Neoadjuvant Treatment With Palbociclib and Exemestane Plus Trastuzumab and Pyrotinib in Estrogen Receptor (ER)-Positive, HER2-positive Breast Cancer

neoPEHP is a multicohort, open-label, exploratory, phase 2 study. Patients were eligible if they had previously untreated, histologically confirmed, unilateral, invasive, HER2-positive, ER-positive breast cancer and were suitable for neoadjuvant therapy. Patients were treated every 3 weeks with intravenous trastuzumab (8 mg/kg loading dose followed by 6 mg/kg) and oral pyrotinib (400 mg po QD) for six cycles plus oral palbociclib (125 mg once a day for 21 days in a 4-week cycle) and oral exemestane (25 mg po QD) every 4 weeks for 24 weeks. The primary endpoints was pathological complete response.