A Study to Evaluate the Safety and Efficacy of K-321 Eye Drops After Descemetorhexis in Participants With Fuchs Endothelial Corneal Dystrophy (FECD)

May 21, 2026 updated by: Kowa Research Institute, Inc.

A Double-Masked, Randomized, Placebo-Controlled, Parallel-Group, 12-Week Administration With Two-Week Gradual Dose Taper Phase and 38-Week Follow-Up Phase, Phase 3 Study to Investigate the Safety and Efficacy of Ripasudil (K-321) Eye Drops After Descemetorhexis in Subjects With Fuchs Endothelial Corneal Dystrophy

A study to assess the safety and efficacy of K-321 in participants with FECD after descemetorhexis.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
107

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada, V5Z 1K1
        • Dr. Greg Moloney
    • Ontario
      • Oakville, Ontario, Canada, L6H 0J8
        • Prism Eye Institute - Mississauga-Oakville
      • Ottawa, Ontario, Canada, K1H 8L6
        • Ottawa Hospital
      • Ottawa, Ontario, Canada, K1G 5L1
        • Precision Cornea Centre
  • Denmark
    • Capital
      • Glostrup Municipality, Capital, Denmark, 2600
        • Rigshospitalet Glostrup-Nordre Ringvej 57
    • Central Jutland
      • Aarhus N, Central Jutland, Denmark, 8200
        • Aarhus Universitetshospital
  • Germany
      • München, Germany, 81377
        • LMU Klinikum der Universität
    • Baden-Wurttemberg
      • Heidelberg, Baden-Wurttemberg, Germany, 69120
        • Universitatsklinikum Heidelberg
      • Tübingen, Baden-Wurttemberg, Germany, 72076
        • Universitatsklinikum Tubingen
    • Bavaria
      • Erlangen, Bavaria, Germany, 91054
        • Universitatsklinkum Erlangen-Ulmenweg 18
    • North Rhine-Westphalia
      • Cologne, North Rhine-Westphalia, Germany, 50931
        • Uniklinik Köln
      • Düsseldorf, North Rhine-Westphalia, Germany, 40225
        • Universitätsklinikum Düsseldorf
    • Saarland
      • Homburg, Saarland, Germany, 66424
        • Universität des Saarlandes
    • Saxony
      • Leipzig, Saxony, Germany, 04103
        • Universitatsklinikum Leipzig
  • Spain
      • Barcelona, Spain, 08035
        • Instituto de Microcirugia Ocular
      • Barcelona, Spain, 08022
        • Institut Catala de Retina (ICR)
      • Barcelona, Spain, 08017
        • Oftalvist - Barcelona
    • Barcelona
      • Badalona, Barcelona, Spain, 08916
        • Hospital Universitario Germans Trias i Pujol
      • Manresa, Barcelona, Spain, 08243
        • Althaia Xarxa Assistencial Universitaria Manresa
    • Córdoba
      • Córdoba, Córdoba, Spain, 14012
        • Hospital Arruzafa
    • Principality of Asturias
      • Oviedo, Principality of Asturias, Spain, 33012
        • Instituto Oftalmologico Fernandez Vega
  • United Kingdom
    • Lancashire
      • Liverpool, Lancashire, United Kingdom, L7 8XP
        • The Royal Liverpool University Hospital
    • London, City of
      • London, London, City of, United Kingdom, EC1V 2PD
        • Moorfields Eye Hospital
    • Northumberland
      • Newcastle upon Tyne, Northumberland, United Kingdom, NE1 4LP
        • Royal Victoria Infirmary
  • United States
    • California
      • Los Angeles, California, United States, 90033
        • Keck Hospital of USC
      • Los Angeles, California, United States, 90095
        • Jules Stein Eye Institute
      • Los Angeles, California, United States, 90048
        • Macy Eye Center
      • Palo Alto, California, United States, 94303
        • Byers Eye Institute at Stanford
      • Sacramento, California, United States, 95815
        • Sacramento Eye Consultants
    • Florida
      • Fort Myers, Florida, United States, 33907
        • Gorovoy MD Eye Specialists
      • Gainesville, Florida, United States, 32605
        • University of Florida
      • Miami, Florida, United States, 33418
        • Bascom Palmer Eye Institute
      • Naples, Florida, United States, 34103
        • Bascom Palmer Eye Institute - Naples
    • Georgia
      • Atlanta, Georgia, United States, 30339-5971
        • Eye Consultants of Atlanta
    • Kansas
      • Wichita, Kansas, United States, 67208-3648
        • Grene Vision Group
    • Kentucky
      • Lexington, Kentucky, United States, 40508
        • University of Kentucky
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts Eye and Ear Infirmary
    • Michigan
      • Ann Arbor, Michigan, United States, 48105
        • W Kellogg Eye Center
      • Grand Rapids, Michigan, United States, 49546
        • Verdier Eye Center
    • Nebraska
      • Omaha, Nebraska, United States, 68137
        • Vance Thompson Vision - Omaha
    • New Mexico
      • Albuquerque, New Mexico, United States, 87109
        • Eye Associates of New Mexico
    • New York
      • New York, New York, United States, 10017
        • NYU Langone Health
    • North Dakota
      • West Fargo, North Dakota, United States, 58078
        • Vance Thompson Vision West Fargo
    • Ohio
      • Cleveland, Ohio, United States, 44106
        • University Hospitals Cleveland Medical Center - 11100 Euclid Ave
    • Oregon
      • Portland, Oregon, United States, 97210
        • Devers Eye Institute
      • Portland, Oregon, United States, 97239
        • Casey Eye Institute - OHSU
    • Texas
      • Dallas, Texas, United States, 75390
        • University of Texas Southwestern Medical Center
      • Houston, Texas, United States, 77025
        • Houston Eye Associates
      • San Antonio, Texas, United States, 78229
        • R and R Eye Research, LLC.
    • Wisconsin
      • Madison, Wisconsin, United States, 53705
        • University of Wisconsin - 2870 University Ave

