315P - Real-world experience of niraparib as maintenance therapy in newly diagnosed advanced ovarian cancer: A single-center retrospective study

Background

Based on PRIMA and PRIME, Niraparib is approved by FDA and NMPA for first-line maintenance of OC regardless of biomarker status. Niraparib is widely used in China, while its efficacy and safety in real world remains to be verified. The purpose of this study was to evaluate the efficacy and safety of niraparib as maintenance in newly diagnosed advanced OC.

Methods

We retrospectively collected patients with pathologically confirmed diagnosis of OC, who received niraparib as first-line maintenance therapy at the Department of Gynecology, Tianjin Cancer Hospital between January 2021 and December 2022. Demographics, baseline characteristics, clinical outcomes and adverse events were collected. The history of niraparib use, including the time from the end of chemotherapy to the start of maintenance therapy, the starting dose, and the stable dose used after 3 months, were also collected.

Results

102 patients were enrolled. The median age was 58 years and 84.3% were FIGO stage III/IV. 18.6% BRCAmut, 58.8% BRCAwt and 22.5% BRCAunkown, while 36.3% HRD deficient, 12.7% HRD proficient and 51% HRD unkown. 53.9% received NACT, 76.5% were R0 after surgery and 62.7% were CR after chemotherapy. Median follow-up was 10.5m. In the ITT population, the mPFS was not reached, with a 24-month PFS rate of 52.5%. The mPFS of BRCAmut, BRCAwt, and BRCAunknown was not reached, 14.4 and 14.6m, respectively. The 24-month PFS rates were 90%, 48.4% and 37.9%, respectively. The mPFS of HRD deficient and HRD proficient were both not reached. 84.3% of patients experienced any grade TEAEs, while 17.6% experienced TEAEs of grade ≥3. TEAEs leading to treatment interruption was 36.3%, leading to dose reduction was 29.4%, leading to discontinuation was 0.98%. The most common hematological TEAEs were platelet count decreased (28.4%) while grade ≥3 TEAEs was 5.9%, white blood cell count decreased (20.6%) and neutrophil count decreased (26.5%). Non-hematologic TEAEs were nausea (31.4%), fatigue (30.4%) and insomnia (21.6%).

Conclusions

In the real world, niraparib maintenance in newly diagnosed advanced OC is effective and safe, which was consistent with previous RCT. More clinical related factors affecting prognosis will be further explored.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Tianjin Medical University Cancer Institute & Hospital.

Funding

Committee of Gynecological Oncology, Tianjin anti-cancer association.

Disclosure

All authors have declared no conflicts of interest.