Proof-of-concept Study Evaluating Subcutaneous Amlitelimab in Adult Participants With Moderate to Severe Hidradenitis Suppurativa

This is a parallel, Phase 2, 2-arm, double-blind, randomized, multicenter, multinational, placebo-controlled study to evaluate efficacy, safety, pharmacokinetics (PK), and biological effects of treatment of subcutaneous injection of amlitelimab compared with placebo in male and female participants aged 18 to 70 years with moderate to severe hidradenitis suppurativa (HS).

The purpose of this study is to measure standardized clinician reported and participant-reported outcomes (ClinRO and PRO), safety, and drug concentration. An optional long-term extension (LTE) period will assess chronic safety and efficacy over an additional 80 weeks of amlitelimab treatment.

Study details include:

• The study duration will be up to 116 weeks, including a 4-week Screening period, a 16-week double-blind treatment period (DBT), an optional 80-week LTE period and a 16-week post-treatment follow-up period.

• All participants who complete the 16-week DBT period will be offered entry into an optional LTE.

• Participants who do not wish to enter the optional LTE period or who stop treatment prior to Week 16 (Visit 6) or stop investigational medicinal product (IMP) administration prior to completing the LTE period will proceed into the 16-week post-treatment follow-up period.

• The number of planned in clinic visits will be up to six during the DBT period with an additional nine during the LTE period, plus one post-treatment follow-up end-of-study visit. Up to 11 optional in clinic visits are allowed for participants who do not wish to self-administer IMP between scheduled in clinic visits during the LTE period.