Study of Telitacicept in Generalized Myasthenia Gravis

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the efficacy and safety of Telitacicept in the treatment of patients with generalized myasthenia gravis.

Detailed Description
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This study consists of a screening period, a double-blind treatment period (part A) and an open-label treatment period (part B). After screening, eligible subjects will be randomized in a 1: 1 ratio to receive either subcutaneous Telitacicept 240 mg or placebo once a week for 24 doses (part A). Completing part A, subjects will automatically enter part B. In part B, all subjects will receive weekly subcutaneous Telitacicept 240 mg for 24 weeks.

Official Title
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A Multi-center, Randomized, Double-blind, Placebo-controlled, Phase III Study of Telitacicept in Patients With Generalized Myasthenia Gravis

Conditions
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Myasthenia Gravis, Generalized

Intervention / Treatment
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* Biological: Telitacicept
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent provided; Male or female patients aged 18-80 years; Diagnosis with generalized myasthenia gravis; MGFA Class II, III, or IVa; AChR-Ab or MuSK-Ab positive; A total MG-ADL score of ≥ 6 with less than 50% of the total score due to ocular symptoms; QMG ≥ 8, with ≥ 4 items score at least 2; Have been on a stable MG SoC regimen. Exclusion Criteria: Patients with autoimmune diseases other than MG; Abnormal laboratory results； Significant cardiovascular disease, liver, kidney, respiratory, endocrine or hematologic disease, or other medical conditions that, in the opinion of the investigator, would preclude the subject's participation in the study or require hospitalization during the study; Acute or chronic infection requiring treatment; Current active hepatitis; HIV antibody positive; Current thymoma-associated immunodeficiency syndrome (Good's syndrome) or thymic surgery within 6 months prior to screening; Received or plan to receive any live vaccine within 3 months prior to randomization; Patients with malignant tumors; Allergy to biological products of human origin; Participation in any clinical trial 28 days prior to randomization or within 5 times the half-life of an investigational drug (whichever is longer); Pregnant or lactating women, and those intending to become pregnant during the trial; Patients considered unsuitable by the investigator to participate in the trial (e.g., patients with severe mental disorders); Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Telitacicept<br>Participants will receive subcutaneous Telitacicept 240 mg once a week for a total of 48 doses in addition to MG SoC. | Biological: Telitacicept<br>* Administered as an SC infusion<br>* Other names: RC18;|
| Placebo Comparator: Placebo<br>Participants will receive subcutaneous placebo once a week for a total of 24 doses (part A) and then weekly subcutaneous Telitacicept 240 mg for 24 doses (part B) in addition to MG SoC. | Drug: Placebo<br>* Administered as an SC infusion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in MG-ADL | The MG-ADL is an 8-item patient-reported scale that measures MG symptoms and functional status. Each item ranges from 0 to 3 for a total score range of 0 to 24. | Week 24 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in MG-ADL | The MG-ADL is an 8-item patient-reported scale that measures MG symptoms and functional status. Each item ranges from 0 to 3 for a total score range of 0 to 24. | Weeks12, 36, 48 | 
| Change from baseline in QMG | The quantitative myasthenia gravis (QMG) score is a 13-item scale used to quantify disease severity in myasthenia gravis (MG). Total QMG score ranges from 0 (no myasthenic findings) to 39 (maximal myasthenic deficits). | Weeks 12, 24, 36, 48 | 
| Proportion of subjects with ≥ 3 points reduction from baseline in MG-ADL | The MG-ADL is an 8-item patient-reported scale that measures MG symptoms and functional status. Each item ranges from 0 to 3 for a total score range of 0 to 24. | Weeks 24, 48 | 
| Proportion of subjects with a decrease of ≥ 5 points from baseline in QMG | The quantitative myasthenia gravis (QMG) score is a 13-item scale used to quantify disease severity in myasthenia gravis (MG). Total QMG score ranges from 0 (no myasthenic findings) to 39 (maximal myasthenic deficits). | Weeks 24, 48 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Myasthenia Gravis, Autoimmune Diseases, Muscle Weakness