Objective: DUO-E/GOG-3041/ENGOT-EN10 (NCT04269200) demonstrated statistically significant and clinically meaningful progression-free survival (PFS) improvement with durvalumab plus carboplatin/paclitaxel, followed by durvalumab with or without olaparib, vs. carboplatin/paclitaxel alone (intention-to-treat [ITT] population) in patients with newly diagnosed advanced or recurrent endometrial cancer. We evaluated efficacy and safety in the Japan subset of DUO-E. Methods: Patients with newly diagnosed International Federation of Gynecology and Obstetrics stage III/IV or recurrent endometrial cancer were randomized 1:1:1 to control arm (carboplatin/paclitaxel + durvalumab placebo [6 cycles] followed by durvalumab placebo + olaparib placebo), durvalumab arm (carboplatin/paclitaxel + durvalumab [1,120 mg every 3 weeks] [6 cycles] followed by durvalumab [1,500 mg every 4 weeks] + olaparib placebo), or durvalumab + olaparib arm (carboplatin/paclitaxel + durvalumab [6 cycles] followed by durvalumab + olaparib [300 mg twice a day]). Dual primary endpoints were investigatorassessed PFS for durvalumab and durvalumab + olaparib arms vs. control. This prespecified exploratory analysis evaluated PFS and safety in the Japan subset. Results: In the Japan subset (n=88) PFS favored durvalumab (hazard ratio=0.61, 95% confidence interval [CI]=0.32–1.12) and durvalumab + olaparib (0.44, 95% CI=0.22–0.85) vs. control; median PFS was 9.9 and 15.1 vs. 9.5 months, and the 18-month PFS rate was 37.0% and 42.1% vs. 22.2%, respectively. The safety profile in the Japan subset was generally consistent with the full safety analysis set and the established profiles of the individual agents. Conclusion Efficacy and safety in the Japan subset were generally consistent with outcomes in the DUO-E ITT population. This Japanese subset analysis of DUO-E supports carboplatin/ paclitaxel + durvalumab followed by durvalumab with or without olaparib as new treatment options in patients with advanced or recurrent endometrial cancer and is the first to report on these regimens in Japanese patients alone.

Objective: To evaluate the long-term efficacy and safety of niraparib in Japanese women with heavily pretreated ovarian cancer. Methods: This was the follow-up analysis of a phase 2, multicenter, open-label, single-arm study in Japanese women with homologous recombination-deficient, platinum-sensitive, relapsed, high-grade serous epithelial ovarian, fallopian tube, or primary peritoneal cancer who had completed 3–4 lines of chemotherapy and were poly(ADP-ribose) polymerase inhibitor naïve. Participants received niraparib (starting dose, 300 mg) once daily in continuous 28-day cycles until objective disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was confirmed objective response rate (ORR), as assessed using Response Evaluation Criteria in Solid Tumors version 1.1. Safety evaluations included treatment-emergent adverse events (TEAEs). Results: 20 patients were enrolled in the study and included in both efficacy and safety analyses. Median total study duration was 759.5 days. Median dose intensity was 201.3 mg/ day. Confirmed ORR was 60.0% (90% confidence interval [CI]=39.4–78.3); 2 patients had complete response and 10 patients had partial response. Median duration of response was 9.9 months (95% CI=3.9–26.9) and the disease control rate was 90.0% (95% CI=68.3–98.8).The most common TEAEs were anemia (n=15), nausea (n=12), and decreased platelet count (n=11). TEAEs leading to study drug dose reduction, interruption, or discontinuation were reported in 16 (80.0%), 15 (75.0%), and 2 patients (10.0%), respectively. Conclusion The long-term efficacy and safety profile of niraparib was consistent with previous findings in the equivalent population in non-Japanese patients. No new safety signals were identified.

Objective: This study evaluated the long-term safety and efficacy of niraparib in Japanese patients with platinum-sensitive recurrent ovarian cancer. Methods: This was a follow-up analysis of a phase 2, multicenter, open-label, single-arm study in Japanese women with platinum-sensitive, relapsed ovarian cancer. Participants received niraparib (starting dose 300 mg) once daily in continuous 28-day cycles. The primary endpoint was the incidence of Grade 3 or 4 thrombocytopenia-related events (defined as the overall incidence of the MedDRA Preferred Terms “thrombocytopenia” and “platelet count decreased”) occurring in the 30 days after initial administration of niraparib, and secondary endpoints included evaluation of treatment-emergent adverse events and progression-free survival. Results: Nineteen patients (median age, 62 years; median body weight, 53.9 kg) were enrolled. As previously reported, the incidence of Grade 3 or 4 thrombocytopenia-related events during the first 30 days of treatment was 31.6%. At data cutoff, median (range) treatment exposure was 504.0 (56–1,054) days and mean ± standard deviation dose intensity was 154.4±77.5 mg/day. The most common treatment-emergent adverse events were nausea (n=14, 73.7%), decreased platelet count (n=12, 63.2%), decreased neutrophil count (n=11, 57.9%), anemia, vomiting, and decreased appetite (all n=9, 47.4%). One patient was diagnosed with treatment-related leukemia, which resulted in death. Median (95% confidence interval) progression-free survival was 18.0 (5.6–26.7) months. Conclusion Overall, the safety profile of niraparib was considered manageable in this study population of Japanese patients with platinum-sensitive, relapsed ovarian cancer and was consistent with that observed in studies of non-Japanese patients.

