Castle Biosciences Announces Presentation of 5-Year Prospective, Multicenter Clinical Outcome Study Confirming Accuracy and Impact of Uveal Melanoma Test

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc., a cancer diagnostics company providing personalized genomic information to improve cancer management decisions, today announced that it will present five-year outcomes from a prospective, multicenter study showing that DecisionDx^®-UM accurately predicts metastatic risk for patients with uveal melanoma and is used by physicians to make patient management decisions based on risk categories determined by the test. The study will be presented at the International Society of Ocular Oncology (ISOO) Biennial Conference held March 22-26 in Los Angeles CA.

The CLEAR study (Clinical Application of DecisionDx-UM Gene Expression Assay Results) was designed to track clinical management and metastatic outcomes of patients with uveal melanoma who were tested with the DecisionDx-UM gene expression profile (GEP) test as part of their diagnostic work-up.

“An accurate understanding of metastatic risk is critical to guiding surveillance planning for patients with uveal melanoma since clinicopathologic staging alone is insufficient,” commented investigator Thomas M. Aaberg, Jr., M.D., Assistant Clinical Professor at Michigan State University Medical School and ocular oncologist with Retina Specialists of Michigan, who presented the study. “The results from the CLEAR study are consistent with previous publications and confirm the accuracy and clinical utility of the DecisionDx-UM test in clinical practice.”

Study Highlights:

• 89 patients from four centers were enrolled between March 2011 and January 2017. Median follow-up time for patients without metastasis was 4.7 years.
• 49 patients (55%) had a low-risk Class 1 test result; 40 patients (45%) had a high-risk Class 2 test result.
• All patients with Class 2 test results were managed with high intensity surveillance (imaging and/or liver function tests every 3-6 months), while 80% of Class 1 patients were managed with low intensity surveillance (imaging and/or liver function tests at a maximum of once each year) (p<0.0001).
• Overall, three (6%) Class 1 patients and 22 (55%) Class 2 patients developed metastasis (p<0.0001). Median time to metastasis was 3.2 years for Class 1 and 2.5 years for Class 2.
• Five-year metastasis-free survival rates were 92% for Class 1 and 42% for Class 2 (p<0.0001).
• In multivariate analysis including age, ciliary body involvement, largest basal diameter and tumor thickness, the DecisionDx-UM Class 2 result was the only statistically significant predictor of metastasis (p<0.0001).
• These findings are consistent with results from previously published prospective studies documenting the accuracy of DecisionDx-UM and impact on patient management.

About DecisionDx-UM

DecisionDx-UM is a GEP test that uses an individual patient’s tumor biology to predict individual risk of metastasis. DecisionDx-UM is the standard of care in the management of uveal melanoma in the majority of ocular oncology practices. Since 2009, the American Joint Committee on Cancer (AJCC; v7 and v8) has included GEP testing for the identification of Class 1 and 2 as a prognostic factor recommended for clinical care. In 2018, the National Comprehensive Cancer Network (NCCN) published guidelines on uveal melanoma that include the DecisionDx-UM test results of Class 1A, Class 1B and Class 2B as prognostic factors to guide clinical care. DecisionDx-UM is the only prognostic test for uveal melanoma that has been validated in prospective, multi-center studies. In addition, the DecisionDx-UM test result has been shown to be a superior predictor of metastasis compared to chromosome 3 status, mutational status, AJCC stage, and cell type, as demonstrated in multiple studies.

It is estimated that nearly 8 in 10 patients diagnosed with uveal melanoma in the U.S. receive the DecisionDx-UM test as part of their diagnostic workup. More information about the test and disease can be found at www.MyUvealMelanoma.com.

About Castle Biosciences

Castle Biosciences is a skin cancer diagnostics company dedicated to helping patients and their physicians make more informed decisions about treatment and follow up care based on the individual molecular signature of the patient’s tumor. The Company currently offers tests for patients with cutaneous melanoma (DecisionDx^®-Melanoma, DecisionDx^®-CMSeq; www.SkinMelanoma.com) and uveal melanoma (DecisionDx^®-UM, DecisionDx^®-PRAME and DecisionDx^®-UMSeq; www.MyUvealMelanoma.com), with programs in development for other underserved cancers, the most advanced of which is focused on patients with cutaneous squamous cell carcinoma. Castle Biosciences is based in Friendswood, Texas (Houston), and has laboratory operations in Phoenix, Arizona. More information can be found at www.CastleBiosciences.com.

DecisionDx-Melanoma, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are the trademarks of Castle Biosciences, Inc. Any other trademarks are the property of their respective owners.

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