Evaluation of Avatrombopag for the Treatment of Thrombocytopenia in Japanese Adults With Chronic ITP

May 15, 2026 updated by: Sobi, Inc.

An Open-label Study to Evaluate the Efficacy and Safety of Avatrombopag for the Treatment of Thrombocytopenia in Japanese Adults With Chronic Immune Thrombocytopenia

Evaluate the efficacy, safety, and PK of avatrombopag given for 26 weeks in Japanese adults with chronic immune thrombocytopenia (ITP).

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.

Detailed Description

This Phase 3, multicenter, open label study will evaluate the efficacy, safety, and population pharmacokinetics (PK) of avatrombopag in Japanese adults with chronic ITP. At least 19 subjects will be enrolled. The study will consist of 3 phases: Pre-enrollment, Primary Investigation, and Extension Phase until market authorization in Japan.

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.
19

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

  • Japan
    • Aichi-ken
      • Toyohashi, Aichi-ken, Japan, 441-8570
        • Sobi Site 105
    • Ehime
      • Tōon, Ehime, Japan, 791-0295
        • Sobi Site 110
    • Fukuoka
      • Iizuka-shi, Fukuoka, Japan, 820-8505
        • Sobi Site 118
      • Kitakyushu, Fukuoka, Japan, 802-8555
        • Sobi Site 116
      • Kurume, Fukuoka, Japan, 830-8543
        • Sobi Site 117
    • Gifu
      • Gifu, Gifu, Japan, 500-8513
        • Sobi Site 114
    • Hiroshima
      • Fukuyama-shi, Hiroshima, Japan, 720-2121
        • Sobi Site 115
      • Hiroshima, Hiroshima, Japan, 730-0052
        • Sobi Site 109
    • Hyōgo
      • Kobe, Hyōgo, Japan, 650-0047
        • Sobi Site 108
    • Ishikawa-ken
      • Kanazawa, Ishikawa-ken, Japan, 920-8650
        • Sobi Site 113
    • Iwata
      • Shiwa-gun, Iwata, Japan, 028-3695
        • Sobi Site 101
    • Kanagawa
      • Fujisawa, Kanagawa, Japan, 251-8550
        • Sobi Site 111
    • Kumamoto
      • Kumamoto, Kumamoto, Japan, 862-8655
        • Sobi Site 119
    • Osaka
      • Hirakata, Osaka, Japan, 573-1191
        • Sobi Site 107
      • Suita, Osaka, Japan, 565-0871
        • Sobi Site 106
    • Tokyo
      • Hachiōji-shi, Tokyo, Japan, 192-0032
        • Sobi Site 104
    • Toyko
      • Bunkyō City, Toyko, Japan, 113-8603
        • Sobi Site 103
    • Yamanashi
      • Chuo-shi, Yamanashi, Japan, 409-3898
        • Sobi Site 102
      • Kofu, Yamanashi, Japan, 400-8506
        • Sobi Site 112

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:

  • Subject has a confirmed diagnosis of chronic immune thrombocytopenia (ITP) (≥12 months duration) and has had an insufficient response to a previous ITP treatment, in the opinion of the Investigator.
  • Subject has an average of 2 platelet counts <30×10^9/L (no single count can be >35×10^9/L). The 2 samples must be obtained ≥48 hours and ≤2 weeks apart.

Exclusion Criteria:

  • Subjects with known secondary immune thrombocytopenia (e.g., with known Helicobacter pylori-induced ITP, subjects infected with known human immunodeficiency virus (HIV) or hepatitis C virus (HCV) or subjects with known systemic lupus erythematosus).
  • Subjects with known inherited thrombocytopenia (e.g., Myosin Heavy Chain 9 (MYH-9) disorders) or hereditary thrombophilic disorders (e.g., Factor V Leiden, antithrombin III deficiency).
  • History of myelodysplastic syndrome (MDS).
  • History of arterial or venous thrombosis.
  • Subjects with a history of significant cardiovascular disease (e.g., congestive heart failure (CHF) New York Heart Association Grade III/IV, arrhythmia known to increase the risk of thromboembolic events [e.g., atrial fibrillation], angina, coronary artery stent placement, angioplasty, coronary artery bypass grafting).
  • Subjects with a history of cirrhosis, portal hypertension, or chronic active hepatitis.
  • Subjects with concurrent malignant disease or receiving cytotoxic chemotherapy for a reason other than ITP treatment.
  • Use of immunoglobulins (IVIg and anti-D) or corticosteroid rescue therapy within 1 week of Day 1/Baseline.
  • Splenectomy or use of rituximab within 12 weeks of Day 1/Baseline.
  • Use of romiplostim or eltrombopag within 1 week of Day 1/Baseline.
  • Use of chronic corticosteroid treatment or azathioprine within 4 weeks of Day 1/Baseline, unless receiving a stable dose for at least 4 weeks.
  • Use of mycophenolate mofetil, cyclosporin A, or danazol within 4 weeks of Day 1/Baseline, unless receiving a stable dose for at least 12 weeks.
  • Use of cyclophosphamide or vinca alkaloid regimens within 4 weeks of Baseline Visit.
  • Currently receiving moderate or strong dual inhibitors/inducers of CYP2C9 and CYP3A4.
  • Serum creatinine ≥1.5× the upper limit of normal (ULN).
  • Serum bilirubin ≥2×ULN.
  • Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥3×ULN.
  • Females who are pregnant (positive beta-human chorionic gonadotropin (β-hCG) test) or breastfeeding.
  • Received treatment with an investigational drug within 30 days or 5 half-lives (whichever is longer) before Day 1/Baseline.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

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.
Other: Avatrombopag
Avatrombopag 20 mg oral tablet
Drug: Avatrombopag Oral Tablet
Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10^9 to 200 x 10^9 as defined in the protocol and in accordance with overseas labeling.
Other Names:
  • Doptelet

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
Cumulative Number of Weeks of Platelet Response
Time Frame: 26 weeks of active treatment
Cumulative number of weeks in which the platelet count is ≥50×10^9/L during 26 weeks of treatment in the absence of rescue therapy.
26 weeks of active treatment

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
Response Rate at Day 8
Time Frame: Day 8
Proportion of subjects with a platelet response ≥50×10^9/L at Day 8 in the absence of rescue therapy
Day 8

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.
Sobi, Inc.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
June 15, 2022

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.
January 17, 2024

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.
October 29, 2025

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).
April 21, 2022

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.
May 5, 2022

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.
May 11, 2022

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.
June 3, 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 15, 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

Keywords

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.
  • AVA-ITP-307

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

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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