A Study to Evaluate the Efficacy and Safety of Subcutaneous Amlitelimab Monotherapy Compared With Placebo in Adult Participants With Severe Alopecia Areata

Inclusion Criteria:

• Definitive diagnosis of AA of more than 6 months.

• Diagnosis of severe AA, as determined by all of the following:

1. Hair loss affecting ≥50% of the scalp, as measured by Severity of Alopecia Tool (SALT) at both screening and baseline visits.

2. Current episode of severe hair loss of less than 8 years. Participants with ahistory of AA of more than 8 years who have observed episodes of terminal hairregrowth over their scalp ("moving patches" spontaneously or followingtreatment) in the past 8 years can be included.

3. Stable disease: no evidence of terminal hair regrowth within 6 months (lessthan 10% improvement over the past 6 months). (guidance: if participant reportsto have quite a bit more hair than 6 months prior, then patient cannot beincluded).

• Willingness in maintaining a consistent hair style and hair care, including hairproducts, and to refrain from weaves, extensions, adhesive wigs, other than bandedperimeter devices, refrain from shaving of scalp hair for 2 weeks prior to eachstudy visit from baseline to the end of study.

Exclusion Criteria:

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

• Participants that are currently experiencing other forms of alopecia, including butnot limited to: androgenetic alopecia, trichotillomania, telogen effluvium, tractionalopecia, scarring alopecia.

• Participants currently with any local or systemic active medical conditions, whichin the opinion of the Investigator would interfere with evaluations of the IMPeffect on AA due to scalp inflammation, including but not limited to seborrheicdermatitis requiring topical treatment to the scalp, lupus erythematosus, lichenplanus, psoriasis, secondary syphilis, tinea capitis, thyroiditis, systemicsclerosis, hair transplants, micropigmentation/tattoo of the scalp.

• Received the specified treatment regimens within the timeframe outlined in theprotocol.

• Prior use of any oral JAKi or the topical JAKi ruxolitinib for more than 24 months,regardless if washout period is respected.

• Participants with shaved heads must not enter the study until hair has grown backand SALT score can be reliably administered.

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