In order to explore the real situation of niraparib in clinical application more comprehensively and deeply, we conducted the first multicenter, real-world study in China. This large observational study used real-world data to assess the effectiveness and safety of niraparib as maintenance therapy in patients with advanced ovarian cancer (AOC) in China and investigated clinical factors associated with prolonged benefits of niraparib so as to achieve the maximum clinical benefit of patients.

This is a retrospective multicentric study including advanced ovarian cancer patients that have used niraparib as first-line maintenance therapy after chemotherapy from fourteen hospitals in China between January 2019 and December 2021. The database lock-time was on December 31, 2022. All data were retrieved from the patients' medical records. Clinical data, including patient demographics, clinicopathological characteristics, residual disease after primary surgery, genetic-testing results and so on, were collected. Missing information was supplemented by telephone follow-up or face-to-face inquiries (only for patients who were alive and accessible). The incidence of AEs, as well as dose reductions, dose interruption, and discontinuation of treatment due to AEs were recorded.All analyses were performed on the safety population. The categorical variables were described as a frequency and percentage, and the continuous variables were described as a median and range. No formal sample size calculation was performed since the study was exploratory. Survival analyses were conducted using the Kaplan-Meier method and log-rank test. 95% confidence intervals (CIs) were calculated using the Clopper-Pearson method. Univariate and multivariate Cox regression models were established to determine factors that could affect the PFS for patients receiving niraparib maintenance treatment. Missing data were assigned as unknown for the univariate and multivariate analysis. The method of cox analysis was stepwise regression, and the screening criterion was Akaike Information Criterion (AIC). A P-value of <0.05 was considered statistically significant. Descriptive statistics (number and percentage) were used to summarize the safety data by treatment. Statistical analyses were performed using the R software version 4.2.2 (R Project for Statistical Computing).

Inclusion Criteria:

• 18 years of age or older
• diagnosed with histologically confirmed ovarian cancer (International Federation of Gynecology and Obstetrics [FIGO] Stage II-IV)
• underwent surgery and first-line chemotherapy and were treated with niraparib as maintenance therapy
• the date to start maintenance therapy with niraparib is from January 2019 to December 2021

Exclusion Criteria:

• had experienced other malignancies within the previous 5 years
• enrolled in clinical trials in which investigators were blinded to the treatments
• with a previous or current diagnosis of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML)

advanced ovarian cancer patients that have used niraparib as first-line maintenance therapy after chemotherapy from fourteen hospitals in China between January 2019 and December 2021