This is a Phase III, multicenter, randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of Telitacicept for the treatment of Ocular Myasthenia Gravis (OMG).Approximately 120 eligible subjects aged 12 to 80 years with a diagnosis of OMG (Myasthenia Gravis Foundation of America [MGFA] Clinical Classification Type I) will be randomized in a 1:1 ratio to receive either Telitacicept or a matching placebo. Subjects must be on a stable standard-of-care therapy and have an MG Impairment Index (PRO) ocular score of ≥6 at screening and baseline.The dose is age and weight based.The primary objective is to evaluate the efficacy of Telitacicept compared to placebo in treating OMG.The primary efficacy endpoint is the change from baseline in the MGII (PRO) ocular score at Week 24. Secondary endpoints include changes from baseline in other ocular and total scores from MGII, Myasthenia Gravis-Activities of Daily Living (MG-ADL), MG Clinical Absolute Score, and the 15-item Myasthenia Gravis Quality of Life Revised scale (MG-QOL15r). Safety and tolerability will be monitored throughout the study.

This is a Phase III, multicenter, randomized, double-blind, placebo-controlled, parallel-group study to assess the efficacy and safety of Telitacicept in subjects with Ocular Myasthenia Gravis (OMG). The study will be conducted at multiple centers.

Eligible subjects will be randomized in a 1:1 ratio to one of two treatment arms:

Arm 1: Telitacicept Arm 2: Placebo Randomization will be stratified by two factors: Acetylcholine Receptor (AChR) antibody status (positive vs. negative) and age (<18 years vs. ≥18 years).

Primary Objective:

To evaluate the efficacy of Telitacicept compared to placebo in the treatment of subjects with Ocular Myasthenia Gravis.

Primary Endpoint:

Change from baseline in the Myasthenia Gravis Impairment Index (Patient-Reported Outcomes) [MGII (PRO)] ocular score at Week 24.

Study Population:

A total of approximately 120 subjects will be enrolled.

Intervention:

Subjects will receive either Telitacicept or a matching placebo. The dose will be determined based on the subject's age and body weight at baseline.

The placebo will be identical in appearance to Telitacicept to maintain the blind.

Safety Assessments:

Safety and tolerability will be assessed through the monitoring and recording of adverse events (AEs), serious adverse events (SAEs), vital signs, physical examinations, and regular laboratory tests (hematology, serum chemistry, urinalysis). An independent Data Monitoring Committee (DMC) will be established to monitor the safety of the trial.

Inclusion Criteria:

1. Voluntarily signed the informed consent form.
2. Age 12 to 80 years, inclusive, male or female.
3. Body weight ≥30 kg.
4. Diagnosis of Myasthenia Gravis (MG) with documented clinical features consistent with the disease.
5. Myasthenia Gravis Foundation of America (MGFA) Clinical Classification of Type I.
6. On a stable standard-of-care (SOC) treatment regimen.

Exclusion Criteria:

1. Concomitant autoimmune diseases requiring systemic corticosteroid therapy.
2. Clinically significant laboratory abnormalities.
3. Use of other immunosuppressants (not part of the stable SOC) within 1 month prior to randomization.
4. Presence of an acute or chronic infection requiring treatment.
5. Current active hepatitis or history of severe liver disease.
6. Positive for HIV antibodies.
7. Positive for syphilis antibodies (non-specific or specific).
8. Poorly controlled diabetes mellitus, defined as HbA1c >9.0% or fasting blood glucose ≥11.1 mmol/L.
9. Subjects with thymoma (classified as ≤ Stage II for benign and ≥ Stage III for malignant according to the Masaoka staging system) .
10. Presence of uncontrolled chronic degenerative diseases, psychiatric disorders, or neurological diseases other than MG that could interfere with study assessments.
11. Other diseases causing ptosis, peripheral muscle weakness, or diplopia (e.g., Graves' ophthalmopathy, blepharospasm, progressive external ophthalmoplegia, muscular dystrophy, brainstem or cranial nerve lesions, etc.).
12. Known allergy to human-derived biological products.