Neoadjuvant niraparib monotherapy for unresectable, homologous recombination deficiency-positive, high-grade serous ovarian cancer (NANT): a multicentre, single-arm, phase 2 trial
In brief
After niraparib, surgeons removed all visible cancer in 80% of operated patients
In this single-arm trial, 32 of 40 operated patients with HRD-positive advanced ovarian cancer had no visible cancer remaining after surgery following two cycles of niraparib alone. The drug also shrank tumors in 30 of 48 patients assessed, but serious adverse events occurred in 28%, and severe blood-cell problems were common. Randomized trials must show how this approach compares with standard chemotherapy.
- Journal
- The Lancet. Oncology (Q1)
- Published
- 7 October 2026
- Study design
- Non-randomized / quasi-experimental trial
- Evidence level
- Level 2, Moderate (CEBM 2b)
- Authors
- Dan Liu, Zikun Peng, Wei Zhang, Cui Feng, Ping Wang, Jundong Li, et al.
- PMID
- 42843394
- DOI
- 10.1016/S1470-2045(26)00387-6
Why clinicians should know about it
- Picked for Surgical Oncology (paper of the day, 9 October 2026): Neoadjuvant niraparib monotherapy for unresectable ovarian cancer
Abstract
BACKGROUND: Neoadjuvant chemotherapy followed by interval debulking surgery is standard treatment for advanced ovarian cancer that is unlikely to achieve optimal cytoreduction. We aimed to evaluate a chemotherapy-free regimen of neoadjuvant niraparib monotherapy in homologous recombination deficiency (HRD)-positive disease initially unsuitable for primary debulking surgery. METHODS: This single-arm, phase 2 trial was conducted at six tertiary hospitals in China. Eligible patients were aged 18-75 years, had treatment-naïve, FIGO stage III-IV HRD-positive high-grade serous or endometrioid ovarian cancer, an ECOG performance status of 0-2, with a low likelihood of complete primary debulking surgery based on prespecified criteria. Patients received oral niraparib monotherapy for two 28-day cycles with an individualised starting dose of 200 mg or 300 mg. Protocol-permitted supportive care was provided as clinically indicated. Co-primary endpoints were investigator-assessed objective response rate in the response-evaluable population and R0 resection rate after interval debulking surgery in the operated population. Safety was assessed in all patients who received at least one dose of niraparib. The trial was registered with ClinicalTrials.gov (NCT04507841), is closed to enrolment, and this report presents the primary analysis. FINDINGS: Between Jan 8, 2021, and Jul 18, 2023, 127 patients were screened, and 67 were enrolled into the study. All enrolled patients were female and self-identified as Han Chinese (median age 55 years [IQR 50-62]). At the data cutoff (Dec 29, 2025), median follow-up was 37·7 months (IQR 31·8-48·5). Among 48 response-evaluable patients, 30 achieved an objective response, with an objective response rate of 63% (95% CI 47-76). Among 40 operated patients, 32 achieved R0 resection, with an R0 resection rate of 80% (95% CI 64-91). The most common grade 3-4 treatment-related adverse events were thrombocytopenia in 32 (48%) of 67 patients, leukopenia in 13 (19%) patients, anaemia in 12 (18%) patients, and neutropenia in nine (13%) patients. Serious adverse events occurred in 19 (28%) patients. No treatment-related deaths occurred. INTERPRETATION: Neoadjuvant niraparib showed anti-tumour activity and enabled R0 resection in selected patients with HRD-positive advanced ovarian cancer who were initially unsuitable for primary debulking surgery. This strategy remains investigational and requires randomised validation against standard platinum-taxane neoadjuvant chemotherapy. FUNDING: National Key Technology Research and Development Program of China, National Natural Science Foundation of China, Natural Science Foundation of Hubei Province, Innovative Drug Research and Development National Science and Technology Major Project, and Zai Lab (Shanghai). TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.