Efficacy and Safety of Pyrotinib Maleate Combined With ARX788 Neoadjuvant Treatment in Stage II-III HER2-positive Breast Cancer Patients Who Have Poor Outcomes After Treatment With Trastuzumab and Pertuzumab
Next-generation Site-specific human epidermal growth factor receptor 2 (HER2)-targeting Antibody-drug Conjugate (ARX788) is an antibody-conjugated drug. Results from the phase I safety, tolerability and pharmacokinetic trial of ARX788 single drug in Chinese patients with advanced HER2 breast cancer indicated a good safety of the test drug, and responses to anti-tumor therapy were observed in the target dose group. Phase II clinical trial is being carried out gradually. This trial is designed to observe the effectiveness and safety of pyrotinib maleate combined with ARX788 neoadjuvant treatment in stage II-III HER2-positive breast cancer patients experiencing a poor efficacy of trastuzumab and pertuzumab.
• Female patients aged ≥ 18 but ≤ 75 years (The maximal age of the subjects enrolled in the Phase 3 study of pyrotinib is 75 years old, and there is no safety data for the use of the drug in older people);
• Diagnosis of breast cancer meets the following criteria: Histologically confirmed invasive breast cancer; Tumor staging: Stage II-III patients who meet the 8th edition of AJCC Cancer Staging Manual; Patients who have undergone neoadjuvant therapy with trastuzumab and pertuzumab and have been assessed as SD (an increase of 0-20%), PD, inoperable or failing to meet the breast-conserving requirements; Failing to meet the breast-conserving requirements is defined as not meeting the following criteria: tumor size of T1 and T2 stage, proper breast volume, proper tumor-to-breast volume ratio, and able to maintain a good breast shape after surgery.
• HER2-positive breast cancer pathologically confirmed is defined as Immunohistochemical method (IHC3+) or FISH+;
• Eastern Cooperative Oncology Group (ECOG) level 0-1;
• The functional level of major organs must conform to the following requirements: Neutrophils (ANC) ≥ 1.5×109/L (with no use of growth factors within 14 days); Platelet count (PLT) ≥ 100×109/L (with no correct treatment within 7 days ); Hemoglobin (Hb) ≥ 90 g/L (with no correct treatment within 7 days ); Total bilirubin (TBIL) ≤ 1.5×upper limit of normal (ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3×ULN; Urea nitrogen and creatinine ≤ 1.5×ULN and creatinine clearance ≥ 50 mL/min (Cockcroft-Gault formula); Cardiac color Doppler ultrasound: left ventricular ejection fraction (LVEF) ≥ 50%; 12-lead electrocardiogram: QT interval ≤ 480 ms;
• Able to receive needle biopsy;
• Patients who participate in the trial voluntarily, sign an informed consent, have good compliance and are willing to comply with the follow-up visit.