CHICAGO--(BUSINESS WIRE)--Castle Biosciences, Inc., a provider of molecular diagnostics to improve cancer treatment decisions, today announced that three abstracts detailing results from studies of DecisionDx®-Melanoma were presented at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting being held in Chicago, IL from June 2-6. Presentations included an interim analysis of a prospective, multicenter registry study, test performance in Stage III cutaneous (skin) melanoma patients and an analysis of test performance in patients with melanoma of the head and neck. The molecular diagnostic test uses tumor biology to provide an individual risk of recurrence in cutaneous melanoma patients.
“Performance of a Prognostic 31-Gene Expression Profile Test in Stage III Cutaneous Melanoma Subjects”
Prospective, Multicenter Registry Study
In the abstract, “Interim Analysis of Survival Outcomes in a Prospective Multicenter Cohort Evaluating a Prognostic 31-Gene Expression Profile (GEP) Test for Melanoma” (Abstract #9573), outcome results from 322 patients with Stage I-III cutaneous melanoma who received DecisionDx-Melanoma testing were discussed. The DecisionDx-Melanoma test was performed to determine molecular class for each patient, with a Class 1 result indicating low 5-year risk of metastasis and a Class 2 result indicating high risk. Endpoints of recurrence-free survival (RFS), distant metastasis-free survival (DMFS) and overall survival (OS) were assessed using Kaplan-Meier and Cox regression analyses.
The abstract reports an interim analysis at year 3 of an anticipated 5-year prospective, multicenter registry study. Median follow-up time for this analysis was 1.5 years for event-free patients.
Summary of Study Results:
- Interim analysis results confirm the association between DecisionDx-Melanoma class result and outcomes (p<0.0001).
- Consistent with prior studies, significantly different recurrence rates were observed for low-risk Class 1 (2%) and high-risk Class 2 (27%) groups, with 1.5-year RFS rates of 97% for patients in the Class 1 group compared with 77% for those in the Class 2 group (p<0.0001).
- 80% (20 of 25) of patients who experienced recurrences during the study had a Class 2 GEP result. In comparison, 40% (10 of 25) of patients with recurrences had a sentinel lymph node- (SLN) positive result and 60% (15 of 25) had ulcerated primary tumors.
- In this study, 83% (10 of 12) of patients who developed distant metastases were identified as high-risk by the DecisionDx-Melanoma test, compared to 50% (6 of 12) who had a SLN-positive result, indicating that the GEP test can improve the identification of high-risk cutaneous melanoma patients.
- High negative predictive values (NPV) of 98% for recurrence and 99% for distant metastasis demonstrate that a Class 1 outcome was associated with a low risk of metastasis during the study.
“This prospective, multicenter study adds to the growing body of evidence that the DecisionDx-Melanoma test produces consistent, clinically meaningful results,” noted study co-investigator Eddy C. Hsueh, M.D., Professor and Director, Division of Surgical Oncology, St. Louis University Hospital. “The alignment of these results with previous studies shows that the DecisionDx-Melanoma test provides accurate, independent prognostic information across multiple practice settings.”
“It is important to identify early stage patients with melanoma who are at an increased risk of recurrence so that appropriate surveillance can be provided,” commented study co-investigator Kelly M. McMasters, M.D., Ph.D., Chair of the Department of Surgery, University of Louisville. “The results from this interim analysis confirming the association of the DecisionDx-Melanoma class with patient outcome align with my experience in clinical practice showing that assessing tumor biology can provide important, clinically impactful prognostic information.”
Multicenter, Validation Study of Stage III Patients
In the abstract, “Performance of a Prognostic 31-Gene Expression Profile Test in Stage III Cutaneous Melanoma Subjects” (Abstract #9578), results from 207 patients with Stage III cutaneous melanoma were reported.
