J Gynecol Oncol.  2021 Mar;32(2):e21. 10.3802/jgo.2021.32.e21.

Phase 2 single-arm study on the safety of maintenance niraparib in Japanese patients with platinum-sensitive relapsed ovarian cancer

• Takehara K
• Matsumoto T
• Hamanishi J
• Hasegawa K
• Matsuura M
• Miura K
• Nagao S
• Nakai H
• Tanaka N
• Tokunaga H
• Ushijima K
• Watari H
• Yokoyama Y
• Kase Y
• Sumino S
• Suri A
• Itamochi H
• Takeshima N

• KMID: 2526362
• DOI: http://doi.org/10.3802/jgo.2021.32.e21

Abstract

Objective
The primary objective of this study was to evaluate the safety of niraparib 300 mg/day in Japanese patients with platinum-sensitive, relapsed ovarian cancer in a maintenance setting.
Methods
Phase 2, multicenter, open-label, single-arm study enrolled Japanese patients with platinum-sensitive, relapsed ovarian cancer who had received ≥2 platinum-based regimens. The primary endpoint (incidence of grade 3 or 4 thrombocytopenia-related events within 30 days after initial niraparib administration) was justified by the incidences of a global pivotal phase 3 study and its post-hoc safety analysis on thrombocytopenia, the major hematological adverse event of niraparib. The overall safety analysis examined other treatment-emergent adverse events (TEAEs).
Results
Enrolled patients (n=19) had a median (min, max) body weight of 53.9 (40.8–79.1) kg; all but one patient weighed <77 kg. Most (94.7%) patients initially received niraparib 300 mg/day but this decreased in subsequent cycles (mean±standard deviation dose intensity, 191.6±65.7 mg/day). In total, 6/19 (31.6%) patients experienced grade 3 or 4 thrombocytopenia-related events within 30 days of initial niraparib administration. Other common TEAEs included nausea, and decreased platelet or neutrophil counts. No progression-free or overall survival events occurred; only 1 of 4 response-evaluable patients had a post-baseline tumor assessment (stable disease).
Conclusion
The incidence of grade 3 or 4 thrombocytopenia-related events in Japanese ovarian cancer patients was similar to that in the corresponding non-Japanese study. Overall, the safety profile was acceptable and consistent with the known safety profile and previous experience with niraparib.

Keyword

Ovarian Cancer; Niraparib; Phase 2; Maintenance Therapy; Japanese