Early Discovery Data Shows Ability of Castle Biosciences’ Pipeline Program to Distinguish Between Responders and Non-Responders to an Atopic Dermatitis Therapy

Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced new data showing the ability of its pipeline test in development to distinguish between responders and non-responders to an atopic dermatitis (AD) therapy and also distinguish between AD, psoriasis (PSO) and mycosis fungoides (MF) skin lesions.

The goal of Castle’s innovative pipeline initiative is to develop a genomic test aimed at guiding systemic therapy selection for patients with moderate-to-severe AD, PSO and related conditions. Additional updates regarding development of this pipeline program are expected in 2024.

“We are excited about our early results that show the ability of our inflammatory skin disease pipeline program to distinguish between patients diagnosed with moderate-to-severe AD who will respond and who will not respond to an AD systemic therapy,” said Robert Cook, Ph.D., senior vice president of research and development at Castle Biosciences. “We look forward to additional development data in 2024 and are targeting launch of the test by the end of 2025.”

“A test of this type would be a significant step forward in the care of patients suffering from these debilitating conditions,” added Aaron Farberg, M.D., FAAD, lead poster author and double-board certified dermatologist, Mohs surgeon and chief medical officer of Bare Dermatology in Dallas. “The test’s results could help clinicians personalize therapy selection for patients based on their molecular profile and potentially help spare them from enduring multiple ineffective and expensive medication courses before finding one that controls their symptoms.”

Castle shared data regarding its innovative pipeline initiative at the recent 2023 Fall Clinical Dermatology Conference^® (FC23). In addition to therapy responder data in patients diagnosed with AD, the Company also presented data confirming that gene expression differences exist between AD, PSO and MF skin lesions which could assist clinicians in making an appropriate diagnosis. This is clinically significant as incorrectly treating inflammatory skin diseases can not only delay a critical diagnosis but may further complicate a patient’s disease if incorrectly prescribed a medication for the wrong condition.

Additional updates regarding development of this pipeline program are expected in 2024. Castle’s poster from FC23 may be viewed here.

About Castle’s Inflammatory Skin Disease Pipeline Test

Inflammatory skin disease accounts for a significant number of patient visits to both primary care and dermatology clinics across the United States every year. Psoriasis (PSO) and atopic dermatitis (AD) are among the most common inflammatory skin conditions, and patient quality of life is severely impacted by these chronic diseases. Fortunately, systemic medications developed over the past 15 years have demonstrated a significant improvement in patients’ lives. In the United States alone, there are about 18 million patients diagnosed with PSO and AD, and approximately 450,000 patients annually are eligible for these systemic therapies. While there are now many effective treatment options available for those with moderate-to-severe inflammatory skin diseases, current clinical practice relies on a trial-and-error approach for therapy selection.

To answer this unmet clinical need, in 2021, Castle initiated a prospective, multi-center clinical study (IDENTITY) to develop and validate a gene expression profile (GEP) test to help guide systemic therapy selection for patients with moderate-to-severe AD, PSO and other related diseases. In 2022, the Company initiated a second, prospective study (SIGNAL-MF) to investigate the possibility of the pipeline test including an ancillary component to help identify lesions that may be MF, a rare and serious type of skin cancer, often referred to as cutaneous T-cell lymphoma, that is easily mistaken for AD and PSO. MF requires a rigorous histologic and molecular workup to diagnose, and patients with MF being treated for presumed AD or PSO can further delay this critical diagnosis.

More information about Castle’s tests can be found at www.CastleTestInfo.com.

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, uveal melanoma, Barrett’s esophagus and mental health conditions. 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, DecisionDx-UM, DecisionDx-PRAME, DecisionDx-UMSeq, TissueCypher and IDgenetix 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 continued ability to use the Company’s inflammatory skin disease pipeline test to distinguish between responders and non-responders to an AD therapy and also distinguish between AD, PSO and MF skin lesions; the ability of the pipeline test to help clinicians personalize therapy selection for patients based on their molecular profile and potentially help spare them from enduring multiple ineffective and expensive medication courses; the timing of data releases and updates; the ability of the Company’s initial test iteration to identify super-responder patients with moderate-to-severe AD; and the timing of the launch of the initial iteration of the Company’s inflammatory skin disease pipeline test. The words “can,” “may” 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, including with respect to the discussion of the Company’s inflammatory skin disease pipeline test 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 year ended December 31, 2022, our Quarterly Report on Form 10-Q for the three months ended June 30, 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.

View source version on businesswire.com: https://www.businesswire.com/news/home/20231102811020/en/