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): 18.0-999.0,  DS Stage I Plasma Cell Myeloma DS Stage II Plasma Cell Myeloma DS Stage III Plasma Cell Myeloma Refractory Plasma Cell Myeloma Patients must have histologically or cytologically confirmed multiple myeloma meeting with symptomatic disease requiring treatment; patients considered to have high risk disease (defined as chromosome 13 deletion by cytogenetics; t(4;14), t(14;16) or 17p deletion by fluorescence in situ hybridization [FISH], B2-M > 5.5 g/dL, immunoglobulin A [IgA] phenotype) in first remission (>= partial remission [PR]) or patients with relapsed myeloma responding to salvage therapy (>= PR) based on the International Uniform Response are eligible Patients must have measurable disease utilizing serum or urine protein electrophoresis or serum kappa / lambda light chain assay Patients must be planning to proceed to single autologous transplantation according to institutional standards and must receive this transplantation prior to implementation of GDC-0449 Concomitant bisphosphonate use is allowed as clinically indicated Eastern Cooperative Oncology Group (ECOG) performance status =< 2 (Karnofsky >= 60%) Life expectancy of greater than 6 months Women of child-bearing potential and men must use two forms of contraception (i.e., barrier contraception and one other method of contraception) at least 4 weeks prior to GDC-0449 treatment, for the duration of study participation, and for at least 12 months post-treatment; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately Women of childbearing potential are required to have a negative serum pregnancy test (with a sensitivity of at least 25 mIU/mL) within 10-14 days and within 24 hours prior to the first dose of GDC-0449 (serum or urine); a pregnancy test (serum or urine) will be administered every 4 weeks if their menstrual cycles are regular or every 2 weeks if their cycles are irregular while on study within the 24-hour period prior to the administration of GDC-0449; a positive urine test must be confirmed by a serum pregnancy test; prior to dispensing GDC-0449, the investigator must confirm and document the patient's use of two contraceptive methods, dates of negative pregnancy test, and confirm the patient understands of GDC-0449 cause serious or life-threatening birth defects Women of childbearing potential are defined as follows Patients with regular menses