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

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Takeda Development Center Americas Inc.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Hemic and Lymphatic Diseases [C15]

Trial duration

19 Dec 2025 → ongoing

Decision date (initial)

2025-11-05

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

Yes

Funding sources

Takeda Development Center Americas, Inc.

External identifiers

EU CT number

2025-521692-31-00

ClinicalTrials.gov

NCT06948318

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Others, Pharmacodynamic, Efficacy, Safety, Therapy, Pharmacokinetic

Safety: To evaluate the long-term safety and tolerability of mezagitamab in participants ≥18 years of age with chronic primary ITP.

Secondary objectives 5

1. 1. Efficacy: To evaluate the long-term efficacy of mezagitamab in participants ≥18 years of age with chronic primary ITP.
2. 2. To evaluate the reduction in concomitant ITP medications in participants ≥18 years of age with chronic primary ITP.
3. 3. To assess the use of rescue therapy in participants ≥18 years of age.
4. 4. To collect PK concentration of mezagitamab.
5. 5. To characterize the immunogenicity of mezagitamab.

Conditions and MedDRA coding

Chronic Primary Immune Thrombocytopenia

Study design 3 periods

Regulatory references

Scientific advice from competent authorities

Food And Drug Administration

Plan to share 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#8). 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.

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 2

1. 1. The participant has completed TAK-079-3002 (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.
2. 2. The participant has provided informed consent (that is, in writing, documented via a signed and dated ICF) and any required privacy authorization before the initiation of any trial procedures.

Exclusion criteria 5

1. 1. Key Exclusion criteria for TAK-079-3002 participants: The participant has a history of severe allergic or anaphylactic reactions to recombinant proteins or excipients used in the mezagitamab formulation.
2. 2. Key Exclusion criteria for TAK-079-1004 participants: The participant has had any thrombotic or embolic event within 12 months before signing the ICF.
3. 3. The participant has had a splenectomy within 3 months before signing the ICF.
4. 4. The participant has received anti-CD20 treatment within 12months before screening and either of the following applies: • The last dose was received within 6 months before screening. • 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.
5. 5. The participant has received any monoclonal/polyclonal antibody for immunomodulation within 6 months before Day 1.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 2

1. 01. Occurrence of TEAEs and serious TEAEs.
2. 02. Occurrence of TEAEs leading to permanent withdrawal of mezagitamab

Secondary endpoints 5

1. 01• Duration of platelet response. • Duration between on-demand treatment courses. • Time to initiation of the first on-demand treatment course. • Occurrence of complete response. • Occurrence of ITP remission.
2. 02. Reduction in dose and/or frequency of concomitant ITP medications throughout the trial.
3. 03. Use of rescue therapy.
4. 04. The PK concentration at selected timepoints during and after intervention.
5. 05. Occurrence of ADA and NAb.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Takeda Development Center Americas Inc.

Sponsor organisation

Takeda Development Center Americas Inc.

Address

500 Kendall Street

City

Cambridge

Postcode

02142-1108

Country

United States

Scientific contact point

Organisation

Takeda Development Center Americas Inc.

Contact name

Takeda

Public contact point

Organisation

Takeda Development Center Americas Inc.

Contact name

Takeda

Third parties 16

Locations

12 EU/EEA countries · 41 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 81 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

12 submissions — initial application plus substantial / non-substantial modifications