e15539 Background: Real world HRU in second-line aOC has not been well quantified. The objective of this study was to assess HRU and treatment patterns in women with previously-treated aOC subsequently treated with nonplatinum chemotherapy (CT). Methods: A retrospective study was conducted using the SEER-Medicare linked dataset. The population included women ≥ 65 years who were diagnosed with incident, distant-stage aOC between 1993-2005 and who had ≥ 3 months of claims data before diagnosis. The study cohort included patients previously treated with platinum-based CT and re-treated following a ≥ 90 day treatment-free interval (TFI) with nonplatinum-based CT in 2000-2005. Patients were followed from the first claim for retreatment with a nonplatinum CT regimen until either death or the end of the claims data (12/31/2007). Measures of HRU included hospitalizations, outpatient visits, physician visits, hospice care, home health care, and skilled nursing facility (SNF) visits. Costs of each HRU event were estimated by summing all Medicare payments, primary insurer payments, patient copayments and deductibles for services in the claims files. Average healthcare costs per patient per event type (e.g., hospitalization) are calculated as total event cost per event divided by number of patients with the event. Results: 2,166 previously treated aOC patients subsequently received nonplatinum CT as second-line therapy. Mean age was 74.0 years (SD 5.6). The mean treatment duration in the non- platinum CT period was 317 days (SD 354). Paclitaxel and pegylated liposomal doxorubicin (PLD) were the most commonly used nonplatinum CT agents. Paclitaxel use declined from 38.1% to 30.0% while PLD use increased from 16.4% to 26.8% from 2000-2005. Rate of hospitalization was 1.3 per person-year. Mean hospitalization cost per patient was $10,466 (SD $10,846). Mean SNF and hospice care costs per patient were $7,416 (SD $6,907) and $6,955 (SD $11,416) respectively. Conclusions: Both paclitaxel and PLD were frequently used nonplatinum-based CTs in women with aOC who were previously treated with platinum-based agents. Hospitalization costs per patient were substantial. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Amgen Amgen Amgen