Evaluation of Tonabersat for DME

NCT05727891 | Active Not Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: DRCR Protocol ANUG1EY014231
• Study Type: interventional
• Target: 128
• Locations: 1 country
• Sites: 28

Brief Summary

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.

Conditions

Diabetic Macular Edema

Outcome Measures

Primary Outcomes (1)

• Mean change in central subfield thickness

  6 months

Secondary Outcomes (4)

• Mean change in retinal volume from baseline

  6 months

• Percentage of eyes central subfield thickness below optical coherence machine- and sex-specific threshold for DME and at least a 10% decrease from baseline

  6 months

• Mean change in visual acuity from baseline

  6 months

• Percentage of eyes receiving other treatment for DME prior to the 6 month visit

  6 months

Study Arms (2)

Placebo

PLACEBO COMPARATOR

Other: Placebo

Tonabersat (80 mg)

ACTIVE COMPARATOR

Drug: Tonabersat

Interventions

Tonabersat 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.

Tonabersat (80 mg)

Placebo 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.

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults with type 1 or 2 diabetes mellitus
• 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
• Media clarity, pupillary dilation, and study participant cooperation sufficient for adequate OCT

You may not qualify if:

• 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

Sponsors & Collaborators

• National Institutes of Health (NIH): collaborator
• National Eye Institute (NEI): collaborator
• Juvenile Diabetes Research Foundation: collaborator
• Jaeb Center for Health Research: lead

Study Sites (28)

Retina Associates of Southern California

Huntington Beach, California, 92647, United States

Location

Loma Linda University

Loma Linda, California, 92354, United States

Location

East Bay Retina Consultants, Inc.

Oakland, California, 94609, United States

Location

Southern California Desert Retina Consultants, Inc.

Palm Desert, California, 92211, United States

Location

Macula Retina Vitreous Institute

Torrance, California, 90503, United States

Location

National Ophthalmic Research Institute

Fort Myers, Florida, 33912, United States

Location

University of Florida- Jacksonville

Jacksonville, Florida, 32209, United States

Location

Central Florida Retina Institute

Lakeland, Florida, 33805, United States

Location

Florida Retina Consultants

Lakeland, Florida, 33805, United States

Location

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

Pinellas Park, Florida, 33782, United States

Location

Southeast Retina Center

Augusta, Georgia, 30909, United States

Location

Thomas Eye Group

Sandy Springs, Georgia, 30328, United States

Location

Illinois Retina Associates

Oak Park, Illinois, 60304, United States

Location

Midwest Eye Institute

Indianapolis, Indiana, 46290, United States

Location

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

West Monroe, Louisiana, 71291, United States

Location

Elman Retina Group

Baltimore, Maryland, 21237, United States

Location

Boston Medical Center Corporation

Boston, Massachusetts, 02118, United States

Location

Joslin Diabetes Center

Boston, Massachusetts, 02215, United States

Location

Mayo Clinic

Rochester, Minnesota, 55905, United States

Location

Retina Research Institute, LLC

St Louis, Missouri, 63128, United States

Location

Retina-Vitreous Surgeons of Central NY, PC

Liverpool, New York, 13088, United States

Location

Verum Research LLC

Eugene, Oregon, 97401, United States

Location

The Trustees of the University of Pennsylvania

Philadelphia, Pennsylvania, 19104, United States

Location

Pittsburg Clinical Trial Consortium

Sewickley, Pennsylvania, 15143, United States

Location

Hilton Head Retina Institute

Hilton Head Island, South Carolina, 29926, United States

Location

Retina Consultants of Texas, PA

Bellaire, Texas, 77401, United States

Location

Texas Retina Associates

Lubbock, Texas, 79424, United States

Location

Retinal Consultants of Texas

San Antonio, Texas, 78240, United States

Location

MeSH Terms

Interventions

tonabersat

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomized, double-masked, placebo-controlled clinical trial

Study Record Dates

• First Submitted: February 6, 2023
• First Posted: February 14, 2023
• Study Start: May 2, 2023
• Primary Completion: June 27, 2025
• Study Completion: January 1, 2026
• Last Updated: December 11, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (28)