A Study to Investigate the Safety and Efficacy of Ripasudil (K-321) Eye Drops After Cataract Surgery

July 14, 2026 updated by: Kowa Research Institute, Inc.

A Double-Masked, Randomized, Placebo-Controlled, Parallel-Group, 12-Week Treatment and 14-week Extension, Phase 3 Study to Investigate the Safety and Efficacy of Ripasudil (K-321) Eye Drops After Cataract Surgery

The purpose of this study is to assess the safety and efficacy of K-321 in subjects after cataract surgery

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

330

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

  • Puerto Rico
      • San Juan, Puerto Rico, 00921
        • Centro Oftalmologico Metropolitano
  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85032
        • Cornea and Cataract Consultants of Arizona
      • Scottsdale, Arizona, United States, 85260
        • Schwartz Laser Eye Center
    • California
      • Hemet, California, United States, 92545
        • Inland Eye Specialists
      • Inglewood, California, United States, 90301
        • United Medical Research Institute
      • La Mesa, California, United States, 91942
        • Alvarado Eye Associates
      • Long Beach, California, United States, 90805
        • SoCal Eye Physicians and Associates
      • Newport Beach, California, United States, 92663
        • Visionary Research Institute
      • Oceanside, California, United States, 92056
        • Pendleton Eye Center
      • Petaluma, California, United States, 94954
        • North Bay Eye Associates
      • Rancho Cordova, California, United States, 95670
        • Martel Eye Medical Group
      • Torrance, California, United States, 90505
        • Wolstan and Goldberg Eye Associates
      • Torrance, California, United States, 90505
        • Premiere Practice Management, LLC
    • Colorado
      • Grand Junction, Colorado, United States, 81501
        • ICON Eye Care
    • Florida
      • Fort Myers, Florida, United States, 33901
        • Eye Associates of Fort Myers
      • Jacksonville, Florida, United States, 32204
        • Levenson Eye Associates
      • Tampa, Florida, United States, 33603
        • International Research Center
    • Georgia
      • Morrow, Georgia, United States, 30260
        • Clayton Eye Clinical Research, LLC
    • Kansas
      • Overland Park, Kansas, United States, 66210
        • Durrie Vision
    • Kentucky
      • Louisville, Kentucky, United States, 40206
        • Eye Care Institute/Butchertown Clinical Trials
    • Maine
      • Portland, Maine, United States, 04101
        • Maine Eye Center
    • Michigan
      • Fraser, Michigan, United States, 48026
        • Fraser Eye Care Center
    • Missouri
      • Kansas City, Missouri, United States, 64133
        • Silverstein Eye Centers
      • St Louis, Missouri, United States, 63131
        • Ophthalmology Associates
      • St Louis, Missouri, United States, 63128
        • Tekwani Vision Center
      • St Louis, Missouri, United States, 63131
        • Ophthalmology Consultantants, Ltd.
      • Washington, Missouri, United States, 63090
        • Comprehensive Eye Care, Ltd.
    • Montana
      • Bozeman, Montana, United States, 59718
        • Vance Thompson Vision-MT
    • Nebraska
      • Omaha, Nebraska, United States, 68137
        • Vance Thompson Vision- NE
    • Nevada
      • Las Vegas, Nevada, United States, 89119
        • Wellish Vision Institute
      • Las Vegas, Nevada, United States, 89145
        • Center for Sight
    • New York
      • New York, New York, United States, 10017
        • NYU Grossman School of Medicine
      • Poughkeepsie, New York, United States, 12603
        • Seeta Eye center
    • North Dakota
      • West Fargo, North Dakota, United States, 58078
        • Vance Thompson Vision ND
    • Ohio
      • Cincinnati, Ohio, United States, 45242
        • Cincinnati Eye Institute
      • Mason, Ohio, United States, 45040
        • Cincinnati Eye Institute
    • Pennsylvania
      • Kingston, Pennsylvania, United States, 18704
        • Eye Care Specialists
    • South Dakota
      • Sioux Falls, South Dakota, United States, 57108
        • Vance Thompson Vision
    • Texas
      • Austin, Texas, United States, 78751
        • Keystone Research
      • Cedar Park, Texas, United States, 78613
        • Hill Country Eye Center
      • El Paso, Texas, United States, 79902
        • Louis M. Alpern, M.D., M.P.H.,P.A.
      • Houston, Texas, United States, 77008
        • Houston Eye Associates
      • Lakeway, Texas, United States, 78738
        • Lake Travis Eye & Laser Center
      • Mission, Texas, United States, 78572
        • DCT-Shah Research, LLC dba Discovery Clinical Trials
      • San Antonio, Texas, United States, 78212
        • Terry Eye Associates

