Study of Bet v1 Antibodies Effect on Eye Allergy Symptoms in Adolescents and Adults With Birch Pollen Allergy

A Randomized, Double-Masked, Placebo-Controlled, Phase 3 Study to Assess the Efficacy and Safety of Bet v 1 Monoclonal Antibodies in Participants With Allergic Conjunctivitis Due to Birch Pollen Allergy

This study is researching 2 experimental drugs, REGN5713 and REGN5715. The study drugs will be either of these drugs given alone (either REGN5713 or REGN5715) or given together (REGN5713 and REGN5715) to reduce eye allergy signs and symptoms due to birch tree pollen allergy.

The aim of the study is to see how safe and effective the study drugs are at lowering eye allergy signs and symptoms compared with placebo.

The study will also evaluate whether the combination (REGN5713-5715) has different effectiveness than REGN5713 or REGN5715 alone.

The study is looking at several other research questions, including:

• What side effects may happen from taking the study drugs
• How much of the study drugs is in the blood at different times
• Whether the body makes antibodies against the study drugs (which could make the drug less effective or could lead to side effects)

Study Overview

• Status: Recruiting
• Conditions: Allergic Conjunctivitis
• Intervention / Treatment: Drug: REGN5713; Drug: REGN5715; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 350
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Clinical Trials Administrator; Phone Number: 844-734-6643; Email: clinicaltrials@regeneron.com

Study Locations

• United States
  • Massachusetts
    • Andover, Massachusetts, United States, 01810
      • Recruiting
      • Andover Eye Associates

Participation Criteria

Eligibility Criteria

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

Description

Key Inclusion Criteria:

1. Positive SPT to birch allergen extract
2. Positive allergen specific Immunoglobulin E (sIgE) tests for birch and Bet v 1
3. Positive CAC criteria

Key Exclusion Criteria:

1. Significant and/or severe environmental allergies causing symptoms (outside of the challenge setting) that are expected to interfere with study assessments
2. Presence of any ophthalmic disease/abnormality/condition that may interfere with study assessments, affect the study outcomes or negatively impact participant safety
3. A clinical history of asthma with treatment of asthma requiring systemic (oral or parenteral) corticosteroid treatment more than twice within prior 12 months or once within 3 months prior to screening visit 1 or has been hospitalized or has attended the Emergency Room/Urgent Care facility for asthma in the 12 months prior to screening

Note: Other protocol defined Inclusion/Exclusion criteria apply.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Drug: Placebo; Administered per protocol
Experimental: REGN5713-5715	Drug: REGN5713; Administered per protocol; Other Names: Bremzalerbart; Drug: REGN5715; Administered per protocol; Other Names: Atisnolerbart
Experimental: REGN5713	Drug: REGN5713; Administered per protocol; Other Names: Bremzalerbart
Experimental: REGN5715	Drug: REGN5715; Administered per protocol; Other Names: Atisnolerbart

