First in Human of Single and Multiple Doses of MOR106

Inclusion Criteria: \- Able and willing to give voluntary written informed consent Single ascending dose (SAD) * Negative urine drug screen * Male between 18-50 years of age * A body mass index (BMI) between 18-30 kg/m², inclusive. * Judged to be in good health Multiple ascending dose (MAD) * Male or female between 18-65 years of age * A BMI between 18-30 kg/m² * Diagnosis of Atopic Dermatitis (AD) for at least 6 months as per the Hanifin and Rajka Criteria * EASI ≥ 16 at the screening and baseline visits * IGA score ≥3 (on the 0 to 4 IGA scale, in which 3 is moderate and 4 is severe) at the screening and baseline visits * Greater than or equal to 10% body surface area (BSA) of AD involvement at screening * Willingness to continue stable use of an additive free, basic, bland emollient twice daily for at least 7 days before the baseline visit * Subject is a candidate for systemic therapy and is not responding adequately or has a contraindication to topical corticosteroids and/or topical calcineurin inhibitors (per Investigator's judgement) * Absence of current active, latent or history of tuberculosis (TB) infection based on medical history and as determined by a negative QuantiFERON TB Gold test at screening * Female subjects must have a negative serum pregnancy test at screening and a negative urine pregnancy test at baseline * Female subjects of childbearing potential must use a highly effective method contraception from 28 days prior to the first dose of study drug, during the study and for at least 24 weeks after the last dose Exclusion Criteria: * Known hypersensitivity to study drug ingredients. * History of or a current immunosuppressive condition * Symptoms of clinically significant illness in the 3 months before the initial study drug administration. * Any concurrent illness, condition, disability, or clinically significant abnormality * Treatment with any drug known to have a well-defined potential for toxicity to a major organ in the last 3 months preceding the initial study drug administration. * A history of significant psychological, neurologic, hepatic, renal, endocrine, cardiovascular, gastrointestinal (GI), pulmonary, or metabolic disease. MAD only * Active (skin) infection requiring systemic antibiotics * immunosuppressive/immunomodulating drugs or phototherapy 4 weeks prior to baseline * Treatment with topical corticosteroids (TCS) or topical calcineurin inhibitors (TCI) within 2 weeks before the baseline * Treatment with biologics within 5 half-lives (if known) or 12 weeks prior to baseline visit * history of immunosuppression * Regular use (more than 2 visits per week) of a tanning booth/ parlor within 4 weeks of the screening visit * Regular daily use of oral nonsteroidal anti-inflammatory drugs (NSAIDs), except low-dose aspirin (≤200 mg/day) for cardioprotection, within 7 days prior to screening