PARP inhibitors are especially effective in cancers with deficiencies in DNA repair mechanisms. This concept is known as synthetic lethality, where two concurrent defects (in this case, BRCA mutation and PARP inhibition) result in cell death. Drugs like olaparib, rucaparib, and niraparib are approved for treating ovarian and breast cancers with BRCA mutations. These drugs exploit the reliance of cancer cells on PARP-mediated repair due to their compromised alternative DNA repair pathways.
