Avatrombopag for the Treatment of Thrombocytopenia in Pediatric Subjects With Immune Thrombocytopenia for ≥6 Months

April 2, 2026 updated by: Sobi, Inc.

Randomized, Double-blind, Placebo-controlled Study With Open-label Extension Phase to Evaluate the Efficacy and Safety of Avatrombopag for the Treatment of Thrombocytopenia in Pediatric Subjects With Immune Thrombocytopenia for ≥6 Months

A Phase 3b Study to Evaluate the Efficacy and Safety of Avatrombopag for the Treatment of Thrombocytopenia in Pediatric Subjects with Immune Thrombocytopenia for ≥6 Months

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Subjects will be randomized in to blinded therapy of avatrombopag or placebo in a 3:1 ratio for a period of 12 weeks. Subjects who complete the 12 week treatment period and are eligible may continue to the open label extension phase which will last 2 years.

Study Type

Interventional

Enrollment (Actual)

75

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

  • France
    • Occitanie
      • Toulouse, Occitanie, France, 31059
        • Site 201
    • Île-de-France Region
      • Paris, Île-de-France Region, France, 75019
        • Site 202
  • Germany
    • Baden-Wurttemberg
      • Freiburg im Breisgau, Baden-Wurttemberg, Germany, 79106
        • Site 301
    • Free and Hanseatic City of Hamburg
      • Hamburg, Free and Hanseatic City of Hamburg, Germany, 20246
        • Site 302
    • Schleswig-Holstein
      • Kiel, Schleswig-Holstein, Germany, 24105
        • Site 303
    • State of Berlin
      • Berlin, State of Berlin, Germany, 13353
        • Site 304
  • Hungary
      • Budapest, Hungary, 1094
        • Site 801
      • Miskolc, Hungary, 3526
        • Site 802
      • Pécs, Hungary, 7623
        • Site 803
  • Poland
    • Kuyavian-Pomeranian Voivodeship
      • Bydgoszcz, Kuyavian-Pomeranian Voivodeship, Poland, 85-667
        • Site 502
    • Masovian Voivodeship
      • Warsaw, Masovian Voivodeship, Poland, 02-091
        • Site 503
    • Silesian Voivodeship
      • Zabrze, Silesian Voivodeship, Poland, 41-800
        • Site 505
    • Warmian-Masurian Voivodeship
      • Olsztyn, Warmian-Masurian Voivodeship, Poland, 10-561
        • Site 501
    • Łódź Voivodeship
      • Lodz, Łódź Voivodeship, Poland, 91-738
        • Site 504
  • Russia
      • Chelyabinsk, Russia, 454076
        • Site 907
      • Moscow, Russia, 117198
        • Site 904
      • Moscow, Russia, 117997
        • Site 906
      • Moscow, Russia, 119049
        • Site 901
      • Nizhny Novgorod, Russia, 603136
        • Site 902
      • Saint Petersburg, Russia, 197022
        • Site 905
      • Volgograd, Russia, 400138
        • Site 903
  • Turkey (Türkiye)
      • Adana, Turkey (Türkiye), 01330
        • Site 701
      • Ankara, Turkey (Türkiye), 06230
        • Site 704
      • Antalya, Turkey (Türkiye), 07059
        • Site 706
      • Antalya, Turkey (Türkiye), 07160
        • Site 702
      • Denizli, Turkey (Türkiye), 20160
        • Site 705
      • Istanbul, Turkey (Türkiye), 34093
        • Site 709
      • Istanbul, Turkey (Türkiye), 34093
        • Site 710
      • Istanbul, Turkey (Türkiye), 34764
        • Site 703
      • Izmir, Turkey (Türkiye), 35100
        • Site 707
      • Mersin, Turkey (Türkiye), 33110
        • Site 708
  • Ukraine
      • Vinnytsia, Ukraine, 21029
        • Site 952
    • Kharkivs’ka Oblast’
      • Kharkiv, Kharkivs’ka Oblast’, Ukraine, 61000
        • Site 954
  • United Kingdom
    • England
      • Birmingham, England, United Kingdom, B4 6NH
        • Site 405
      • Liverpool, England, United Kingdom, L12 2AP
        • Site 408
      • London, England, United Kingdom, SE5 9RS
        • Site 403
      • London, England, United Kingdom, W12 0HS
        • Site 410
      • London, England, United Kingdom, WC1N 3JH
        • Site 407
      • Manchester, England, United Kingdom, M13 9WL
        • Site 402
      • Sheffield, England, United Kingdom, S10 2TH
        • Site 401
    • Wales
      • Cardiff, Wales, United Kingdom, CF14 4XW
        • Site 406
  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85016
        • Site 112
    • California
      • Long Beach, California, United States, 90806
        • Site 103
      • Orange, California, United States, 92868
        • Site 119
      • Sacramento, California, United States, 95817
        • Site 109
      • San Francisco, California, United States, 94158
        • Site 101
    • Colorado
      • Aurora, Colorado, United States, 80045
        • Site 111
    • Delaware
      • Wilmington, Delaware, United States, 19803
        • Site 120
    • Florida
      • Gainesville, Florida, United States, 32610
        • Site 117
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • Site 116
    • Illinois
      • Peoria, Illinois, United States, 61615
        • Site 107
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Site 104
    • Minnesota
      • Minneapolis, Minnesota, United States, 55404
        • Site 105
    • Mississippi
      • Jackson, Mississippi, United States, 39216
        • Site 114
    • Nevada
      • Las Vegas, Nevada, United States, 89135
        • Site 102
    • New Jersey
      • Morristown, New Jersey, United States, 07960
        • Site 108
    • North Carolina
      • Charlotte, North Carolina, United States, 28203
        • Site 118
      • Durham, North Carolina, United States, 27710
        • Site 113
    • Ohio
      • Columbus, Ohio, United States, 43205
        • Site 106
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Site 121
    • Rhode Island
      • Providence, Rhode Island, United States, 02903
        • Site 110
    • Texas
      • Houston, Texas, United States, 77030
        • Site 115

