A Study to Investigate Vaccine Responses in Subcutaneous Amlitelimab Treated Atopic Dermatitis Participants Aged 18 Years and Older Compared With Placebo (HYDRO)

A Randomized, Double-blind, Placebo-controlled Phase 2 Study to Evaluate the Effect of Amlitelimab on Vaccine Antibody Responses in Adult Participants With Moderate to Severe Atopic Dermatitis

This is a Phase 2, multicenter, randomized, double-blind placebo controlled, 2-arm study to evaluate the effect of amlitelimab on vaccine antibody responses, and the safety of amlitelimab concurrently administered with non-live vaccines in adult participants with moderate-to-severe atopic dermatitis (AD).

The purpose of this study is to compare the immune responses to concomitantly administered Boostrix (tetanus, diphtheria, and acellular pertussis [Tdap]) and Pneumovax 23 (PPSV) vaccines in adult participants with moderate-to-severe AD treated with amlitelimab versus placebo. The study will evaluate the percentage of participants achieving a positive anti-tetanus response at Week 16 (primary endpoint) and a positive anti-pneumococcal response at Week 16 (key secondary endpoint).

Study details include:

The study duration will be up to 36 weeks (for participants not entering the LTS17367 [RIVER-AD]).

The screening period will be 9 days to 4 weeks. The treatment duration will be up to 16 weeks. The post-treatment safety follow-up period will be16 weeks. The number of visits will be up to 7 (or 6 for those entering LTS17367 [RIVER-AD]).

Study Overview

• Status: Completed
• Conditions: Dermatitis Atopic
• Intervention / Treatment: Drug: Amlitelimab; Biological: Tdap vaccine; Biological: PPS vaccine; Drug: Placebo

