This study aims to explore the efficacy and safety of neratinib combined with fulvestrant and eribulin in the treatment of HR+/HER2+ advanced breast cancer after trastuzumab deruxtecan resistance. The treatment regimen of neratinib + fulvestrant + eribulin in this study is expected to provide a new and effective therapeutic strategy for patients with triple-positive breast cancer who develop resistance to trastuzumab deruxtecan, and offer novel therapeutic insights for advanced triple-positive breast cancer.
Female patients aged ≥18 years and ≤75 years;
ECOG performance status of 0-2;
Definition of HER2 positivity: IHC 3+ or IHC 2+/ISH positive prior to T-DXd treatment;
Definition of HR positivity: ER or PR ≥1%;
Severe allergic reactions to neratinib, eribulin, fulvestrant, or any of their excipients;
Prior treatment with neratinib, other small-molecule anti-HER2 TKIs, or eribulin;
Patients with inflammatory breast cancer;
A history of other malignant tumors within the past 5 years or concurrent malignant tumors (including cured malignant tumors such as carcinoma in situ of the cervix, basal cell carcinoma, or squamous cell carcinoma);