Evaluation of Tonabersat for DME

Diabetic Macular Edema Clinical Trial

— AN  

Official title:

A Phase 2 Evaluation of Tonabersat for Diabetic Macular Edema (Protocol AN)

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05727891
• Other study ID #: DRCR Protocol AN
• Secondary ID: UG1EY014231
• Status: Recruiting
• Phase: Phase 2
• Start date: May 2, 2023
• Est. completion date: May 2025

Study information

• Verified date: June 2024
• Source: Jaeb Center for Health Research
• Contact: Cynthia Stockdale, MSPH
• Phone: 8139758690
• Email: DRCRNET[@]JAEB.ORG
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Description:

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 128
• Est. completion date: May 2025
• Est. primary completion date: November 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Key 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

Key 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

Related Conditions & MeSH terms

• Diabetic Macular Edema
• Macular Edema

Intervention

Drug:
• 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.

Other:
• 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.

Locations

Country	Name	City	State
United States	Southeast Retina Center	Augusta	Georgia
United States	Elman Retina Group	Baltimore	Maryland
United States	Boston Medical Center Corporation	Boston	Massachusetts
United States	Joslin Diabetes Center	Boston	Massachusetts
United States	Verum Research LLC	Eugene	Oregon
United States	National Ophthalmic Research Institute	Fort Myers	Florida
United States	Hilton Head Retina Institute	Hilton Head Island	South Carolina
United States	Retina Associates of Southern California	Huntington Beach	California
United States	Midwest Eye Institute	Indianapolis	Indiana
United States	University of Florida- Jacksonville	Jacksonville	Florida
United States	Central Florida Retina Institute	Lakeland	Florida
United States	Florida Retina Consultants	Lakeland	Florida
United States	Retina-Vitreous Surgeons of Central NY, PC	Liverpool	New York
United States	Loma Linda University	Loma Linda	California
United States	Texas Retina Associates	Lubbock	Texas
United States	Illinois Retina Associates	Oak Park	Illinois
United States	East Bay Retina Consultants, Inc.	Oakland	California
United States	Southern California Desert Retina Consultants, Inc.	Palm Desert	California
United States	The Trustees of the University of Pennsylvania	Philadelphia	Pennsylvania
United States	Southeast Eye Institute, P.A. dba Eye Associates of Pinellas	Pinellas Park	Florida
United States	Mayo Clinic	Rochester	Minnesota
United States	Retina Research Institute, LLC	Saint Louis	Missouri
United States	Thomas Eye Group	Sandy Springs	Georgia
United States	Pittsburg Clinical Trial Consortium	Sewickley	Pennsylvania
United States	Macula Retina Vitreous Institute	Torrance	California

Sponsors (4)

Lead Sponsor	Collaborator
Jaeb Center for Health Research	Juvenile Diabetes Research Foundation, National Eye Institute (NEI), National Institutes of Health (NIH)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mean change in central subfield thickness		6 months
Secondary	Mean change in retinal volume from baseline		6 months
Secondary	Percentage of eyes central subfield thickness below optical coherence machine- and sex-specific threshold for DME and at least a 10% decrease from baseline	Composite outcome, gender-specific spectral domain optical coherence tomography equivalent of 250 µm on Zeiss Stratus optical coherence tomography	6 months
Secondary	Mean change in visual acuity from baseline		6 months
Secondary	Percentage of eyes receiving other treatment for DME prior to the 6 month visit		6 months