Japanese Study of Niraparib in Homologous Recombination–Deficient Ovarian Cancer
Posted: Monday, February 8, 2021
The PARP inhibitor niraparib has demonstrated activity against ovarian, breast, and castrate-resistant prostate cancers in previous studies. According to a recent single-arm phase II study, published in the Journal of Gynecologic Oncology, niraparib appears to have a comparable safety profile among Japanese women with heavily pretreated, homologous recombination–deficient ovarian cancer, as seen in an equivalent population of non-Japanese women. Aikou Okamoto, MD, PhD, of The Jikei University School of Medicine, Tokyo, and colleagues identified no new safety signals among the patient population.
In this phase II study, the research team evaluated objective response rates among 20 Japanese women with relapsed, high-grade serous ovarian, fallopian tube, or primary peritoneal cancer. Eligible patients had previously been treated with three to four lines of therapy. The starting dose of niraparib was 300 mg once daily for 28-day cycles until objective progressive disease, unacceptable toxicity, consent withdrawal, or treatment discontinuation.
At data cutoff, four patients had discontinued treatment due to adverse events (n = 1) or progressive disease (n = 3). The objective response rate in the full analysis set was 35% (n = 7), with one complete response and six partial responses. The disease control rate was 90%.
Each of the patients reported at least one adverse event. Frequently reported adverse events, including anemia, nausea, and decreased platelet counts, were observed in more than half of the treatment population. Although treatment-emergent adverse events caused a single patient to discontinue treatment, dose reductions or interruptions occurred in 14 patients (70%) and 15 patients (75%), respectively.
“The study results demonstrated efficacy of niraparib in Japanese women who are heavily pretreated, which was considered comparable to the equivalent population in non-Japanese patients. Additionally, the safety profile was acceptable and consistent with the known safety profile of niraparib and previous experience with niraparib in non-Japanese patients,” the study team concluded.
Disclosure: For full disclosures of the study authors, visit ejgo.org.