The Efficacy and Safety of Leflunomide or Azathioprine Therapy in Myasthenia Gravis Patients After Expand Thymectomy

Study Overview
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Brief Summary
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This is a randomized controlled clinical study. The investigators screen of eligible patients, randomized divide into the following two groups: corticosteroids + azathioprine group, corticosteroids + leflunomide group. The investigators treat the enrolled patients, estimate efficacy and observed the side effects according to the requirements of program. The investigators establish a clinical database for recording patients date and statistical analysis. Evaluation of short-term and long-term efficacy of thymectomized myasthenia gravis patients in the different group prove that what kind of treatment can improve the cure rate. The investigators will evaluate the acute toxicity (gastrointestinal side effects, liver and kidney dysfunction) and long-term toxicity (immune dysfunction, gonadal suppression) when the investigators apply these therapy in the treatment of different clinical types of myasthenia gravis.

Official Title
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The Efficacy and Safety of Leflunomide or Azathioprine Therapy in Myasthenia Gravis Patients After Expand Thymectomy

Conditions
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Myasthenia Gravis

Intervention / Treatment
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* Drug: Azathioprine
* Drug: Leflunomide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 12 to 65 years； Myasthenia gravis: Patients who are diagnosed as generalized or ocular myasthenia gravis have experienced extended thymectomy (including thymic hyperplasia and thymoma)， no significant complications in 6 months after operation , and does not received any immunosuppressants or glucocorticoids treatments. do not applied in plasmapheresis or immunoglobulins treatment during 3 months . women of child-bearing period do not have a plan of pregnant for at least 3 year. Written consent of the patient, after informing Exclusion Criteria: The liver , kidney or glycometabolic function is abnormal Seriously complications, such as infection or symptom in central nervous system, The patients who suffering from malignancy or a history of malignancy, a variety of sexually transmitted diseases and HIV infection, tuberculosis infection, and other condition which need to prohibit the use of immunosuppressive patients. Be allergic to leflunomide, azathioprine Pregnant or suckling period woman Accompanied with mental disorders and have difficult to communication Experienced myasthenia crisis in 3 months. suffering from clear cardiopulmonary functional and brain abnormalities Have a history of refractory hypertension or peptic ulcer . One of the white blood cells, hemoglobin, and platelet count obvious abnormalities

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 65 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Azathioprine<br>cholinesterase inhibitors+Glucocorticoid +Azathioprine | Drug: Azathioprine<br>* The basic therapy of each group is cholinesterase inhibitors (pyridostigmine 36mg / kg / d). Group 1 glucocorticoid + Azathioprine: Glucocorticoid (0.25mg/kg/d )plus Azathioprine at a starting dose of 50mg/d for 14 days, then increase up to 2mg/kg in 2 weeks.If no adverse events occurred , maintain the dose until 48 weeks.<br>|
| Active Comparator: Leflunomide<br>cholinesterase inhibitors+glucocorticoid+Leflunomide | Drug: Leflunomide<br>* The basic therapy of each group is cholinesterase inhibitors (pyridostigmine 36mg / kg / d). Group 2 glucocorticoid + Leflunomide: Glucocorticoid (0.25mg/kg/d )plus Leflunomide 20mg/d for adult, 10mg/d for child. if no adverse events occurred , maintain the dose until 48 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the percent of achieving good response | Pharmacologic Remission (PR) was the primary efficacy endpoint observed. Record the time the patient appears from the time of medication to the time of PR, and calculate the percentage of PR patients in each arm. Criteria for PR: The patient has had no symptoms or signs of MG for at least 1 year and continues to take some form of therapy for MG. There is no weakness of any muscle on careful examination by someone skilled in the evaluation of neuromuscular disease. Isolated weakness of eyelid closure is accepted. Patients taking cholinesterase inhibitors are excluded from this category because their use suggests the presence of weakness. | 144 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The changes of the disease severity and the antibody titer during the follow-up | The magnitude by which QMG or ADL scores are reduced. Total amount of steroid used during the follow-up. Level of the acetylcholine receptor antibody. | 144 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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myasthenia gravis, leflunomide