Objective: To evaluate the long-term efficacy and safety of niraparib in Japanese women with heavily pretreated ovarian cancer. Methods: This was the follow-up analysis of a phase 2, multicenter, open-label, single-arm study in Japanese women with homologous recombination-deficient, platinum-sensitive, relapsed, high-grade serous epithelial ovarian, fallopian tube, or primary peritoneal cancer who had completed 3–4 lines of chemotherapy and were poly(ADP-ribose) polymerase inhibitor naïve. Participants received niraparib (starting dose, 300 mg) once daily in continuous 28-day cycles until objective disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was confirmed objective response rate (ORR), as assessed using Response Evaluation Criteria in Solid Tumors version 1.1. Safety evaluations included treatment-emergent adverse events (TEAEs). Results: 20 patients were enrolled in the study and included in both efficacy and safety analyses. Median total study duration was 759.5 days. Median dose intensity was 201.3 mg/ day. Confirmed ORR was 60.0% (90% confidence interval [CI]=39.4–78.3); 2 patients had complete response and 10 patients had partial response. Median duration of response was 9.9 months (95% CI=3.9–26.9) and the disease control rate was 90.0% (95% CI=68.3–98.8).The most common TEAEs were anemia (n=15), nausea (n=12), and decreased platelet count (n=11). TEAEs leading to study drug dose reduction, interruption, or discontinuation were reported in 16 (80.0%), 15 (75.0%), and 2 patients (10.0%), respectively. Conclusion The long-term efficacy and safety profile of niraparib was consistent with previous findings in the equivalent population in non-Japanese patients. No new safety signals were identified.

Objective: This study evaluated the long-term safety and efficacy of niraparib in Japanese patients with platinum-sensitive recurrent ovarian cancer. Methods: This was a follow-up analysis of a phase 2, multicenter, open-label, single-arm study in Japanese women with platinum-sensitive, relapsed ovarian cancer. Participants received niraparib (starting dose 300 mg) once daily in continuous 28-day cycles. The primary endpoint was the incidence of Grade 3 or 4 thrombocytopenia-related events (defined as the overall incidence of the MedDRA Preferred Terms “thrombocytopenia” and “platelet count decreased”) occurring in the 30 days after initial administration of niraparib, and secondary endpoints included evaluation of treatment-emergent adverse events and progression-free survival. Results: Nineteen patients (median age, 62 years; median body weight, 53.9 kg) were enrolled. As previously reported, the incidence of Grade 3 or 4 thrombocytopenia-related events during the first 30 days of treatment was 31.6%. At data cutoff, median (range) treatment exposure was 504.0 (56–1,054) days and mean ± standard deviation dose intensity was 154.4±77.5 mg/day. The most common treatment-emergent adverse events were nausea (n=14, 73.7%), decreased platelet count (n=12, 63.2%), decreased neutrophil count (n=11, 57.9%), anemia, vomiting, and decreased appetite (all n=9, 47.4%). One patient was diagnosed with treatment-related leukemia, which resulted in death. Median (95% confidence interval) progression-free survival was 18.0 (5.6–26.7) months. Conclusion Overall, the safety profile of niraparib was considered manageable in this study population of Japanese patients with platinum-sensitive, relapsed ovarian cancer and was consistent with that observed in studies of non-Japanese patients.

