In Novel Cohort, New Data Confirms DecisionDx®-SCC Provides Significant, Independent and Clinically Actionable Risk-Stratification of Patients, Including in Various High-Risk Subgroups

Rhea-AI Summary

Castle Biosciences, Inc. (CSTL) announces the largest study of its DecisionDx-SCC test for high-risk cutaneous squamous cell carcinoma, demonstrating improved predictive accuracy and personalized treatment pathways. The study highlights the test's ability to guide risk-appropriate treatment decisions, reducing overtreatment and undertreatment, based on patients' biological risk of metastasis.

Insights

Oncology Doctor

The recent findings on the performance of the DecisionDx-SCC test, developed by Castle Biosciences, have significant implications for the treatment of high-risk cutaneous squamous cell carcinoma (SCC). As an Oncology Doctor, the ability to stratify patients based on their risk of metastasis using gene expression profiling is a substantial advancement. The test categorizes patients into low, higher and highest risk categories, which can lead to more personalized treatment plans. This is particularly important given that SCC can be aggressive and the current staging systems may not fully capture the biological risk of metastasis.

From a clinical perspective, the integration of DecisionDx-SCC results with existing staging systems and guidelines can potentially reduce healthcare costs by avoiding overtreatment in low-risk patients and undertreatment in those with aggressive tumor biology. Furthermore, the improved predictive accuracy for metastasis-free survival rates presents a clearer picture for clinicians when making treatment decisions. This could lead to better patient outcomes and more efficient use of resources such as imaging and adjuvant radiation therapy (ART).

Medical Research Analyst

As a Medical Research Analyst, the data from this multi-center study not only validates the DecisionDx-SCC test but also emphasizes its independent prognostic value over traditional risk classification systems. The statistical significance (p<0.001) of the test's ability to stratify risk in various patient subgroups, including those with different stages of SCC, is a noteworthy outcome. This precision in risk stratification can be a game-changer for clinical management, as it allows for more tailored approaches to patient care.

The use of gene expression profile testing in clinical practice is a step towards more data-driven medicine, which can lead to better outcomes and potentially lower overall treatment costs. The study's findings also suggest that the test could have a considerable impact on the medical community's approach to high-risk SCC, potentially setting a new standard for how patients are evaluated and treated.

Market Research Analyst

The publication of the study on Castle Biosciences' DecisionDx-SCC test is likely to have a positive impact on the company's market position. As a Market Research Analyst, it's important to note that the adoption of such tests can lead to a competitive advantage in the precision medicine market, especially within oncology. The ability to offer a test that improves metastatic risk prediction and integrates with current treatment guidelines could increase demand for the company's product, potentially leading to growth in market share and revenue.

Investors may view this development favorably, as it demonstrates the company's commitment to evidence-based innovations and could signal future growth prospects. However, it's also important to monitor how the medical community and insurance providers respond to the test in terms of adoption and reimbursement, as these factors will play a crucial role in the test's commercial success.

Largest study of gene expression profile testing in patients with high-risk cutaneous squamous cell carcinoma (SCC) supports test’s ability to provide clinically actionable risk stratification to guide treatment decisions for patients diagnosed with this impactful skin cancer

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced the publication of a new multi-center performance study of its DecisionDx-SCC risk stratification test. The study, published in Dermatology and Therapy and available here, analyzed the independent performance of DecisionDx-SCC from risk factors and traditional staging systems (i.e., Brigham and Women’s Hospital (BWH) and American Joint Committee on Cancer Staging Manual 8th Edition (AJCC8) staging), and demonstrated significantly improved predictive accuracy when the test’s results were integrated with the staging systems and National Comprehensive Cancer Network^® (NCCN) guidelines to guide risk-appropriate treatment pathway decisions that can improve patient outcomes.

