Subjects found eligible following the screening period were randomized 3:1 to initial treatment with tralokinumab 300 mg every 2 weeks (Q2W) or placebo. Randomization was stratified by region (Asia, Australia, Europe, and North America) and disease severity (Investigator's Global Assessment [IGA] 3 or 4).
Subjects achieving a clinical response at Week 16 (defined as IGA of 0 or 1 on a 5-point scale ranging from 0 [clear] to 4 [severe], or at least 75% reduction in Eczema Area and Severity Index [EASI] score from baseline [EASI75]) continued into maintenance treatment that continued until Week 52.
Subjects randomized to tralokinumab in the initial treatment period and who achieved a clinical response at Week 16 (defined by IGA 0 or 1, or EASI75) were re-randomized 2:2:1 to one of the following Q2W maintenance regimens stratified by region (Asia, Australia, Europe, and North America) and IGA response at Week 16 (IGA 0/1 or IGA >1):
- Tralokinumab 300 mg Q2W.
- Tralokinumab 300 mg Q4W (alternating dose administrations tralokinumab 300 mg and placebo).
- Placebo.
Subjects randomized to placebo in the initial treatment period who achieved a clinical response at Week 16 (defined by IGA 0 or 1, or EASI75) continued to receive placebo Q2W in the maintenance treatment period.
Subjects not achieving a clinical response at Week 16 as well as those who met the criteria listed below during maintenance treatment were transferred to open-label tralokinumab 300 mg Q2W treatment with optional use of topical corticosteroid (TCS) up to Week 52.
Transfer to open-label treatment during maintenance:
Subjects with IGA=0 at Week 16: IGA of at least 2 and not achieved EASI75 over at least a 4-week period (i.e. over 3 consecutive visits).
Subjects with IGA=1 at Week 16: IGA of at least 3 and not achieved EASI75 over at least a 4-week period (i.e. over 3 consecutive visits).
Subjects with IGA >1 at Week 16: not achieved EASI75 over at least a 4-week period (i.e. over 3 consecutive visits).
Subjects transferring to open-label treatment had the option to self-administer tralokinumab in their home after adequate training (at 3 dosing visits in the open-label period after additional consent has been obtained) by site staff at the investigator's discretion.
After completion of the maintenance treatment period (or open-label treatment), all subjects, except for those who entered the open-label long-term extension trial, continued in a 14-week off-treatment follow-up period for the assessment of safety and anti-drug antibody (ADA).