AUA 2017: Interim Results of a Novel ‘Adaptive’ Registration-Utility Trial Assessing the Performance of Exodx (Prostate) Intelliscore (EPI): A Non-DRE Urine Exosome Gene Expression Assay to Predict High Grade Disease on Initial Biopsy

Boston, MA ( Dr. Partin and colleagues presented their work today at the 2017 AUA Annual meeting’s late-breaking abstract session, discussing their initial results from a non-DRE urine biomarker ExoDx Prostate (IntelliScore) (EPI). EPI is a non-DRE urine exosome gene expression assay, and the authors previously demonstrated that it discriminates Gleason 7 prostate cancer from Gleason 6 and benign disease [1], potentially reducing the number of unnecessary biopsies.

In this prospective two cohort trial, the authors have two groups of men: Group 1 (G1) - men scheduled for a biopsy, and Group 2 (G2) - men for which the decision to biopsy is uncertain. The G1 consensus results, including EPI cut-point recommendation, will be applied to G2 patients with clinical utility, ease of adoption, patient response and health economic data reported. In this interim analysis, the authors assessed the results from the G1 group and initial cut-point comparison to the original validation trial. Enrollment is limited to initial biopsy patients only, those ≥50 years of age and PSA 2-10 ng/mL. Among 9 sites, demographics of the 96 (of targeted) 500 G1 patients enrolled are comparable to the validation study with regards to age (mean 64 years), PSA (mean 5.78 ng/mL), race (75% white), family history (positive 23%), and DRE findings (81% non-suspicious DRE). In the interim results, positive biopsy rate is 59%, with 22% Gleason 6 disease and 37% ≥ Gleason 3+4 disease. The EPI test validated (15.6) vs. adjusted (20) cut-points both resulted in a NPV 90, with sensitivity of 94% and 92%, respectively. The number of avoided biopsies is greater (30%) with the adjusted cut-point of 20 vs. the original validated cutpoint (21%), only missing 1 ≥ Gleason 4+3 case.

In summary, the interim results from a prospective trial of the EPI biomarker have similar performance to the original validation setting. By adjusting the cut-point, there is added benefit without significant risk of missing clinically relevant disease. We readily await the results from the full trial.

1. McKiernan J, Donovan MJ, O’Neill V, et al. A novel urine exosome gene expression assay to predict high-grade prostate cancer at initial biopsy. JAMA Oncol 2016;2(7):882-889.

Speaker: Alan Partin, Johns Hopkins Hospital, Baltimore, MD, USA

Co-Authors: Phillipp Torkler, Mikkel Noerholm, Johan Skog, Michael Donovan

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA