Study Testing Response Effect of KY1005 Against Moderate-to-Severe Atopic Dermatitis, The STREAM-AD Study

This is an interventional, randomized, parallel group, treatment, Phase IIb, double blind, 5-arm study to assess the effect of Anti-OX40L Monoclonal Antibody (KY1005) in adult participants with moderate to severe atopic dermatitis.

The estimated duration is 28 days for screening and then up to approximately day 477 (last dose no later than day 337+140 days safety follow-up) for all patients unless enrolled into the LTE (Long-Term Extension) protocol (NCT05492578) at either Day 169 depending on responder status or no later than Day 365 due to loss of clinical response.


Eligibility Criteria:
Inclusion Criteria:

* Adults (18 to \< 75 years of age) with AD as defined by the American Academy of Dermatology Consensus Criteria for 1 year or longer at Baseline.
* EASI of 12 or higher at the Screening Visit and 16 or higher at Baseline.
* IGA of 3 or 4 at Baseline.
* AD involvement of 10% or more of body surface area (BSA) at Baseline.
* Baseline worst/maximum pruritus NRS of ≥4.
* Documented history, within 6 months prior to Baseline, of either inadequate response or inadvisability of topical treatments.
* Must have applied a stable dose of topical bland emollient (simple moisturizer, no additives \[e.g., urea\]) at least twice daily for a minimum of 7 consecutive days before Baseline.
* Able to complete patient questionnaires.
* Able and willing to comply with requested study visits/telephone visits and procedures.
* Able and willing to provide written informed consent.
* For patients who decide to join the biopsy sub-study be able and willing to provide skin biopsies.

Exclusion Criteria:

* Treatment within specific time windows before the baseline visit for the management of atopic dermatitis such as topical or systemic corticosteroids, biologic or investigational therapies and/or phototherapy.
* Known history of, or suspected, significant current immunosuppression, including history of invasive opportunistic infections despite infection resolution or otherwise recurrent infections of abnormal frequency or prolonged duration.
* Weight \<40 kg or \>150 kg at Baseline.
* Treatment with a live (attenuated) immunization within 12 weeks prior to Baseline.
* Men and women (of reproductive potential) unwilling to use birth control and women who are pregnant or breastfeeding.
* Any malignancies or history of malignancies prior to Baseline (except for non-melanoma skin cancer that has been excised and cured for more than 3 years prior to Baseline; in situ cervical carcinoma that has been excised and cured).
* Positive for human immunodeficiency virus (HIV), hepatitis B or hepatitis C at the screening visit.
* 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.
* In the Investigator's opinion, any clinically significant laboratory results from the clinical chemistry, hematology or urinalysis tests at the Screening Visit.
* Concurrent participation in any other clinical study, including non-interventional studies.

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