Largest Prospective Study to Date Further Supports Performance of DecisionDx®-UM for Metastatic Risk Stratification in Uveal Melanoma and Utility of PRAME Biomarker for Refining Risk When Considered with DecisionDx-UM Class Result

Oral presentation at ARVO shares ground-breaking findings from the ongoing Collaborative Ocular Oncology Group (COOG) study 2 (COOG2) of patients with uveal melanoma (UM)

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced new data from a study further confirming the performance of its DecisionDx-UM test as a robust independent predictor of metastasis-free survival (MFS) in patients diagnosed with UM. Further, the study provides prospective validation data supporting Preferentially Expressed Antigen in Melanoma (PRAME) as a risk refinement tool when considered in the context of a Class 1 or Class 2 DecisionDx-UM test result. The data was presented at the Association for Research in Vision and Ophthalmology (ARVO) 2024 Annual Meeting in Seattle.

Uveal melanoma is an aggressive cancer of the eye, and despite high primary tumor cure rates, metastatic disease spread eventually impacts about half of all patients.1 The DecisionDx-UM test is considered the standard of care in the management of newly diagnosed UM to assist in determining risk of metastasis, which is critical for informing appropriate treatment plans.

“The latest findings from the COOG2 study not only further support DecisionDx-UM’s ability to predict metastatic risk, but also highlight the utility of PRAME as a valuable adjunct biomarker for further risk refinement when considered in conjunction with a DecisionDx-UM result,” said lead study author and COOG investigator Zelia Correa, M.D., Ph.D., professor of ophthalmology and director of ocular oncology at the Bascom Palmer Eye Institute and Sylvester Comprehensive Cancer Center of the University of Miami Miller School of Medicine. “The study data provides support for combining the reported expression status of the PRAME gene with the DecisionDx-UM class result to enhance metastatic risk prediction. Specifically, distinguishing between PRAME-negative (-) and PRAME-positive (+) subgroups within DecisionDx-UM Class 1 and Class 2 tumors provides additional biological insights into an individual patient’s likelihood of metastasis. This information can be utilized to optimize surveillance and guide more nuanced and risk-aligned treatment decisions.”

Details regarding the presentation at ARVO are included below:

• Oral Presentation Title: Collaborative Ocular Oncology Group study 2 (COOG2): Prospective multi-center validation of the 15-gene expression profile (GEP)/PRAME molecular prognostic tool for uveal melanoma in 1586 patients
• Session Type: Paper Session (Wednesday, May 8)
• Presentation Number: 4273
• Summary: This prospective, multi-center study included 1,586 patients with posterior UM tumors enrolled across 26 ocular oncology centers in the United States and Canada. In the study, a DecisionDx-UM Class 2 result was the most robust independent predictor of MFS (HR 6.03; 95% CI, 4.49-8.09); P