A Study of Mezagitamab in Adults With Primary Immunoglobulin A Nephropathy Receiving Stable Background Therapy

NCT05174221 | Completed Phase 1 FDA Drug

• 3 other identifiers: TAK-079-10062024-516743-34-00jRCT2011220009
• Study Type: interventional
• Target: 17
• Locations: 11 countries
• Sites: 26

Brief Summary

This study will have two parts. The main aims are to:

• check the side effects from mezagitamab.
• check for long-term side effects from mezagitamab. Before starting the study, participants will be asked to provide a 24-hour urine sample. A few weeks later, if enrolled they will begin receiving a subcutaneous injection (under the skin) of mezagitamab once a week for 8 weeks then once every 2 weeks for 16 weeks. When treatment has ended, there will be a 24-week follow-up period. Participants who receive benefit from the treatment may continue in the second part of the study where they will be monitored for up to 96 weeks and possibly retreated for another 24 weeks.

Conditions

Kidney Disease; Glomerulonephritis

Keywords

Drug Therapy

Outcome Measures

Primary Outcomes (3)

• Main Study: Percentage of Participants With one or More Treatment-emergent Adverse Events (TEAEs), Grade 3 or Higher TEAEs, Serious Adverse Events (SAEs), and Adverse Events (AEs) Leading to Mezagitamab Discontinuation

  The severity of TEAEs will be graded using National cancer institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 5.0.

  Up to Week 48

• LTE Observation Period: Percentage of Participants With one or More TEAEs, Grade 3 or Higher TEAEs and SAEs

  The severity of TEAEs will be graded using NCI-CTCAE version 5.0.

  Up to Week 96

• LTE Retreatment Period: Percentage of Participants With one or More TEAEs, SAEs, Grade 3 or Higher TEAEs and AEs leading to Mezagitamab Discontinuation

  The severity of TEAEs will be graded using NCI-CTCAE version 5.0.

  Retreatment Week 0 to 48

Secondary Outcomes (8)

• Main Study: Ctrough: Observed Serum Trough Concentrations of Mezagitamab

  Week 0 Pre-dose and at multiple time points (up to Week 48)

• Main Study: Serum IgA Levels

  Week 0 Pre-dose and at multiple time points (up to Week 48)

• Main Study: Percent Change From Baseline in Proteinuria Based on Urine Protein to Creatinine Ratio (UPCR)

  Week 36

• Main Study: Percentage of Participants Based on Antidrug Antibody (ADA) Levels in Serum

  Up to Week 48

• LTE Observation Period: Serum IgA Levels

  Week 56 Pre-dose and at multiple time points (up to Week 96)

Study Arms (1)

Mezagitamab

EXPERIMENTAL

Mezagitamab, subcutaneous injection, once weekly for 8 weeks then once every 2 weeks for 16 weeks in the Main Study. Same dosing regimen will be repeated in LTE Retreatment Period.

Drug: Mezagitamab

Interventions

Mezagitamab DRUG

TAK-079 subcutaneous injection.

Also known as: TAK-079

Mezagitamab

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Renal biopsy report supporting diagnosis of primary IgAN or IgA vasculitis-associated nephritis within 10 years prior to the screening visit.
• UPCR greater than or equal to (\>=) 1 milligram per milligram (mg/mg) or urine protein excretion (UPE) \>=1 gram per day (g/day) by 24-hour urine collection during the screening period.
• Estimated glomerular filtration rate (eGFR) \>=45 milliliter per minute per 1.73 square meter (mL/min/1.73m\^2) at screening.
• Receiving stable background therapy for IgAN (angiotensin-converting enzyme inhibitor \[ACE-I\] or angiotensin receptor blocker \[ARB\]) for 12 weeks prior to screening. The ACE-I and ARB dose should represent the maximum tolerated or maximum labeled dose, as determined by the investigator, for a minimum of 3 months and remain stable during the entire duration of the study.

You may not qualify if:

