2. Histologically or cytologically confirmed HR+/HER2- (HER2 IHC 0/IHC 1+ or IHC 2+ with FISH-negative) locally advanced unresectable or metastatic breast cancer, as defined by ASCO/CAP guidelines;
3. Prior treatment with CDK4/6i combined with endocrine therapy, with radiologically confirmed disease progression;
4. Presence of evaluable lesions;
5. Received ≤2 lines of chemotherapy for advanced disease;
6. Adequate organ function and performance status (ECOG score ≤2);
7. Signed informed consent.
You may not be if
1. Previous treatment with topoisomerase 1 (TOP-1) inhibitor-based therapy;
2. Severe cardiac, hepatic, or renal dysfunction or other serious comorbidities;
3. History of moderate to severe interstitial lung disease (ILD) with concurrent pulmonary insufficiency;
4. Symptomatic brain metastases;
5. History of allergy to key components of the investigational ADC drugs (e.g., payload, antibody, or linker);
6. Patients with active chronic inflammatory bowel disease (ulcerative colitis, Crohn's disease) or a history of intestinal obstruction or gastrointestinal (GI) perforation;
7. Uncontrolled cardiovascular diseases (e.g., NYHA Class III/IV heart failure, myocardial infarction within 6 months);
8. Active infections (e.g., HIV, active HBV/HCV infection);
9. Pregnant or lactating women.
Clareo Health | Cohort Study on Sequential ADC Therapy in HR-positive/HER2-negative Advanced Breast Cancer
