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Monoclonal Antibodies

aflibercept for Retinopathy of Prematurity (BUTTERFLEYE Trial)

Phase 3
Waitlist Available
Research Sponsored by Regeneron Pharmaceuticals
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Zone I Stage 1 plus, or 2 plus, or 3 non-plus or 3 plus, or Zone II Stage 2 plus or 3 plus, or Aggressive posterior retinopathy of prematurity (AP-ROP)
Key
Timeline
Screening 3 weeks
Treatment Varies
Follow Up baseline to week 52 of chronological age
Awards & highlights

BUTTERFLEYE Trial Summary

This trial is testing whether aflibercept is more effective than laser treatment for retinopathy of prematurity (ROP), and also looking at safety and side effects.

Eligible Conditions
  • Retinopathy of Prematurity

BUTTERFLEYE Trial Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
Select...
You are born before 32 weeks or weigh less than 1500 g.

BUTTERFLEYE Trial Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~baseline to week 52 of chronological age
This trial's timeline: 3 weeks for screening, Varies for treatment, and baseline to week 52 of chronological age for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Percentage of Participants With Absence of Active Retinopathy of Prematurity (ROP) and Unfavorable Structural Outcomes From Baseline to Week 52 of Chronological Age
Secondary outcome measures
Percentage of Participants Requiring Intervention With a Second Treatment Modality From Baseline to Week 52 of Chronological Age
Percentage of Participants With Ocular Treatment-emergent Adverse Events (TEAEs) and Treatment-emergent Serious Adverse Events (TESAEs)
Percentage of Participants With Recurrence of ROP Through Week 52 of Chronological Age
+1 more

Side effects data

From 2020 Phase 4 trial • 20 Patients • NCT02559180
5%
Hypertension and Hyperglycemia
5%
Chest pain
5%
Bilateral lower limb cellulitis
5%
Death of unknown cause
100%
80%
60%
40%
20%
0%
Study treatment Arm
Single Arm

BUTTERFLEYE Trial Design

2Treatment groups
Experimental Treatment
Group I: Laser GroupExperimental Treatment1 Intervention
Patients will undergo laser treatment in each eligible eye at baseline.
Group II: Aflibercept GroupExperimental Treatment1 Intervention
Patients will receive a single intravitreal (IVT) injection per eligible eye at baseline.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
aflibercept
2015
Completed Phase 4
~1850
laser photocoagulation
2014
Completed Phase 4
~190

Find a Location

Who is running the clinical trial?

Regeneron PharmaceuticalsLead Sponsor
613 Previous Clinical Trials
379,332 Total Patients Enrolled
3 Trials studying Retinopathy of Prematurity
321 Patients Enrolled for Retinopathy of Prematurity
Clinical Trial ManagementStudy DirectorRegeneron Pharmaceuticals
258 Previous Clinical Trials
250,572 Total Patients Enrolled
1 Trials studying Retinopathy of Prematurity
112 Patients Enrolled for Retinopathy of Prematurity

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

Who else is applying?

What state do they live in?
New York
District of Columbia
How old are they?
18 - 65
What site did they apply to?
Regeneron Study Site
What portion of applicants met pre-screening criteria?
Met criteria
~24 spots leftby Mar 2025