Evaluating Avacopan in the Treatment of ANCA-Associated Vasculitis: Design, Development and Positioning of Therapy

Abstract

Recently, avacopan has been approved for the treatment of ANCA-associated vasculitis (AAV). Avacopan is an inhibitor of the C5a-receptor, which plays an important role in chemotaxis and the amplification loop of inflammation in AAV. In the most recent, international guidelines avacopan is recommended as steroid-sparing agents for the management of AAV. Here, we review the clinical trials that have led to demonstrate that avacopan is an effective treatment option in the management of AAV, where it can significantly reduce the cumulative dosage of glucocorticoids (GC). Despite the new guideline recommendations, clear guidance on how to employ avacopan in real-world clinical practice is lacking. We therefore also address in this review the data and clinical experience with avacopan obtained from real-world evidence. Combining preclinical studies, clinical trials, and real-world evidence helps to provide a better position of avacopan for the management of AAV in routine clinical practice, taking advantage of the GC-sparing effects of avacopan as a possible solution for the current challenge of reducing GC-toxicity in AAV patients. Furthermore, we delineate current knowledge gaps and future research areas that need to be addressed.

Keywords: ANCA; C5a inhibition; antineutrophil cytoplasmic antibody; complement; glucocorticoid toxicity; pauci-immune glomerulonephritis.

Figure 1

The amplification loop of AAV targeted by avacopan: binding of ANCA-antibodies to PR3 or MPO on primed neutrophils activates the alternative complement pathway resulting in generation of C5a. In turn, C5a will induce chemotaxis of more neutrophils and primes them for further activation by ANCAs. Blocking of the C5a receptor with avacopan prevents this amplification loop and reduces vessel injury and organ damage.