Study data showed more than half of patients who used targeted systemic therapies modified treatment due to lack of efficacy
Among patients surveyed in the study, 94% of those open to a new systemic therapy expressed interest in molecular testing to help identify a more effective treatment
FRIENDSWOOD, Texas, Sept. 24, 2026 /PRNewswire/ -- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced the publication of a new study highlighting the challenges patients with atopic dermatitis (AD) experience in achieving their treatment goals and strong patient interest in molecular testing to help guide systemic therapy selection. The findings support the clinical need for molecular guidance in AD care. Castle's AdvanceAD-Tx test is designed to address this need by helping personalize systemic therapy decisions based on an individual patient's underlying disease biology.
Castle Biosciences
"One thing came through clearly in this study: patients want better control of their disease and more information to help guide their treatment decisions," said study author Diego Ruiz Dasilva, M.D., board-certified dermatologist at Forefront Dermatology in Virginia Beach, Virginia. "AdvanceAD-Tx gives us an opportunity to bring objective molecular information into those conversations, helping personalize systemic treatment decisions and expedite the path to an effective therapy and symptom relief."
The study, published in Dermatology and Therapy, evaluated the treatment experiences, priorities and perspectives of patients with AD and their caregivers.1 Key findings include:
Among participants who had used targeted systemic therapies, 55% modified their treatment due to lack of efficacy.
Overall, 83% of respondents expressed interest in molecular testing to guide treatment selection, increasing to 94% among those open to initiating a new systemic therapy.
The study included 43 patients and caregivers who participated in a 32-question assessment at the 2024 National Eczema Association Eczema Expo. Respondents identified itch control (70%), effective skin clearance (58%) and safety or absence of side effects (50%) as the most important factors when considering AD treatment. Among participants who had used systemic therapy, inadequate skin clearance and persistent itching were the most frequently reported reasons for switching systemic therapies or adding topical treatment.
This new paper complements an earlier prospective, multicenter clinical validation study in the Journal of the American Academy of Dermatology that demonstrated the ability of Castle's AdvanceAD-Tx test to identify differences in systemic therapy class response in patients with moderate-to-severe AD.² Patients identified by the test as having a Janus kinase (JAK) Inhibitor Responder Profile who were treated with a JAK inhibitor were 5.5 times more likely to achieve at least 90% improvement in Eczema Area and Severity Index (EASI-90) by three months and achieved that response 3.8 times faster than patients with the same molecular profile who were treated with a T helper type 2 (Th2)-targeted therapy. Patients identified by the test as having a Th2 Molecular Profile showed comparable clinical outcomes with either therapy class.