This double-blind, placebo-controlled study is designed to evaluate the safety and efficacy of ENV-294 in adults with moderate-to-severe atopic dermatitis (AD). The study will compare three dose levels of ENV-294 with placebo administered for 12 weeks. Participants will undergo screening, receive study treatment, and complete scheduled assessments of disease activity, symptoms, quality of life, safety, pharmacokinetics, and biomarker responses.

Inclusion Criteria:

In order to participate in this study all participants must:

1. Be at least 18 years of age at the time of signing the ICF.

2. Have chronic AD (also known as atopic eczema) that was diagnosed at least 12 months prior to Screening.

3. Have a history of inadequate response or intolerance to topical corticosteroids or other topical treatments for AD within 6 months before Screening and/or inadequate response to a systemic therapy within 12 months before Screening.

4. Have moderate-to-severe AD, at Screening and Baseline, as defined by the following criteria:

   1. A vIGA score of 3 (moderate) or 4 (severe)
   2. EASI score of ≥16
   3. Body surface area involvement of ≥10%

5. Have PP-NRS score ≥4 Screening and Baseline - the baseline score refers to a weekly average.

6. Use a bland emollient daily for at least 1 week prior to Day 1 and agree to continue using that same emollient daily at the same frequency (minimally, once daily) throughout the study.

7. Participants of reproductive potential (male and female participants) must practice effective methods of contraception as per protocol.

Exclusion Criteria:

Participants are excluded if they:

1. Have any clinically significant medical condition or physical/laboratory/ECG/vital signs abnormality that would, in the opinion of the investigator, put the participant at undue risk or interfere with interpretation of study results.
2. Have clinically significant abnormalities in any of the clinical laboratory evaluations at Screening or Baseline as determined by the Investigator.
3. Have the presence of any concomitant skin conditions (eg, psoriasis, seborrheic dermatitis) or have large tattoos that would interfere with clinical assessment, evaluation of AD, or treatment response as determined by the investigator.
4. Have an ongoing clinically significant skin infection or is receiving treatment for infection that may interfere with assessment of AD as determined by the investigator.
5. Are pregnant or breastfeeding or are planning to become pregnant during the duration of the study and for 90 days after the last administration of study drug.
6. Are taking or have taken any prespecified prohibited therapies within a specific timeframe as determined by the Investigator.