A Phase 3, Open-label, Uncontrolled Single-arm Study to Evaluate the Efficacy, Pharmacokinetics, and Safety of Avacopan in Combination With a Rituximab or a Cyclophosphamide-containing Regimen in Children from 6 Years to 18 Years of Age with Active ANCA-associated Vasculitis (AAV)

Investigating the Safety and Effects of an Investigational Medication in Children with ANCA-associated Vasculitis

S
Stacey Tarvin, MD

Primary Investigator

Enrolling By Invitation
6 years - 17 years
All
Phase 3
1 participants needed
1 Location

Brief description of study

The rationale of this phase 3 study is to explore whether avacopan combined with a rituximab (RTX) or cyclophosphamide (CYC)-containing regimen is safe and effective in inducing and maintaining remission in pediatric subjects with active ANCA-associated vasculitis (AAV). The findings from this study may establish avacopan as an effective and safe therapeutic option when used with a RTX or CYC-containing regimen in pediatric subjects with active AAV. If this combination therapy demonstrates improved efficacy and safety, it could potentially become a recommended therapeutic option in clinical practice. In addition, understanding the pharmacokinetic (PK) parameters of avacopan will aid in optimizing dosing regimens in pediatric subjects, leading to improved therapeutic outcomes and reduced toxicity.
 
THIS STUDY IS ENROLLING BY INVITATION ONLY

Detailed description of study

This phase 3, open-label, uncontrolled single arm study is designed to explore the efficacy, pharmacokinetics, and safety of avacopan in combination with a RTX or CYC-containing regimen, in children from 6 years to  18 years of age with active AAV. Experimental: Avacopan.  Participants will receive avacopan twice-daily (BID) administered as oral tablets or liquid formula for 52 weeks.
 
Study duration for a single subject will be:
 
 Screening duration: up to 30 days
 Treatment duration: 52 weeks (0 to 26 weeks: remission-induction phase; 27 to
52 weeks: remission-maintenance phase). Avacopan administered twice daily
via oral route.
 Safety follow-up duration: 8 weeks after last avacopan dose administration.
Subjects who discontinue avacopan prior to week 52 are encouraged to remain
in the study for as long as possible until completion of the week 52 assessment.
 

Eligibility of study

You may be eligible for this study if you meet the following criteria:

  • Conditions: Vasculitis, Riley
  • Age: 6 years - 17 years
  • Gender: All

Inclusion Criteria:

  • Male and female children and adolescents from 6 to < 18 years of age
  • Clinical diagnosis of granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA), consistent with Chapel-Hill Consensus Conference definitions (Jennette et al, 2013)
  • Newly diagnosed or relapsed AAV with positive test for anti-PR3 or anti-MPO antibodies
  • At least 1 PVAS major item, at least 3 PVAS nonmajor items, or at least the 2 renal items of proteinuria and hematuria.
  • eGFR > 15 mL/min/1.73 m2 (using modified Schwartz equation per central lab guidelines)
  • Participants must have a bodyweight of ≥ 15 kg at day 1.

Exclusion Criteria:

  • Any other known multisystem autoimmune disease including eosinophilic granulomatosis with polyangiitis (Churg-Strauss), systemic lupus erythematosus , IgA vasculitis (Henoch-Schönlein), rheumatoid vasculitis, Sjogren's syndrome, anti-glomerular basement membrane disease, or cryoglobulinemic vasculitis
  • Alveolar hemorrhage requiring invasive pulmonary ventilation support anticipated to last beyond the screening period of the study
  • Any medical condition requiring or expected to require continued use of immunosuppressive treatments, including corticosteroids that may cause confoundment with study assessments and study conclusions.

This study investigates the safety and effects of an investigational medication combined with a regimen containing either rituximab or cyclophosphamide in children with ANCA-associated vasculitis (AAV). ANCA-associated vasculitis is a condition where the body's immune system mistakenly attacks blood vessels, causing inflammation. The study focuses on children aged 6 to less than 18 years who have active AAV.

Participants will take the investigational medication as oral tablets or liquid twice daily for 52 weeks. The study will include a remission-induction phase for the first 26 weeks, followed by a remission-maintenance phase for the remaining 26 weeks. After completing the treatment, there will be an 8-week safety follow-up to monitor participants' health.

  • Who can participate: Children and adolescents aged 6 to less than 18 years with a clinical diagnosis of granulomatosis with polyangiitis or microscopic polyangiitis can participate. They must have active AAV, a positive test for specific antibodies, and meet certain health criteria.
  • Study details: Participants will take the investigational medication twice daily for 52 weeks. The study includes a remission-induction phase and a remission-maintenance phase, with a safety follow-up period after treatment.
  • Study timelines: The study will last 52 weeks.
Updated on 17 Sep 2025. Study ID: RHEU-AMGEN-AAV, 23341
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Interested in the study?

This study is accepting only persons who receive care at a certain clinic or doctor or who are part of an invited group. Questions about this study can be directed to the study team listed in the description or contact your doctor to see if you are eligible.

Accepting Referrals by Invitation Only