Speaking from the European Society for Medical Oncology (ESMO) 2019 congress in Barcelona, Spain, Jonathan Ledermann, MD, FRCP, University College London, London, UK, discusses the use of rucaparib for both maintenance and monotherapy treatment in patients with ovarian cancer, highlighting the ARIEL3 trial (NCT01968213), ARIEL2 trial (NCT01891344) and Study 10 (NCT01482715). Here, Prof. Ledermann talks about the safety and tolerability of this PARP inhibitor in ovarian cancer.