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

January 16, 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 Simultaneous Cataract Surgery and Descemetorhexis in Subjects With Fuchs Endothelial Corneal Dystrophy

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

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

110

Phase

  • 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 Locations

  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada, 2000
        • Dr. Greg Moloney
    • Ontario
      • Oakville, Ontario, Canada, L5L 1W8
        • Prism Eye Institute - Mississauga-Oakville
      • Ottawa, Ontario, Canada, K1G 5L1
        • Precision Cornea Centre
  • Denmark
    • Capital
      • Glostrup Municipality, Capital, Denmark, 2600
        • Rigshospitalet Glostrup-Valdemar Hansens Vej 1-23
    • Central Jutland
      • Aarhus N, Central Jutland, Denmark, 8200
        • Aarhus Universitetshospital
  • Germany
      • München, Germany, 81377
        • LMU Klinikum der Universität
    • Baden-Wurttemberg
      • Heidelberg, Baden-Wurttemberg, Germany, 91054
        • 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 Koln
      • Düsseldorf, North Rhine-Westphalia, Germany, 40225
        • Universitatsklinikum Dusseldorf
    • Saarland
      • Homburg, Saarland, Germany, 66424
        • Universität des Saarlandes
  • 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, 17001
        • 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
    • Tyne and Wear
      • Newcastle upon Tyne, Tyne and Wear, 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, 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
      • Palm Beach Gardens, Florida, United States, 33136
        • Bascom Palmer Eye Institute
    • Kansas
      • Wichita, Kansas, United States, 67208
        • Grene Vision Group-Wichita
    • Kentucky
      • Lexington, Kentucky, United States, 40508
        • University Of Kentucky
    • 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 - Albuquerque - Northside
    • 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
      • Blue Ash, Ohio, United States, 45242
        • Cincinnati Eye Institute-1945 Cei Dr
      • Cleveland, Ohio, United States, 44106
        • University Hospitals Cleveland Medical Center - 11100 Euclid Ave
    • Oregon
      • Portland, Oregon, United States, 97210
        • Devers Eye Institute
    • 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 School of Medicine and Public Health

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

Ages Eligible for Study

  • 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
  • Meet all other inclusion criteria outlined in the Clinical Study Protocol.

Exclusion Criteria:

  • Is a female subject 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)
  • Meet any other exclusion criteria outlined in the 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
Intervention / Treatment
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

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

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 Endothelial Cell Density (ECD) (cells/mm2) 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

Kowa Research Institute, Inc.

Investigators

  • 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)

May 11, 2023

Primary Completion (Actual)

January 17, 2025

Study Completion (Actual)

October 24, 2025

Study Registration Dates

First Submitted

April 6, 2023

First Submitted That Met QC Criteria

April 21, 2023

First Posted (Actual)

April 24, 2023

Study Record Updates

Last Update Posted (Actual)

January 22, 2026

Last Update Submitted That Met QC Criteria

January 16, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • K-321-303

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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