Successful treatment with avacopan (CCX168) in a pediatric patient with C3 glomerulonephritis

Abstract

Background: C3 glomerulonephritis (C3GN) is a subtype of C3 glomerulopathy (C3G), characterized by dysregulation of the alternative pathway of complement and by dominant C3 by immunofluorescence on the kidney biopsy. There is no approved treatment for patients with C3G. Immunosuppressive drugs as well as biologics have been used with limited success. In recent decades, substantial advances in the understanding of the complement system have led to the development of new complement inhibitors. Avacopan (CCX168) is an orally administered small-molecule C5aR antagonist that blocks the effects of C5a, one of the most potent pro-inflammatory mediators of the complement system.

Case report: We describe a child with biopsy-proven C3GN treated with avacopan. She was enrolled in the ACCOLADE double-blind placebo-controlled Phase 2 study (NCT03301467), where during the first 26 weeks she was randomized to receive an avacopan-matching placebo orally twice daily, while in the following 26 weeks, the study was open-label and she received avacopan. After a wash-out period, she was restarted on avacopan through an expanded access program.

Conclusions: In this case, use of avacopan in a pediatric patient with C3GN was safe and well tolerated. On avacopan, the patient was able to discontinue mycophenolate mofetil (MMF) while maintaining remission.

Keywords: Alternative pathway of complement; Avacopan; C3 glomerulopathy; C5a complement receptor inhibitor; Child; Membranoproliferative glomerulonephritis.