Phase 2 Study of Adaptive Capecitabine Therapy for Metastatic Estrogen Receptor Positive, HER2 Negative Breast Cancer

What this Trial Is About

Researchers are evaluating adaptive therapy with capecitabine in patients with metastatic estrogen receptor ER positive, HER2 negative breast cancer. This phase II trial studies how adjusting capecitabine doses based on tumor response using imaging and tumor markers affects tumor growth control. Capecitabine is an antimetabolite that breaks down into fluorouracil to kill tumor cells, and adaptive therapy aims to manage tumor burden by modifying treatment doses. Participants start in an initial standard phase receiving standard-dose capecitabine orally twice daily for 14 days of each 21-day cycle. If their disease responds or remains stable after two cycles, they enter an adaptive phase with reduced capecitabine doses adjusted every cycle based on tumor burden assessed by CT scans and blood tests. Dose adjustments include reductions or increases of 50% depending on tumor response. Additional procedures include blood sample collection, CT or MRI imaging, and bone scans as needed. During the study, participants undergo regular assessments including blood tests, imaging, and quality of life questionnaires. Researchers monitor tumor progression, overall survival, adverse events, and quality of life up to five years. After treatment, participants are followed every three months for up to three years. The study also explores circulating tumor DNA as a marker for tumor burden and investigates gene signatures related to treatment response and resistance.

Adaptive Therapy With Capecitabine for Treatment of Metastatic ER Positive, HER2 Negative Breast Cancer