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): 14.0-999.0,  Leukemia Must be >14 years of age 2. Must be diagnosed with refractory or relapsed AML or ALL. 3. Must have adequate organ function as demonstrated by the following: o Alanine Aminotransferase (ALT) (SGOT) and/or Aspartate Aminotransferase (AST) (SGPT) equal to or less than 1.5x upper limit of normal o Serum creatinine equal to or less than 2.5 mg/dL 4. Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, 1, or 2 5. At least 2 weeks from prior leukemia-directed treatment to starting treatment drug (except for hydroxyurea, which is allowed if clinically indicated but should be stopped after 2 weeks of receiving study drug, and glucocorticoids, which are allowed but should be stopped upon starting treatment drug). 6. Treatment-related toxicities from prior therapies must have resolved to Grade equal to or less than 1 (except for peripheral neuropathy, which should resolve to grade equal to or less than 2) 7. No active malignancies with the exception of basal cell or squamous cell carcinoma of the skin, or carcinoma "in situ" of the cervix or breast. 8. Females of childbearing potential (FCBP)(A female of childbearing potential is a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months) must have negative pregnancy test. FCBP and males participating in the study must agree to use a reliable form of contraception or to practice complete abstinence from heterosexual intercourse while participating in the study and for at least 28 days after discontinuation from the study. If pregnancy or a positive pregnancy test does occur in a study subject, treatment with the study drug must be immediately discontinued  Known positive status for HIV, or known active hepatitis A, B, or C infection. 2. Any serious medical condition or psychiatric illness that would prevent, (as judged by the treating physician) the subject from signing the informed consent form or any condition, including the presence of laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study or confounds the ability to interpret data from the study. 3. Pregnant or lactating females. 4. Acute promyelocytic leukemia 5. Concurrent use of strong inducers or strong inhibitors of cytochrome P450 3A4 (CYP3A4). Strong inducers are rifampin and St. John's Worth. Strong inhibitors are HIV-antivirals, clarythromycin, itraconazole, ketoconazole, nefazodone, and telithromycin. 6. Participating in any other research trial