Cancer stem cell assay for identification of effective treatments for platinum-resistant recurrent ovarian cancer.

e17584 Background: Disease recurrence and progression of ovarian cancer is a common event, which is accompanied by the development of platinum-resistant or refractory disease. The presence of chemo-resistant cancer stem cells (CSCs) contributes to tumor propagation, maintenance, and treatment resistance of this difficult to treat disease. The choice of appropriate chemotherapy is critical to the management of advanced epithelial ovarian cancer. We developed a CSCs assay (ChemoID) that identifies the most effective chemotherapy for individual patients from a panel of FDA-approved chemotherapies. Methods: Ascites or interventional radiology biopsies were collected under physician order from 85 consecutive patients affected by 3rd relapsed ovarian cancer. Test results from the assay were used to treat patients with the highest cell kill drugs, taking into consideration their health status and using dose reductions, if needed. Our study assessed the correlation of the ChemoID test results to treatment outcomes independently of other biomarkers. A retrospective chart analysis and review of CT and PET scans were performed to determine patients’ outcomes for tumor response, progression-free survival (PFS), and overall survival (OS). Results: We observed that recurrent ovarian cancer patients treated with high-cell kill chemotherapy agents guided by the ChemoID drug response assay had an improvement in their median PFS and OS when compared to historical median PFS and OS and/or when compared to patients who could not receive high cell kill chemotherapies (PFS low cell kill 3.5 months vs. high cell kill 12.0 months; OS low cell kill 6.0 months vs. high cell kill 15.0 months). Conclusions: The current evidence strongly suggests that the ChemoID assay predicted the effectiveness of specific therapies, as well as improved outcomes for patients treated with assay-sensitive therapies.