A Clinical Study in Patients With Chronic Idiopathic Thrombocytopenic Purpura in R788

August 4, 2025 updated by: Kissei Pharmaceutical Co., Ltd.

A Phase III Study in Patients With Chronic Idiopathic Thrombocytopenic Purpura in R788

The purpose of this study is to investigate the efficacy, safety and pharmacokinetics of R788 compared with placebo, and to investigate the safety and efficacy of long term dosing of R788 in patients with chronic idiopathic thrombocytopenic purpura.

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.
34

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 Locations

  • Japan
      • Multiple Locations, Japan
        • Research Site

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

20 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Japanese patients
  • Patients diagnosed with idiopathic thrombocytopenic purpura at least 6 months before acquisition of consent
  • Patients with a platelet count averages <30000/μL during screening period. Each platelet count should not exceed 35000/μL.
  • Patients who have used and failed or who were intolerant at least 1 typical regimen for the treatment of ITP before informed consent (with or without splenectomy)

Exclusion Criteria:

  • Patients with thrombocytopenia associated with other disease
  • Patients with autoimmune hemolytic anemia
  • Patients with poorly controlled hypertension
  • Patients with a history or active coagulopathy

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: Double

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: R788
Patients are administered R788 for 24 weeks (double-blind period), followed by R788 for up to 52 weeks (open-label period). Patients who have completed open-label period and meet the criteria are eligible to continue R788 treatment over a 3 year period (extension - period).
Drug: R788
Oral administration
Placebo Comparator: Placebo
Patients are administered Placebo for 24 weeks (double-blind period), followed by R788 for up to 28 weeks (open-label period). Patients who have completed open-label period and meet the criteria are eligible to continue R788 treatment over a 3 year period (extension - period).
Drug: Placebo
Oral administration
Drug: R788
Oral administration

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
Measure Description
Time Frame
Achievement Rate of Stable Platelet Response
Time Frame: 24 weeks (Period I)
The percentage of subjects who achieved stable platelet response (defined as a platelet count of ≥50000/μL at 4 or more of the 6 visits from Weeks 14 to 24)
24 weeks (Period I)

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
Percentage of patients with overall response
Time Frame: 12 weeks
Percentage of patients with a platelet count ≥50000/μL on at least 1 of 6 visits from Week 2 to Week 12
12 weeks
Duration of maintained platelet count
Time Frame: 52 weeks
Duration of maintained platelet count since first achievement of a platelet count ≥50000/μL after administration of the study drug
52 weeks
Percentage of patients with a platelet count ≥50000/μL
Time Frame: Every 2 weeks up to Week 24, every 4 weeks up to Week 52 and every 8 weeks up to 3 years
Percentage of patients with a platelet count ≥50000/μL at the specified evaluation time point
Every 2 weeks up to Week 24, every 4 weeks up to Week 52 and every 8 weeks up to 3 years
Percentage of patients with a platelet count increase ≥20000/μL above baseline and ≥30000/μL
Time Frame: Every 2 weeks up to Week 24, every 4 weeks up to Week 52 and every 8 weeks up to 3 years
Percentage of patients with a platelet count increase ≥20000/μL above baseline and ≥30000/μL at the specified evaluation time point
Every 2 weeks up to Week 24, every 4 weeks up to Week 52 and every 8 weeks up to 3 years

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Duration of Platelet Response
Time Frame: R788 treatment period (maximum duration of exposure was 1184 days)
Period from the first measurement day on which a platelet count of ≥50000/μL for at least 28 consecutive days was achieved to the first measurement day on which platelet count fell below 50000/μL for at least 28 consecutive days
R788 treatment period (maximum duration of exposure was 1184 days)

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.
Kissei Pharmaceutical Co., Ltd.

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 Director: Yoshitaka Shimizu, Kissei Pharmaceutical Co., Ltd.

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.
December 24, 2019

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.
December 21, 2021

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.
September 25, 2023

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).
October 15, 2019

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.
October 16, 2019

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.
October 18, 2019

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.
August 11, 2025

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.
August 4, 2025

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.
December 1, 2023

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.
  • R788-1301

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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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