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,  Adenocarcinoma of the Oesophagus Adenocarcinoma of the Gastro-oesophageal Junction Adenocarcinoma of the Stomach All Patients Histologically verified inoperable locally advanced or metastatic adenocarcinoma of the oesophagus, oesophago-gastric junction, or stomach Completion of 6 cycles of first-line chemotherapy for locally advanced / metastatic disease (this must have included a platinum and fluoropyrimidine in all cases; HER-2 positive patients must have received trastuzumab alongside chemotherapy) with > stable disease on the end of treatment CT scan. If your patient has received first line therapy, delivered on a two weekly basis e.g. they should have received 8 cycles Disease which, following first-line chemotherapy, remains inoperable and unsuitable for definitive chemoradiotherapy Able to proceed with maintenance treatment within 28 days of the last day of the last cycle of chemotherapy Formalin fixed paraffin embedded (FFPE) blocks of diagnostic tissue available for biomarker analysis Any prior chemotherapy or radiotherapy in the adjuvant setting must have been completed at least 6 months prior to the first occurrence of metastatic disease No prior radiotherapy in the advanced disease setting. Patients receiving palliative radiotherapy to sites of disease that are not measurable may be eligible and should be discussed with the Chief Investigator Male/female patients aged ≥18 years WHO Performance status 0, 1 or 2  All Patients Concurrent enrolment in another clinical trial unless it is an observational (non-interventional) clinical study Tumours of squamous histology Documented brain metastases, central nervous system metastases or leptomeningeal disease Patients who have not recovered from clinically significant effects of any prior surgery, radiotherapy or any other anti-neoplastic therapies. All toxicities must have resolved to grade 1 or less, with the exception of peripheral neuropathy which must be < grade 2 according to NCI CTCAE version 4.0 Any major surgery within 4 weeks prior to the start of study treatment Uncontrolled hypertension (systolic blood pressure >180 mm Hg or diastolic blood pressure >100 mm Hg) Clinically significant (i.e. active) cardiac disease e.g. symptomatic coronary artery disease, symptomatic congestive heart failure, uncontrolled cardiac dysrhythmia, or myocardial infarction within the last 12 months. Patients with any prior history of clinically significant cardiac failure are excluded from study entry History of interstitial lung disease (e.g., pneumonitis or pulmonary fibrosis) or evidence of interstitial lung disease on baseline chest CT scan Lack of physical integrity of the upper gastro-intestinal tract, malabsorption syndrome, or inability to take oral medication