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REGN1908

Phase 3

Allergic Conjunctivitis | Small molecule | Ophthalmology |Regeneron Pharmaceuticals, Inc.|Trials Updated: May 8, 2026

REGN1908 development status

Highest phase Phase 3
Registered trials 2 across 1 sponsor since Sep 2024

REGN1908 target and mechanism

Molecular targetFelD1
Target classAllergen
ModalitySmall molecule

Also known as Freneslerbart

Success Probability

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Market & Valuation

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Trial Design

RandomizedDouble-BlindPLACEBO_CONTROLLED
Total Trials1
Total Enrollment64

FDA Designations

No designations recorded

REGN1908 clinical trials

REGN1908 · 1 trial · 1 indication

Phase 3 1
NCT06602726A Study to Demonstrate How Well REGN1908-1909 Works in Reducing Ocular Allergy Signs and Symptoms in Adult Participants With Cat AllergyAllergic Conjunctivitis
COMPLETED64 Analytics
PHASE3COMPLETED
A Study to Demonstrate How Well REGN1908-1909 Works in Reducing Ocular Allergy Signs and Symptoms in Adult Participants With Cat Allergy
Allergic ConjunctivitisUnlock trial analytics

Study Endpoints

Primary Endpoints

Ocular itch score
At day 8 post-Conjunctival Allergen Challenge (CAC)

Assessed using the Ora Calibra® Conjunctival Allergen Challenge Ocular Itching Scale, a 0-4 point scale where 0= none and 4= incapacitating itch, 0.5 unit increments

Secondary Endpoints

Conjunctival redness score
At day 8 post-CAC
Percent change in cat titrated Skin prick test (tSPT)
Baseline and day 8
Tearing score
At day 8 post-CAC
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Study Design & Arms

AllocationRANDOMIZED
MaskingQUADRUPLE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
REGN1908-1909EXPERIMENTAL -
PlaceboPLACEBO_COMPARATOR -

Interventions

NameTypeDescription
REGN1908DRUGAdministered per the protocol
REGN1909DRUGAdministered per the protocol
PlaceboDRUGAdministered per the protocol
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Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites4

Key Inclusion Criteria: 1. Documented or participant-reported history of moderate to severe cat allergy for at least 2 years with bothersome ocular symptoms being near cat(s) 2. Positive SPT with cat allergen extract (mean wheal diameter at least 5 mm greater than the negative control) at screening...

Countries:United StatesCanada
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Frequently asked questions about REGN1908

What is REGN1908 used for?

REGN1908 is being developed for allergic conjunctivitis, specifically ocular allergy signs and symptoms in adults with cat allergy. It is a small molecule therapeutic candidate from Regeneron Pharmaceuticals. The clinical program has focused on reducing eye allergy symptoms triggered by cat allergen exposure in adult participants.

What does REGN1908 target?

REGN1908 targets FelD1, the major cat allergen protein. By binding to FelD1, the drug is designed to interfere with the allergen that triggers allergic responses in sensitized individuals. This target class is an allergen, distinguishing it from antibody or receptor targets typical of other allergy therapies.

Who is developing REGN1908?

REGN1908 is being developed by Regeneron Pharmaceuticals, Inc., which trades on the Nasdaq under the ticker REGN. Regeneron is the sponsor of the clinical program evaluating the drug in allergic conjunctivitis for patients with cat allergy.

What phase is REGN1908 in?

REGN1908 is in Phase 3 clinical development. A Phase 3 trial has been completed, and the drug remains investigational. It has not been approved by the FDA for any indication. The completed Phase 3 study enrolled 64 participants and evaluated the drug in adults with cat allergy.

What clinical trials is REGN1908 in?

REGN1908 has been studied in one completed Phase 3 trial, NCT06602726, titled A Study to Demonstrate How Well REGN1908-1909 Works in Reducing Ocular Allergy Signs and Symptoms in Adult Participants With Cat Allergy. The trial enrolled 64 adults, was randomized, double-blind, and placebo-controlled, and took place in the United States and Canada.