A Follow-up Study of Mezagitamab in Adults With Chronic Primary Immune Thrombocytopenia

August 12, 2026 updated by: Takeda

A Phase 3, Open-label, Multicenter Continuation Trial to Evaluate the Long-term Safety and Efficacy of Mezagitamab Subcutaneous Injection in Adults With Chronic Primary Immune Thrombocytopenia

Primary immune thrombocytopenia (ITP) is a condition where the immune system mistakenly destroys platelets, which are cells that help stop bleeding. This leads to a lower number of platelets, making it easier to bruise or bleed. The main aim of this study is to check how safe mezagitamab is and how well it is tolerated by adults with chronic primary ITP, if given over a longer time. Other aims are to learn how effective treatment with mezagitamab is and how the body processes it (called pharmacokinetics or PK) over a longer time.

Participants of the following previous mezagitamab studies will be invited to join this continuation study: TAK-079-3002 and TAK-079-1004. In this continuation study, participants will receive mezagitamab when certain protocol criteria are met.

During the study, participants will visit their study clinic several times.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

150

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 Contact

Study Locations

  • Australia
    • Australian Capital Territory
      • Garran, Australian Capital Territory, Australia, 2605
        • Recruiting
        • Canberra Hospital
        • Principal Investigator:
          • Philip Choi
        • Contact:
    • New South Wales
      • Concord, New South Wales, Australia, 2139
        • Not yet recruiting
        • Concord Repatriation General Hospital
        • Principal Investigator:
          • Vivien Chen
        • Contact:
      • Kogarah, New South Wales, Australia, 2217
        • Recruiting
        • St George Hospital
        • Contact:
        • Principal Investigator:
          • Amanda Hugman
      • Liverpool, New South Wales, Australia, 2170
        • Recruiting
        • University of New South Wales (UNSW) - Liverpool Hospital - Liverpool Cancer Therapy Centre
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Danny Hsu
      • Westmead, New South Wales, Australia, 2145
    • Victoria
      • Melbourne, Victoria, Australia, 3000
        • Not yet recruiting
        • Peter MacCallum Cancer Centre
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Isaac Goncalves
      • Melbourne, Victoria, Australia, 3005
        • Recruiting
        • The Alfred Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Huyen Tran
      • Melbourne, Victoria, Australia, 3004
        • Recruiting
        • Monash University - Australian Centre for Blood Diseases (ACBD)
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Zane Kaplan
    • Western Australia
      • Murdoch, Western Australia, Australia, 6150
        • Not yet recruiting
        • Fiona Stanley Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Dominic Pepperell
      • West Perth, Western Australia, Australia, 6005
        • Recruiting
        • Perth Blood Institute
        • Principal Investigator:
          • Ross Baker
        • Contact:
  • Bulgaria
      • Plovdiv, Bulgaria, 4002
        • Recruiting
        • Medical Center "Fama Medical"
        • Contact:
        • Principal Investigator:
          • Katya Sapunarova
      • Sofia, Bulgaria, 1431
        • Recruiting
        • UMHAT Sv. Ivan Rilski
        • Principal Investigator:
          • Atanas Radinoff
        • Contact:
          • Site Contact
      • Sofia, Bulgaria, 1750
        • Recruiting
        • UMHAT SofiaMed, OOD
        • Principal Investigator:
          • Tzvetan Alaykov
        • Contact:
      • Stara Zagora, Bulgaria, 6003
        • Not yet recruiting
        • University Multiprofile Hospital for Active Treatment - Prof. Dr. Stoyan Kirkovich AD
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Mariya Todorova
    • Sofia-Grad
      • Sofia, Sofia-Grad, Bulgaria, 1606
        • Recruiting
        • Military Medical Academy Multiprofile Hospital for Active Treatment - Sofia
        • Principal Investigator:
          • Viktoria Barbukova
        • Contact:
  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100730
        • Recruiting
        • Peking Union Medical College Hospital
        • Principal Investigator:
          • Tienan Zhu
        • Contact:
    • Guangdong
      • Guangzhou, Guangdong, China, 510080
        • Not yet recruiting
        • Guangdong Provincial People's Hospital
        • Principal Investigator:
          • Chengwei Luo
        • Contact:
    • Guangxi
      • Nanning, Guangxi, China, 530021
        • Recruiting
        • The First Affiliated Hospital of Guangxi Medical University
        • Principal Investigator:
          • Peng Cheng
        • Contact:
    • Hebei
      • Shijiazhuang, Hebei, China, 050031
        • Recruiting
        • The First Hospital of Hebei Medical University
