Castle Biosciences’ AdvanceAD-Tx Identifies 30% of AD Patients as JAK Responders with 5.5× EASI-90
Castle Biosciences' AdvanceAD-Tx test identified 30% of moderate-to-severe atopic dermatitis patients as JAK Inhibitor responders, who achieved EASI-90 rates of 45.5% by three months—5.5-fold higher and nearly fourfold faster than with Th2-targeted therapy. Responders also recorded 36.4% full skin clearance and 54.5% flare-free outcomes versus under 17% with Th2 profiles.
1. Study Design and Cohort
Castle Biosciences conducted a prospective, multicenter clinical validation of AdvanceAD-Tx in moderate-to-severe atopic dermatitis patients aged 12 and older. The non-invasive gene expression profile test analyzes 487 genes from lesional skin scrapings to assign a JAK Inhibitor Responder Profile or Th2 Molecular Profile, with 30% of patients classified as JAKi responders.
2. Key Efficacy Findings
Patients with a JAK Inhibitor Responder Profile treated with JAK inhibitors achieved 45.5% EASI-90 rates at three months versus 8.3% for Th2-targeted therapies (5.5× higher) and reached response nearly four times faster. These responders also achieved 36.4% complete skin clearance, 45.5% itch resolution, 54.5% flare-free rates and 45.5% DLQI of zero compared to single-digit outcomes in Th2-profile patients.
3. Commercial Implications
Following its limited access launch in late 2025, this validation study reinforces AdvanceAD-Tx’s value proposition for personalized systemic therapy decisions. The data may accelerate clinician adoption, streamline treatment selection, and drive future revenue growth for Castle Biosciences.