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Is at least 18 years old at the screening visit (Visit 1)
  • Has a diagnosis of FECD at Visit 1
  • Meets all other inclusion criteria outlined in clinical study protocol

Exclusion Criteria:

  • Is a female patient of childbearing potential and any of the following is true:

    1. is pregnant or lactating/breastfeeding, or
    2. is not surgically sterile, not post-menopausal (no menses for the previous 12 months), or not practicing an effective method of birth control as determined by the Investigator (eg, oral contraceptives, double barrier methods, hormonal injectable or implanted contraceptives, tubal ligation, or partner with vasectomy)
  • Has a study eye with a history of cataract surgery within 90 days of Visit 1
  • Meet any other exclusion criteria outlined in clinical study protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: K-321
K-321 ophthalmic solution four times daily (QID) for 12 weeks followed by a two-week gradual dose taper phase and 38-week follow-up phase
Drug: Ripasudil
K-321 ophthalmic solution
Other Names:
  • K-321
Placebo Comparator: Placebo
Placebo ophthalmic solution QID for 12 weeks followed by a two-week gradual dose taper phase and 38-week follow-up phase
Drug: Placebo
Placebo ophthalmic solution

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Time to improvement in best corrected (distance) visual acuity (BCVA) by ETDRS letter score during the first 12 weeks
Time Frame: Baseline to Week 12
Baseline to Week 12

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Time to improvement in best corrected (distance) visual acuity (BCVA) by ETDRS letter score during the first 12 weeks
Time Frame: Baseline to Week 12
Baseline to Week 12
Time to achievement in best corrected (distance) visual acuity (BCVA) by ETDRS letter score during the first 12 weeks
Time Frame: Baseline to Week 12
Baseline to Week 12
Central corneal ECD at Week 12
Time Frame: Week 12
Central corneal endothelial cell images will be captured by non-contact specular microscopy.
Week 12
Time to achievement of no corneal edema during the first 12 weeks
Time Frame: Baseline to Week 12
Baseline to Week 12
Time to exceed in BCVA pre-DSO ETDRS letter score during the first 12 weeks
Time Frame: Baseline to Week 12
Baseline to Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Kowa Research Institute, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Shona Pendse, MD, MMSc, Kowa Pharma Development Co.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 30, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 22, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 20, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 21, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 21, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 3, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • K-321-301

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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