Benzinga | Oct 26, 2021 08:27AM EDT

Castle Biosciences Highlights New Data Further Validating Performance Of Co.'s DecisionDx DiffDx -Melanoma Test

Presentation highlights data from second independent study validating DecisionDx(r) DiffDx(tm)-Melanoma as an ancillary melanoma diagnostic tool for difficult-to-diagnose melanocytic lesions

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (NASDAQ:CSTL), a company applying innovative diagnostics to inform disease management decisions and improve patient outcomes, today announced new data further validating the performance of the Company's DecisionDx(r) DiffDx(tm)-Melanoma test as a highly accurate, ancillary tool to aid in the diagnosis of melanocytic lesions with ambiguous histopathology. The data was shared in a poster presentation at The American Society of Dermatopathology (ASDP) 58th Annual Meeting, held virtually Oct. 20-24.

DiffDx-Melanoma is part of Castle's Comprehensive Diagnostic Offering (CDO), leveraging the strengths of both myPath(r) Melanoma and DiffDx-Melanoma. These two gene expression profile (GEP) tests were designed to provide a highly accurate, objective result to aid dermatopathologists and dermatologists in characterizing difficult-to-diagnose melanocytic lesions.

The poster, titled "Performance of the 35 Gene Expression Profile (GEP) Test for Use as an Adjunctive Melanoma Diagnostic Tool in a New Independent Validation Cohort," describes the performance of DiffDx-Melanoma, independent of myPath Melanoma and also as part of the clinical CDO workflow. The poster can be viewed here.

"In clinical practice, difficult-to-diagnose melanocytic lesions often present a challenge for dermatopathologists, particularly when there is hesitation in the diagnosis of melanoma," said Gregory A. Hosler, M.D., Ph.D., dermatopathologist at ProPath in Dallas. "In this study, DiffDx-Melanoma demonstrated its ability to provide dermatopathologists additional information to help guide and potentially increase confidence in a diagnosis, if any uncertainty exists, to help clinicians provide their patients with the most appropriate care."

Study background and findings:

* The Institutional Review Board (IRB)-approved study reviewed 644 melanocytic lesions and associated de-identified clinical data from patients ? 18 years of age.

* Lesions were independently reviewed by at least two dermatopathologists for diagnostic adjudication and included in the study if they received at least two out of three reviews that were diagnostically concordant.

* Accuracy metrics demonstrated highly accurate performance of the DiffDx-Melanoma test (96% sensitivity and 92.2% specificity; intermediate result 2.3%) across lesion subtypes reported (excluding spitzoid lesions), including those with subtype discordance.

* Separately, the clinical Comprehensive Diagnostic Workflow leverages myPath Melanoma with DiffDx-Melanoma. Clinical order data from June 3-Aug. 31, 2021, showed that this workflow was able to increase the reporting of actionable test results of either benign or malignant from 78% for myPath Melanoma alone to 99% when used in conjunction with DiffDx-Melanoma.

* Overall, the study data demonstrated that DiffDx-Melanoma was an accurate, objective ancillary tool that provided information to aid in the diagnosis of melanocytic lesions of uncertain malignant potential, thus enhancing diagnostic confidence and the delivery of clinically, actionable results to healthcare providers.