Castle's Innovative Gene Expression Tests Transform Clinical Decisions for Skin Cancer

Castle Biosciences presents innovative gene expression profile tests at the 2024 Winter Clinical Dermatology Conference, revolutionizing skin cancer and inflammatory skin disease treatment. Castle's DecisionDx-Melanoma and DecisionDx-SCC tests offer precise risk assessments for melanoma and squamous cell carcinoma, while MyPath Melanoma clarifies difficult diagnoses. The company is also developing a test for personalized therapy in inflammatory skin conditions, heralding a new era in dermatology.

Robert Cook, Senior Vice President of R&D at Castle Biosciences, expressed the company's commitment to challenging existing disease management paradigms stating:  “We are committed to challenging current disease management paradigms and building the evidence supporting our portfolio of clinically actionable molecular tests and their use to improve decision-making for patients with skin cancers and inflammatory skin diseases.”

Personalized Care: DecisionDx-Melanoma Test

The highlight of Castle's showcase was the DecisionDx-Melanoma test. This test goes beyond traditional staging by integrating a patient's unique tumor biology into a risk assessment model. Utilizing a proprietary algorithm, the i31-GEP, it can predict the likelihood of melanoma recurrence with startling accuracy.

The study, conducted on 1,831 patients as part of their routine clinical care, validated the DecisionDx-Melanoma test and its integrated i31-GEP ROR algorithm. This approach helps in identifying high-risk patients for recurrence, guiding interventions such as imaging surveillance and immunotherapy.

Redefining Risk in Carcinoma: DecisionDx-SCC Test

Traditionally, risk assessment in cutaneous squamous cell carcinoma (cSCC) has been challenging, especially in identifying metastatic potential in lower-staged tumors. The 40-gene expression profile (40-GEP) test, known as DecisionDx-SCC, has been shown to identify cSCC patients at high risk of metastasis within lower-staged tumors.

This is a crucial advancement, particularly for lower-staged tumors where up to one-third of metastatic events have been reported. DecisionDx-SCC significantly improves risk assessment by providing clinically actionable information for nodal staging or postoperative adjuvant radiation.

MyPath Melanoma: Clarifying Diagnostic Ambiguities

A significant concern in dermatology is the diagnosis of melanocytic lesions, notorious for their diagnostic ambiguity. Castle's MyPath Melanoma test addresses this issue by providing clarity in cases where histopathological reviews are inconclusive. 

The study, involving a large cohort of patients with suspicious lesions (n=3,317), revealed that approximately 24% were difficult to diagnose. This finding underscores the need for an objective diagnostic tool like MyPath Melanoma, which aids in delivering an accurate diagnosis and ensuring appropriate patient management.

Inflammatory Skin Disease Pipeline Program

Castle's innovative pipeline initiative is focused on developing genomic tests for mycosis fungoides, atopic dermatitis, and psoriasis. The goal is to create a test that guides systemic therapy selection for patients with moderate-to-severe atopic dermatitis, psoriasis, and related conditions.

The poster presented at the Winter Clinical – Hawaii builds on the data previously showcased at the 2023 Fall Clinical Dermatology Conference. It highlights the pipeline test's ability to identify distinct gene expression profiles for super-responders to AD and PSO therapies and to differentiate between AD, PSO, and mycosis fungoides skin lesions.

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