This thesis presents a comprehensive analysis of recent pharmacological advancements in the treatment of breast cancer, emphasizing the role of molecular subtyping and personalized medicine. It outlines the limitations of traditional therapies like endocrine treatment and chemotherapy, which have prompted the development of targeted therapies such as CDK4/6 inhibitors, PARP inhibitors, antibody-drug conjugates (ADCs), and immune checkpoint inhibitors. The thesis gives particular attention to innovations for HER2-low and Trop-2-expressing tumors, expanding treatment options for previously underserved subtypes. It also explores the significance of genomic profiling and companion diagnostics in tailoring treatments to individual tumor characteristics. Finally, the thesis addresses ongoing challenges, including drug resistance and global disparities in access, and discusses emerging technologies like mRNA therapeutics and CRISPR-based strategies as future directions in breast cancer care.