        • Principal Investigator:
          • Qingchi Liu
        • Contact:
      • Wuhan, Hebei, China, 430022
        • Recruiting
        • Union Hospital Tongji Medical College Huazhong University of Science and Technology
        • Principal Investigator:
          • Yu Hu
        • Contact:
    • Henan
      • Zhengzhou, Henan, China, 450004
        • Recruiting
        • Henan Cancer Hospital
        • Principal Investigator:
          • Hu Zhou
        • Contact:
    • Jiangsu
      • Suzhou, Jiangsu, China, 215006
        • Not yet recruiting
        • The First Affiliated Hospital of Soochow University - Shizijie Campus
        • Principal Investigator:
          • Jie Yin
        • Contact:
    • Jiangxi
      • Nanchang, Jiangxi, China, 330006
        • Recruiting
        • The First Affiliated Hospital of Nanchang University - Donghu Campus
        • Principal Investigator:
          • Ruibin Huang
        • Contact:
    • Liaoning
      • Shenyang, Liaoning, China, 110004
        • Not yet recruiting
        • Shengjing Hospital of China Medical University - Nanhu Campus
        • Principal Investigator:
          • Aijun Liao
        • Contact:
          • Site Contact
          • Phone Number: +8618940259833
    • Shaanxi
      • Xi'an, Shaanxi, China, 710068
        • Not yet recruiting
        • Shaanxi Provincial People's Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Yi Wang
    • Shandong
      • Jinan, Shandong, China, 250012
        • Recruiting
        • Qilu Hospital of Shandong University
        • Principal Investigator:
          • Ming Hou
        • Contact:
    • Shanghai Municipality
      • Shanghai, Shanghai Municipality, China, 201508
        • Recruiting
        • Jinshan Hospital of Fudan University
        • Principal Investigator:
          • Yunfeng Cheng
        • Contact:
    • Sichuan
      • Chengdu, Sichuan, China, 610041
        • Recruiting
        • West China Hospital Sichuan University
        • Principal Investigator:
          • Yuping Gong
        • Contact:
    • Tianjin Municipality
      • Tianjin, Tianjin Municipality, China, 300020
        • Recruiting
        • Institute of Hematology and Blood Diseases Hospital Chinese Academy of Medical Sciences - PPDS
        • Principal Investigator:
          • Yunfei Chen
        • Contact:
    • Yunnan
      • Kunming, Yunnan, China, 650101
        • Recruiting
        • The Second Affiliated Hospital of Kunming Medical University
        • Principal Investigator:
          • Zeping Zhou
        • Contact:
    • Zhejiang
      • Hangzhou, Zhejiang, China, 310006
        • Not yet recruiting
        • Zhejiang Provincial Hospital of Chinese Medicine - Main
        • Principal Investigator:
          • Baodong Ye
        • Contact:
  • Croatia
      • Zagreb, Croatia, 10000
        • Not yet recruiting
        • Clinical Hospital Centar Zagreb
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Drazen Pulanic
  • Greece
      • Pátrai, Greece, 264 43
        • Not yet recruiting
        • Olympion General Clinic & Rehabilitation Center
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Argiris Symeonidis
      • Thessaloniki, Greece
        • Recruiting
        • General Hospital of Thessaloniki George Papanikolaou
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Antonia Syrigou
  • Hong Kong
    • Pok Fu Lam
      • Hong Kong, Pok Fu Lam, Hong Kong
        • Recruiting
        • Queen Mary Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Yok Lam Kwong
  • Italy
      • Bologna, Italy, 40123
        • Not yet recruiting
        • Azienda Ospedaliera Universitaria Policlinico Sant'Orsola Malpighi
        • Principal Investigator:
          • FRANCESCA PALANDRI
        • Contact:
          • Site Contact
      • Milan, Italy, 20162
        • Not yet recruiting
        • ASST Grande Ospedale Metropolitano Niguarda - Presidio Ospedaliero Ospedale Niguarda
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Monica Carpenedo
      • Monza, Italy, 20900
        • Not yet recruiting
        • Fondazione IRCCS San Gerardo dei Tintori
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Filippo Achille Brioschi
      • Novara, Italy, 28100
        • Recruiting
        • A.O.U. Maggiore della Carità
        • Principal Investigator:
          • Andrea Patriarca
        • Contact:
      • Rome, Italy, oo133
        • Not yet recruiting
        • Azienda Ospedaliera Universitaria Policlinico Tor Vergata
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Francesco Buccisano
      • Torino, Italy, 10126
        • Not yet recruiting
        • AOU Città della Salute e della Scienza di Torino
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Alessandra Borchiellini
      • Trieste, Italy, 34129
        • Recruiting
        • Azienda Sanitaria Universitaria Giuliano Isontina
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Elisa Lucchini
      • Vicenza, Italy, 36100
        • Recruiting
