Evaluation of 611 in Chinese Adults With Moderate to Severe Atopic Dermatitis

Inclusion Criteria:

• Subject must be able to understand and comply with the requirements of the study. andmust participate voluntarily and sign the written informed consent.
• Male or female adults ages 18 to 64 years old when signing the informed consent.
• AD (according to American Academy of Dermatology Consensus Criteria, 2014) that hadbeen present for at least 1 years before the screening visit.
• Eczema Area and Severity Index (EASI) score greater than or equal to (>=) 16 at thescreening and baseline visits.
• Investigator's Global Assessment (IGA) score >=3 (on the 0 to 4 IGA scale, in which 3was moderate and 4 was severe) at the screening and baseline visits.
• Participants with >=10 percent (%) body surface area (BSA) of AD involvement at thescreening and baseline visits.
• Baseline Pruritus Numerical Rating Scale (NRS) average score for maximum itchintensity >=4.
• Recent history (within 12 months before the screening visit) of inadequate response totreatment with topical medications or for whom topical treatments were otherwisemedically inadvisable (e.g., because of important side effects or safety risks).
• Have applied a stable dose of topical emollient (moisturizer) twice daily for at leastthe 7 consecutive days immediately before the baseline visit.
• Female subjects of reproductive age (and their male partners) and male subjects (andtheir female partners) must use highly effective contraception throughout the studyperiod and for at least 3 months after the last dose. The subjects had no plans topregnancy, donate sperm or donate egg during the whole study period and for at least 3months after the last dose.

Exclusion Criteria:

• Presence of skin comorbidities that may interfere with study assessments
• Presence of active endoparasitic infections; or suspected endoparasitic.
• Any history of vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC).
• History of malignancy within 5 years before the baseline visit, except completelytreated in situ carcinoma of the cervix at least 1 year, completely treated andresolved non-metastatic squamous or basal cell carcinoma of the skin at least 1 year.
• Active chronic or acute infection requiring treatment with systemic anti-infectivetherapy within 2 weeks before the baseline visit, or superficial skin infectionswithin 1 week before the baseline visit.
• Known or suspected history of immunosuppression, including history of invasiveopportunistic infections (e.g., histoplasmosis, listeriosis, coccidioidomycosis,pneumocystosis, aspergillosis) despite infection resolution: or unusually frequentinfections, per investigator judgment.
• Active TB, unless that was well documented that the participants had adequatelytreated.
• Any medical condition that, in the opinion of the investigator, is serious or unstableand may affect the subject's safety and/or prevent the subject from completing thestudy
• Patients who have received any of the following treatments: a) Treatment with topicaldrugs such as corticosteroids, topical calcineurin inhibitors, PDE inhibitors, orJanus kinase (JAK) inhibitors within 2 weeks before baseline; b) Treatment withsystemic traditional Chinese medicine (TCM) within 4 weeks before baseline ortreatment with topical TCM; c) Have undergone bleaching baths ≥ twice within 2 weeksbefore baseline; d) Treatment with systemic corticosteroids or otherimmunosuppressive/immunomodulating substances (e.g., cyclosporine, mycophenolatemofetil, azathioprine, methotrexate, interferon-gamma [IFN-γ], oral JAK inhibitors,compound glycyrrhizin, azathioprine, mycophenolate mofetil, or methotrexate,) within 4weeks before baseline or 5 drug half-lives (if known), whichever is longer; e)Treatment with phototherapy (narrow band ultraviolet B [NBUVB], ultraviolet B [UVB],ultraviolet A1 [UVA1], psoralen + ultraviolet A [PUVA]), sunbed or any other lightemitting device (LED) therapy within 4 weeks before baseline; f) Treatment with celldepletion agents (e.g., rituximab) within 6 months before baseline. Treatment withother biological agents (e.g., dupilumab) within 3 months before baseline or 5 drughalf-lives (if known), whichever is longer; g) History of inadequate response totreatment with anti-IL-4 and/or IL13 agents (e.g., dupilumab), in the opinion of theinvestigator. h) Treatment with allergen specific immunotherapy (SIT) within 6 monthsbefore the screening visit. i) Initiation of treatment of AD with prescriptionmoisturizers or moisturizers containing additives such as ceramide, hyaluronic acid,urea, or filaggrin degradation products during the screening period (participants maycontinue using stable doses of such moisturizers if initiated before the screeningvisit).
• Presence of any one of the following lab abnormalities at screening or baseline: a)Total bilirubin > 1.5 times the upper limit of normal (ULN); b) Alanineaminotransferase (ALT) or aspartate aminotransferase (AST) > 2 ULN; c) Serumcreatinine (Cr) > 1.5×ULN; d) White blood cell count below the lower limit of normal (LLN) , was judged clinically significant by the investigator, and not suitable forinclusion in the study;
• HBsAg-positive with HBV DNA copy number beyond normal limit of the HBV DNA test, orHCV antibodies (HCV Ab)-positive with HCV RNA copy number beyond normal limit of theHCV RNA test, human immunodeficiency virus antibody (HIV Ab) positive, serum syphilishelix antibody (TP Ab) positive with syphilis helix titrating positive at screening;
• History of alcohol or drug abuse within 6 months before baseline.
• History of hypersensitivity to 611 or their excipients.
• Have been vaccinated with live (attenuated) vaccine within 2 months before baseline orplanned during the study period;
• Have used any investigational drug/treatment within 8 weeks before baseline;
• Planned or anticipated major surgical procedure during the patient's participation inthis study.
• Pregnant or lactating women, or subjects with pregnancy or lactation plans during thestudy period.
• Any reason which, in the opinion of investigator, would prevent the subject fromparticipating in the study.