Overview

This phase 2b study is designed to evaluate the safety and efficacy of KT-621 in participants with moderate-to-severe atopic dermatitis (AD), a common form of eczema. The main goals of this study are to learn how effective KT-621 is at reducing the severity and extent of AD, the safety and tolerability of KT-621, how KT-621 behaves in the body, and how the body responds to KT-621. This is a 16-week double-blind, placebo-controlled study with a 52-week open-label period.

Eligibility

Inclusion Criteria:

• Must be 18 years (or the legal age of consent in the jurisdiction in which the study is taking place) to 75 years of age, inclusive, at the time of signing the ICF.
• Must have chronic AD that has been present for at least 3 years before the Screening visit.
• Must have an EASI score ≥ 16 at the Screening and Baseline visits.
• Must have a vIGA-AD score ≥ 3 (scale of 0 to 4) at the Screening and Baseline visits.
• Must have at least 10% BSA of AD involvement at the Screening and Baseline visits.
• Must have a weekly average Peak Pruritus NRS value ≥ 4 at the Baseline visit.
• Must have a documented history within the 6 months prior to the Baseline visit of either an inadequate response to, or inability to take, topical medications for the treatment of AD.
• Must apply a stable dose of moisturizer at least twice daily for at least 7 consecutive days immediately prior to the Baseline visit. Participants should be willing to continue using moisturizer twice daily during the study.
• Must be willing and able to comply with scheduled visits, treatment plan, laboratory tests, other study-related procedures, and questionnaires, including completing the electronic diary (e-diary), for the duration of the study as required by the study protocol.
• Must agree to contraceptive requirements in compliance with the clinical study and local requirements.

Exclusion Criteria:

• Must not have an unstable course of AD (spontaneously improving or rapidly deteriorating) as determined by the Investigator in the 4 weeks before the baseline visit.
• Must not have other skin conditions, such as contact dermatitis, psoriasis, tinea corporis, or lupus erythematosus, that may interfere with study assessments.
• Must not have a clinically relevant history of respiratory, gastrointestinal (GI), renal, hepatic, hematological, lymphatic, endocrinological, neurological, cardiovascular, psychiatric, musculoskeletal, genitourinary, immunological, ophthalmological, or connective tissue diseases or disorders.
• Must not have any surgical or medical procedure planned during participation in the study.
• Must not have a history of alcohol or substance abuse within the previous 2 years.
• Must not be pregnant or breastfeeding; must not be a woman planning to become pregnant or breastfeed during the study.
• Must not have a history of lack of response to any medication targeting interleukin (IL)-4, IL-13, and/or janus kinase (JAK)- signal transducer and activator of transcription (STAT) pathways (e.g. dupilumab, tralokinumab, upadacitinib, abrocitinib) at approved doses after at least 16 weeks of therapy.
• Must not have results from clinical laboratory safety tests that are outside the local reference range at Screening.
• Must not have been dosed with any investigational drug or device in a clinical study within 8 weeks or 5 half-lives (whichever is longer) of KT-621 administration.
• Female participants of childbearing potential must not have a positive or undetermined pregnancy result at the Screening and baseline visits.
• Must not have any known factor, condition, or disease that might interfere with treatment compliance, study conduct or interpretation of the results.
• Must not be taking or have taken any prespecified prohibited therapies within a specific timeframe as evaluated by the Investigator.
• Must not have a known sensitivity to any of the components of KT-621.
• Must not be a member of the investigational team or his/her immediate family.