Evaluation of NM26-2198 in Healthy Subjects and in Patients With Moderate-to-severe Atopic Dermatitis (AD)

Open to people ages 18 years and up

1. SAD: Non-Asian ethnicity with grandparents and parents of non-Asian descent or Japanese descent having all four Japanese grandparents born in Japan.
2. SAD and MAD in Healthy Volunteers: Male or female aged 18 to 55 years; MAD: Male or female ≥18 years of age.
3. ALL COHORTS: Weight of 45 kg to 100 kg and BMI of 18.0 to 30.0 kg/m2.
4. SAD and MAD in Healthy Volunteers: Non-childbearing, non-breastfeeding females or males willing to use double barrier contraception or abstention from sex and sperm donation during the study; MAD: Males willing to use double barrier contraception or abstention from sex and sperm donation during the study; non-childbearing females or females of childbearing potential using protocol-defined method contraception, and who is not pregnant, lactating, or breastfeeding.
5. MAD: Diagnosis of chronic AD.
6. MAD: EASI score ≥16.
7. MAD: vIGA-AD™ score of ≥3.
8. MAD: Atopic lesions cover ≥10% of body surface area (BSA).
9. MAD: PP-NRS score ≥4.
10. MAD: Daily use of non-prescription emollient.

Note: Other protocol-defined Inclusion criteria apply.

1. SAD and MAD in Healthy Volunteers: Any clinically-relevant medical history or lab abnormality, including positive test for SARS-CoV-2, Hepatitis B or C, or HIV; MAD: Clinically-significant, abnormal laboratory findings, or positive test for SARS-CoV-2, Hepatitis B or C, or HIV.
2. ALL COHORTS: Clinically important ECG abnormalities or history/evidence thereof.
3. SAD and MAD in Healthy Volunteers: Use of prescription or non-prescription medications (except occasional use of paracetamol).
4. MAD: Diagnosis of protocol-specified skin diseases other than AD, or history of other significant skin condition that could interfere with study assessments.
5. MAD: History or ongoing allergy/hypersensitivity or history, or history of hypersensitivity to biological drugs.
6. MAD: Recent receipt of immunoglobulin or blood products.
7. MAD: Recent treatment with protocol-specified investigational treatments, or any prior treatment with dupilumab, tralokinumab, lebrikizumab, nemolizumab, or other protocol-specified drugs.
8. MAD: AD with recent ocular involvement requiring chronic ocular corticosteroid treatment.
9. MAD: Chronic pruritis due to conditions other than AD.
10. MAD: Acute AD superinfection, recent superficial skin infection, or other chronic/acute infection requiring protocol-defined treatments.
11. MAD: Recent use of sedating antihistimines, systemic corticosteroids, cytotoxic treatments, other immunosuppressive/immunomodulating agents, and other protocol-specified prohibited medications.
12. MAD: Recent topical corticosteroid or prescription moisturizer use.

Note: Other protocol-defined Exclusion criteria apply.