First-in-Human Trial to Assess REGN20423 in Healthy Adult Participants and Adult Participants with Atopic Dermatitis

2025-524205-32-00 Protocol R20423-HV-2555 Human pharmacology (Phase I) - First administration to humans Authorised, recruitment pending

Status Authorised, recruitment pending · 1 EU/EEA countries · 1 sites · Protocol R20423-HV-2555

Overview

Sponsor-declared trial summary

Phase Human pharmacology (Phase I) - First administration to humans
Status Authorised, recruitment pending
Participants planned 144
Countries 1
Sites 1

Atopic Dermatits

Key facts

Sponsor
Regeneron Pharmaceuticals Inc.
Participant type
Patients, Healthy volunteers
Age range
18-64 years
Gender
Male and Female
Therapeutic area
Diseases [C] - Skin and Connective Tissue Diseases [C17]
Decision date (initial)
2026-04-30
Transition trial
No
Low-intervention
No
Rare-disease indication
No
Vulnerable population
No

Trial design

CTIS Part I — objectives, methods, condition coding

Conditions and MedDRA coding

Atopic Dermatits

VersionLevelCodeTermSystem organ class
21.1 LLT 10003639 Atopic dermatitis 10040785

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Regeneron Pharmaceuticals Inc.

Sponsor organisation
Regeneron Pharmaceuticals Inc.
Address
777 Old Saw Mill River Road
City
Tarrytown
Postcode
10591-6717
Country
United States

Scientific contact point

Organisation
Regeneron Pharmaceuticals Inc.
Contact name
Medical Affairs

Public contact point

Organisation
Regeneron Pharmaceuticals Inc.
Contact name
Medical Affairs

Locations

1 EU/EEA country · 1 investigational sites

By country

CountryMS statusPlanned subjectsSites
Belgium Authorised, recruitment pending 64 1
Rest of world
United States
80

Investigational sites

Belgium

1 site · Authorised, recruitment pending
UZ Leuven
Center for Clinical Pharmacology, Herestraat 49, 3000, Leuven

Application history

4 submissions — initial application plus substantial / non-substantial modifications

#TypeCodeSubmittedReference MSConclusionDecision date
1 INITIAL IN 2026-03-13 Belgium Acceptable with conditions
2026-04-30
2026-04-30
2 NON SUBSTANTIAL MODIFICATION NSM-1 2026-05-06 Belgium Acceptable with conditions
2026-04-30
2026-05-06
3 SUBSTANTIAL MODIFICATION SM-1 2026-05-07 Belgium Acceptable
2026-05-21
2026-05-21
4 NON SUBSTANTIAL MODIFICATION NSM-2 2026-05-28 Belgium Acceptable
2026-05-21
2026-05-28