Novel targeted therapies and immunological strategies for breast cancer treatment

The therapeutic landscape for breast cancer (BC) continues to evolve dramatically beyond conventional therapies, ushering in a new era of precision medicine. In this review we synthesize the current evidence and developments of the most promising targeted therapies reshaping BC treatment. We explore the mechanism and clinical application of antibody-drug conjugates (ADCs), which deliver cytotoxic payloads directly to tumor cells, and bi-specific antibodies that engage immune effectors. We detail the paradigm of synthetic lethality brought by PARP inhibitors for BRCA-mutant cancers and the pivotal role of CDK4/6 inhibitors in hormone receptor-positive disease. Furthermore, we examine emerging strategies that target key oncogenic pathways, including Akt, FGFR, and MEK, alongside anti-angiogenic drugs, immune checkpoint inhibitors (ICIs) and therapeutic cancer vaccines. Collectively, these modalities represent a multifaceted armamentarium aimed at overcoming resistance and improving outcomes. This review highlights the current landscape of targeted and immunological strategies in BC, synthesizes efficacy and safety data across therapeutic classes, and identifies critical knowledge gaps including biomarker development, resistance mechanisms, and the need for rationally designed combination regimens.