First-Line Niraparib Maintenance Shows Manageable Real-World Safety Profile in Epithelial Ovarian Cancer

Real-world maintenance therapy with frontline niraparib (Zejula) monotherapy led to mild or moderate prespecified events of interest (PSEOI) that generally resolved and did not lead to treatment discontinuation in patients with epithelial ovarian cancer, according to data from the retrospective 1INSPIRE study presented during the 2026 SGO Annual Meeting.¹

At a median follow-up of 22.6 months (IQR, 16.1-33.5), patients included in the analysis (n = 218) experienced thrombocytopenia, anemia, and neutropenia at rates of 60.1% (95% CI, 53.3%-66.6%), 58.7% (95% CI, 51.9%-65.3%), and 33.9% (95% CI, 27.7%-40.6%), respectively. These hematologic events were generally mild or moderate in severity and led to treatment discontinuation in 7.4%, 5.4%, and 5.7% of patients, respectively. Notably, no patients developed myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML); secondary primary malignancies occurred in 0.9% (95% CI, 0.1%-3.3%) of patients.

“This retrospective, observational, chart review 1NSPIRE study provides key insights on the real-world safety profile and clinical management of [frontline] niraparib [maintenance] for patients with advanced epithelial ovarian cancer treated in routine clinical practice,” Lisa Landrum, MD, PhD, and her coauthors wrote in a poster presentation of the data. “Specifically, real-world safety outcomes, including the absence of MDS/AML and a low incidence rate of secondary primary malignancies were consistent with the results and established 1LM niraparib monotherapy safety profile from previous studies.”

Landrum is the chair of the Department of Obstetrics & Gynecology, the Mary Fendrich Hulman Professor of Gynecologic Oncology, and a professor of obstetrics and gynecology at Indiana University School of Medicine in Indianapolis.

In April 2020, the FDA approved niraparib as maintenance therapy for adult patients with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to first-line platinum-based chemotherapy.² The regulatory decision was supported by data from the phase 3 PRIMA trial (NCT02655016) which demonstrated that patients who received maintenance niraparib experienced a significant progression-free survival benefit compared with those who received placebo (HR 0.62; 95% CI, 0.50-0.76; P < .0001).

How was 1INSPIRE designed?

1INSPIRE was a retrospective, multicenter, medical chart review study that included adult patients with epithelial ovarian cancer who received first-line niraparib between April 1, 2020, and April 1, 2023.¹ The study enrolled patients from 18 clinical sites in the United States.

The study authors collected PSEOI data, defined as events including but not limited to thrombocytopenia, anemia, neutropenia, MDS/AML, and secondary primary malignancies. PSEOIs were counted as individual events based on start and end dates. PSEOI data were collected from index through 30 days after the end date of first-line treatment with niraparib. Clinical management data were also collected via patient charts and consisted of dose reduction, increase, interruption, and schedule change, as well as treatment discontinuation rates.

The objectives of the study were to characterize the real-world clinical outcomes, safety profile, and clinical management of patients with epithelial ovarian cancer treated with frontline niraparib monotherapy.

At baseline, the median age of the overall population was 67 years (IQR, 60-73). Most patients were less than 75 years old (80.7%), White (85.3%), had an ECOG performance status of 0 or 1 (88.1%), had stage III disease at initial diagnosis (60.6%), had serous histology (89.0%), and had no visible residual disease (58.5%). Nearly all patients (99.5%) received first-line platinum-containing regimens, and 8.7% received a frontline bevacizumab (Avastin)–containing regimen. The median time from the end of frontline therapy to the initiation of treatment with niraparib was 48 days (IQR, 35.0-66.0).

What additional data from the study were shared?

Additional findings from 1NSPIRE revealed that mild thrombocytopenia, anemia, and neutropenia occurred at respective rates of 26.6% (95% CI, 20.9%-33.0%), 35.3% (95% CI, 29.0%-42.1%), and 13.8% (95% CI, 9.5%-19.1%). These events occurred at moderate severity at rates of 25.2% (95% CI, 19.6%-31.5%), 26.6% (95% CI, 20.9%-33.0%), and 17.4% (95% CI, 12.6%-23.1%), respectively. Patients recovered from these events or they resolved at rates of 91.9%, 84.7%, and 96.5%, respectively.

Thrombocytopenia, anemia, and neutropenia were managed via dose interruptions art respective rates of 49.4%, 21.8%, and 19.3%. Dose reductions were employed at rates of 35.5%, 15.1%, and 15.7%, respectively. Notably, a significant portion of patients who developed thrombocytopenia (38.9%), anemia (71.1%), and neutropenia (63.5%) had a history of these events during first-line chemotherapy.

“The high resolution rates and low number of discontinuations of hematologic PSEOIs may be attributed to effective dose-management strategies used by health care professionals,” Landrum and her coauthors wrote in their conclusion.

Disclosures: Landrum reports participation in a scientific advisory board for GSK and receipt of honoraria and travel support from the American Board of Obstetrics & Gynecology.

References

1. Landrum LM, Thaker PH, Calderon Boyle TA, et al. Real-world safety profile and clinical management of patients with epithelial ovarian cancer who received first-line maintenance niraparib therapy: final results from the 1NSPIRE chart review study. Presented at: 2026 SGO Annual Meeting; April 10-13, 2026; San Juan, Puerto Rico.
2. FDA approves niraparib for first-line maintenance of advanced ovarian cancer. FDA. April 29, 2020. Accessed April 11, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-niraparib-first-line-maintenance-advanced-ovarian-cancer