Z650 in Advanced Esophageal Squamous Cell Carcinoma With EGFR Over Expression or Gene Amplification

Inclusion Criteria: * Histologically or cytologically confirmed Stage IIIB or IV ESCC * At least experienced one regimens of chemotherapy prior to study * Histological or cytological evidence of EGFR overexpression or gene copy number increased * Measurable disease according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) * Toxicity recovered to NCI CTCAE v.4.03 Grade ≤1 from previous treatments (except alopecia) * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 or 1 * Life expectancy of ≥ 12 weeks * Adequate organ function * Subject Consent * Signed and dated informed consent document indicating that the patient (or legally acceptable representative) has been informed of all the pertinent aspects of the trial prior to performing this study. * Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures. Exclusion Criteria: * Prior treatments * EGFR targeted therapy, or major surgery within 4 weeks prior to study treatment * Nitrosourea and mitomycin chemotherapy within 6 weeks prior to study treatment * Had received any investigational agent from other clinical study within 4 weeks prior to study treatment or are currently participating in other clinical trials * Gastrointestinal diseases that could affect the absorption of Z650, (e.g., serious swallowing obstruction, chronic diarrhea, bowel obstruction); * Symptomatic, untreated or unstable central nervous system metastases (patient are only permitted if treated, asymptomatic and stable for at least 4 weeks prior to start of study treatment) * History of interstitial lung disease * Uncontrolled hypertension that require more than two anti-hypertensive agents to control, or systolic blood pressure (BP) \>140mmHg or diastolic BP \>90 mmHg before the first administration * Doppler ultrasound evaluation of Left ventricular ejection fraction \< 50% * Male with QTc interval \> 450 ms or female with QTc interval \> 470 ms * History of immunodeficiency, or other acquired or congenital immunodeficiency, or history of organ transplantation * Any disease of the following bellowed within 6 months prior to administration: Myocardial infarction, or unstable angina, coronary or peripheral artery bypass graft, congestive heart failure, or cerebrovascular events (including transient ischemic attack) * Active infection of hepatitis B virus (HBV)/hepatitis C virus (HCV), or infection of Human immunodeficiency virus (HIV) * Other malignancies within 5 years prior to enrollment, with the exception of carcinoma in situ of the cervix, basal or squamous cell skin cancer * History of serious allergic reactions attributed to excipients of Z650, including mannitol, sodium carboxymethyl starch, aerosol, magnesium stearate and silicified microcrystalline cellulose * Pregnant women, or patients not agree to use of effective contraceptions during the study or within 6 month after the study * Any other reason the investigator considers the patient is not suitable to participate in the study