Patient description: The patient is a 16-year-old girl recently diagnosed with myasthenia gravis, class IIa. She complains of diplopia and weakness affecting in her upper extremities. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She is on acetylcholinesterase inhibitor treatment combined with immunosuppressants. But she still has some symptoms. She does not smoke or use illicit drugs. She is not sexually active, and her menses are regular. Her physical exam and lab studies are not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 18.0-85.0,  Myasthenia Gravis, Generalized Anti-acetylcholine receptor (AChR) antibody positive Confirmed diagnosis of generalized myasthenia gravis (MG) Myasthenia Gravis Foundation of America (MGFA) classification of Class II, III, or IVa inclusive at Screening QMG >= 10 at Screening. Note: Subjects who only have a history of ocular MG may not enroll Receiving standard of care MG treatment at a stable dose consisting of any one of the following for the time intervals delineated below (time intervals apply to medications and maintenance of stable dose level): 1. Cholinesterase inhibitor (pyridostigmine or equivalent) for at least 2 weeks prior to Screening and no immunosuppressants 2. Cholinesterase inhibitor (pyridostigmine or equivalent) for at least 2 weeks prior to Screening AND/OR only one of the following: 1. Prednisone (up to 60 mg/day or equivalent) for at least 2 months prior to Screening, OR 2. Azathioprine for at least 6 months prior to Screening, OR 3. Mycophenolate mofetil for at least 6 months prior to Screening, OR 4. Methotrexate for at least 6 months prior to Screening, OR 5. Cyclosporine or tacrolimus for at least 3 months prior to Screening 3. Cholinesterase inhibitor (pyridostigmine or equivalent) for at least 2 weeks prior to Screening AND/OR prednisone (up to 60 mg/day or equivalent) for at least one month prior to Screening and only one of the following: 1. Azathioprine for at least 6 months prior to Screening, OR 2. Mycophenolate mofetil for at least 6 months prior to Screening, OR 3. Methotrexate for at least 6 months prior to Screening, OR 4. Cyclosporine or tacrolimus for at least 3 months prior to Screening  Have received cyclophosphamide or any other immunosuppressive agent apart from the ones allowed per within the past 6 months Any change in MG treatment regimen between Screening (Week -3, Visit 0) and Baseline (Week 0, Visit 1) Greater than two point change in QMG score, increased or decreased, between Screening (Week -3, Visit 0) and Baseline (Week 0, Visit 1) Any episode of myasthenic crisis in the one month prior to Screening Evidence of malignancy within the past 5 years (non-melanoma skin cancer, carcinoma in situ of cervix is allowed) or thymoma potentially requiring surgical intervention during the course of the trial (intent to perform thymectomy) Thymectomy within the preceding 6 months Rituximab, belimumab, eculizumab or any monoclonal antibody used for immunomodulation within the past 12 months Have received immune globulin (Ig) treatment given by intravenous (IV), subcutaneous, or intramuscular route within the last 3 months Current known hyperviscosity or hypercoagulable state Currently receiving anti-coagulation therapy (vitamin K antagonists, nonvitamin K antagonist oral anticoagulants [e.g., dabigatran etexilate, rivaroxaban, edoxaban, and apixaban], parenteral anticoagulants [e.g., fondaparinux]). Note that oral anti-platelet agents are allowed (e.g., aspirin, clopidogrel, ticlodipine)