A Pivotal Safety and Efficacy Study of OCS-01 Eye Drops in Participants With Diabetic Macular Edema (DIAMOND 1)

A Phase 2/3 Double-Masked, Randomized, 2 Stage, Multicenter Study of the Efficacy and Safety of OCS-01 Eye Drops in Subjects With Diabetic Macular Edema

The primary objective of this study is to evaluate the efficacy and safety of the topical ophthalmic administration of OCS- 01 as compared to Vehicle in participants with Diabetic Macular Edema (DME).

Study Overview

• Status: Completed
• Conditions: Diabetic Macular Edema
• Intervention / Treatment: Drug: Dexamethasone ophthalmic suspension (OCS-01); Drug: Vehicle

Detailed Description

A Phase 2/3 Pivotal Double-masked, Randomized, Vehicle-controlled, 2 stage, Multicenter Study of the Efficacy and Safety of OCS-01 Eye Drops in Participants with Diabetic Macular Edema

Stage 1: To select a dose and dosing regimen for OCS-01 in participants with DME and evaluate the efficacy and safety of OCS-01 as compared to Vehicle in participants with DME.

Stage 2: To evaluate the efficacy and safety of OCS-01 as compared to Vehicle at Week 52 in participants with DME.

• Study Type: Interventional
• Enrollment (Actual): 552
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • HKU Eye Centre
  • Kowloon, Hong Kong
    • Chinese University of Hong Kong Eye Centre
• India
  • Gujarat
    • Surat, Gujarat, India, 395001
      • Shivam Retina Clinic and Eye Hospital
  • Karnataka
    • Bengaluru, Karnataka, India, 560094
      • Nethra Eye Hospital
  • Kerala
    • Kochi, Kerala, India, 682041
      • Amrita Institute Of Medical Sciences & Research Centre
  • Maharashtra
    • Nagpur, Maharashtra, India, 440025
      • Sarakshi Netralaya
  • Odisha
    • Bhubaneswar, Odisha, India, 751024
      • L V Prasad Eye Institute
  • Uttar Pradesh
    • Noida, Uttar Pradesh, India, 201301
      • ICARE Eye Hospital & Post Graduate Institute
• Taiwan
  • Changhua
    • Changhua, Changhua, Taiwan, 500
      • Changhua Christian Hospital
  • Taichung
    • Taichung, Taichung, Taiwan, 40447
      • China Medical University Hospital
  • Taipei
    • Taipei, Taipei, Taiwan, 11217
      • Taipei Veterans General Hospital
  • Taoyuan
    • Taoyuan, Taoyuan, Taiwan, 33305
      • Chang Gung Memorial Hospital
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85016
      • Arizona Retina and Vitreous Consultants
    • Phoenix, Arizona, United States, 85050
      • Phoenix Retina Associates
  • Arkansas
    • Springdale, Arkansas, United States, 72764
      • Retina Partners of Northwest Arkansas
  • California
    • Beverly Hills, California, United States, 90211
      • Retina-Vitreous Associates Medical Group
    • Encino, California, United States, 91436
      • The Retina Partners
    • Modesto, California, United States, 95356
      • Retinal Consultants Medical Group
    • Pasadena, California, United States, 91107
      • California Eye Specialists Medical Group
    • Redlands, California, United States, 92374
      • Retina Consultants of Southern California
    • Redlands, California, United States, 92373
      • California Eye Specialists Medical Group
    • Santa Maria, California, United States, 93454
      • California Retina Consultants
  • Connecticut
    • Waterford, Connecticut, United States, 06385
      • Retina Group of New England
  • Florida
    • Deerfield Beach, Florida, United States, 33064
      • Rand Eye Institute
    • Jacksonville, Florida, United States, 32216
      • Florida Retina Institute
    • Miami, Florida, United States, 33143
      • Medeye Associates
    • Orlando, Florida, United States, 32806
      • Florida Retina Institute
    • Palm Beach Gardens, Florida, United States, 33410
      • Retina Care Specialists
    • Stuart, Florida, United States, 34994
      • East Florida Eye Institute
  • Georgia
    • Augusta, Georgia, United States, 30909
      • Southeast Retina Center
  • Illinois
    • Elmhurst, Illinois, United States, 60126
      • Retina Associates
    • Lemont, Illinois, United States, 60439
      • University Retina
  • Indiana
    • Carmel, Indiana, United States, 46290
      • Midwest Eye Institute
  • Maryland
    • Hagerstown, Maryland, United States, 21740
      • Cumberland Valley Retina Consultants
  • Minnesota
    • Saint Louis Park, Minnesota, United States, 55416
      • Retina Consultants of Minnesota
  • Missouri
    • St Louis, Missouri, United States, 63128
      • The Retina Institute
  • New York
    • Liverpool, New York, United States, 13088
      • Retina-Vitreous Surgeons of Central New York
  • North Carolina
    • Wake Forest, North Carolina, United States, 27587
      • North Carolina Retina Associates
  • Ohio
    • Cincinnati, Ohio, United States, 45202
      • Velocity (Meridian) Clinical Research
  • Oregon
    • Eugene, Oregon, United States, 97401
      • Verum Research LLC
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19141
      • Vision Research Solutions in Philadelphia
  • South Carolina
    • Beaufort, South Carolina, United States, 29902
      • Retina Consultants of Charleston
    • Ladson, South Carolina, United States, 29456
      • Charleston Neuroscience Institute
  • South Dakota
    • Rapid City, South Dakota, United States, 57701
      • Black Hills Regional Eye Institute
  • Texas
    • Abilene, Texas, United States, 79606
      • Retina Research Institute of Texas
    • Austin, Texas, United States, 78705
      • Retina Consultants of Austin/Austin Research Center for Retina
    • Dallas, Texas, United States, 75231
      • Texas Retina Associates
    • Grapevine, Texas, United States, 76051
      • Retina Center Of Texas
    • McAllen, Texas, United States, 78503
      • Valley Retina Institute PA d.b.a. Gulf Coast Eye Institute
    • Tyler, Texas, United States, 75703
      • Tyler Retina Consultants
    • Willow Park, Texas, United States, 76087
      • Strategic Clinical Research Group
  • Virginia
    • Lynchburg, Virginia, United States, 24502
      • Piedmont Eye Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria (selection) - Stage 1:

