DecisionDx^®-UM Overview

Standard of Care For Predicting Metastatic Risk in Uveal Melanoma

Uveal melanoma, commonly known as ocular or choroidal melanoma, is a rare cancer of the eye with approximately 2,000 patients diagnosed annually in the U.S. At the time of initial diagnosis, approximately 97% of patients are free of metastasis.  However, within five years, approximately 30% of patients will develop metastasis – rising to nearly 50% in the following years.

Before the introduction of our DecisionDx-UM test, traditional clinical and pathologic factors and other molecular diagnostic tests were available to help determine the likelihood of metastasis, but the lack of prospective studies, coupled with low accuracy, resulted in these factors and tests not having wide acceptance for clinical management of patients in the U.S. As a result, nearly all U.S. centers grouped patients into a single, high-risk treatment plan that included frequent, high-intensity surveillance using advanced imaging, frequent clinical visits and encouragement to enroll in clinical studies.

The introduction of our DecisionDx-UM test changed how uveal melanoma is managed.  DecisionDx-UM is a proprietary GEP (gene expression profile) test that helps healthcare providers predict the risk of metastasis in patients with uveal melanoma. We licensed the intellectual property for DecisionDx-UM from Washington University in St. Louis, Missouri, completed analytical validation, and made the DecisionDx-UM available for clinical use in late 2009 for use in patients diagnosed with uveal melanoma without evidence of metastatic disease. DecisionDx-UM identifies which patients are at low risk for progression of their disease so that their physicians can appropriately de-escalate the level of care provided.

Proven Clinical Validity and Utility of DecisionDx-UM

The DecisionDx-UM test has been the subject of 19 peer-reviewed publications supporting its clinical validity and utility.  The initial prospective, multi-center Collaborative Ocular Oncology Group, or COOG study found a 97% negative predictive value for the risk of metastasis.  This study also compared DecisionDx-UM to the traditional clinical and pathology factors as well as chromosome 3 status, which is an alternative molecular test to predict the risk of metastasis in uveal melanoma, and found that the only statistically significant factor in predicting a likelihood of metastasis was DecisionDx-UM.  Five studies have been published that show that healthcare providers and patients use the DecisionDx-UM test to de-escalate management.

As a result of the consistency across studies, in 2019, we delivered DecisionDx-UM test results to more than 1,500 patients, representing approximately 75% of diagnosed patients who were managed by 90% of ocular oncology institutions.

Uveal Melanoma Tissue Repository

Castle Biosciences created a tissue repository to enable all DecisionDx-UM patients to have access to their own tumor tissue for future use. This could include taking advantage of targeted treatments, clinical trials, and further prognostic testing as they become available.