A Study to Evaluate the Treatment Response and Safety of Two Dose Regimens of Subcutaneous Amlitelimab Monotherapy Compared With Treatment Withdrawal in Participants Aged 12 Years and Older With Moderate-to-severe Atopic Dermatitis

This is a multinational, multicenter, randomized, double-blind, placebo-controlled, parallel, Phase 3 study for treatment of participants aged 12 years and older diagnosed with moderate-to-severe atopic dermatitis (AD).

The main objective of this study is to evaluate if those participants who received amlitelimab dose 1 in the parent studies (EFC17559 \[COAST-1\], EFC17560 \[COAST 2\], EFC17561 \[SHORE\]) and were responders can maintain their response either remaining at dose 1 or switching to dose 2 of amlitelimab compared to treatment withdrawal.

Study details include:

The study duration will be up to 64 weeks (for participants not entering the LTS17367 \[RIVER-AD\] study) including a 48-week randomized double-blind period, and a 16-week safety follow-up.

The study duration will be up to 48 weeks for participants entering the LTS17367 \[RIVER-AD\] study at the Week 48 visit of EFC17600 (ESTUARY).

The total treatment duration will be up to 48 weeks. The total number of visits will be up to 14 visits (or 13 visits for those entering LTS17367 \[RIVER-AD\] study).


Eligibility Criteria:
Inclusion Criteria:

* Participants must be at least 12 years of age inclusive, at the time the informed consent is signed.
* Must have participated, received study treatment without permanent investigational medicinal product (IMP) discontinuation, and adequately completed the assessments required for the treatment period in one of the three 24-week parent studies EFC17559 (COAST-1), EFC17560 (COAST-2) or EFC17561 (SHORE) for moderate-to-severe AD.
* Able and willing to comply with requested study visit and procedures.
* Body weight must be ≥ 25 kg.

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

* Developed a medical condition that would preclude participation as described in Permanent Discontinuation of EFC17559 (COAST-1)/EFC17560 (COAST-2)/EFC17561 (SHORE) clinical trial protocols.
* Having received any prohibited medication or procedure for AD that resulted in IMP discontinuation in the parent study EFC17559 (COAST-1), EFC17560 (COAST-2) or EFC17561 (SHORE).
* Participants who, during their participation in the parent study EFC17559 (COAST-1) /EFC17560 (COAST-2)/EFC17561 (SHORE), developed an adverse event (AE) or a serious adverse event (SAE) deemed related to amlitelimab, which in the opinion of the Investigator could indicate that continued treatment with amlitelimab may present an unreasonable risk for the participant.
* Participants who have had IMP permanently discontinued for any reason before or at the time of the planned first dose in the EFC17600 (ESTUARY) study.
* Conditions in the parent study EFC17559 (COAST-1)/EFC17560 (COAST-2)/EFC17561 (SHORE) that led to Investigator - or Sponsor-initiated withdrawal of participant from the study (eg, non-compliance, inability to complete study assessments, etc.).
* Participant not suitable for participation, whatever the reason, as judged by the Investigator, including medical or clinical conditions, or participants potentially at risk of noncompliance to study procedures.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.