Darsilide Combined With AI, Trastuzumab and Patuzumab in the Neoadjuvant Treatment of HR+/HER2+ Breast Cancer

This study is intended to carry out a single arm, prospective, open clinical study, and use Darsilide combined with endocrine therapy, Trastuzumab and Patuzumab to treat early or locally advanced breast cancer of TPBC before surgery. It is intended to further explore the efficacy and safety of the new adjuvant treatment for TPBC patients with step-down therapy. All participants received 150mg of darcilib once a day. Take it continuously for 21 days, then stop taking it for 7 days, with a treatment cycle of 28 days.Letrozole 2.5mg once daily (premenopausal patients treated with OFS).Trastuzumab (8mg/kg first dose, 6mg/kg sequential) and Patuzumab (840mg first dose, 420mg/kg sequential) were administered intravenously every 3 weeks, or fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection (1200 mg pertuzumab plus 600 mg trastuzumab loading dose in 15 mL, followed by 600 mg pertuzumab plus 600 mg trastuzumab maintenance doses in 10 mL), both administered every 3 weeks, with all patients receiving 8 cycles of treatment. After starting treatment and before surgery, subjects will be monitored through breast MRI to evaluate clinical tumor remission. The primary endpoint was the pCR rate in the group receiving darcilib+letrozole+HP treatment, defined as the proportion of patients who achieved pCR after surgery after neoadjuvant therapy.