Study of Doxycycline Added to Neoadjuvant Chemotherapy for Early ERHER2- Breast Cancer to Target Cancer Stem Cells

What this Trial Is About

Researchers are evaluating the use of doxycycline, an older and affordable antibiotic, to target cancer stem cells in patients with early-stage estrogen receptor positive ER and human epidermal growth factor receptor 2-negative HER2- breast cancer. These cancer stem cells are believed to cause treatment resistance and cancer recurrence, and the study aims to see if doxycycline can improve patients response to standard neoadjuvant chemotherapy. This is a phase II, open-label clinical trial focusing on this specific breast cancer subtype with low rates of complete tumor response to current treatments. Participants will receive neoadjuvant chemotherapy consisting of four cycles of epirubicin and cyclophosphamide every three weeks, followed by 12 weekly doses of paclitaxel. Alongside chemotherapy, doxycycline will be given orally at a dose of 200 mg per day from day 5 to day 18 of each chemotherapy cycle. The study will analyze tumor samples before and after treatment to assess changes in cancer stem cell markers and measure pathological response to treatment. During the trial, participants will undergo tumor biopsies and surgery after completing chemotherapy. Researchers will assess the presence of ALDH1, a marker of cancer stem cells, and evaluate pathological complete response by checking for any remaining invasive cancer in the breast and lymph nodes. Additional measures include tumor shrinkage on imaging, patient adherence to doxycycline, and patient-reported treatment burden. The study monitors safety and treatment effects up to 30 days after the last treatment dose, with a total participation period spanning from registration through surgery and follow-up assessments.

NEODOXy: Targeting Breast Cancer Stem Cells With Doxycycline