Preoperative Immunotherapy Combined With Stereotactic Radiation Therapy Boost in the Treatment of HER2-negative Breast Cancer
NCT Number: NCT06472583
Acronym: BREAST-BOOSTER
Status: RECRUITING
Study Type: INTERVENTIONAL
Phases: PHASE2
Conditions: Breast Cancer
Interventions: DRUG: Keytruda|RADIATION: Preoperative radiation therapy|DRUG: Placebo
Sponsor: Maria Sklodowska-Curie National Research Institute of Oncology
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 78
Study Design: Allocation: RANDOMIZED|Intervention Model: SINGLE_GROUP|Masking: DOUBLE (PARTICIPANT, INVESTIGATOR)|Primary Purpose: TREATMENT
Start Date: 2024-04-11
Completion Date: 2028-02-28
Locations: Maria Sklodowska-Curie National Research Institute of Oncology , Gliwice Branch, Gliwice, Poland

Summary:
The goal of the study is to assess the safety and effectiveness of the combination of anti-PD1 immunotherapy (pembrolizumab) and radiotherapy in the preoperative treatment of HER2-negative breast cancer resistant to classical chemotherapy.

The subject of the intervention will be:

1. Randomly assigned in a 2:1 ratio and double-blinded addition of pre-operative immunotherapy with pembrolizumab or placebo to standard chemotherapy
2. Addition of preoperative radiotherapy boost delivered with a CyberKnife radiosurgery system concomitantly with the use of paclitaxel (+/- carboplatin) and pembrolizumab / placebo.

Primary Outcome Measures: The histopathological confirmation of complete tumor regression in postoperative material performed in a population of 52 patients receiving immunotherapy in combination with radiotherapy, The statistical analysis will be performed by comparison to the initial assumptions, according to Simon's scheme. The finding of complete tumor regression (confirmed histopathologically) in more than 11 patients out of the group of 52 enrolled will be treated as fulfillment of the primary endpoint., Rating histopathology of the collected material during surgery
Secondary Outcome Measures: Assessment of complete regression in postoperative histopathological examination in the population of all 78 patients receiving preoperative chemotherapy and radiotherapy, The finding of of complete tumor regression in more than 13 patients out of the group of 78 included and receiving both chemotherapy and radiotherapy will be treated as fulfillment of the secondary endpoint criterion., Rating histopathology of the collected material during surgery|The assessment of the response to preoperative treatment by assessing postoperative material in histopathological examination, Assessment of regression under the influence of pembrolizumab in postoperative histopathological examination using the quantitative method, taking into account the degree of partial regression, Rating histopathology of the collected material during surgery|The comparison of the Invasive Disease Free Survival time the group treated with pembrolizumab with radiotherapy to the group treated with placebo with radiotherapy, Invasive Disease Free Survival time will be evaluated according to Proposal for Standardized Definitions for Efficacy End Points in Adjuvant Breast Cancer Trials, The entire observation period,an average of 4 years|Quality of life evaluated by QLQ-C30 questionnaire (Quality of Live questionnaire) comparision beteewen groups, General health condition based on the QLQ-C30 scale, Assessment approximately 4 months after surgical treatment|Safety and tolerance (number of participants with treatment-related adverse events)., Assessment of safety and tolerance of treatment according to Common Terminology Criteria for Adverse Events v. 5.0;, During the study, an average of 5 years