To evaluate the efficacy and safety of the SHR6390 in combination with anastrozole, pyrotinib, and trastuzumab in patients with ER-positive, HER2-positive breast cancer in the neoadjuvant setting.

Inclusion Criteria:

1. Written informed consent for all study according to local regulatory requirements prior to beginning specific protocol procedures.
2. Age at diagnosis ≥18 years and ≤75 years, female.
3. Histologically confirmed diagnosis of Unilateral ER+/HER2+ breast cancer. ER-positivity is defined as >1% stained cells；HER2-positivity is defined as IHC 3+ or if IHC scored 2+, in-situ hybridisation (ISH) suggests amplified HER2 gene.
4. Tumor diameter >2 centimeters with the clinical stage being classified as from IIa to IIIc.
5. ECOG ≤ 1, LVEF ≥ 55%.
6. Laboratory requirements: for hematology, absolute neutrophil count (ANC) ≥1.5 × 109 / L and platelets ≥100 × 109 / L and hemoglobin ≥90 g/L; for hepatic function, total bilirubin ≤1.5 × UNL, AST and ALT ≤2.5 × UNL; for renal function, SCr ≤1.5 × UNL.

Exclusion Criteria:

1. Evidence of bilateral invasive breast cancer or metastatic disease (M1).
2. Pevious treatment with chemotherapy, hormonal therapy, an investigational drug for any type of malignancy, or radiation therapy.
3. Any of the following exist in the last 6 months: known or suspected congestive heart failure (≥ NYHA II), persistent arrhythmias (≥ grade 2), atrial fibrillation of any grade, coronary / peripheral bypass, symptomatic congestive heart failure, cerebrovascular accidents (including transient cerebral hemorrhage attacks or symptomatic pulmonary embolism).
4. Known hypersensitivity reaction to one of the compounds or incorporated substances used in this protocol.
5. Active infection or severe symptomatic visceral disease in the last 4 weeks.
6. Patients with HIV infection or known AIDS, or patients with infection of active hepatitis B (HBV DNA ≥1000IU / ml) or hepatitis C (hepatitis C antibody is positive and HCV RNA is above the lower limit of detection of the analytical method).
7. Prior malignancy with a disease-free survival of < 5 years, except curatively treated basalioma of the skin, pTis of the cervix uteri.
8. Pregnant or lactating patients. Patients of childbearing potential must implement adequate non-hormonal contraceptive measures (barrier methods, intrauterine contraceptive devices, sterilization) during study treatment.
9. Participation in another clinical trial with any investigational, not marketed drug within 30 days prior to study entry.
10. Not eligible for the trial assessed by the investigators of our study.