**24. Future perspective**

TNBC is the most aggressive, lethal and complex subtype of breast cancer. What makes it more aggressive is the lack of targeted therapies leaving chemotherapy as the main treatment option available. However, chemotherapy itself mostly lacks target specificity and can harm normal healthy cells of an individual. Moreover, another treatment option that is immunotherapy also faces some problems showing inefficacy due to escape of tumor cells from immune surveillance. Nevertheless, a strategy known as drug repurposing has shown to be a promising strategy to overcome the inefficacy of available treatment options. In drug repurposing, an existing chemotherapeutic drug can be repurposed to modulate its efficacy. In this chapter, we have focused primarily on repurposing the available drugs whether PARP inhibitors or MEK inhibitors, vaccines including the ones under clinical trials as well by combining them with other available immunotherapeutic options like immune checkpoint inhibitors, PD-1/PD-L1 antibodies etc. Also the currently used epigenetic therapy drugs also are known to show significant efficacy in modulating immunotherapy responses in patients suffering from cancers especially TNBC. From our point of view combining drugs with other target specific drugs like drugs targeting immune system components provides a significant insight as it repurposes the drug whether chemotherapeutic or epigenetic drug making it target specific.

*Drug Repurposing - Molecular Aspects and Therapeutic Applications*
