1.Phase 2 single-arm study on the safety of maintenance niraparib in Japanese patients with platinum-sensitive relapsed ovarian cancer
Kazuhiro TAKEHARA ; Takashi MATSUMOTO ; Junzo HAMANISHI ; Kosei HASEGAWA ; Motoki MATSUURA ; Kiyonori MIURA ; Shoji NAGAO ; Hidekatsu NAKAI ; Naotake TANAKA ; Hideki TOKUNAGA ; Kimio USHIJIMA ; Hidemichi WATARI ; Yoshihito YOKOYAMA ; Yoichi KASE ; Shuuji SUMINO ; Ajit SURI ; Hiroaki ITAMOCHI ; Nobuhiro TAKESHIMA
Journal of Gynecologic Oncology 2021;32(2):e21-
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.
2.Phase 2 single-arm study on the efficacy and safety of niraparib in Japanese patients with heavily pretreated, homologous recombination-deficient ovarian cancer
Aikou OKAMOTO ; Eiji KONDO ; Toshiaki NAKAMURA ; Satoshi YANAGIDA ; Junzo HAMANISHI ; Kenichi HARANO ; Kosei HASEGAWA ; Takeshi HIRASAWA ; Kensuke HORI ; Shinichi KOMIYAMA ; Motoki MATSUURA ; Hidekatsu NAKAI ; Hiroko NAKAMURA ; Jun SAKATA ; Tsutomu TABATA ; Kazuhiro TAKEHARA ; Munetaka TAKEKUMA ; Yoshihito YOKOYAMA ; Yoichi KASE ; Shuuji SUMINO ; Junpei SOEDA ; Ajit SURI ; Daisuke AOKI ; Toru SUGIYAMA
Journal of Gynecologic Oncology 2021;32(2):e16-
Objective:
To evaluate the efficacy and safety of niraparib in Japanese women with heavily pretreated ovarian cancer.
Methods:
This Phase 2 open-label, single-arm study enrolled Japanese women with homologous recombination deficiency-positive relapsed, high-grade serous ovarian, fallopian tube, or primary peritoneal cancer who had completed 3–4 lines of therapy. The starting dose of niraparib was 300 mg administered once daily in continuous 28-day cycles until objective progressive disease, unacceptable toxicity, consent withdrawal or discontinuation. The primary endpoint, objective response rate (ORR), was assessed by the investigator using RECIST version 1.1. Safety evaluations included the incidence of treatment-emergent adverse events (TEAEs), including serious TEAEs.
Results:
Twenty women were enrolled and the confirmed ORR in the full analysis set (FAS) was 35.0% (7/20), consisting of 1 complete response and 6 partial responses. Disease control rate in the FAS was 90.0%. The most frequently reported TEAEs (>50%) were anemia, nausea, and platelet count decreased. One patient (5.0%) had TEAEs leading to discontinuation of niraparib whereas reductions or interruptions were reported in 14 (70.0%) and 15 (75.0%) patients, respectively. The median dose intensity (202.9 mg daily) corresponded to a relative dose intensity of 67.6%.
Conclusion
Efficacy and safety of niraparib in heavily pretreated Japanese women was comparable to that seen in an equivalent population of non-Japanese women. No new safety signals were identified.