Neoadjuvant Pyrotinib-to-pertuzumab in HER2+ eBC

• Docetaxel (Drug): docetaxel ivgtt q3w, 80-100mg/m2
• Pyrotinib (Drug): pyrotinib 320mg p.o. qd
• Trastuzumab (Herceptin) (Drug): trastuzumab ivgtt q3w, 8mg/kg for initiation, 6mg/kg for maintenance, or 600mg sc q3w
• Pertuzumab (Drug): pertuzumab ivgtt q3w, 840mg for initiation, 420mg for maintenance

Primary outcomes

• tpCR [From enrollment to the end of treatment at 24 weeks]: After completion of neoadjuvant therapy and surgery, no residual invasive carcinoma in the evaluation of hematoxylin and eosin stained of breast and lymph node samples

Secondary outcomes

• bpCR [From enrollment to the end of treatment at 24 weeks]: After completion of neoadjuvant therapy and surgery, no residual invasive carcinoma in the evaluation of hematoxylin and eosin stained breast samples
• EFS [through study completion, an average of 2 year]: The time interval from randomization to the first recording of the following events: disease progression (before surgery), as determined by investigator reference RECIST1.1, combined with clinical evaluation, final judgment; postoperative disease recurrence (local, regional, distal, or contralateral); second primary malignancy; Death from any cause
• OS [through study completion, an average of 5 year]: Time interval from randomization to death from any cause.
• Early ctDNA clearance [From enrollment to the end of treatment at 24 weeks]: The rate of ctDNA clearance after first two cycles of neoadjuvant treatments
• Late ctDNA clearance [From enrollment to the end of treatment at 24 weeks]: The rate of ctDNA clearance after first four cycles of neoadjuvant treatments
• rCR [From enrollment to the end of treatment at 24 weeks]: After completion of neoadjuvant therapy, no lesions presenting washout kinetic curve pattern in MRI
• Number of participants with treatment-related adverse events as assessed by CTCAE v4.0 [From enrollment to the end of treatment at 24 weeks]

Sex: Female, ages: 18 Years to 70 Years

Inclusion Criteria:

1. Signed informed consent.
2. Age: Female patients aged 18-70 years.
3. Breast cancer meeting the following criteria:

   1. Histologically confirmed invasive breast cancer, with primary tumor diameter ≥ 2.0 cm, Stage II-III as assessed by local standard methods.
   2. HER2-positive breast cancer, defined as Immunohistochemistry (IHC) score 3+ or In Situ Hybridization (ISH) showing HER2 gene amplification.
4. Eastern Cooperative Oncology Group (ECOG) performance status score ≤ 1.
5. All required baseline laboratory tests and imaging studies completed before randomization.
6. Adequate organ function
7. For non-menopausal (amenorrhea < 12 months) or non-surgically sterile female patients (without ovaries and/or uterus): Agreement to abstain or use reliable and effective contraception during treatment and for at least 6 months after the last dose of study treatment.
8. Investigator judgment that the patient can comply with the study protocol.

Exclusion Criteria:

1. Bilateral breast cancer or metastatic (Stage IV) breast cancer.
2. Significant cardiac disease:

   1. History of myocardial infarction, acute coronary syndrome, or coronary angioplasty/stenting/bypass within the past 6 months.
   2. New York Heart Association (NYHA) Class II-IV congestive heart failure (CHF) or history of NYHA Class III or IV CHF.
   3. High-risk uncontrolled arrhythmias, such as atrial tachycardia, resting heart rate > 100 bpm, significant ventricular arrhythmias (e.g., ventricular tachycardia), or higher-grade atrioventricular (AV) block.
   4. Angina requiring anti-anginal medication.
   5. Clinically significant valvular heart disease.
   6. ECG evidence of transmural myocardial infarction.
3. Other malignancies within the past 5 years, except cured carcinoma in situ of the cervix or non-melanoma skin cancer.
4. Severe systemic infection or patients with other serious diseases.
5. Major non-breast surgery within 4 weeks of randomization, or patients who have not fully recovered from such surgery.
6. Known history of Human Immunodeficiency Virus (HIV) infection.
7. Active hepatitis B or hepatitis C virus infection.
8. Known allergy or intolerance to the study drugs or their excipients.
9. Prior cytotoxic chemotherapy, endocrine therapy, biological therapy, or radiotherapy for any reason.
10. Currently enrolled in or previously participated in a study of an investigational drug and received investigational treatment or used an investigational device within 4 weeks before the first dose of study treatment (12 months for investigational drugs/devices with anti-cancer or anti-proliferative properties).
11. Vaccination with a live vaccine within 30 days before the first dose of the investigational drug.
12. Psychiatric illness or substance abuse history that could affect compliance with trial requirements.
13. Pregnancy or breastfeeding, or female patients of childbearing potential who refuse to take appropriate contraceptive measures during the trial.
14. Patients judged by the investigator to be unsuitable for participation in this study.