• Kidney biopsy confirming significant renal disease other than IgAN.
• Secondary IgAN (such as with significant liver disease, inflammatory bowel disease, and seronegative spondyloarthropathies).
• Evidence of rapidly progressive glomerulonephritis (loss of \>=50 percent (%) of eGFR within 3 months prior to the screening visit).
• Diagnosis of nephrotic syndrome defined as 24-hour proteinuria greater than (\>) 3.5 g/day, hypoalbuminemia (smaller than \[\<\] 30 g/L) with or without peripheral edema at the screening visit.
• Diagnosis of acute active extrarenal IgA vasculitis (Henoch-Schönlein purpura) manifested by the involvement of other organs (palpable purpura, abdominal pain, and arthritis) at the screening visit and within 1 year prior to the screening visit.
• Previous treatment with immunosuppressive agents such as cyclophosphamide, mycophenolate mofetil (MMF), cyclosporine, azathioprine, calcineurin inhibitors within 6 months prior to the screening visit or expected use of any of these agents for the duration of the study.
• Use of systemic corticosteroids within 4 months from screening visit or expected use for the duration of the study.
• Use of B-cell-directed biologic therapies such as blisibimod, belimumab, rituximab, ocrelizumab or have used other biologics (example, anti-tumor necrosis factor \[TNF\], abatacept, anti-interleukin \[IL\]-6) within 6 months prior to the screening visit or expected use of any of these agents for the duration of the study.
• Participation in another investigational study within 4 weeks or 5 half-lives of study drug, whichever is longer, before the screening visit (the 4-week window is derived from the date of the last study procedure, and/or AE related to the study procedure in the previous study, to the screening visit of the current study) or expected use of an investigational agent from another investigational study during the time of this study.
• Administration of any vaccine within 28 days before the screening visit or of any live or live-attenuated vaccination planned for the duration of the study.
• An opportunistic infection smaller than or equal to (\<=) 12 weeks before screening visit or currently receiving treatment for a chronic opportunistic infection, such as tuberculosis (TB), pneumocystis pneumonia, cytomegalovirus, herpes simplex virus, herpes zoster, or atypical mycobacteria. A mild, localized herpes simplex infection within 12 weeks of study dosing is allowed, as long as the lesion has resolved prior to Day 1.
• A positive T-cell interferon-gamma release assay (TIGRA) (result through QuantiFERON-TB Gold test or T-Spot/Elispot) at the screening visit.
• A positive test result for hepatitis B surface antigen, or hepatitis B core antibody, or hepatitis C antibody, or HIV antibody/antigen at screening. However, an individual who has a known history of chronic hepatitis C and has been treated and fully cured of the disease, confirmed with a negative hepatitis C virus RNA polymerase chain reaction (PCR) test at screening, is not excluded on the basis of the positive hepatitis C antibody alone.
• Inadequate organ and bone marrow function at screening visit.
• Presence of uncontrolled or New York Heart Association (NYHA 1994) Class 3 or 4 congestive heart failure at the screening visit.

Sponsors & Collaborators

• Takeda: lead

Study Sites (26)

Amicis Research Center - Northridge - Nordhoff

Northridge, California, 91324, United States

Location

Boise Kidney and Hypertension Institute - Frenova

Nampa, Idaho, 83687, United States

Location

NorthShore University HealthSystem

Evanston, Illinois, 60201, United States

Location

Core Research Group

Milton, Queensland, 4064, Australia

Location

Monash Health, Monash Medical Centre

Clayton, Victoria, 3168, Australia

Location

Royal Melbourne Hospital

Parkville, Victoria, 3050, Australia

Location

Beijing Friendship Hospital,Capital Medical University

Beijing, Beijing Municipality, 100050, China

Location

Guangdong Provincial Peoples Hospital

Guangzhou, Guangdong, 510080, China

Location

The First Affiliated Hospital of Xi'an Jiaotong University

Xi'an, Shaanxi, 710061, China

Location

Szegedi Tudomanyegyetem Szent-Gyorgyi Albert Klinikai Kozpont

Szeged, Csongrád megye, 6720, Hungary

Location

Semmelweis Egyetem

Budapest, 1083, Hungary

Location

ASST degli Spedali Civili di Brescia - Spedali Civili di Brescia

Brescia, Lombardy, 25123, Italy

Location

Kasugai Municipal Hospital

Kasugai-Shi, Aiti, 486-0804, Japan

Location

Fujita Health University Hospital

Toyoake-shi, Aiti, 470-1192, Japan

Location

Hiroshima University Hospital

Hiroshima, Hiroshima, 734-8551, Japan

Location

Sapporo City General Hospital

Sapporo, Hokkaido, 060-8604, Japan

Location

National University Hospital- Singapore

Singapore, 119074, Singapore

Location

Seoul National University Hospital

Seoul, Seoul Teugbyeolsi, 03080, South Korea

Location

Ajou University Hospital

Suwon, 16499, South Korea

Location

Hospital Universitario Marques de Valdecilla

Santander, Cantabria, 39008, Spain

Location

Hospital Universitario Vall d'Hebron - PPDS

Barcelona, 08035, Spain

Location

Fundacio Puigvert

Barcelona, 8025, Spain

Location

Taipei Medical University Shuang Ho Hospital

New Taipei City, 23561, Taiwan

Location

National Taiwan University Hospital

Taipei, 100, Taiwan

Location

Leicester General Hospital

Leicester, Leicestershire, LE5 4PW, United Kingdom

Location

Hull Royal Infirmary

Hull, HU3 2JZ, United Kingdom

Location

Related Publications (1)

• Ahmad SB, Jefferson JA. Targeting B Cells and Plasma Cells in Glomerular Disease. J Am Soc Nephrol. 2025 Jun 4;36(9):1844-1857. doi: 10.1681/ASN.0000000772.

  PMID: 40465397 DERIVED

Related Links

• Click here for more information about this trial in easy-to-understand language, including a Plain Language Summary of the results if the trial has been completed.

MeSH Terms

Conditions

Kidney Diseases; Glomerulonephritis

Condition Hierarchy (Ancestors)

Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Nephritis

Study Officials

• Study Director

  Takeda

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 14, 2021
• First Posted: December 30, 2021
• Study Start: November 9, 2022
• Primary Completion: December 15, 2025
• Study Completion: December 15, 2025
• Last Updated: January 26, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• 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.

Locations

JP (4); HU (2); TW (2); US (3); GB (2); CN (3); ES (3); AU (3); SG (1); IT (1); KR (2)