Patient description: The patient is a 35-year-old woman with myasthenia gravis, class IIa. She complains of diplopia and fatigue and weakness that affects mainly her upper limbs. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She takes pyridostigmine 60 mg three times a day. But she still has some symptoms that interfere with her job. She is a research coordinator and has 3 children. Her 70-year-old father has hypertension. She does not smoke or use illicit drugs. She drinks alcohol occasionally at social events. Her physical exam and lab studies were 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): 18.0-75.0,  Graves Ophthalmopathy Patients willing and capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form 2. A diagnosis of Graves' disease based on the presence of hyperthyroidism (either untreated or treated with antithyroid drugs) associated with detectable anti-thyrotropic hormone (TSH) receptor autoantibodies (TRAb). Patients must be euthyroid under control on stable medical regimen and every effort will be made to maintain the euthyroid status for the entire duration of the clinical trial 3. A moderate-to-severe GO, defined as the presence of at least one of the following an exophthalmos ≥2 mm compared with normal values for sex and race; presence of inconstant to constant diplopia; a lid retraction ≥2 mm 4. Active GO: CAS (4) ≥ 3 out of 7 points in the most affected eye 5. Male and female patients of age: 18-75 years 6. Creatinine values within the reference range 7. Indexes of liver function: aspartate aminotransferase (AST), alanine aminotransferase (ALT), Gamma-glutamyl transferase (γGT), alkaline phosphatase, total and direct bilirubin) within the normal range 8. Normal blood count, absence of diseases of hematopoiesis 9. Women of childbearing potential (WOCBP, namely not in menopause or in menopause since less than two years; in all other instances women will be considered as non-WOCBP) and men who are sexually active with WOCBP must use any contraceptive method with a failure rate of less than 1% per year (as indicated in Appendix) for at least 6 and 7,5 months, respectively, after the last dose of the investigational drug (see also 2014_09_Heads of Medicines Agencies (HMA)_Clinical Trial Facilitation Group (CTFG)_Contraception.pdf, namely the "2014 CTFG Reccommendations related to contraception and pregnancy testing in clinical trials") 10. Compliant patients, regular follow-up possible  Optic neuropathy 2. Treatment with glucocorticoids, other immunosuppressive drugs or selenium for the last three months 3. Contraindications to Sirolimus: hypersensitivity to the active substance or to any of the excipients; use of medications interfering with the pharmacokinetic and/or pharmacodynamic properties of rapamycin (e.g. CYP3A4 inhibitors or inducers; see "prohibited therapies") 4. Pregnant or lactating females as determined by positive serum or urine human chorionic gonadotropin (HCG) test at baseline 5. Acute or chronic liver disease 6. Relevant malignancies 7. Current and/or previous diseases of hematopoiesis 8. Recent (≤1 year) history of alcoholism or drug abuse 9. Mental illness that prevent patients from comprehensive, written informed consent