RO4929097 and Vismodegib in Treating Patients With Breast Cancer That is Metastatic or Cannot Be Removed By Surgery

This phase I trial studies the side effects and best dose of RO4929097 (gamma-secretase/Notch signalling pathway inhibitor RO4929097) when given together with vismodegib in treating patients with breast cancer that is metastatic or cannot be removed by surgery. RO4929097 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Drugs used in chemotherapy, such as vismodegib, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving RO4929097 and vismodegib together may slow the growth of tumor cells and may be a more active treatment for advanced breast cancer.