Inclusion Criteria:

• Participant must be 18 years of age, inclusive, or older at the time of signing the informed consent.
• Participated in KY1005-CT05 (DRI17366) for moderate to severe AD and received study treatment, adequately completed the assessments required for the treatment period. Participants must only be enrolled from 1 of the following 3 groups:
  • The first group: participants at Week 24 in the KY1005-CT05 (DRI17336) study who have not achieved an >= Eczema Area and Skin Severity Index (EASI)-75 and are Investigator Global Assessment (IGA) 2, 3 or 4.
  • The second group: participants entering the LTE between Week 28 and Week 52 of the parent study, due to loss of clinical response in the part 2 of the parent study. Loss of clinical response is defined as the first instance of < EASI-50 during the second study period.
  • The third group: participants at Week 24 in KY1005-CT05 (DRI17336) who have been re-randomized and who subsequently complete the study to Week 52, enter safety follow-up and experience worsening of their AD during safety follow-up or thereafter.
• Provide signed informed consent and able to comply with the requirements of the

  protocol.

Exclusion Criteria:

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

• Any participant who has received prohibited systemic therapies, as per KY1005-CT05 (DRI17366) clinical trial protocol, either during or after completion of KY1005-CT05 (DRI17366) will not be eligible for the long-term extension (LTE).
• Participants who, during their participation in KY1005-CT05 (DRI17366), developed an adverse events (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.
• Conditions in KY1005-CT05 (DRI17366), consistent with protocol-defined criteria for permanent IMP discontinuation, if deemed related to amlitelimab or led to Investigator or Sponsor-initiated withdrawal of participant from the study (e.g., non-compliance, inability to complete study assessments, etc.).
• Developed a medical condition that would preclude participation as per KY1005-CT05 (DRI17366) clinical trial protocol.
• Concurrent participation in any other clinical study, including non-interventional studies.
• Only in those participants entering after completion of KY1005-CT05 (DRI17366) safety follow-up
  1. Newly diagnosed Tuberculosis (TB) or non-TB mycobacterial infections requiring treatment (including a positive QuantiFERON®-TB Gold blood test at the screening visit),
  2. Positive for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb) or hepatitis C antibody (HCV Ab) at the screening visit.
  3. Laboratory values at the Screening Visit:
  4. Serum creatinine > 1.6 mg/dL (141 micromol/L) in female patients and > 1.9 mg/dL (168 micromol/L) in male patients, ii) Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2.0 x upper limit of normal (ULN), iii) Serum total bilirubin >1.5 x ULN (except for subjects with Gilbert's syndrome, where total bilirubin must not exceed 3.0 mg/dL or 50 micromol/L), iv) In the Investigator's opinion, any additional clinically significant laboratory results from the clinical chemistry, haematology or urinalysis tests at the Screening visit.
  5. In the Investigator's opinion any significant abnormality on 12-lead ECG at the screening visit.
• History of or known or suspected hypersensitivity to amlitelimab or the matching

  placebo formulation, or excipients used in the presentation of amlitelimab or placebo, or in preparation for administration. History of or known or suspected severe hypersensitivity reactions to other mAbs and/or their excipients.

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