1. Have a signed informed consent form before any study-specific procedures are performed.
2. Have DME with presence of intraretinal and/or subretinal fluid in the study eye, with central subfield thickness (CST) of ≥310 µm by SD-OCT at screening (Visit 1) (as assessed by an independent reading center).
3. Have a documented diagnosis of type 1 or type 2 diabetes mellitus at Visit 1 (Screening).

Inclusion Criteria (selection) - Stage 2:

1. Have a signed informed consent form before any study-specific procedures are performed.
2. Have DME with presence of intraretinal and/or subretinal fluid in the study eye, with central subfield thickness (CST) of ≥310 µm by SD-OCT at screening (Visit 1) (as assessed by an independent reading center).
3. Have a documented diagnosis of type 1 or type 2 diabetes mellitus prior to Visit 1 (Screening).

Exclusion criteria (selection) - Stage 1 and Stage 2:

1. Have macular edema considered to be because of a cause other than DME.
2. Have a decrease in BCVA because of causes other than DME.
3. Have a known history of significant macular ischemia which would prevent gain in visual acuity in the study eye.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: OCS-01; dexamethasone ophthalmic suspension,1.5% [15 mg/ mL]	Drug: Dexamethasone ophthalmic suspension (OCS-01); Stage 1: Participants will be dosed with one eye drop of OCS-01 6 times per day for 6 weeks (induction phase) followed by 3 times per day for 6 weeks (maintenance phase). Stage 2: Participants will be dosed with one eye drop of OCS-01 6 times per day for 6 weeks (induction phase) followed by 3 times per day for 46 weeks (maintenance phase).; Other Names: Dexamethasone
Placebo Comparator: Vehicle Vehicle; Placebo is a Vehicle ophthalmic suspension of OCS-01	Drug: Vehicle; Stage 1: Participants will be dosed with one eye drop of vehicle 6 times per day for 6 weeks (induction phase) followed by 3 times per day for 6 weeks (maintenance phase). Stage 2: Participant will be dosed with one eye drop of vehicle 6 times per day for 6 weeks (induction phase) followed by 3 times per day for 46 weeks (maintenance phase).; Other Names: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change in BCVA (Best Corrected Visual Acuity)	Assessed using ETDRS (Early Treatment Diabetes Retinopathy Study) letters score: higher numbers on the ETDRS chart representing better visual acuity	Week 52

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change in BCVA	BCVA will be assessed using ETDRS letters score: higher numbers on the ETDRS chart representing better visual acuity.	Baseline, Week 12 and Week 24
Percentage of Participants with a 3-line or Greater Gain in BCVA	BCVA will be assessed by ETDRS letters score: higher numbers on the ETDRS chart representing better visual acuity.	Baseline, Week 52
Mean Change in Central Subfield Thickness (CST)	CST will be measured by SD-OCT.	Baseline, Week 52

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Treatment Emergent Adverse events (TEAEs)	An adverse event (AE) is defined as any untoward medical occurrence in a clinical investigation participant. TEAEs are those AEs that occur after administration of the study product and are therefore temporally associated with the use of the study product.	Up to Week 52

Collaborators and Investigators

• Sponsor: Oculis
• Collaborators: ICON plc
• Investigators: Principal Investigator: Veeral S Sheth, MD, University Retina - Lemont

Study record dates

Study Major Dates

• Study Start (Actual): October 19, 2021
• Primary Completion (Actual): April 10, 2026
• Study Completion (Actual): April 10, 2026

Study Registration Dates

• First Submitted: September 2, 2021
• First Submitted That Met QC Criteria: October 1, 2021
• First Posted (Actual): October 4, 2021

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 30, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Eye drop; Topical ophthalmic suspension
• Additional Relevant MeSH Terms: Eye Diseases; Retinal Diseases; Retinal Degeneration; Macular Degeneration; Edema; Macular Edema; Polycyclic Compounds; Pregnadienes; Pregnanes; Steroids; Fused-Ring Compounds; Steroids, Fluorinated; Pregnadienetriols; Dexamethasone
• Other Study ID Numbers: DX219

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No