Triple-negative breast cancer (TNBC) is the deadliest breast cancer subtype, in part due to lack of targeted therapy. Therefore, there is a need to improve methods that determine if treatment is effective and to develop targeted therapies. Cancer cells reprogram their metabolism to enable tumour growth. In doing so, they release metabolites into blood and urine that can act as signals of tumour and treatment status, known as biomarkers. Rather than assessing treatment effectiveness months after therapy, measuring metabolite biomarkers may allow clinicians to determine response to therapy in real-time and early during treatment. Moreover, metabolite biomarkers can also indicate if a tumour is susceptible to specific treatment, thereby tailoring effective therapy to the individual patient. The proposed research program will determine how tumour metabolite biomarkers can indicate effective response and susceptibility to TNBC treatment. Ultimately, this work will contribute to validating metabolite biomarkers that can be used by clinicians to make informed patient care decisions and improve TNBC treatment.