Efficacy and Safety Study of QAW039 in the Treatment of Patients With Moderate to Severe Atopic Dermatitis.

Key Inclusion Criteria: * Presence of atopic dermatitis confirmed by Itchy skin condition in the past 12 months plus three, or more, of the following: * History of involvement of the skin creases (fronts of elbows, behind knees, fronts of ankles, around neck or around eyes) * Personal history of asthma or hay fever * History of generally dry skin in the past year * Onset before age of 2 years * Visible flexural dermatitis * Patients with an EASI score of ≥15 at screening and stable AD (not currently experiencing an acute flare of their AD). * Patients that have been treated with topical corticosteroids or topical calcineurin inhibitors on at least one occasion, or could not use topical drugs (due to contraindications, side effects, etc.) and are candidates for or have previously received systemic treatment. Key Exclusion Criteria: * History of hypersensitivity to any of the study drugs (including local anesthesia) or to drugs of similar chemical classes (CRTh2 antagonists) * History of serious allergic reactions to any allergen, such as anaphylactic shock or life-threatening asthma, prior intubation, respiratory arrest, hospitalization due to asthma within the last 3 months or seizures as a result of asthma * History of clinically significant ECG abnormalities or screening/baseline ECG that demonstrated clinical significant abnormalities which could affect patient safety or interpretation of study results * History of long QT syndrome or whose QTc interval (Frederica's) was prolonged (\>450 msec for males and females) at screening * Use of topical prescription treatment (e.g., topical corticosteroids, calcineurin inhibitors, antibiotics, etc.) within two weeks prior to initial dosing of study drug. Patient use of emollients was encouraged * Exception: For local atopic dermatitis flares during this 2-week interval, mild topical corticosteroids may be taken short term (up to one week) * Recent previous systemic treatment with phototherapy, systemic antihistamines, immunosuppressive agents (e.g., cyclosporine, mycophenolate, or oral tacrolimus, including therapeutic proteins) * Patients on maintenance immunotherapy who either began their allergen specific immunotherapy regimen or had a clinically relevant change to their immunotherapy within one month prior to granting informed consent * Patients on high-dose statin therapy (\>40 mg fluvastatin or 20 mg simvastatin, atorvastin, pravastatin, or rosuvastatin \[10 mg if Asian\]) * Excessive exposure to UV light in the three weeks prior to study start (screening), including tanning and sun beds and/or planning excessive sunbathing or beach holidays with associated sun bathing during the treatment period * History of hypertrophic scarring * Body mass index \<17 or \>40 kg/m2