        • Azienda ULSS 8 Berica - Ospedale San Bortolo
        • Principal Investigator:
          • Giuseppe Carli
        • Contact:
    • Campania
      • Naples, Campania, Italy, 80131
        • Not yet recruiting
        • Azienda Ospedaliera Universitaria Federico II
        • Principal Investigator:
          • Fabrizio Pane
        • Contact:
    • Lazio
      • Rome, Lazio, Italy, oo610
        • Not yet recruiting
        • Universita Degli Studi Di Roma La Sapienza - Umberto I Policlinico Di Roma
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Cristina Santoro
    • Sicily
      • Catania, Sicily, Italy, 95122
        • Not yet recruiting
        • Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi
        • Principal Investigator:
          • Ugo Consoli
        • Contact:
  • Japan
      • Ibaraki, Japan, 311-3193
        • Not yet recruiting
        • National Hospital Organization Mito Medical Center
        • Principal Investigator:
          • Chikashi Yoshida
        • Contact:
    • Chiba
      • Chuo-ku, Chiba, Japan, 260-0852
        • Not yet recruiting
        • Chiba Aoba Municipal Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Yokota Akira
      • Narashino-shi, Chiba, Japan, 275-8580
        • Not yet recruiting
        • Chibaken Saiseikai Narashino Hospital
        • Principal Investigator:
          • Ryuko Cho
        • Contact:
    • Kanagawa
      • Yokohama, Kanagawa, Japan, 232-0024
        • Not yet recruiting
        • Yokohama City University Medical Center
        • Principal Investigator:
          • Takuya Miyazaki
        • Contact:
    • Miyagi
      • Sendai, Miyagi, Japan, 980-8574
        • Recruiting
        • Tohoku University Hospital
        • Principal Investigator:
          • Noriko Fukuhara
        • Contact:
          • Site Contact
    • Osaka
      • Hirakata-shi, Osaka, Japan, 573-1191
        • Recruiting
        • Kansai Medical University Hospital
        • Principal Investigator:
          • Tomoki Ito
        • Contact:
      • Osaka, Osaka, Japan, 542-0081
        • Recruiting
        • Hematology Ohta Clinic,Shinsaibashi
        • Principal Investigator:
          • Kensuke Ohta
        • Contact:
          • Site Contact
          • Phone Number: 81 6-6245-2117
      • Suita-shi, Osaka, Japan, 565-0871
        • Recruiting
        • Osaka University Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Kato Hisashi
    • Saitama
      • Iruma-gun, Saitama, Japan, 350-0495
        • Recruiting
        • Saitama Medical University Hospital
        • Principal Investigator:
          • Yoshitaka Miyakawa
        • Contact:
          • Site Contact
    • Tokyo
      • Bunkyo-ku, Tokyo, Japan, 113-8655
        • Recruiting
        • The University of Tokyo Hospital
        • Principal Investigator:
          • Mineo Kurokawa
        • Contact:
      • Itabashi-ku, Tokyo, Japan, 173-8610
        • Recruiting
        • Nihon University Itabashi Hospital
        • Contact:
        • Principal Investigator:
          • Otake Shimon
      • Sumida-ku, Tokyo, Japan, 130-0022
        • Recruiting
        • Tokyo Metropolitan Bokutoh Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Kosugi Nobuharu
    • Yamanashi
      • Kofu, Yamanashi, Japan, 400-8506
        • Recruiting
        • Yamanashi Prefectural Central Hospital
        • Principal Investigator:
          • Masaki Iino
        • Contact:
          • Site Contact
          • Phone Number: 055-253-7111
  • Netherlands
    • South Holland
      • Rotterdam, South Holland, Netherlands, 3015 GD
        • Not yet recruiting
        • Erasmus Medical Center, Department of Hematology
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Arend Jan Gerard Jansen
      • The Hague, South Holland, Netherlands, 2545AA
        • Not yet recruiting
        • Hagaziekenhuis
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Tanja Netelenbos
  • Poland
    • Kuyavian-Pomeranian Voivodeship
      • Bydgoszcz, Kuyavian-Pomeranian Voivodeship, Poland, 85-048
        • Withdrawn
        • In-Vivo Sp. z o.o.
    • Masovian Voivodeship
      • Warsaw, Masovian Voivodeship, Poland, 02-776
        • Not yet recruiting
        • Instytut Hematologii i Transfuzjologii Klinika Zaburzen Hemostazy i Chorob Wewnetrznych
        • Principal Investigator:
          • Jerzy Windyga
        • Contact:
          • Site Contact
    • Silesian Voivodeship
      • Katowice, Silesian Voivodeship, Poland, 40-523
        • Not yet recruiting
        • Pratia Onkologia Katowice - PRATIA
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Sebastian Grosicki
    • Łódź Voivodeship
      • Lodz, Łódź Voivodeship, Poland, 93-513
        • Not yet recruiting
        • N. Copernicus Provincial MCOT in Lodz
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Jacek Trelinski
  • South Korea
      • Daegu, South Korea, 41944
        • Not yet recruiting
        • Kyungpook National University Hospital
