説明
Doxycycline has been investigated as a complementary agent in HER2-positive breast cancer; its anti-mitochondrial and anti-stem-cell properties may modestly enhance trastuzumab activity without clinically significant adverse pharmacokinetic interaction.
機序
Doxycycline inhibits mitochondrial biogenesis in cancer stem cells, potentially sensitising HER2-positive tumour cells to trastuzumab; there is no known pharmacokinetic interaction between these agents.
臨床的意義
Preclinical and limited early-phase clinical data suggest benefit; no well-established adverse interaction. The combination is not yet standard of care.
対処法
No dose adjustment required if co-used in an investigational context; monitor for additive GI side effects (nausea, diarrhoea) and doxycycline-related photosensitivity.