“Data-driven risk assessment is the foundation of sound clinical decision-making,” said Ashley Wysong, M.D., M.S., lead study author, professor, distinguished chair of dermatology and founding chair of the department of dermatology at the University of Nebraska Medical Center. “Incorporating DecisionDx-SCC test results into the management of high-risk SCC can help ensure patients receive the best care possible by incorporating their biological risk of metastasis into the treatment plan. Use of the test in clinical practice can help with optimization of healthcare resources by reducing both overtreatment of patients with a low biological risk of metastasis and undertreatment of patients with aggressive tumor biology.”

The DecisionDx-SCC test was developed and validated to improve the accuracy of metastatic risk prediction for patients with high-risk SCC, classifying patients as low (Class 1), higher (Class 2A) or highest risk (Class 2B) of regional or distant metastasis within three years based on the gene expression profile of their tumor. The data in this study support use of the test’s results in the clinical management of high-risk SCCs as they can provide impactful risk-stratification to guide risk-appropriate treatment pathway decisions, such as the use of nodal assessment (i.e., imaging) and adjuvant radiation therapy (ART).

The goal of this study was to present an independent validation of the DecisionDx-SCC test in a novel performance cohort (n=534) and then merge it with the test’s initial independent validation cohort (n=420) to evaluate the performance of the test in providing independent prognostic value to risk classification systems, individual clinicopathologic risk factors and clinically relevant patient populations.^1-2 In the study, DecisionDx-SCC demonstrated statistically significant risk-stratification of patients with high-risk SCC (p<0.001); 3-year metastasis-free survival rates were 94.1%, 81.1% and 56.8% for patients with Class 1, Class 2A and Class 2B test results, respectively. The entire population had 3-year metastasis-free survival of 87.5%. DecisionDx-SCC also provided significant and clinically actionable risk stratification in various patient subgroups, including NCCN high and very high-risk, lower-stage BWH tumors and Medicare-eligible patients, further stratifying risk to help guide important treatment decisions for these patients.

Generally, treatment pathways for patients with SCC are based on population-based estimates of risk, informed by guidelines and traditional staging systems (AJCC8 and BWH) which use various clinicopathological risk factors to predict a patient’s risk of metastasis. Multivariate analyses demonstrated that DecisionDx-SCC Class 2A and 2B test results were independent and significant predictors of metastasis when evaluated in the context of NCCN risk stratification, AJCC8 and BWH staging, and various clinicopathologic risk factors, such as immunosuppression, poor differentiation and tumor thickness (>6mm) (p<0.001). Importantly, integrating DecisionDx-SCC with individual clinicopathologic risk factors or risk classification systems (AJCC8 and BWH) significantly improved the accuracy for prediction of metastatic events (ANOVA for model deviance, p<0.0001 for all models). These data support the use of DecisionDx-SCC test results, informed by a patient’s tumor biology, to guide personalized patient treatment decisions aligned to a patient’s risk of metastasis over three years. These decisions could include risk-aligned reductions in treatment intensity for patients with low risk (Class 1) test results and intensified treatment, such as consideration of ART, for patients at a higher risk of experiencing metastasis (Class 2A and 2B).

“Castle is committed to improving the care of patients with SCC through broader use of our DecisionDx-SCC test,” said Matthew Goldberg, M.D., board-certified dermatologist and dermatopathologist, and senior vice president, medical, at Castle Biosciences. “As such, we continue to develop evidence showing that our test adds independent prognostic value to the clinical and pathologic risk factors used for guiding risk-informed treatment plans within current guidelines. The DecisionDx-SCC test result is interpreted by the treating clinician in the context of what they already know about their patient’s tumor to improve their prognostic accuracy and inform more closely risk-aligned management decisions with the goal of improving clinical outcomes for their patients with high-risk skin cancer.”

