Kidney Week

Abstract: INFO20-SA

The PIONEER Trial: Expanding Evaluation of Atacicept, a B-Cell-Activating Factor (BAFF) and A Proliferation-Inducing Ligand (APRIL) Inhibitor, to Pediatric Patients with IgAN

Session Information

• Informational Posters - 3
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• No subcategory defined

Authors

• Trachtman, Howard, University of Michigan, Ann Arbor, Michigan, United States

Howard Trachtman, MD, FASN

• Barratt, Jonathan, University of Leicester, Leicester, England, United Kingdom

Jonathan Barratt, MBChB, PhD

• Lafayette, Richard A., Stanford University, Stanford, California, United States

Richard A. Lafayette, MD

• Sheng, Tao, Vera Therapeutics Inc, Brisbane, California, United States

Tao Sheng, PhD

• Winterberg, Pamela D., Vera Therapeutics Inc, Brisbane, California, United States

Pamela D. Winterberg, MD

• Tumlin, James A., Emory University School of Medicine, Atlanta, Georgia, United States

James A. Tumlin, MD, FASN

• Wanner, Christoph, University Hospital of Wüzburg, Wüzburg, Germany

Christoph Wanner, MD

• Chertow, Glenn M., Stanford University, Stanford, California, United States

Glenn M. Chertow, MD, MPH, FASN

Description

IgA nephropathy (IgAN) is a chronic, B-cell-mediated kidney disease in which the key cytokines BAFF and APRIL drive production of galactose-deficient IgA1 (Gd-IgA1) and associated anti-glycan antibodies, resulting in glomerular immune-complex deposition and progressive kidney injury. Atacicept is a native human TACI-Fc fusion protein that inhibits both BAFF and APRIL with picomolar binding affinity. In the ORIGIN program, atacicept demonstrated statistically significant reductions in Gd-IgA1, hematuria and proteinuria, with stabilization of estimated glomerular filtration rate (eGFR) through 96 weeks in the ORIGIN 2b trial.
Pediatric-onset IgAN can lead to substantial long-term morbidity, with approximately 39% of children in the RaDaR registry progressing to kidney failure during a median follow-up of 8 years. There are no approved therapies for pediatric IgAN.
PIONEER (NCT06983028) is an ongoing, global, open-label, Phase 2 basket trial evaluating the safety and efficacy of atacicept in antibody-mediated glomerular diseases, including an expanded cohort of participants with IgAN. Pediatric IgAN cohorts include children aged ≥2 to <18 years and weighing ≥14 kg with biopsy-confirmed IgAN or IgA vasculitis with nephritis (IgAVN) and a urine protein-to-creatinine ratio (UPCR) ≥1.0 g/g (Figure). Enrollment will be staged by age and weight categories. Participants ≥40 kg receive weekly subcutaneous injections of atacicept 150 mg for 52 weeks.
Primary endpoints for the pediatric study include safety and tolerability, pharmacokinetics, and change from baseline in UPCR at Week 36. Secondary endpoints include change from baseline in eGFR and Gd-IgA1 at Weeks 36 and 52.
PIONEER will provide the first evaluation of atacicept in children with IgAN and IgAVN and help characterize its safety, pharmacokinetics, and efficacy in these populations.

Funding

• Vera Therapeutics