ONC201 With a Methionine-Restricted Diet in Patients With Metastatic Triple Negative Breast Cancer

This phase II trial studies how well Akt/ERK inhibitor ONC201 (ONC201) with a methionine-restricted (MR) diet works in treating participants with triple negative breast cancer that has spread to other places in the body or cannot be removed by surgery. ONC201 activates a process that leads to the death of a cell. ONC201 is able to target tumor cells to get rid of them, but does not affect normal cells. MR diet is a methionine-free amino acid modified medical food. The addition of an intermittent MR diet may enhance the activity of ONC201. Giving ONC201 and an MR diet may work better in treating participants with breast cancer.