Combined Chemo-immunotherapy Plus SBRT in Neoadjuvant Treatment for Luminal Subtype Breast Cancer

Condition(s) studied

Investigational drug(s) / intervention(s)

Neoadjuvant radiotherapy: Neoadjuvant Radiotherapy Regimen: 1. Radiotherapy Technique: Stereotactic Body Radiation Therapy (SBRT) Radiation Dose and Fractionation: 8 Gy per fraction, for a total of 3 fractions, amounting to a total dose of 24 Gy 2. Radiotherapy Schedule: Irradiation begins on the second day of the first chemotherapy cycle and is administered every other day 3. Target Volume Definition: The radiotherapy target volume is defined based on baseline imaging (e.g., CT, MRI, or PET-CT) 4. Radiotherapy Equipment and Planning: Treatment is delivered using a linear accelerator equipped with Image-Guided Radiotherapy (IGRT) technology to ensure precise irradiation and dose optimization

Neoadjuvant Chemotherapy (NACT): Neoadjuvant Chemotherapy Regimen: A sequential chemotherapy strategy is adopted, with the specific regimen as follows: Taxane-based Chemotherapy Phase (T Phase): Nab-paclitaxel (125 mg/m²), administered by intravenous infusion on Day 1 and Day 8 of each 21-day cycle (Q3W), for a total of 4 cycles. Anthracycline-based Combination Chemotherapy Phase (EC Phase): Epirubicin (75-100 mg/m²) in combination with cyclophosphamide (600 mg/m²), administered by intravenous infusion every 21 days (Q3W), for a total of 4 cycles. The EC phase commences upon completion of the T phase.

Immunotherapy (Sintilimab): Immunotherapy Regimen: Sintilimab (200 mg), administered by intravenous infusion every three weeks (Q3W). Dosing begins on Day 2 of the chemotherapy cycles, for a total of 8 treatment cycles.

Study summary

This study is a prospective, randomized controlled clinical trial designed to evaluate the efficacy and safety of combining radiotherapy, chemotherapy, and immunotherapy in the neoadjuvant treatment of high-risk HR+/HER2- breast cancer patients.

The study plans to enroll treatment-naïve HR+/HER2- breast cancer patients aged 18-75 with high-risk features (e.g., tumor size ≥3 cm or lymph node positivity, Ki-67 ≥20%). Eligible subjects will be randomized in a 1:1 ratio into two groups: the control group will receive neoadjuvant chemotherapy (nab-paclitaxel followed by epirubicin + cyclophosphamide) in combination with sintilimab immunotherapy; the experimental group will receive the same chemotherapy and immunotherapy regimen with the addition of stereotactic body radiotherapy (SBRT) administered early during treatment, at a prescribed dose of 8 Gy per fraction for 3 fractions, with one fraction per day.

The study has dual primary endpoints: pathological complete response (pCR,) and objective response rate (ORR ). Secondary endpoints include 3-year event-free survival (EFS), incidence of adverse events (CTCAE v5.0), and postoperative cosmetic outcomes of the breast. The study design incorporates hierarchical testing to control for multiplicity, and long-term follow-up is planned to evaluate survival benefits.

The study has been approved by the ethics committee, and all participants are required to provide written informed consent. The results are expected to offer a novel neoadjuvant treatment strategy for high-risk HR+/HER2- breast cancer patients and improve their therapeutic outcomes.

Eligibility

Primary outcome measure(s)

• Pathological complete response rate（pCR） — Pathological diagnosis results were obtained tithin one month after the operation
  Postoperative pathological assessment (tumor Miller-Payne system grading and axillary lymph node pathological assessment)

Trial sites (1)

More First Affiliated Hospital of Wenzhou Medical University trials in China

Other trials for the same condition