        • Principal Investigator:
          • Sang-Kyun Sohn
        • Contact:
          • Site Contact
      • Seoul, South Korea, 03722
        • Recruiting
        • Severance Hospital, Yonsei University Health System
        • Contact:
          • Site Contact
        • Principal Investigator:
          • June-Won Cheong
      • Seoul, South Korea, 06351
        • Recruiting
        • Samsung Medical Center
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Jun Ho Jang
      • Seoul, South Korea, 5505
        • Not yet recruiting
        • Asan Medical Center
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Je-Hwan Lee
      • Seoul, South Korea, 2841
        • Recruiting
        • Korea University Anam Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Yong Park
      • Seoul, South Korea, 03080
        • Not yet recruiting
        • Seoul National University Hospital (SNUH)
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Youngil Koh
    • Gyeonggi-do
      • Seongnam-si, Gyeonggi-do, South Korea, 13620
        • Recruiting
        • Seoul National University Bundang Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Soo-Mee Bang
  • Spain
      • Burgos, Spain, 9006
        • Not yet recruiting
        • C.A.U de Burgos - Hospital Universitario de Burgos
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Tomas Jose Gonzalez-Lopez
      • Salamanca, Spain, 37007
        • Not yet recruiting
        • Hospital Universitario De Salaman
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Jose Ramon Gonzalez-Porras
      • Seville, Spain, 41013
        • Recruiting
        • Hospital Universitario Virgen del Rocio
        • Principal Investigator:
          • Maria Eva Mingot Castellano
        • Contact:
    • Mardrid
      • Alcorcón, Mardrid, Spain, 28922
        • Not yet recruiting
        • Hospital Universitario Fundación Alcorcón
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Francisco Javier Penalver Parraga
      • Madrid, Mardrid, Spain, 28007
        • Not yet recruiting
        • Hospital General Universitario Gregorio Marañón
        • Principal Investigator:
          • Cristina Pascual Izquierdo
        • Contact:
      • Madrid, Mardrid, Spain, 28041
        • Not yet recruiting
        • Hospital Universitario 12 de Octubre
        • Principal Investigator:
          • Denis Zafra Torres
        • Contact:
  • Turkey (Türkiye)
      • Edirne, Turkey (Türkiye), 22030
        • Not yet recruiting
        • Trakya Universitesi Tip Fakultesi Hastanesi
        • Contact:
        • Principal Investigator:
          • Ahmet Muzaffer Demir
      • Edirne, Turkey (Türkiye), 22030
        • Not yet recruiting
        • Cerrahpasa Tip Fakultesi
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Cem Ar Muhlis
      • Sakarya, Turkey (Türkiye), 54290
        • Not yet recruiting
        • Sakarya University Education and Research Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Tuba Hacibekiroglu
    • Ankara
      • Mamak, Ankara, Turkey (Türkiye), 6620
        • Not yet recruiting
        • Ankara University Faculty of Medicine Cebeci Hospital, Department of Hematology
        • Principal Investigator:
          • Selami Toprak
        • Contact:
    • Aydın
      • Efeler, Aydın, Turkey (Türkiye), 9100
        • Not yet recruiting
        • Aydin Adnan Menderes University Medical Faculty-Hematology Department
        • Principal Investigator:
          • Irfan Yavasoglu
        • Contact:
  • United Kingdom
      • London, United Kingdom, NW1 2PG
        • Not yet recruiting
        • University College London Hospitals
        • Principal Investigator:
          • Marie Ann Scully
        • Contact:
      • London, United Kingdom, W12 0HS
        • Recruiting
        • Imperial College Healthcare NHS Trust
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Nicola Cooper
      • London, United Kingdom, E11BB
        • Recruiting
        • Barts Health NHS Trust, Royal London Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Chen Frederick
    • East Midlands
      • Leicester, East Midlands, United Kingdom, LE1 5WW
        • Recruiting
        • University Hospitals of Leicester NHS Trust
        • Principal Investigator:
          • Mamta Garg
        • Contact:
    • Hampshire
      • Southampton, Hampshire, United Kingdom, SO16 6YD
    • London
      • Southwark, London, United Kingdom, DE1 9RT
        • Not yet recruiting
        • Guy's Hospital - Guy's & St. Thomas NHS Foundation Trust
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Vickie McDonald
    • Merseyside
      • Liverpool, Merseyside, United Kingdom, L7 8XP
        • Not yet recruiting
        • Royal Liverpool and Broadgreen University Hospitals NHS Trust
        • Contact:
          • Site Contact
        • Principal Investigator:
          • David Simcox
    • Scotland
      • Glasgow, Scotland, United Kingdom, G312ER
        • Not yet recruiting
        • Greater Glasgow Health Board
