Presentations at EADO Highlight Potential Impact of Castle Biosciences’ DecisionDx-Melanoma and DecisionDx-SCC Tests on the Management of Patients with Skin Cancer

Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, will share new data at the 20th European Association of Dermato-Oncology (EADO) Congress, being held April 4-6, 2024, in Paris, France, that demonstrate the ability of its DecisionDx-Melanoma and DecisionDx-SCC tests to improve clinical-decision making through precise risk-stratification of patients with cutaneous melanoma (CM) and squamous cell carcinoma (SCC).

“Our DecisionDx-Melanoma test informs two questions: which patients can consider foregoing an SLNB, and what is the risk of recurrence so the most appropriate follow-up treatment plan can be implemented,” said Robert Cook, Ph.D., senior vice president of research and development at Castle Biosciences. “It is of high importance that when a test identifies patients with a low likelihood of a positive SLNB, and thus they could forgo this surgical procedure, the patients also have a low risk of metastatic outcomes. The data from our prospective, multicenter study show just that – SLNB-eligible patients who had a DecisionDx-Melanoma Class 1A (lowest risk) test result and made the decision with their physician to forego an SLNB had excellent outcomes during the follow-up period. We believe it is this kind of evidence that should be required in order for clinicians to safely adopt a molecular test that rules out an SLNB surgical procedure.

“Our second DecisionDx-Melanoma poster shows that the clinical use of our test is also associated with a 30% cost savings improvement … a win-win situation.”

Castle will present the following posters at EADO:

DecisionDx-Melanoma

• Title: Patients who forego sentinel lymph node biopsy after 31-GEP testing are not harmed: A prospective, multicenter analysis
• Abstract: A-262
• Summary: This study shares data from Castle’s prospective, multicenter study of patients with T1-T2 CM tumors who were being considered for an SLNB. Within a median follow-up time of two years, none of the patients with low-risk DecisionDx-Melanoma test results (Class 1A) who decided to forego SNLB based on their results had a tumor recurrence. These study data support use of the DecisionDx-Melanoma test to inform SLNB decisions and show that it can identify patients at low risk of sentinel lymph node (SLN) positivity who may safely forego the SLNB procedure, reducing healthcare costs and procedure complications.

• Title: The health economic impact of the 31-gene expression profile test for treatment and surveillance management plans in patients with cutaneous melanoma
• Abstract: A-223
• Summary: The DecisionDx-Melanoma test has been validated to predict individual risk of SLNB positivity and five-year risk of recurrence and metastasis for patients with CM. This study explored the cost-savings impact of using the DecisionDx-Melanoma test to guide risk-aligned clinical decision-making versus using the current melanoma staging standard, a patient’s AJCC stage. Costs of National Comprehensive Cancer Network (NCCN) guideline-recommended practices for patients with melanoma that were evaluated in the study included: SLNB, clinical visit schedules, imaging surveillance and adjuvant treatment for eligible patients. The study determined that using DecisionDx-Melanoma test results to guide decision-making could save commercial payers more than $3 million (30% cost savings per one million plan members over five years) compared to care guided by AJCC stage, with 95% of such potential cost savings occurring during the first year post-diagnosis (year one projected savings of approximately $2.5 million).

DecisionDx-SCC