BACKGROUND: Ovarian cancer (OC) is the fifth leading cause of cancer death in women and has the highest mortality rate of gynecological cancers. Niraparib was recently approved by the FDA for the maintenance treatment of adult patients with advanced epithelial OC in complete or partial response to first-line platinum-based chemotherapy (PBC) regardless of biomarker status. OBJECTIVE: To estimate the direct economic impact on US payers of adding niraparib as a first-line maintenance therapy for patients with advanced OC. METHODS: The model considered 2 scenarios: a current scenario in which niraparib does not have regulatory approval for first-line maintenance therapy and a future scenario in which niraparib has regulatory approval for first-line maintenance therapy. The budget impact was calculated as the difference in cost between the 2 scenarios. The budget impact model (BIM) considered 2 different US health care payer perspectives: a commercial health plan and a Medicare plan. Both payer perspectives were assumed to have a hypothetical 1 million affiliates that were covered. Epidemiological data was used to estimate the eligible incident population of patients with OC. Active surveillance, bevacizumab (as a monotherapy), and olaparib (as a monotherapy restricted to patients with the breast cancer gene [BRCA] mutation) were included in the model as alternative maintenance treatment options (maintenance treatment options required 1% market share for inclusion). Cost categories considered in the BIM included diagnostic testing, treatment acquisition and administration, treatment-emergent adverse events, and subsequent therapy. Results were presented as an incremental budget impact to payers over 3 years. RESULTS: For a commercial health plan of 1 million affiliates, the estimated impact of adding niraparib as a first-line maintenance treatment option for advanced epithelial OC was calculated as $87,906, $93,106, and $87,037 for years 1, 2, and 3, respectively. The average budget impact per member per month was $0.007. For a Medicare health plan of 1 million affiliates, the estimated impact was calculated as $206,785, $219,017, and $204,739 for years 1, 2, and 3, respectively. The average budget impact per member per month was $0.018. One-way sensitivity analyses suggested that budget impact was most sensitive to the treatment duration and market share of niraparib, the non-treatment-specific data on overall survival rates, and the treatment duration of bevacizumab. Treatment of drug-specific adverse events had little impact on the budget model. CONCLUSIONS: The model estimated a minimal budget impact to both a commercial or Medicare health plan following the introduction of niraparib as a first-line maintenance therapy for patients with advanced epithelial OC who are in complete or partial response to first-line PBC regardless of biomarker status. DISCLOSURES: This study was financially supported by GlaxoSmithKline. Liu, Hawkes, Maiese, and Hurteau are employees of GlaxoSmithKline. Travers was employed by GlaxoSmithKline at the time of this study. Spalding and Walder are employees of FIECON Ltd., which was contracted by GlaxoSmithKline to develop the budget impact model used in this study.