臨床研究等提出・公開システム

A Phase 2b, Randomized, Double-blind, Placebo-controlled, Parallel-group, Multicenter, Dose-ranging Study With an Open-label Period Investigating the Efficacy and Safety Profile of KT-621 Administered Orally to Participants with Moderate to Severe Atopic Dermatitis

A Study of KT-621 Administered Orally to Participants with Moderate to Severe Atopic Dermatitis

Watanabe Toshiyo

PPD-SNBL K.K.

St Luke's Tower 12F 8-1, Akashi-cho, Chuo-ku, Tokyo

toshiyo.watanabe@thermofisher.com

Watanabe Toshiyo

PPD-SNBL K.K.

St Luke's Tower 12F 8-1, Akashi-cho, Chuo-ku, Tokyo

+81-80-7709-2664

toshiyo.watanabe@thermofisher.com

Not Recruiting

Feb. 16, 2026

Interventional

randomized controlled trial

double blind

placebo control

parallel assignment

treatment purpose

- 12 to 75 years of age, inclusive, at the time of signing the informed consent form (ICF) or informed assent form (IAF)
- Chronic AD that has been present for at least 3 years (for participants >= 18 years of age) or 1 year (for participants < 18 years of age) before the Screening visit, with the diagnosis of AD confirmed by photographs at Screening
- EASI score >= 16 at the Screening and Baseline visit
- vIGA-AD score >= 3 (scale of 0 to 4) at the Screening and Baseline visits
- At least 10% BSA of AD involvement at the Screening and Baseline visits
- Weekly average Peak Pruritus NRS >= 4 at the Baseline visit
- History within the 6 months prior to the Baseline visit of either an inadequate response to, or contraindication to topical medications for the treatment of AD
- Application of a stable dose of moisturizer at least twice daily for at least 7 consecutive days immediately prior to the Baseline visit

- An unstable course of AD (spontaneously improving or rapidly deteriorating) as determined by the Investigator in the 4 weeks prior to Baseline.
- Known history of, or suspected, significant current immunosuppression, including a history of invasive opportunistic or helminth infections despite infection resolution or otherwise recurrent infections of abnormal frequency or prolonged duration
- Clinically significant history or evidence of any active or suspected parasitic infection within 4 weeks of the Baseline visit, or travel within the 3 months before baseline to areas of high parasitic exposure, as determined by local or international health guidelines or epidemiological data
- Chronic or acute infection requiring treatment with systemic antibiotics, antivirals, antiparasitics, antiprotozoals, or antifungals within 4 weeks of the Baseline visit, or superficial skin infections within 1 week of the Baseline visit
- Presence of other skin conditions, such as contact dermatitis, psoriasis, tinea corporis, or lupus erythematosus, that may interfere with study assessments
- Any other clinically significant disease, condition, or medical history that, in the opinion of the Investigator, would interfere with participant safety, study evaluations, and/or study procedures
- Prohibited therapy received within a specified time frame prior to the Baseline visit
- History of inadequate response to any therapeutic agent targeting IL-4, IL-13, and/or the JAK-STAT pathway (eg, dupilumab, lebrikizumab, upadacitinib, abrocitinib) at approved doses.

Both

Atopic Dermatitis

Oral administration of KT-621 or matching Placebo QD

Percent change from baseline to Week 16 in the EASI score

- Proportion of participants with EASI-75 at Week 16
- Proportion of participants who achieve a vIGA-AD score of 0 to 1 (on a 5-point scale) and a reduction from baseline of at least 2 points at Week 16
- Proportion of participants with at least a 4-point improvement in the Peak Pruritus NRS at Week 16
- Proportion of participants with EASI-90 at Week 16
- Proportion of participants with EASI-50 at Week 16
- Percentage change from baseline to Week 16 in Peak Pruritus NRS score
- Percentage change from baseline to Week 16 in BSA affected by AD
- Percentage change from baseline to Week 16 in the SCORAD score
- Change from baseline to Week 16 in the POEM
- Change from baseline to Week 16 in the DLQI

+81-42-648-5551

Dec. 25, 2025

No

Canada/United States of America/Czech Republic/Germany/Poland/Australia/South Korea