Abstract CT280: A pragmatic study of the clinical utility of genomic classifiers in guiding prostate cancer treatment decisions: Impact of treatment selection, oncologic outcomes, and treatment-related adverse events (PROMPT-Bx)

Abstract Background: Prostate cancer (PCa) risk models based on clinicopathological features have been widely adopted by clinicians to inform treatment decisions. Prolaris provides greater prognostic power for evaluating risk of distant metastases and PCa-specific mortality than traditional risk models. Evidence is limited for how treatment decisions informed by genomic classifiers (GCs) impact treatment selection and intensification decisions, oncologic outcomes, and treatment-related adverse events (AEs) in a real-world setting. Methods: PROMPT-Bx is a multicenter, observational, pragmatic study in patients with newly diagnosed primary PCa. Registration was not required since study is non-interventional. IRB approval was obtained from Advarra (Pro00088502). Study sites routinely treat newly diagnosed localized PCa and accurately reflect real-world diagnosis and treatment of the disease. Patients who are eligible for and elect to pursue GC testing will be informed of the study and offered the chance to participate following provision of informed consent. Diagnostic biopsy samples will be used for Prolaris, with results reported back as part of standard clinical workflow. Providers will be surveyed about management decisions prior to and after receiving results. Treatment selection, oncological outcomes, and AEs will be collected from participating sites. The study is expected to enroll 3350 patients with 5 years of follow up. Primary objectives are to evaluate clinical utility of Prolaris to identify candidates for active surveillance as well as treatment intensity decisions, based on metastasis risk. Secondary objectives include evaluating non-inferiority of Prolaris recommendations compared to treatment-related AEs, impact on decision making, and prognostic utility for metastasis and biochemical recurrence. Metastasis, adverse pathology, biochemical recurrence, and treatment related AEs will be determined from the time of diagnostic biopsy and compared across NCCN risk groups using survival analyses. This study provides one of the first opportunities to better understand the utility of GC testing for patients and providers in a real-world setting. The trial is enrolling as planned, and first data analysis will occur 6 months after full enrolment. Citation Format: Brent Mabey, Lauren Lenz, Thaylon Davis, Alexander Gutin, Katherine Johansen Taber, Dale Muzzey, Jeff Jasper, Matthew Schiewer. A pragmatic study of the clinical utility of genomic classifiers in guiding prostate cancer treatment decisions: Impact of treatment selection, oncologic outcomes, and treatment-related adverse events (PROMPT-Bx) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT280.