A Study of Pyrotinib Plus Capecitabine Versus Lapatinib Plus Capecitabine in Patients With HER2+Metastatic Breast Cancer Who Have Prior Received Anthracyclin, Taxane or Trastuzumab

Inclusion Criteria

• •Aged ≥18 and ≤70 years.
• •ECOG performance status of 0 to 1.
• •Life expectancy of more than 12 weeks.
• •At least one measurable lesion exists.(RECIST 1.1).
• •Histologically or cytologic confirmed HER2 positive advanced breast cancer which failed prior therapies.
• •Required laboratory values including following parameters:
• •ANC: ≥ 1.5 x 10\^9/L;Platelet count: ≥ 100 x 10\^9/L;Hemoglobin: ≥ 9.0 g/dL;Total bilirubin: ≤ 1.5 x upper limit of normal (ULN);ALT and AST: ≤ 1.5 x ULN;BUN and creatine clearance rate: ≥ 50 mL/min;LVEF: ≥ 50%;QTcF: \< 470 ms for female and \< 450 ms for male.
• •Signed informed consent