Results of New Study with Castle Biosciences’ Skin Melanoma Gene Expression Test Published in Current Medical Research and Opinion

Castle Biosciences, Inc., a provider of molecular diagnostics to improve cancer treatment decisions, today announced the publication of a prospectively designed, multicenter, decision impact study of its gene expression profile (GEP) test for cutaneous melanoma. The DecisionDx^®-Melanoma GEP test accurately predicts metastatic risk independent of current diagnostic modalities including AJCC staging. The paper, “Clinical impact of a 31-gene expression profile test for cutaneous melanoma in 156 prospectively and consecutively tested patients,” was recently published in the peer-reviewed journal Current Medical Research and Opinion.

The study was designed to ascertain clinical management changes determined by the test outcome, which classifies cutaneous melanoma patients as either low risk (Class 1) or high risk (Class 2) for recurrence. Results showed that the GEP test outcome changed clinical management for over half of the tested patients.

“Results of this study support the use of this GEP test as an important tool for guiding follow-up care for patients diagnosed with cutaneous melanoma,” commented study author, Adam C. Berger, MD, FACS, Chief, Section of Surgical Oncology and Deputy Vice Chair for Clinical Research in the Department of Surgery at Thomas Jefferson University Hospital. “The GEP test’s ability to accurately predict the relative risk of disease recurrence is changing how physicians approach follow-up care, particularly in cases with a Class 2 test result predicting a high risk for future metastatic disease.”

STUDY HIGHLIGHTS

In this study, medical records of cutaneous melanoma patients consecutively tested with DecisionDx-Melanoma at 6 medical practices (three dermatology and three surgical oncology practices) from May 2013 to December 2015, were reviewed under an IRB-approved protocol. Investigators reported clinical management plans included frequency of physical exams, frequency and modality of imaging, and referrals to surgical and medical oncologists. Clinical management plans before and after receipt of the DecisionDx-Melanoma test results were collected to assess the impact on clinical decision making.

Summary of Results:

• 156 cutaneous melanoma patients met inclusion criteria with complete AJCC staging and management information:
  • 42% percent of patients were Stage I, 47% were Stage II, and 8% were Stage III;
  • 61% (95) had a low risk Class 1 GEP test result and 39% (61) had a high risk Class 2 result.
• Documented changes in management were observed in 53% (82) patients:
  • 77% of Class 2 patients underwent management changes compared to 37% of Class 1 patients (p<0.0001 by Fisher’s exact test);
  • 94% (77/82) of these changes were concordant with the risk indicated by the test result (p< 0.0001 by Fisher’s exact test), with increased management intensity for Class 2 patients and reduced management intensity for Class 1 patients.

“We are extremely pleased with the continued clinical adoption of DecisionDx-Melanoma,” said Derek Maetzold, President and CEO of Castle Biosciences. “The test complements traditional staging tools to provide the most accurate prognostic information from which to plan a patient’s follow-up care. The GEP test may also help investigators improve the design of clinical trials to advance adjuvant treatment in patients who are identified as high risk, Class 2.”

The paper can be accessed from the Current Medical Research and Opinion website.

About Melanoma

Cutaneous melanoma is diagnosed in approximately 76,000 people in the U.S. each year, according to the American Cancer Society. Seventy-five percent are diagnosed as Stage I or II, meaning there is no evidence of the melanoma spreading beyond the primary tumor. It is not the most prevalent form of skin cancer, but it is the most aggressive. Unlike other more common skin malignancies such as basal cell and squamous cell carcinomas, melanoma often spreads to other parts of the body, either via the lymphatic or blood system, resulting in cancers of distant organs including the brain or lungs. So, while it represents just 4% of skin cancers, melanoma accounts for about 80% of skin cancer-related deaths.

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.