Inclusion Criteria: - Participant must be 18 years of age, inclusive, or older at the time

of signing the informed consent.

• Participated in an amlitelimab clinical trial for moderate to severe AD and received study treatment, adequately completed the assessments required for the treatment period.
  • Have reached the rollover timepoint to LTS17367 at the last visit of the treatment period of their parent study SFY17915
  • Participants in DRI17366 must only be enrolled from 1 of the following 3 groups:
    • The first group: participants at Week 24 in the DRI17336 study who have not achieved an ≥ Eczema Area and Skin Severity Index (EASI)-75 and are Investigator Global Assessment (IGA) ≥ 2.
    • The second group: participants entering LTS17367 between Week 28 and Week 52 of the parent study, due to loss of clinical response in the part 2 of the parent study. Timepoints for entering LTS17367 are Weeks 28, 32, 36, 40, 44, 48 or 52. For DRI17366 loss of clinical response is defined as the first instance of < EASI 50 during the second study period and where rescue therapy is no longer permitted.
  • The third group: participants at Week 24 in DRI17366 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:

• Developed a medical condition that would preclude participation as described in the permanent discontinuation
• Known history of or suspected significant current immunosuppression, including history of invasive opportunistic infections or helminthic infections despite infection resolution or otherwise recurrent infections of abnormal frequency or prolonged duration
• History of solid organ or stem cell transplant
• Any malignancies or history of malignancies prior to Baseline (except for non-melanoma skin cancer that has been excised and completely cured for more than 5 years prior to Baseline)
• Participants positive for human immunodeficiency virus; participants with any of the following results at Screening (Visit 1) or at any point during the parent study: presence of HBsAg with or without HBV DNA PCR test, or presence of anti-HBc Ab or presence of anti-HBs Ab with positive HBV DNA PCR test; positive HCVAb confirmed by positive HCV RNA
• History (within last 2 years prior to Baseline) of prescription drug or substance abuse, including alcohol, considered significant by the Investigator
• Participants with active TB, latent TB, a history of incompletely treated TB, suspected extrapulmonary TB infection, non-TB mycobacterial infection, or who are at high risk of contracting TB (such as close contact with individuals with active or latent TB) or received Bacillus Calmette-Guérin (BCG)-vaccination within 12 weeks prior to screening
• Participants with an intermediate or a positive IGRA test are excluded from the study unless all of the following conditions are met:
  1. Have a history of prior documented completed chemoprophylaxis for latent TB infection (with a treatment regimen as per local guidelines), OR treated for active TB infection
  2. Have been in written form approved for participation in the present trial by a TB specialist who ruled out latent or active TB infection or other mycobacterial infection in the participant
  3. For whom review and approval from Sponsor have been granted are eligible
• Severe concomitant illness that would in the Investigator's opinion inhibit the

  patient's participation in the study, including for example, but not limited to, hypertension, renal disease, neurological conditions, heart failure and pulmonary disease

• Skin co-morbidity that would adversely affect the ability to undertake AD assessments
• Any medical or psychiatric condition which, in the opinion of the Investigator may present an unreasonable risk to the study patient as a result of his/her participation in this clinical study, may make patient's participation unreliable, or may interfere with study assessments
• In the Investigator's opinion, medical conditions related to prior AD medications that have not healed/fully recovered for more than 2 weeks before screening visit, including, but not limited to, conjunctivitis, keratitis, eosinophilic conditions, arthralgia, herpes zoster, thrombosis