Detailed Description

The study duration will be up to 36 weeks

• Study Type: Interventional
• Enrollment (Actual): 224
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2W 4X9
      • Investigational Site Number : 1240019
    • Calgary, Alberta, Canada, T3A 2N1
      • Investigational Site Number : 1240023
    • Edmonton, Alberta, Canada, T5J 3S9
      • Investigational Site Number : 1240016
  • Ontario
    • Barrie, Ontario, Canada, L4M 7G1
      • Investigational Site Number : 1240014
    • Hamilton, Ontario, Canada, L8L 3C3
      • Investigational Site Number : 1240020
    • London, Ontario, Canada, N6H 5L5
      • Investigational Site Number : 1240017
    • Newmarket, Ontario, Canada, L3Y 5G8
      • Investigational Site Number : 1240018
    • Richmond Hill, Ontario, Canada, L4B 1A5
      • Investigational Site Number : 1240024
    • Toronto, Ontario, Canada, M2N 3A6
      • Investigational Site Number : 1240021
    • Toronto, Ontario, Canada, M4E 1R7
      • Investigational Site Number : 1240026
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35209
      • Clinical Research Center of Alabama - Homewood- Site Number : 8401101
  • Arizona
    • Scottsdale, Arizona, United States, 85260
      • Center for Dermatology and Plastic Surgery- Site Number : 8401119
  • California
    • Anaheim, California, United States, 92801
      • Orange County Clinical Trials- Site Number : 8401271
    • Fountain Valley, California, United States, 92708
      • First OC Dermatology- Site Number : 8401025
    • Fremont, California, United States, 94538
      • Center for Dermatology Clinical Research- Site Number : 8401018
    • Fresno, California, United States, 93720
      • Valley Research- Site Number : 8401097
    • La Mesa, California, United States, 91942
      • Paradigm Clinical Research Centers- Site Number : 8401273
    • Lafayette, California, United States, 94549
      • Sunwise Clinical Research- Site Number : 8401022
    • Lancaster, California, United States, 93534
      • Antelope Valley Clinical Trials- Site Number : 8401099
    • Lomita, California, United States, 90717
      • Torrance Clinical Research- Site Number : 8401027
    • Santa Monica, California, United States, 90404
      • Clinical Science Institute- Site Number : 8401028
  • Colorado
    • Denver, Colorado, United States, 80209
      • Velocity Clinical Research - Denver Site Number : 8401168
  • Florida
    • Boca Raton, Florida, United States, 33431
      • Daxia Trials- Site Number : 8401145
    • Boynton Beach, Florida, United States, 33436
      • Encore Medical Research of Boynton Beach- Site Number : 8401030
    • Fort Myers, Florida, United States, 33912
      • Alliance for Multispeciality Research - Fort Myers- Site Number : 8401111
    • Hialeah, Florida, United States, 33016
      • Doral Medical Research- Site Number : 8401094
    • Kendall, Florida, United States, 33183
      • C&R Research Services - Kendall- Site Number : 8401029
    • Miami, Florida, United States, 33142
      • Acevedo Clinical Research Associates- Site Number : 8401088
    • Miami, Florida, United States, 33173
      • Florida International Research Center- Site Number : 8401091
    • Miami, Florida, United States, 33142
      • Future Care Solution - Miami- Site Number : 8401144
    • Miami, Florida, United States, 33157
      • Sanchez Clinical Research- Site Number : 8401095
    • Miami Lakes, Florida, United States, 33016
      • Wellness Clinical Research - Miami Lakes- Site Number : 8401109
    • Orlando, Florida, United States, 32806
      • K2 South Orlando - South Orange Avenue- Site Number : 8401268
    • Pensacola, Florida, United States, 32501
      • SEC Clinical Research- Site Number : 8401270
    • St. Petersburg, Florida, United States, 33705
      • Global Clinical Professionals (GCP)- Site Number : 8401045
    • Tampa, Florida, United States, 33607
      • Clinical Research Trials of Florida- Site Number : 8401023
  • Idaho
    • Boise, Idaho, United States, 83709
      • Paradigm Clinical Research - Boise- Site Number : 8401272
  • Kentucky
    • Louisville, Kentucky, United States, 40217
      • Skin Sciences- Site Number : 8401039
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70809
      • Velocity Clinical Research at The Dermatology Clinic- Site Number : 8401072
    • Gretna, Louisiana, United States, 70053
      • BRCR Global Gretna- Site Number : 8401243
  • Montana
    • Missoula, Montana, United States, 59804
      • Boeson Research - Missoula- Site Number : 8401269
  • Nevada
    • Henderson, Nevada, United States, 89052
      • Henderson Clinical Trials- Site Number : 8401169
  • New York
    • Rochester, New York, United States, 14623
      • Skin Search Rochester- Site Number : 8401216
  • North Carolina
    • Durham, North Carolina, United States, 27701
      • Velocity Clinical Research - Durham- Site Number : 8401175
  • Ohio
    • Cincinnati, Ohio, United States, 45246
      • Velocity Clinical Research - Springdale- Site Number : 8401153
  • Oregon
    • Medford, Oregon, United States, 97504
      • Velocity Clinical Research - Medford- Site Number : 8401170
  • Pennsylvania
    • Camp Hill, Pennsylvania, United States, 17011
      • Vial Health - DermDox Dermatology- Site Number : 8401031
  • Rhode Island
    • East Greenwich, Rhode Island, United States, 02818
      • Velocity Clinical Research - Providence- Site Number : 8401179
  • South Carolina
    • Charleston, South Carolina, United States, 29414
      • Velocity Clinical Research - Charleston - Ashley Town Center Drive- Site Number : 8401174
    • Columbia, South Carolina, United States, 29204
      • Velocity Clinical Research - Columbia- Site Number : 8401176
  • Texas
    • Cedar Park, Texas, United States, 78613
      • Velocity Clinical Research - Austin- Site Number : 8401173
    • Dallas, Texas, United States, 75231
      • Modern Research Associates- Site Number : 8401093
    • Houston, Texas, United States, 77008
      • Heights Dermatology & Aesthetic Center- Site Number : 8401143
    • San Antonio, Texas, United States, 78258
      • Discovery Clinical Trials - San Antonio - Stone Oak Parkway- Site Number : 8401026
    • San Antonio, Texas, United States, 78229
      • Dermatology Clinical Research Center of San Antonio- Site Number : 8401100
    • Southlake, Texas, United States, 76092
      • Stryde Research - Epiphany Dermatology- Site Number : 8401185
  • Utah
    • Pleasant View, Utah, United States, 84404
      • Ogden Clinic Mountain View (Avacare) Site Number : 8401167

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participants must be 18 years of age (when signing informed consent form)
• Diagnosis of AD for at least 1 year (defined by the American Academy of Dermatology Consensus Criteria)
• Documented history (within 6 months before screening) of either inadequate response or inadvisability to topical treatments
• Validated Investigator Global Assessment scale for atopic dermatitis (vIGA-AD) of 3 or 4 at baseline visit
• Eczema area and severity index (EASI) score of 12 or higher at baseline
• AD involvement of 10% or more of body surface area (BSA) at baseline
• Able and willing to comply with requested study visits and procedures
• Body weight ≥40 kg and ≤150 kg

Exclusion Criteria:

