(8R,9S)-Talazoparib is primarily used in the treatment of certain types of cancer, particularly in patients with advanced or metastatic breast cancer. It is specifically effective in cases where the cancer is associated with BRCA1 or BRCA2 gene mutations. The compound works by inhibiting the enzyme PARP (poly ADP-ribose polymerase), which plays a crucial role in the repair of DNA damage. By blocking PARP, (8R,9S)-Talazoparib prevents cancer cells from repairing their DNA, leading to cell death and slowing the progression of the disease. This targeted therapy offers a more precise approach compared to traditional chemotherapy, often resulting in fewer side effects and improved outcomes for patients with specific genetic profiles.