About DecisionDx^®-SCC

DecisionDx-SCC is a 40-gene expression profile test that uses an individual patient’s tumor biology to predict individual risk of cutaneous squamous cell carcinoma metastasis for patients with one or more risk factors. The test result, in which patients are stratified into a Class 1 (low), Class 2A (higher) or Class 2B (highest) risk category, predicts individual metastatic risk to inform risk-appropriate management. Peer-reviewed publications have demonstrated that DecisionDx-SCC is an independent predictor of metastatic risk and that integrating DecisionDx-SCC with current prognostic methods can add positive predictive value to clinician decisions regarding staging and management.

About Castle Biosciences

Castle Biosciences (Nasdaq: CSTL) is a leading diagnostics company improving health through innovative tests that guide patient care. The Company aims to transform disease management by keeping people first: patients, clinicians, employees and investors.

Castle’s current portfolio consists of tests for skin cancers, Barrett’s esophagus, mental health conditions and uveal melanoma. Additionally, the Company has active research and development programs for tests in other diseases with high clinical need, including its test in development to help guide systemic therapy selection for patients with moderate-to-severe atopic dermatitis, psoriasis and related conditions. To learn more, please visit www.CastleBiosciences.com and connect with us on LinkedIn, Facebook, X and Instagram.

DecisionDx-Melanoma, DecisionDx-CMSeq, DecisionDx-SCC, MyPath Melanoma, DiffDx-Melanoma, TissueCypher, IDgenetix, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are trademarks of Castle Biosciences, Inc.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the “safe harbor” created by those sections. These forward-looking statements include, but are not limited to, statements concerning: the ability of DecisionDx-SCC to (i) significantly improve predictive accuracy to guide risk-appropriate treatment pathway decisions that can improve patient outcomes and (ii) optimize healthcare resources in clinical practice. The words “can,” “potential” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements that we make. These forward-looking statements involve risks and uncertainties that could cause our actual results to differ materially from those in the forward-looking statements, including, without limitation: subsequent study or trial results and findings may contradict earlier study or trial results and findings or may not support the recommendations and guidelines presented in this report, including with respect to the discussion of DecisionDx-Melanoma in this press release; actual application of our tests may not provide the aforementioned benefits to patients; and the risks set forth under the heading “Risk Factors” in our Annual Report on Form 10-K for the twelve months ended December 31, 2023, and in our other filings with the SEC. The forward-looking statements are applicable only as of the date on which they are made, and we do not assume any obligation to update any forward-looking statements, except as may be required by law.

1. Wysong A, Newman JG, Covington KR, et al. Validation of a 40-gene expression profile test to predict metastatic risk in localized high-risk cutaneous squamous cell carcinoma. J Am Acad Dermatol. 2021;84(2):361-369.
2. Ibrahim SF, Kasprzak JM, Hall MA, et al. Enhanced metastatic risk assessment in cutaneous squamous cell carcinoma with the 40-gene expression profile test. Future Oncol. 2022;18(7):833-847.

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Investor Contact:

Camilla Zuckero

czuckero@castlebiosciences.com

Media Contact:

Allison Marshall

amarshall@castlebiosciences.com

Source: Castle Biosciences Inc.

FAQ

What is Castle Biosciences, Inc.'s ticker symbol?

The ticker symbol for Castle Biosciences, Inc. is CSTL.

What was the focus of the study announced by Castle Biosciences, Inc.?

The study focused on the performance of the DecisionDx-SCC risk stratification test for patients with high-risk cutaneous squamous cell carcinoma.

What are the risk classifications provided by the DecisionDx-SCC test?

The test classifies patients as low (Class 1), higher (Class 2A), or highest risk (Class 2B) of regional or distant metastasis within three years based on their tumor's gene expression profile.

How does DecisionDx-SCC help in treatment decisions?

The test's results can guide risk-appropriate treatment pathway decisions, such as nodal assessment and adjuvant radiation therapy, based on patients' biological risk of metastasis.

What improvements did DecisionDx-SCC show in the study?

The test demonstrated statistically significant risk-stratification of patients with high-risk SCC, providing significant and clinically actionable risk stratification in various patient subgroups.