• Skin co-morbidity that would adversely affect the ability to undertake AD assessments
• Receipt of any vaccine (expect influenza and COVID-19 vaccines) within 3 months prior to screening
• Receipt of any pneumococcal vaccine within approximate timeframe of 5 years prior to screening
• Prior receipt of two or more doses of Pneumovax 23 at any time
• Receipt of any tetanus-, diphtheria-, or pertussis-containing vaccine within approximate timeframe of 5 years prior to screening
• Participants for whom administration of the pneumococcal vaccine provided in this study is contraindicated or medically inadvisable, according to local label of the vaccine
• Participants for whom administration of the tetanus, diphtheria, and pertussis vaccine provided in this study is contraindicated or medically inadvisable, according to local label of the vaccine
• Having received any of the specified therapy within the specified timeframe(s) prior to the baseline visit
• Known history of or suspected significant current immunosuppression
• Any malignancies or history of malignancies prior to baseline (excluding non-melanoma skin cancer excised and cured >5 years prior to baseline)
• History of solid organ or stem cell transplant
• Any active or chronic infection including helminthic infection requiring systemic treatment within 2 weeks prior baseline
• Positive for human immunodeficiency virus (HIV), Hepatitis B or hepatitis C at screening visit
• Participants with active tuberculosis (TB), latent TB, a history of incompletely treated TB, suspected extrapulmonary TB infection, or who are at high risk of contracting TB

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Amlitelimab; Participants will receive amlitelimab and vaccines as per protocol.	Drug: Amlitelimab; Subcutaneous injection in abdomen, outer thigh, or upper arm; Biological: Tdap vaccine; Intramuscular (IM) injection into the deltoid muscle of the upper arm; Biological: PPS vaccine; Intramuscular or subcutaneous injection into the deltoid muscle of the upper arm
Placebo Comparator: Placebo; Participants will receive placebo matching amlitelimab and vaccines as per protocol.	Biological: Tdap vaccine; Intramuscular (IM) injection into the deltoid muscle of the upper arm; Biological: PPS vaccine; Intramuscular or subcutaneous injection into the deltoid muscle of the upper arm; Drug: Placebo; Subcutaneous injection in abdomen, outer thigh, or upper arm

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of participants with a positive tetanus response at Week 16	Positive tetanus response is defined as ≥2.5 IU/mL in anti-tetanus immunoglobulin G [IgG] titer for participants with a pre-vaccination baseline [Week 12] tetanus antibody titer of >1 IU/mL or a titer ≥ 3-fold increase for participants with a pre-vaccination titer of ≤1 IU/mL).	Week 16

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of participants with a positive pneumococcal vaccine response at Week 16	Positive pneumococcal vaccine response is defined as a ≥2-fold increase from baseline in anti-pneumococcal antibodies (APAb) against >50% of the 23 serotypes.	Week 16
Percentage of participants who experienced treatment-emergent adverse events (TEAE), including serious adverse events (SAE) and adverse events of special interest (AESI)		Week 0 up to Week 32
Percentage of participants with potentially clinically significant abnormalities (PCSA) for vital signs and clinical laboratory assessments		Week 0 up to Week 32
Percentage of participants discontinued from study treatment due to TEAEs		Week 0 up to Week 32
Proportion of participants with validated Investigator Global Assessment scale for atopic dermatitis (vIGA-AD) of 0 (clear) or 1 (almost clear) and a reduction of ≥2 points from baseline at Week 16	The vIGA-AD is an Investigator-completed assessment scale used to determine severity of AD and clinical response to treatment. It is based on a 5-point scale, ranging from 0 (clear) to 4 (severe).	Week 16
Proportion of participants with a ≥75% reduction in EASI score (EASI-75) from baseline at Week 16	The EASI is an Investigator-assessed validated tool used to measure the extent (area) and severity of AD using a 4-point scale; 0 (absent) to 3 (severe).	Week 16
Serum amlitelimab concentrations		Week 0 up to Week 16
Incidence of antidrug antibodies (ADAs) of amlitelimab		Week 0 up to Week 16

Collaborators and Investigators

• Sponsor: Sanofi
• Investigators: Study Director: Clinical Sciences & Operations, Sanofi

Publications and helpful links

Helpful Links

• SFY17915 Plain Language Results Summary

Study record dates

Study Major Dates

• Study Start (Actual): October 6, 2023
• Primary Completion (Actual): October 1, 2025
• Study Completion (Actual): January 16, 2026

Study Registration Dates

• First Submitted: August 23, 2023
• First Submitted That Met QC Criteria: August 23, 2023
• First Posted (Actual): August 29, 2023

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 8, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Genetic Diseases, Inborn; Immune System Diseases; Hypersensitivity, Immediate; Hypersensitivity; Skin Diseases; Skin Diseases, Genetic; Skin Diseases, Eczematous; Dermatitis; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Skin and Connective Tissue Diseases; Dermatitis, Atopic; Immunologic Factors; Physiological Effects of Drugs; Vaccines
• Other Study ID Numbers: SFY17915 (Sanofi Identifier); U1111-1280-8357 (Registry Identifier: ICTRP)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No