First-line maintenance therapy with niraparib in advanced platinum-sensitive ovarian cancer: two 'long responder' case reports and review of the current literature.

The standard of care for newly diagnosed advanced ovarian cancer is surgical cytoreduction plus platinum-based chemotherapy; however, recurrent disease frequently occurs after treatment. Poly(ADP-ribose) polymerase (PARP) inhibitors as first-line maintenance therapy have been demonstrated to significantly reduce the risk of disease progression or death in patients with advanced ovarian cancer who have a complete or partial response to first-line platinum-based chemotherapy. Niraparib is the only PARP inhibitor that offers a significant progression-free survival benefit compared with placebo in this patient population regardless of the homologous recombination status. However, predictive factors for treatment responses and approaches to dose optimization remain to be investigated. In this study, two Chinese patients with newly diagnosed advanced ovarian cancer exhibited long-term responses to niraparib treatment, and hematological toxicity was successfully managed by dose adjustment. The literature on clinical trials and real-world experience on the efficacy, tolerability, and dose individualization of niraparib treatment in Western and Chinese patients was also reviewed. Future research is warranted to identify the characteristics of 'long responders' to niraparib treatment.