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

NCT04132050 | Completed Phase 3 Results

• 1 other identifier: R788-1301
• Study Type: interventional
• Target: 34
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Idiopathic Thrombocytopenic Purpura

Outcome Measures

Primary Outcomes (1)

• Achievement Rate of Stable Platelet Response

  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)

Other Outcomes (1)

• Duration of Platelet Response

  R788 treatment period (maximum duration of exposure was 1184 days)

Study Arms (2)

R788

EXPERIMENTAL

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

Placebo

PLACEBO COMPARATOR

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: R788; Drug: Placebo

Interventions

R788 DRUG

Oral administration

Placebo; R788

Placebo DRUG

Oral administration

Placebo

Eligibility Criteria

• Age: 20 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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)

You may not qualify if:

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

Sponsors & Collaborators

• Kissei Pharmaceutical Co., Ltd.: lead

Study Sites (1)

Research Site

Multiple Locations, Japan

Location

MeSH Terms

Conditions

Purpura, Thrombocytopenic, Idiopathic

Interventions

fostamatinib

Condition Hierarchy (Ancestors)

Purpura, Thrombocytopenic; Purpura; Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Thrombotic Microangiopathies; Thrombocytopenia; Blood Platelet Disorders; Cytopenia; Hemorrhagic Disorders; Autoimmune Diseases; Immune System Diseases; Hemorrhage; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Skin Manifestations; Signs and Symptoms

Results Point of Contact

• Title: Clinical Development Division
• Organization: Kissei Pharmaceutical Co., Ltd.

rinsyousiken@pharm.kissei.co.jp

Email olly

Study Officials

• Yoshitaka Shimizu

  Kissei Pharmaceutical Co., Ltd.

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 15, 2019
• First Posted: October 18, 2019
• Study Start: December 24, 2019
• Primary Completion: December 21, 2021
• Study Completion: September 25, 2023
• Last Updated: August 11, 2025
• Results First Posted: August 11, 2025

Record last verified: 2023-12

Locations

JP (1)