This study is a single-arm, exploratory clinical trial, aiming to include patients with HER2-positive advanced breast cancer. It intends to explore the efficacy and safety of trastuzumab combined with pyrotinib, capecitabine ± endocrine therapy as a first-line maintenance treatment for HER2+ advanced breast cancer after induction therapy with rucaparib trastuzumab.
After the subjects meet the screening criteria and are enrolled, they receive induction therapy with rucaparib trastuzumab. Among them, patients without disease progression enter the maintenance treatment period and receive trastuzumab combined with pyrotinib, capecitabine ± endocrine therapy (±OFS) for treatment. Until disease progression, or toxicity becomes intolerable, or withdrawal of informed consent, or the investigator determines that the medication must be discontinued. During the study period, imaging evaluations are conducted according to the RECIST 1.1 standard, and the center assessment results are the final results.
During the study period, the efficacy indicators such as PFS, ORR, DOR, CBR, and safety indicators of the subjects are evaluated according to the established trial standards, and statistical descriptions are conducted.
Female participants aged 18 to 75 years (inclusive)
HER2-positive breast cancer confirmed by histology or cytology (HER2 positivity defined as IHC 3+ or ISH+ in primary or metastatic lesions); locally advanced or metastatic breast cancer not amenable to curative surgery (participants eligible for curative treatment are excluded);
Clear HR status (HR-positive defined as ER and/or PR positive in primary or metastatic lesions, with ≥1% of tumor cells showing ER and/or PR staining);
No prior systemic anticancer therapy during the recurrent/metastatic phase (except ≤1 line of endocrine therapy allowed);
Patients with active central nervous system metastases who have not undergone surgery or radiation therapy, except those whose condition has been stable for at least one month after treatment and who have discontinued corticosteroids for more than 2 weeks.
A history of other malignancies within the past 5 years, excluding cured cases of cutaneous basal cell carcinoma, cervical carcinoma in situ, and papillary thyroid carcinoma.
Presence of third-space fluid accumulation (e.g., large volume ascites, pleural effusion, pericardial effusion) that cannot be controlled by drainage or other means.
Patients who have received surgery (defined as major cancer-related surgery), radiation therapy, chemotherapy, immunotherapy, molecularly targeted therapy, biological therapy, or participated in other drug clinical trials within 4 weeks prior to the first dose of study medication.