Niraparib: A Review in First-Line Maintenance Therapy in Advanced Ovarian Cancer

Plain Language Summary In 2021, ovarian cancer is predicted to be responsible for approximate to 43,770 deaths in Europe and the USA combined. Niraparib (Zejula (TM)) is a once-daily oral treatment for first-line maintenance therapy in adults with advanced ovarian cancer that is responsive to chemotherapy. Although other agents of the same drug class (e.g. olaparib) are only approved for use against tumours with compromised DNA repair mechanisms, niraparib is approved without this restriction. Niraparib reduced the risk of disease progression or death in patients with newly diagnosed ovarian cancer, irrespective of whether the patients had compromised or functional DNA repair mechanisms. Abnormal blood counts are the main safety concern with niraparib, though adverse drug reactions may be managed through monitoring and interrupting or decreasing the dosage. Starting treatment at a personalised lower dosage may also reduce the likelihood of adverse drug reactions. Niraparib is a useful option for first-line maintenance therapy for advanced ovarian cancer, regardless of the patient's DNA repair mechanisms, and is a promising option for patients with functional DNA repair mechanisms, a group for which maintenance treatment options are limited. Niraparib (Zejula (TM)) is a PARP inhibitor which is approved for maintenance therapy in adults with advanced ovarian cancer in complete or partial response to platinum-based chemotherapy. In a placebo-controlled phase III trial in patients with newly diagnosed advanced ovarian cancer, niraparib significantly extended progression free survival in two predefined populations, namely a patient population with altered homologous-recombination DNA repair pathways [i.e. homologous-recombination deficiency positive (HRd)] and the overall trial population. A prespecified exploratory subgroup analysis indicated that niraparib was also efficacious in patients who were homologous recombination deficiency negative or homologous recombination proficient (HRp). Niraparib has a manageable tolerability profile with myelosuppression as the main safety concern. Haematological reactions were managed with monitoring and dose reduction or interruption. A weight- and platelet count-based individualised dosage regimen introduced during the trial (and subsequently approved) appeared to improve haematological tolerability. Niraparib is a useful option for first-line maintenance therapy for advanced ovarian cancer in adults who responded to platinum-based chemotherapy, regardless of homologous-recombination deficiency status and is a promising option for HRp patients, for whom maintenance treatment options are limited.