ABT-737 is an orally available inhibitor of the nuclear enzymes poly(ADP-ribose) polymerase (PARP) 1 and 2, with potential antineoplastic activity. Upon administration, ABT-767 selectively binds to PARP 1 and 2, thereby preventing repair of damaged DNA via the base excision repair (BER) pathway. This agent enhances the accumulation of DNA strand breaks and promotes genomic instability eventually leading to apoptosis. ABT-767 may enhance the cytotoxicity of DNA-damaging agents and reverse tumor cell chemo- and radioresistance.