Triple-negative breast cancer (TNBC) is a heterogeneous disease comprising several biologically distinct subtypes. However, treatment is currently mainly relying on chemotherapy as there are no targeted therapies specifically approved for TNBC. Despite initial responses to chemotherapy, resistance frequently and rapidly develops and metastatic TNBC has a poor prognosis. New targeted approaches are, therefore, urgently needed. Currently, bevacizumab, a monoclonal anti-vascular endothelial growth factor (VEGF)-A antibody, is the only targeted agent with an approval for the therapy of metastatic breast cancer, but does not provide a specific benefit in the TNBC subtype.