Shuuji Sumino

Niraparib in Japanese patients with heavily pretreated, homologous recombination-deficient ovarian cancer: final results of a multicenter phase 2 study

To evaluate the long-term efficacy and safety of niraparib in Japanese women with heavily pretreated ovarian cancer. 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). 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. 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. ClinicalTrials.gov Identifier: NCT03759600.

Niraparib in Japanese patients with platinum-sensitive recurrent ovarian cancer: final results of a multicenter phase 2 study

This study evaluated the long-term safety and efficacy of niraparib in Japanese patients with platinum-sensitive recurrent ovarian cancer. 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. 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. 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. ClinicalTrials.gov Identifier: NCT03759587.