant tumors within 5 years prior to screening, including solid tumors, hematological malignancies, and carcinoma in situ (excluding fully resected and cured basal cell carcinoma, squamous cell carcinoma, and cervical carcinoma in situ);

9. Pregnant or breastfeeding women; for women of childbearing potential, a positive serum pregnancy test at screening, or unwilling to use reliable contraception (physical barriers [patient or partner] and spermicide, contraceptive pills, patches, injections, intrauterine devices or systems), and continuing for at least 4 months after the last administration of the study drug. Men of childbearing potential unwilling to use effective contraceptive measures during the period from signing the informed consent to 6 months after the last medication;

10. Any other diseases determined by the investigator that would make the subject unsuitable for participation in this study;

11. Presence of the following clinically significant diseases:

    1. Echocardiography during the screening period shows a left ventricular ejection fraction (EF) below 50% or below the lower limit of normal values at the research center; history of chronic congestive heart failure, functional class NYHA III-IV;
    2. Any of the following events occurred within 3 months prior to signing the informed consent: myocardial infarction, acute coronary syndrome, viral myocarditis, pulmonary embolism, stroke; coronary revascularization surgery within 6 months;
    3. Electrocardiogram during the screening period indicates QTc interval >480ms (according to Fridericia's correction formula, where QTc=QT/RR^0.33), or history of severe QTc interval prolongation;

12. Laboratory test values during the screening period show the following abnormalities:

    1. Aspartate aminotransferase (AST) > 3× upper limit of normal (ULN), alanine aminotransferase (ALT) > 3× ULN, total bilirubin > 1.5× ULN (unless due to Gilbert's syndrome);
    2. Platelet count <50,000/μL (or <50 × 10^9/L), hemoglobin <9 g/dL (or <90 g/L), white blood cells <2.0 × 10^3/μL, absolute neutrophil count <1.0 × 10^3/μL;
    3. Creatinine clearance (CLcr) <60 mL/min (calculated using the Cockcroft-Gault formula: [140 - age (years)] × [weight (kg)] × (0.85, if female) / [72 × serum creatinine (mg/dL)]) or undergoing dialysis during screening.