Evaluation of Tonabersat for DME

NCT ID: NCT05727891

Last Updated: 2025-12-11

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

PHASE2

Total Enrollment

128 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-05-02

Study Completion Date

2026-01-31

Brief Summary

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This randomized clinical trial will evaluate the effect of tonabersat compared with placebo on central subfield thickness (CST) in eyes with center-involved diabetic macular edema (CI-DME) and good visual acuity.

Detailed Description

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The primary objective is to assess the effects of tonabersat, an orally administered Connexin43 hemichannel inhibitor, on central subfield thickness (mean change) compared with placebo in eyes with CI-DME and good visual acuity at 6 months.

Exploratory objectives will evaluate biomarkers of kidney function for potential benefit. Furthermore, this phase 2 study is being conducted to determine whether the conduct of a phase 3 trial has merit and provide information on outcome measures needed to design a phase 3 trial.

Conditions

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Diabetic Macular Edema

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Randomized, double-masked, placebo-controlled clinical trial
Primary Study Purpose

TREATMENT

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors

Study Groups

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Placebo

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type OTHER

Two pills of Study Drug (placebo) is taken orally once daily. It is recommended the Study Drug be taken at bedtime. The first dose (two pills) will be taken at bedtime on the day the participant is randomized.

Tonabersat (80 mg)

Group Type ACTIVE_COMPARATOR

Tonabersat

Intervention Type DRUG

Two pills of Study Drug (80 mg tonabersat) is taken orally once daily. It is recommended the Study Drug be taken at bedtime. The first dose (two pills) will be taken at bedtime on the day the participant is randomized.

Interventions

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Tonabersat

Two pills of Study Drug (80 mg tonabersat) is taken orally once daily. It is recommended the Study Drug be taken at bedtime. The first dose (two pills) will be taken at bedtime on the day the participant is randomized.

Intervention Type DRUG

Placebo

Two pills of Study Drug (placebo) is taken orally once daily. It is recommended the Study Drug be taken at bedtime. The first dose (two pills) will be taken at bedtime on the day the participant is randomized.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

1. Adults with type 1 or 2 diabetes mellitus
2. At least one eye with:

* Best corrected E-ETDRS visual acuity letter score ≥ 74 (i.e., 20/32 or better)
* Ophthalmoscopic evidence of center-involved DME in study eye confirmed by central subfield thickness on spectral domain OCT
* Zeiss Cirrus: ≥ 290 µm in females, ≥ 305 µm in males
* Heidelberg Spectralis: ≥ 305 µm in females, ≥ 320 µm in males

* Recruitment will be monitored with a goal to have equal proportions in the following categories above the CI-DME thresholds: \<75 μm, 75 μm to \<175 μm, ≥175 μm
3. Media clarity, pupillary dilation, and study participant cooperation sufficient for adequate OCT

Exclusion Criteria

* Macular edema is considered to be due to a cause other than DME
* Major ocular surgery within prior 4 months, or anticipated after randomization
* History of focal/grid laser or other ocular surgical, intravitreal, or peribulbar treatment for DR or DME within prior 1 year, and no more than 4 anti-VEGF injections within prior 3 years
* Anticipated need to treat DME or DR during the first 6 months, or anticipated need for cataract surgery during study period
* Any history of vitrectomy
* Systemic anti-VEGF or pro-VEGF treatment within 12 months prior to randomization
* History of chronic renal failure requiring dialysis or kidney transplant
* History of moderate to severe hepatic impairment, including known liver function test (LFT) values \> 3x's the upper limit of normal
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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National Institutes of Health (NIH)

NIH

Sponsor Role collaborator

National Eye Institute (NEI)

NIH

Sponsor Role collaborator

Juvenile Diabetes Research Foundation

OTHER

Sponsor Role collaborator

Jaeb Center for Health Research

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Retina Associates of Southern California

Huntington Beach, California, United States

Site Status

Loma Linda University

Loma Linda, California, United States

Site Status

East Bay Retina Consultants, Inc.

Oakland, California, United States

Site Status

Southern California Desert Retina Consultants, Inc.

Palm Desert, California, United States

Site Status

Macula Retina Vitreous Institute

Torrance, California, United States

Site Status

National Ophthalmic Research Institute

Fort Myers, Florida, United States

Site Status

University of Florida- Jacksonville

Jacksonville, Florida, United States

Site Status

Central Florida Retina Institute

Lakeland, Florida, United States

Site Status

Florida Retina Consultants

Lakeland, Florida, United States

Site Status

Southeast Eye Institute, P.A. dba Eye Associates of Pinellas

Pinellas Park, Florida, United States

Site Status

Southeast Retina Center

Augusta, Georgia, United States

Site Status

Thomas Eye Group

Sandy Springs, Georgia, United States

Site Status

Illinois Retina Associates

Oak Park, Illinois, United States

Site Status

Midwest Eye Institute

Indianapolis, Indiana, United States

Site Status

Joseph E. Humble and Raymond Haik PTRS DBA Eye Assoc of Northeast Louisiana

West Monroe, Louisiana, United States

Site Status

Elman Retina Group

Baltimore, Maryland, United States

Site Status

Boston Medical Center Corporation

Boston, Massachusetts, United States

Site Status

Joslin Diabetes Center

Boston, Massachusetts, United States

Site Status

Mayo Clinic

Rochester, Minnesota, United States

Site Status

Retina Research Institute, LLC

St Louis, Missouri, United States

Site Status

Retina-Vitreous Surgeons of Central NY, PC

Liverpool, New York, United States

Site Status

Verum Research LLC

Eugene, Oregon, United States

Site Status

The Trustees of the University of Pennsylvania

Philadelphia, Pennsylvania, United States

Site Status

Pittsburg Clinical Trial Consortium

Sewickley, Pennsylvania, United States

Site Status

Hilton Head Retina Institute

Hilton Head Island, South Carolina, United States

Site Status

Retina Consultants of Texas, PA

Bellaire, Texas, United States

Site Status

Texas Retina Associates

Lubbock, Texas, United States

Site Status

Retinal Consultants of Texas

San Antonio, Texas, United States

Site Status

Countries

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United States

Other Identifiers

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UG1EY014231

Identifier Type: NIH

Identifier Source: secondary_id

View Link

DRCR Protocol AN

Identifier Type: -

Identifier Source: org_study_id

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