olaparib + trastuzumab

A combination therapy consisting of olaparib, a PARP inhibitor, and trastuzumab, an anti-HER2 monoclonal antibody. This combination has shown enhanced anti-tumor effects in HER2-positive breast cancer, particularly in patients with germline BRCA mutations. Mechanistically, olaparib inhibits PARP1, PARP2, and PARP3, preventing DNA repair and leading to cancer cell death, while trastuzumab binds to the HER2 receptor, blocking signaling pathways that promote cancer cell growth and proliferation. Studies have shown that trastuzumab downmodulates the homologous recombination protein PCNA, potentially enhancing olaparib's effectiveness.