Objective: To evaluate the long-term efficacy and safety of niraparib in Japanese women with heavily pretreated ovarian cancer. Methods: This was the follow-up analysis of a phase 2, multicenter, open-label, single-arm study in Japanese women with homologous recombination-deficient, platinum-sensitive, relapsed, high-grade serous epithelial ovarian, fallopian tube, or primary peritoneal cancer who had completed 3–4 lines of chemotherapy and were poly(ADP-ribose) polymerase inhibitor naïve. Participants received niraparib (starting dose, 300 mg) once daily in continuous 28-day cycles until objective disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was confirmed objective response rate (ORR), as assessed using Response Evaluation Criteria in Solid Tumors version 1.1. Safety evaluations included treatment-emergent adverse events (TEAEs). Results: 20 patients were enrolled in the study and included in both efficacy and safety analyses. Median total study duration was 759.5 days. Median dose intensity was 201.3 mg/ day. Confirmed ORR was 60.0% (90% confidence interval [CI]=39.4–78.3); 2 patients had complete response and 10 patients had partial response. Median duration of response was 9.9 months (95% CI=3.9–26.9) and the disease control rate was 90.0% (95% CI=68.3–98.8).The most common TEAEs were anemia (n=15), nausea (n=12), and decreased platelet count (n=11). TEAEs leading to study drug dose reduction, interruption, or discontinuation were reported in 16 (80.0%), 15 (75.0%), and 2 patients (10.0%), respectively. Conclusion The long-term efficacy and safety profile of niraparib was consistent with previous findings in the equivalent population in non-Japanese patients. No new safety signals were identified.

Objective: This study evaluated the long-term safety and efficacy of niraparib in Japanese patients with platinum-sensitive recurrent ovarian cancer. Methods: This was a follow-up analysis of a phase 2, multicenter, open-label, single-arm study in Japanese women with platinum-sensitive, relapsed ovarian cancer. Participants received niraparib (starting dose 300 mg) once daily in continuous 28-day cycles. The primary endpoint was the incidence of Grade 3 or 4 thrombocytopenia-related events (defined as the overall incidence of the MedDRA Preferred Terms “thrombocytopenia” and “platelet count decreased”) occurring in the 30 days after initial administration of niraparib, and secondary endpoints included evaluation of treatment-emergent adverse events and progression-free survival. Results: Nineteen patients (median age, 62 years; median body weight, 53.9 kg) were enrolled. As previously reported, the incidence of Grade 3 or 4 thrombocytopenia-related events during the first 30 days of treatment was 31.6%. At data cutoff, median (range) treatment exposure was 504.0 (56–1,054) days and mean ± standard deviation dose intensity was 154.4±77.5 mg/day. The most common treatment-emergent adverse events were nausea (n=14, 73.7%), decreased platelet count (n=12, 63.2%), decreased neutrophil count (n=11, 57.9%), anemia, vomiting, and decreased appetite (all n=9, 47.4%). One patient was diagnosed with treatment-related leukemia, which resulted in death. Median (95% confidence interval) progression-free survival was 18.0 (5.6–26.7) months. Conclusion Overall, the safety profile of niraparib was considered manageable in this study population of Japanese patients with platinum-sensitive, relapsed ovarian cancer and was consistent with that observed in studies of non-Japanese patients.

The development of new treatments for gynecological malignancies has been conducted mainly through collaborative international phase III trials led by the United States and Europe. The survival outcomes of many gynecological malignancies have greatly improved as a result. Recent large-scale genome-wide association studies have revealed that drug efficacy and adverse event profiles are not always uniform. Thus, it is important to validate new treatment options in each country to safely and efficiently provide newly developed treatment options to patients with gynecological malignancies. The Japanese Gynecologic Oncology Group (JGOG) is conducting 5 cohort studies (JGOG 3026, 3027, 3028, 3030, and 3031) to establish real-world data (RWD) of poly(ADP-ribose) polymerase (PARP) inhibitor use in patients with advanced or recurrent epithelial ovarian cancer. The RWD constructed will be used to provide newly developed PARP inhibitors for women with advanced or recurrent ovarian cancer in a safer and more efficient manner as well as to develop further treatment options. In 2022, The JGOG, Korean Gynecologic Oncology Group, Chinese Gynecologic Cancer Society, and Taiwanese Gynecologic Oncology Group established the East Asian Gynecologic Oncology Trial Group to collaborate with East Asian countries in clinical research on gynecologic malignancies and disseminate new knowledge on gynecologic malignancies from Asia. The JGOG will conduct a collaborative integrated analysis of the RWD generated from Asian countries and disseminate real-world clinical knowledge regarding new treatment options that have been clinically implemented.

Epithelial ovarian cancer remains the lethal gynecological malignancy in women. The representative histotype is high-grade serous carcinoma (HGSC), and most patients with HGSC present at advanced stages with peritoneal dissemination. Since the peritoneal dissemination is the most important factor for poor prognosis of the patients, complete exploration for its molecular mechanisms is mandatory. In this narrative review, being based on the clinical, pathologic, and genomic findings of HGSC, chromosomal instability and epigenetic dynamics have been discussed as the potential drivers for cancer development in the fallopian tube, acquisition of cancer stem cell (CSC)-like properties, and peritoneal metastasis of HGSC. The natural history of carcinogenesis with clonal evolution, and adaptation to microenvironment of peritoneal dissemination of HGSC should be targeted in the novel development of strategies for prevention, early detection, and precision treatment for patients with HGSC.

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.