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Bagot Catherine
    • Staffordshire
      • Stoke-on-Trent, Staffordshire, United Kingdom, ST4 6QG
        • Recruiting
        • University Hospitals of North Midlands NHS Trust, Royal Stoke University Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • David Sutton
    • Yorkshire
      • Leeds, Yorkshire, United Kingdom, LS9 TF
        • Recruiting
        • Leeds Teaching Hospitals NHS Trust
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Hill Quentin
  • United States
    • Arkansas
      • Hot Springs, Arkansas, United States, 71913
        • Not yet recruiting
        • Genesis Cancer and Blood Institute - SCRI
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Lingyi Chen
    • California
      • Los Angeles, California, United States, 90033
        • Not yet recruiting
        • USC Norris Comprehensive Cancer Center - Keck Medicine of USC
        • Principal Investigator:
          • Howard Liebman
        • Contact:
          • Site Contact
    • Colorado
      • Denver, Colorado, United States, 80218
        • Withdrawn
        • Rocky Mountain Cancer Center
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20007
        • Not yet recruiting
        • Georgetown University Medical Center - Lombardi Comprehensive Cancer Center
        • Principal Investigator:
          • Catherine Broome
        • Contact:
          • Site Contact
    • Georgia
      • Atlanta, Georgia, United States, 30308
        • Not yet recruiting
        • Emory University
        • Principal Investigator:
          • Ana Antun
        • Contact:
          • Site Contact
    • Indiana
      • Indianapolis, Indiana, United States, 46260
        • Not yet recruiting
        • Innovative Hematology, Inc.
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Sherwin Desouza
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • Not yet recruiting
        • The University of Iowa
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Steven Lentz
    • Kentucky
      • Louisville, Kentucky, United States, 40202
        • Not yet recruiting
        • University of Louisville Brown Cancer Center
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Kamila Cisak
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Recruiting
        • Massachusetts General Hospital
        • Principal Investigator:
          • David Kuter
        • Contact:
          • Site Contact
      • Worcester, Massachusetts, United States, 01655
        • Not yet recruiting
        • University of Massachusetts Chan Medical School
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Daniel Winokur
    • Missouri
      • Kansas City, Missouri, United States, 64132
        • Not yet recruiting
        • MidAmerica Cancer Center
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Benjamin Fangman
    • New Jersey
      • Morristown, New Jersey, United States, 07960
        • Not yet recruiting
        • American Oncology Partners of Maryland, PA
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Ralph Boccia
    • North Carolina
      • Durham, North Carolina, United States, 27710
        • Not yet recruiting
        • Duke University Hospital
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Ara Metjian
      • Greenville, North Carolina, United States, 27837
        • Not yet recruiting
        • East Carolina University
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Darla Liles
    • Oregon
      • Portland, Oregon, United States, 97239
        • Recruiting
        • Oregon Health & Science University
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Joseph Shatzel
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19140
        • Not yet recruiting
        • Lewis Katz School of Medicine at Temple University
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Michael Bromberg
      • Philadelphia, Pennsylvania, United States, 19104
        • Not yet recruiting
        • Perelman Center for Advanced Medicine (PCAM) Hospital of The University of Pennsylvania Penn Blood Disorders Program
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Adam Cuker
    • Texas
      • Houston, Texas, United States, 77030
        • Not yet recruiting
        • Baylor College of Medicine
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Senthil Sukumar
    • Virginia
      • Norfolk, Virginia, United States, 23502
        • Not yet recruiting
        • Virginia Oncology Associates
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Bremer Celeste
    • Washington
      • Seattle, Washington, United States, 98109
        • Not yet recruiting
        • University of Washingto
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Sandhya Panch
    • Wisconsin
      • Milwaukee, Wisconsin, United States, 53226
        • Not yet recruiting
        • Versiti Wisconsin, Inc
        • Contact:
          • Site Contact
        • Principal Investigator:
          • Lisa Kreuziger

