Study Results with Castle Biosciences’ Uveal Melanoma Gene Expression Test Published in Journal of Oncology

Data confirm accuracy of DecisionDx-UM and demonstrate impact of test results on patient care and follow-up

Castle Biosciences, Inc., a provider of molecular diagnostics to improve cancer treatment decisions, today announced the publication of clinical data on DecisionDx^®-UM, its gene expression profile (GEP) test to predict metastasis in patients diagnosed with uveal melanoma (UM). The paper, “Clinical Performance and Management Outcomes with the DecisionDx-UM Gene Expression Profile Test in a Prospective Multicenter Study” was recently published in the Journal of Oncology.

The prospective, multicenter CLEAR (Clinical Application of DecisionDx-UM Gene Expression Assay Results) study tracked clinical management and metastatic outcomes of 70 UM patients from 4 centers across the U.S. with low-risk Class 1 or high-risk Class 2 GEP test results. None of the patients had evidence of distant metastasis at the time of primary tumor treatment. The CLEAR study demonstrated that the GEP test accurately predicts metastatic risk for UM patients and is being used by physicians to appropriately guide patient care decisions and potentially improve net health outcomes.

“The ability to accurately gauge metastatic risk in uveal melanoma—a cancer for which clinicopathologic staging is inadequate—is an important advance and critical to disease management,” commented study co-author Thomas M. Aaberg, Jr., Assistant Clinical Professor at Michigan State University Medical School and ocular oncologist with Retina Specialists of Michigan. “Results from the CLEAR study support the wide adoption of DecisionDx-UM, and demonstrate the impact the test has made thus far on follow-up care plans for patients. The GEP test is also being used to identify and appropriately enroll patients in clinical trials designed to adjuvantly treat high-risk Class 2 UM patients. We hope to see more of these studies opening up in the near future.”

Study Details

• Study Cohort:
  • 37 patients (53%) had a low-risk Class 1 GEP test result; 33 patients (47%) had a high-risk Class 2 result.
• Clinical Utility:
  • All Class 2 patients were managed with high intensity surveillance (imaging and/or liver function tests every 3-6 months);
  • 81% of Class 1 patients were managed with low intensity surveillance (imaging and/or liver function tests every year);
  • There was a significant difference in management of Class 1 and Class 2 patients (p<0.0001);
  • 33% of Class 2 patients were referred to a medical oncologist for surveillance and/or clinical trial enrollment compared to 11% of Class 1 patients (p=0.04).
• Clinical Outcomes:
  • Overall, two Class 1 (5%) patients and 12 (36%) Class 2 patients developed metastasis (p=0.002) with a median follow-up of 27.3 months;
  • At 3 years, metastasis-free survival rates were 100% for Class 1 and 63% for Class 2 (p=0.003).

“From a clinical utility perspective, findings from the CLEAR study replicate results from an earlier publication that documented the significant impact DecisionDx-UM test results have on patient management. From a performance perspective, this is the fourth prospective clinical study which demonstrated consistent clinical outcomes—an unprecedented level of validation in the field of genomic testing—and we remain confident in the test’s ability to provide actionable prognostic information to physicians and their patients,” said Derek Maetzold, President and CEO of Castle Biosciences.

The paper can be accessed at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944073/

About Uveal Melanoma

Uveal melanoma, while rare, is the most common form of eye cancer in the United States with about 1,600 diagnoses per year. This form of eye cancer may occur in any of the three parts of the uvea. Similar to other melanomas, uveal melanoma begins in cells called melanocytes that help produce the pigments of the skin, hair and eyes. While more common in patients who are middle-aged with fair skin, uveal melanoma can affect people of all complexions and ages.

Although a small percentage (3%) of patients with uveal melanoma have detectable metastatic lesions at the time of diagnosis or treatment of the primary tumor, up to 50% of patients will subsequently develop metastatic disease. This necessitates a rigorously validated, accurate and reliable tool to identify patients likely to develop distant metastasis.

About DecisionDx-UM

The DecisionDx-UM test measures the gene expression profile (GEP), or molecular signature, of an individual’s tumor and identifies with high accuracy the likelihood of metastasis.

The DecisionDx-UM test is standard of care in the management of uveal melanoma in the majority of ocular oncology practices. It is the only test for uveal melanoma that has achieved National Cancer Institute/National Comprehensive Cancer Network Level of Evidence 1A, a critical factor in test adoption and clinical decision-making. Additionally, the American Joint Committee on Cancer recommends gene expression profile testing for use as the results are “clinically significant.” The American Joint Committee on Cancer (AJCC, version 7, 2010) is the only national organization that reviews uveal melanoma and the DecisionDx-UM test is the only clinically available GEP test for use in the U.S. The test has been validated in multiple prospective and retrospective studies. More information about the test and disease can be found at www.MyUvealMelanoma.com.

About Castle Biosciences

Castle Biosciences is a molecular diagnostics company dedicated to helping patients and their physicians make the best possible decisions about their treatment and follow-up care based on the individual molecular signature of their tumor. The Company currently offers tests for patients with uveal melanoma (DecisionDx®-UM;www.MyUvealMelanoma.com) and cutaneous melanoma (DecisionDx®-Melanoma; www.SkinMelanoma.com), with development programs in other underserved cancers. Castle Biosciences is based in Friendswood, TX (Houston), and has laboratory operations in Phoenix, AZ. More information can be found at www.castlebiosciences.com.

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