Mefuparib hydrochloride is primarily used in cancer research due to its role as a potent PARP inhibitor. It is studied for its ability to target and inhibit poly (ADP-ribose) polymerase enzymes, which play a critical role in DNA repair. By blocking these enzymes, it prevents cancer cells from repairing DNA damage, leading to their death. This makes it a promising candidate for treating cancers with defective DNA repair mechanisms, such as BRCA-mutated cancers. It is also explored in combination therapies to enhance the effectiveness of other anticancer treatments like chemotherapy and radiation.