PARP inhibitors in the treatment of ovarian cancer

The recent exciting findings on the use of poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitor (PARPi) maintenance therapy in the first-line and later lines of treatment in ovarian cancer are illustrated. Unprecedented advantages have been shown in first-line therapy not only in BRCA-mutated cancers, but also in tumor exhibiting a homologous recombination repair deficiency (HRD) unrelated to BRCA aberrations. The advantages of PARP maintenance therapy in around 50% of HR-proficient high-grade ovarian cancers are far less clear and, even though of statistical significance, the clinical benefit for the patients may be of borderline significance. The pre-treatment testing of HRD remains a matter of debate especially in the light of the current era of precision medicine. Data on the combination of PARPi with bevacizumab maintenance therapy uncovered additive beneficial therapeutic effects. In recurrent ovarian cancer, results on PARPi maintenance therapy after response to platinum-based reinduction chemotherapy are also excellent. At present, however, PARPi maintenance therapy remains reserved for PARPi-naive patients, since the data on PARPi after PARPi is extremely sparse.