capecitabine + fulvestrant

Capecitabine + fulvestrant is a combination therapy consisting of capecitabine, an oral prodrug of 5-fluorouracil (a cytotoxic antimetabolite), and fulvestrant, a selective estrogen receptor degrader (SERD) that acts as a pure estrogen receptor antagonist. This combination is used in the treatment of hormone receptor-positive, HER2-negative metastatic breast cancer (MBC), particularly in postmenopausal women. Capecitabine interferes with DNA synthesis by inhibiting thymidylate synthase after conversion to 5-FU, leading to cell death. Fulvestrant binds to and accelerates degradation of the estrogen receptor, blocking estrogen signaling required for tumor growth in hormone-sensitive breast cancers. The rationale for combining these agents is based on their complementary mechanisms—capecitabine provides cytotoxic chemotherapy while fulvestrant targets hormonal pathways—potentially resulting in synergistic anti-tumor activity with manageable toxicity profiles[1][2][3].