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

  • Key Inclusion Criteria:

    1. The participant has completed TAK-079-3002 (end of trial [EOT]) or TAK-079-1004 (EOT). Participants from TAK-079-1004 must have had a response to mezagitamab as demonstrated by meeting the criteria for "platelet response" specified for that trial during either the main study or open-label extension.

  • Key Exclusion criteria:

For TAK-079-3002 participants:

1. The participant has a history of severe allergic or anaphylactic reactions to recombinant proteins or excipients used in the mezagitamab formulation.

For TAK-079-1004 participants:

  1. The participant has had any thrombotic or embolic event within 12 months before signing the ICF.
  2. The participant has had a splenectomy within 3 months before signing the ICF.
  3. The participant has active infection with hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV).
  4. History of malignancy (including myelodysplastic syndrome) within 5 years of signing the ICF, except for treated non-melanoma skin cancer or cervical carcinoma in situ.
  5. In the opinion of the investigator, the participant has a serious medical or psychiatric illness that could potentially interfere with the completion of treatment according to this protocol.

  6. The participant has received anti-cluster of differentiation (CD) 20 treatment within 12 months before screening and either of the following applies:

    1. The last dose was received within 6 months before screening.
    2. The last dose was received between 6 and 12 months before screening and the participant has a CD19+ count below the lower limit of normal.
  7. The participant has received any monoclonal or polyclonal antibody for immunomodulation within 6 months before Visit 1.
  8. The participant has been exposed to another investigational agent within 4 weeks or 5 half-lives, whichever is longer, before Visit 1.
  9. The participant has used anticoagulants (for example, vitamin K antagonists, direct oral anticoagulants) within 3 weeks prior to Visit 1.

10 The participant has received a live or live-attenuated vaccine within 4 weeks prior to the first dose of trial treatment or has any live or live-attenuated vaccine planned during the trial.

11. The participant has used the following immunosuppressive agents as specified prior to Visit 1: alkylating agents (for example, cyclophosphamide) within 8 weeks, vinca alkaloids (for example, vincristine) within 4 weeks, sulfones (for example, dapsone) within 3 weeks, antiproliferative agents: (for example, mycophenolate mofetil and azathioprine) within 2 weeks, and calcineurin inhibitors: (for example, cyclosporine) within 2 weeks.

12. The participant has a history of severe allergic or anaphylactic reactions to recombinant proteins or excipients used in the mezagitamab formulation.

Other protocol defined inclusion/exclusion criteria may apply.

