Jonathan Ledermann, MD, FRCP from University College Hospital, London, UK speaks to us about the development of poly ADP ribose polymerase (PARP) inhibitors in the treatment of ovarian cancer at the 2016 annual meeting of the European Society of Medical Oncology (ESMO), held in Copenhagen, Denmark. Prof. Ledermann outlines the success of PARP inhibitor olaparib, which has been licenced in Europe as a maintenance therapy in patients with BRCA mutated ovarian cancer who have responded to platinum-based therapy. During ESMO, results from the Phase III, randomized ENGOT-OV16/NOVA trial were presented (NCT01847274), Prof. Ledermann summarizes the promising results of niraparib in patients with and without BRCA mutations. Prof. Ledermann discusses ongoing trials looking into combining PARP inhibitors with other molecular targets such as anti-angiogenic, providing the example of the NCT02681237 trial which has generated positive results in patients receiving a combination of olaparib and cediranib. Prof. Ledermann believes that future trials will continue to investigate the full scope and potential of PARP inhibitors.