Inducing synthetic lethality using PARP inhibitors.

The enzyme poly(ADP)-ribose polymerase-1 (PARP-1) plays an important role in the repair of DNA damage via a mechanism called base excision repair (BER). Initially, inhibition of PARP-1 showed to be a promising anti-tumor strategy in preclinical models using BRCA1 and BRCA2 deficient tumor cell lines. More recently, several small molecules targeting PARP-1 entered the clinic and demonstrated compelling anti-tumor activity in patients with BRCA deficient breast and ovarian cancers, and in patients with triple-negative breast cancer. In this review we aim to summarize the most recent advances in the development of PARP inhibitors, with a focus on the clinical data.