Follow-up mezagitamab treatment for adults with chronic primary immune thrombocytopenia

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This open-label follow-up invites adults who completed earlier mezagitamab studies (TAK-079-3002 or TAK-079-1004) to receive additional mezagitamab doses when protocol criteria are met. The primary focus is on long-term safety and tolerability, with secondary assessments of sustained efficacy (platelet responses) and pharmacokinetics. Participants will attend periodic clinic visits for infusions, blood tests, and safety monitoring. Enrollment is limited to eligible completers of the listed parent trials, with TAK-079-1004 participants required to have demonstrated a prior platelet response.

Why it matters

Who can join: the full rules

* 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.

Where it's running

• Massachusetts General Hospital
  Boston, Massachusetts, United States Recruiting
• Oregon Health & Science University
  Portland, Oregon, United States Recruiting
• Canberra Hospital
  Garran, Australian Capital Territory, Australia Recruiting
• St George Hospital
  Kogarah, New South Wales, Australia Recruiting
• University of New South Wales (UNSW) - Liverpool Hospital - Liverpool Cancer Therapy Centre
  Liverpool, New South Wales, Australia Recruiting
• Westmead Hospital
  Westmead, New South Wales, Australia Recruiting

+68 more sites. See ClinicalTrials.gov for the full list.

Study contacts

• Study coordinator: Takeda Contact
• Email: medinfoUS@takeda.com
• Phone: +1-877-825-3327

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Mezagitamab treatment for adults with chronic immune thrombocytopenia

  This study is testing if a new treatment called mezagitamab can help adults with chronic immune thrombocytopenia keep their platelet counts stable compared to a placebo.

  Recruiting at 69 sites Phase 3 Takeda · Hot Springs, Arkansas and 123 other locations · NCT06722235

• Mezagitamab for adults with late antibody-mediated rejection after kidney transplant

  Mezagitamab is being tested to see if it is safe and helps kidney transplant patients with late antibody-mediated rejection, compared with a placebo.

  Recruiting at 4 sites Phase 2 Takeda · Los Angeles, California and 34 other locations · NCT07613359

• Efgartigimod IV for adolescents (12–17) with chronic immune thrombocytopenia

  This trial will try intravenous efgartigimod to see if it safely raises platelet counts in people aged 12 to 17 with chronic ITP.

  Recruiting at 26 sites Phase 2/3 argenx · Bordeaux and 25 other locations · NCT07194850

• Mezagitamab for adults with IgA nephropathy

  This trial will test if mezagitamab can reduce protein in the urine of adults with primary IgA nephropathy.

  Recruiting at 186 sites Phase 3 Takeda · Birmingham, Alabama and 185 other locations · NCT06963827

• Romiplostim for Oral TPO-RA Resistant ITP

  This study tests whether adding romiplostim can help adults with immune thrombocytopenia who did not respond to oral TPO-RAs.

  Recruiting The First Affiliated Hospital of Soochow University · Suzhou, Jiangsu · NCT07612319

• CTX112 (zugo-cel) for relapsed/refractory ITP and wAIHA in adults

  This trial tests CTX112, an off-the-shelf CD19 CAR-T therapy, to see if it can help adults with relapsed or refractory ITP or wAIHA.

  Recruiting at 12 sites Phase 1/2 CRISPR Therapeutics · Boston, Massachusetts and 11 other locations · NCT07549698

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.