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

1 year to 17 years (Child)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male or female participants ≥1 and <18 years of age at Screening and Baseline with a diagnosis of primary ITP for ≥6 months duration and has had an insufficient response to a previous treatment, in the opinion of the Investigator.
  • Participant has an average of 2 platelet counts <30×10^9/L with no single count >35×10^9/L in the screening period

Exclusion Criteria:

  • Participants must not have a known history of secondary ITP, any history of arterial or venous thrombosis, including partial or complete thrombosis, known inherited thrombocytopenia, a history of myelodysplastic syndrome (MDS) or known history of congenital heart abnormalities or arrhythmias.

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
Intervention / Treatment
Experimental: Experimental: Avatrombopag Double Blind
Study is 3:1 randomization ratio (avatrombopag to placebo). Investigational product administered orally once daily for 12 weeks
Drug: Avatrombopag
Oral avatrombopag tablet or sprinkle capsule
Other Names:
  • Doptelet
Placebo Comparator: Placebo Comparator:Placebo Double Blind
Study is 3:1 randomization ratio (avatrombopag to placebo). Investigational product administered orally once daily for 12 weeks
Drug: Placebo
Placebo comparator tablet or sprinkle capsule
Experimental: Avatrombopag Open Label Extension
Investigational product administered orally for up to 2 years.
Drug: Avatrombopag
Oral avatrombopag tablet or sprinkle capsule
Other Names:
  • Doptelet

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Durable Platelet Response
Time Frame: Last 8 weeks of 12 week treatment regimen
The proportion of subjects achieving at least 6 out of 8 weekly platelet counts ≥50×10^9/L during the last 8 weeks of the 12 week Treatment Period in the Core Phase, in the absence of rescue medication
Last 8 weeks of 12 week treatment regimen
Alternative Primary: Platelet Response
Time Frame: 12 weeks of treatment
The proportion of subjects for whom at least 2 consecutive platelet assessments are ≥50×10^9/L over the 12 weeks of treatment in the Core Phase in the absence of rescue medication.
12 weeks of treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of Weeks Platelet Count ≥50×10^9/L
Time Frame: 12 weeks of treatment
The percentage of weeks subjects have a platelet count ≥50×10^9/L during 12 weeks of treatment in the Core Phase, in the absence of rescue therapy.
12 weeks of treatment
Platelet Response at Day 8
Time Frame: Day 8
The proportion of subjects with a platelet count ≥50×10^9/L at day 8, in the absence of rescue therapy.
Day 8
Percentage of Weeks Platelet Count Between ≥50×10^9/L and ≤150×10^9/L
Time Frame: 12 weeks of treatment
The percentage of weeks subjects have a platelet count between ≥50×10^9/L and ≤150×10^9/L, during 12 weeks of treatment in the Core Phase, in the absence of rescue therapy.
12 weeks of treatment
Rescue Medications
Time Frame: 12 weeks of treatment
The proportion of subjects who require rescue medications during 12 weeks of treatment in the Core Phase of the study.
12 weeks of treatment
Incidence of Any Bleeding Event (WHO Grade 1-4)
Time Frame: 12 weeks of treatment
Overall incidence of bleeding events associated with ITP measured using the WHO Bleeding Scale (Grade 1-4).
12 weeks of treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

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)

March 5, 2021

Primary Completion (Actual)

November 8, 2023

Study Completion (Actual)

October 28, 2025

Study Registration Dates

First Submitted

August 14, 2020

First Submitted That Met QC Criteria

August 14, 2020

First Posted (Actual)

August 18, 2020

Study Record Updates

Last Update Posted (Actual)

April 22, 2026

Last Update Submitted That Met QC Criteria

April 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AVA-PED-301

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

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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