New drug cocktail shows promise for Hard-to-Treat breast cancer before surgery

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Age ≥18 and ≤70 years 2. Histologically confirmed invasive breast cancer, HR+ (ER ≥1% and/or PR ≥1%) and HER2-low (IHC 1+ or IHC 2+/ISH-) 3. No prior systemic anti-tumor therapy for breast cancer 4. Stage II-III (T1cN1-2M0, T2-4N0-2M0) per AJCC 8th edition 5. At least one of the following intermediate-to-high risk factors: * Axillary lymph node involvement ≥1 * Tumor size≥2 cm * Grade 3 tumor * Ki-67 ≥20% 6. At least one measurable lesion per RECIST 1.1 7. ECOG PS 0-1 8. Adequate organ function (ANC ≥1.5×10⁹/L, platelets ≥100×10⁹/L, Hb ≥90 g/L, TBIL ≤1.5×ULN, ALT/AST ≤2.5×ULN, Cr ≤1.5×ULN or CrCl ≥60 mL/min, LVEF ≥50%, QTcF ≤470 ms in females, DLCO ≥50% predicted 9. Negative pregnancy test (for women of childbearing potential) and agreement to use adequate contraception during and for 6 months after treatment 10. Willing and able to provide informed consent and comply with study procedures Exclusion Criteria: 1. Non-pathologically confirmed breast cancer 2. Bilateral, inflammatory, or occult breast cancer 3. Prior anticancer therapy (chemotherapy, radiotherapy, targeted therapy, endocrine therapy, etc.) 4. Concurrent use of other anticancer treatments 5. Other malignancy within 5 years (except cured basal cell carcinoma or cervical carcinoma in situ) 6. Participation in another interventional clinical trial within 4 weeks prior to first dose 7. Use of immunosuppressive agents or systemic corticosteroids (\>10 mg/day prednisone or equivalent) within 2 weeks prior to first dose 8. Live or attenuated vaccine within 4 weeks prior to first dose 9. Major surgery unrelated to breast cancer within 4 weeks prior to first dose 10. Active or history of autoimmune disease requiring systemic treatment 11. Known immunodeficiency (e.g., HIV positivity) or history of organ transplantation 12. Uncontrolled or significant cardiovascular disease (e.g., NYHA class III/IV heart failure, myocardial infarction, unstable angina, arrhythmia requiring treatment, QTcF \>470 ms, uncontrolled hypertension) 13. Known or suspected interstitial lung disease (ILD) or significant pre-existing pulmonary disease 14. Active hepatitis B (HBsAg positive and HBV DNA ≥500 IU/mL) or hepatitis C (HCV RNA above ULN), cirrhosis, or uncontrolled severe infection 15. Known bleeding or thrombotic tendency 16. Allergy or contraindication to any study drug or excipient 17. Pregnancy, breastfeeding, or positive pregnancy test at baseline 18. Any concurrent condition that may compromise patient safety or study compliance (e.g., uncontrolled hypertension, severe diabetes, active infection) 19. History of neurological or psychiatric disorders (e.g., epilepsy, dementia) or any condition deemed unsuitable by the investigator.