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
Intervention / Treatment
Experimental: Mezagitamab
Eligible participants who completed the TAK-079-3002 or TAK-079-1004 studies can receive on-demand treatment in this continuation study. The on-demand treatment course may be repeated as needed based on the pre-specified on-demand dosing criteria and investigator's clinical judgement.
Drug: Mezagitamab
Mezagitamab injection administered SC.
Other Names:
  • TAK-079

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious TEAEs
Time Frame: Up to approximately 108 weeks
An adverse event (AE) is any untoward medical occurrence in a clinical trial participant, temporally associated with the use of the trial intervention, whether or not the occurrence is considered related to the trial intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of the trial intervention. TEAEs are defined as AEs with start dates at the time of or following the first exposure to mezagitamab in the parent trial for Cohort 1 and in this trial for Cohort 2. A serious TEAE is a TEAE that meets 1 or more of the criteria: results in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect or was otherwise considered medically important.
Up to approximately 108 weeks
Number of Participants With TEAEs Leading to Permanent Withdrawal of Mezagitamab
Time Frame: Up to approximately 108 weeks
An AE is any untoward medical occurrence in a clinical trial participant, temporally associated with the use of the trial intervention, whether or not the occurrence is considered related to the trial intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of the trial intervention. TEAEs are defined as AEs with start dates at the time of or following the first exposure to mezagitamab in the parent trial for Cohort 1 and in this trial for Cohort 2.
Up to approximately 108 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Duration of Platelet Response
Time Frame: Up to approximately 108 weeks
The duration of platelet response will be measured by the cumulative number of weeks on which platelet count was ≥30,000/microliters (μL) and ≥50,000/μL throughout the trial.
Up to approximately 108 weeks
Duration Between On-Demand Treatment Courses
Time Frame: Up to approximately 108 weeks
Up to approximately 108 weeks
Time to Initiation of the First On-Demand Treatment Course
Time Frame: Up to approximately 108 weeks
Up to approximately 108 weeks
Number of Participants With Complete Response
Time Frame: Up to approximately 108 weeks
Complete response is defined as achieving platelet counts ≥100,000/μL on at least 2 visits.
Up to approximately 108 weeks
Number of Participants With Immune Thrombocytopenia (ITP) Remission
Time Frame: Up to approximately 108 weeks
ITP Remission is defined as all platelet counts ≥50,000/μL for at least 24 weeks after any mezagitamab treatment cycle in the absence of further therapy for ITP.
Up to approximately 108 weeks
Number of Participants With Reduction in Dose and/or Frequency of Concomitant ITP Medications
Time Frame: Up to approximately 108 weeks
Concomitant ITP medications are defined as those given in addition to the trial intervention to treat your ITP. These medications include corticosteroids, thrombopoietin receptor agonists (TPO-RA), or fostamatinib.
Up to approximately 108 weeks
Number of Participants Requiring Rescue Therapy
Time Frame: Up to approximately 108 weeks
Up to approximately 108 weeks
Serum Concentrations of Mezagitamab
Time Frame: Pre-dose and at multiple time points post-dose up to Week 104
Pre-dose and at multiple time points post-dose up to Week 104
Number of Participants With Anti-Drug Antibodies (ADA)
Time Frame: Pre-dose and at multiple time points post-dose up to Week 104
Pre-dose and at multiple time points post-dose up to Week 104
Number of Participants With Neutralizing Antibody (NAb)
Time Frame: Pre-dose and at multiple time points post-dose up to Week 104
Pre-dose and at multiple time points post-dose up to Week 104

Collaborators and Investigators

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

Sponsor

Takeda

Investigators

  • Study Director: Study Director, Takeda

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.

Helpful Links

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 14, 2025

Primary Completion (Estimated)

July 29, 2029

Study Completion (Estimated)

July 29, 2029

Study Registration Dates

First Submitted

April 25, 2025

First Submitted That Met QC Criteria

April 28, 2025

First Posted (Actual)

April 29, 2025

Study Record Updates

Last Update Posted (Actual)

August 14, 2026

Last Update Submitted That Met QC Criteria

August 12, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TAK-079-3003
  • 2025-521692-31-00 (Ctis)
  • jRCT2031250237 (Registry Identifier: jRCT)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

IPD Sharing Access Criteria

IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/. For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

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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