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

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).
  • Is planning to undergo cataract surgery in the study eye and has had cataract surgery at Visit 2.
  • Can understand the written informed consent, provides signed written informed consent, and agrees to comply with protocol requirements before any study-specific assessment is performed.
  • Meet all other inclusion criteria outlined in 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. has experienced menarche and is not surgically sterile, not post-menopausal (no menses for the previous 12 months), or not willing to practice an effective method of birth control during the study period as determined by the Investigator (eg, oral contraceptives, double barrier methods, hormonal injectable or implanted contraceptives, tubal ligation, or partner with vasectomy).
    3. has a positive urine pregnancy test result at Visit 2 before cataract surgery.
  • Had intraocular surgery (non-laser surgery) in the study eye within 6 months of Visit 1.
  • Had intraocular laser surgery in the study eye within 3 months 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
Intervention / Treatment
Experimental: Group A
Participants receive K-321 ophthalmic solution Four times daily(QID) for 12 Weeks followed by a 4 week follow-up period with no treatment.
Drug: Ripasudil
K-321 ophthalmic solution
Other Names:
  • K-321
Experimental: Group B
Participants receive K-321 ophthalmic solution Four times daily(QID) for 12 Weeks followed by a 14 week follow-up period with no treatment.
Drug: Ripasudil
K-321 ophthalmic solution
Other Names:
  • K-321
Placebo Comparator: Group C
Participants will receive K-321 Placebo ophthalmic solution QID for 12 Weeks followed by a 4 week follow-up period with no treatment.
Drug: Placebo
Placebo ophthalmic solution
Placebo Comparator: Group D
Participants will receive K-321 Placebo ophthalmic solution QID for 12 Weeks followed by a 14 week follow-up period with no treatment.
Drug: Placebo
Placebo ophthalmic solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in Central Corneal Endothelial Cell Density (ECD) at Week 12
Time Frame: Baseline to Week 12
Central corneal endothelial cell density (ECD) of the study eye, measured by specular microscopy, expressed as cells/mm².
Baseline to Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in Central Corneal ECD at Each Visit
Time Frame: Baseline to Week 26
Central corneal endothelial cell density (ECD) of the study eye, measured by specular microscopy, expressed as cells/mm².
Baseline to Week 26
Change From Baseline in Peripheral Corneal ECD (Nasal)
Time Frame: Baseline to Week 26
Peripheral corneal endothelial cell density (ECD) of the study eye, measured by specular microscopy, expressed as cells/mm².
Baseline to Week 26
Change From Baseline in Peripheral Corneal ECD (Temporal)
Time Frame: Baseline to Week 26
Corneal endothelial cell density (ECD) of the study eye, measured by specular microscopy, expressed as cells/mm².
Baseline to Week 26
Change From Baseline in Central Corneal Thickness
Time Frame: Baseline to Week 26
Corneal thickness measured by contact ultrasound pachymetry or optical pachymetry recorded in micrometers (μm)
Baseline to Week 26
Number of Subjects With No Evidence of Corneal Edema
Time Frame: Baseline to Week 26
Corneal edema of the study eye, evaluated by slit-lamp examination, recorded as present or absent, and categorized by anatomical location.
Baseline to Week 26
Change From Baseline in Best-Corrected Visual Acuity (BCVA)
Time Frame: Baseline to Week 26
Best-corrected visual acuity (BCVA) of the study eye, assessed using Early Treatment Diabetic Retinopathy Study (ETDRS) testing.
Baseline to Week 26
Change From Baseline in VFQ-25 (Overall)
Time Frame: Baseline to Week 26

Visual Function assessed using the National Eye Institute Visual Functioning Questionnaire-25 (VFQ-25), a patient-reported measure of vision-related functioning and quality of life.

Scores range from 0 to 100, with higher scores indicating better visual function and lower scores indicating worse visual function. The total composite score is derived from multiple subscales using the standard VFQ-25 scoring method.
Baseline to Week 26
Shifts in Slit-lamp Biomicroscopy (Bulbar Conjunctiva)
Time Frame: Baseline to Week 26

Shift in slit-lamp biomicroscopy findings of the study eye categorized as Normal, Abnormal - Not Clinically Significant (NCS), or Abnormal - Clinically Significant (CS), reflecting changes relative to baseline.

- Baseline to Post-Baseline Shift
Baseline to Week 26
Shifts in Slit-lamp Biomicroscopy (Cornea)
Time Frame: Baseline to Week 26

Shift in slit-lamp biomicroscopy findings of the study eye, categorized as Normal, Abnormal - Not Clinically Significant (NCS), or Abnormal - Clinically Significant (CS), reflecting changes relative to baseline.

Baseline to Post-Baseline Shift
Baseline to Week 26
Shifts in Dilated Fundoscopy (Central Retina)
Time Frame: Baseline to Week 26

Shift in dilated fundoscopy findings of the study eye, categorized as Normal, Abnormal - Not Clinically Significant (NCS), or Abnormal - Clinically Significant (CS), reflecting changes relative to baseline.

Baseline to Post-Baseline Shift
Baseline to Week 26
Change From Baseline in Intraocular Pressure (mmHg)
Time Frame: Baseline to Week 26
Intraocular pressure (IOP) of the study eye, measured using either a contact or non-contact tonometer, and recorded in millimeters of mercury (mm Hg).
Baseline to Week 26

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)

August 4, 2022

Primary Completion (Actual)

June 22, 2023

Study Completion (Actual)

June 22, 2023

Study Registration Dates

First Submitted

August 25, 2022

First Submitted That Met QC Criteria

August 30, 2022

First Posted (Actual)

September 6, 2022

Study Record Updates

Last Update Posted (Actual)

August 6, 2026

Last Update Submitted That Met QC Criteria

July 14, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • K-321-302

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.

Subscribe