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ocular itch score in participants receiving REGN5713-5715 compared to placebo	Assessed using the Ora Calibra® Conjunctival Allergen Challenge Ocular Itching Scale, a 0-4 scale where 0 = none and 4= incapacitating itch, 0.5 unit increments	At Day 8 post-Conjunctival Allergen Challenge (CAC)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Severity of TEAEs		Up to Day 113
Achievement of at least a 1-point reduction in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving REGN5713-5715 compared to placebo		Baseline to Day 8 post-CAC
Ocular itch score in participants receiving REGN5713-5715 compared to placebo		At Day 57 post-CAC
Conjunctival redness score in participants receiving REGN5713-5715 compared to placebo	Assessed using the Ora Calibra® Hyperemia Scale (for conjunctival [conjunctival redness scale] ciliary [ciliary redness scale], episcleral [episcleral redness scale] vessel beds), a 0 to 4 scale, where 0 = none and 4 = extremely severe, 0.5 unit increments	At Day 8 and Day 57 post-CAC
Achievement of at least a 1-point reduction in conjunctival redness score for at least 2 out of 3 post-CAC time points in participants receiving REGN5713-5715 compared to placebo		Baseline to Day 8 post-CAC
Total Nasal Symptom Score (TNSS) in participants receiving REGN5713-5715 compared to placebo	The TNSS ranges from 0 to 12 and is based on assessment of 4 nasal symptoms graded on a verbal rating scale ranging from 0 (none) to 3 (severe) for nasal congestion, nasal itching, rhinorrhea, and sneezing.	At Day 8 post-CAC
Ocular itch score in participants receiving REGN5715 compared to placebo		At Day 8 and Day 57 post-CAC
Achievement of at least a 1-point reduction in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving REGN5715 compared to placebo		Baseline to Day 8 post-CAC
Conjunctival redness score in participants receiving REGN5715 compared to placebo		At Day 8 post-CAC
Achievement of at least a 1-point reduction in conjunctival redness score in for at least 2 out of 3 post-CAC time points participants receiving REGN5715 compared to placebo		Baseline to Day 8 post-CAC
Ocular itch score in participants receiving REGN5713 compared to placebo		At Day 8 and Day 57 post-CAC
Achievement of at least a 1-point reduction in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving REGN5713 compared to placebo		Baseline to Day 8 post-CAC
Conjunctival redness score in participants receiving REGN5713 compared to placebo		At Day 8 post-CAC
Achievement of at least a 1-point reduction in conjunctival redness score for at least 2 out of 3 post-CAC time points in participants receiving REGN5713 compared to placebo		Baseline to Day 8 post-CAC
Percent change in birch titrated Skin Prick Test (tSPT) in participants receiving REGN5713-5715 compared to placebo	Area Under the Curve (AUC) of the mean wheal diameters	Baseline and at Day 8 post-CAC
Ocular itch score in participants receiving REGN5713-5715 compared to REGN5713		Baseline to Day 8 post-CAC
Ocular itch score in participants receiving REGN5713-5715 compared to REGN5715		Baseline to Day 8 post-CAC
Achievements of different response thresholds for the ocular itch score among participants receiving REGN5713-5715, REGN5713, REGN5715 or placebo		Baseline to Day 8 post-CAC
Achievement of at least a 1-point reduction in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving REGN5713-5715 compared to placebo		Baseline to Day 57 post-CAC
Achievement of at least a 1-point reduction in conjunctival redness score for at least 2 out of 3 post-CAC time points in participants receiving REGN5713-5715 compared to placebo		Baseline to Day 57 post-CAC
Ciliary redness score in participants receiving REGN5713-5715 compared to placebo	Assessed using the Ora Calibra® Hyperemia Scale (for conjunctival [conjunctival redness scale] ciliary [ciliary redness scale], episcleral [episcleral redness scale] vessel beds), a 0 to 4 scale, where 0 = none and 4 = extremely severe, 0.5 unit increments	At Day 8 and Day 57 post-CAC
Episcleral redness score in participants receiving REGN5713-5715 compared to placebo	Assessed using the Ora Calibra® Hyperemia Scale (for conjunctival [conjunctival redness scale] ciliary [ciliary redness scale], episcleral [episcleral redness scale] vessel beds), a 0 to 4 scale, where 0 = none and 4 = extremely severe, 0.5 unit increments	At Day 8 and Day 57 post-CAC
Total redness score in participants receiving REGN5713-5715 compared to placebo	The total redness score is calculated for CAC: range 0 to 12, where higher scores indicate worse responses (calculated as a sum of the bilateral averages for conjunctival redness score, graded 0 = none to 4 = extremely severe + ciliary redness score, graded 0 = none and 4 = extremely severe + episcleral redness score, graded 0 = none and 4 = extremely severe)	At Day 8 and Day 57 post-CAC
Percent change in birch tSPT in participants receiving REGN5713-5715 compared to placebo		Baseline and at Day 57 post-CAC
Percent change in birch tSPT in participants receiving REGN5715 compared to placebo		Baseline, at Day 8 and at Day 57 post-CAC
Percent change in birch tSPT in participants receiving REGN5713 compared to placebo		Baseline, at Day 8 and at Day 57 post-CAC
Occurrence of Treatment-Emergent Adverse Events (TEAEs)		Up to Day 113
Occurrence of Treatment Emergent-Serious Adverse Events (TE-SAEs)		Up to Day 113
Concentrations of total REGN5713 is serum over time		Up to Day 113
Concentrations of total REGN5715 is serum over time		Up to Day 113
Occurrence of Anti-Drug Antibodies (ADA) responses to REGN5713		Up to Day 113
Magnitude of ADA to REGN5713		Up to Day 113
Occurrence of ADA responses to REGN5715		Up to Day 113
Magnitude of ADA to REGN5715		Up to Day 113

Collaborators and Investigators

• Sponsor: Regeneron Pharmaceuticals
• Investigators: Study Director: Clinical Trial Management, Regeneron Pharmaceuticals

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2026
• Primary Completion (Estimated): February 28, 2027
• Study Completion (Estimated): June 15, 2027

Study Registration Dates

• First Submitted: December 17, 2025
• First Submitted That Met QC Criteria: December 29, 2025
• First Posted (Actual): December 30, 2025

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 6, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Birch Pollen Allergy; Ocular allergy symptoms; Ocular allergy signs
• Additional Relevant MeSH Terms: Immune System Diseases; Eye Diseases; Hypersensitivity, Immediate; Hypersensitivity; Conjunctivitis; Conjunctival Diseases; Conjunctivitis, Allergic
• Other Study ID Numbers: R5713-5715-ALG-2556

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.

IPD Sharing Time Frame

When Regeneron has:

• received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development
• made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry)
• the legal authority to share the data, and
• ensured the ability to protect participant privacy

• IPD Sharing Access Criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

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