Jonaid Ahmad Malik, Hend Talkhan, Farhat Fatima, Umme Hani
Drug repurposing is a significant strategy in drug discovery, as it saves substantial amounts of time and money. Drugs already approved for other diseases can be repurposed to target cancer. Cancer remains one of the most fatal diseases, and it still does not have a cure. Developing new drug molecules and advancing them from preclinical to clinical stages can take many years, whereas drug repurposing offers a faster alternative. Many repurposed drugs have already progressed to clinical trials. This paper highlights recent advances in how FDA-approved drugs modulate the immune system to enhance host-based immune responses against cancer, and describes the mechanistic pathways through which these drugs act on immune cells. This paper also discusses how targeting macrophages, immune checkpoints on T-Cells, and other immune cell populations can strengthen immunotherapy. In addition, the paper reviews drugs that have advanced to clinical stages and are showing promising results across different cancers, as well as the challenges associated with clinical translation. This paper outlines how drug repurposing can influence the immune system within the context of cancer chemotherapy.