Benzinga | Nov 5, 2021 09:43AM EDT

Omeros Highlights Presentation Of Data At Annual Meeting Of the American Society Of Nephrology Yesterday

First Report of Narsoplimab's Effects on Complement Activation Markers in Renal Disease Presented at the Annual Meeting of the American Society of Nephrology --

Omeros Corporation (NASDAQ:OMER) today announced that the first report describing the effects of lectin-pathway inhibition by narsoplimab on urinary complement levels in kidney disease was presented yesterday at the Annual Meeting of the American Society of Nephrology (ASN). The work, conducted by a consortium from Denmark and the United Kingdom and led by Peter Garred, MD, DMSc, Chair and Professor of Clinical Molecular Medicine at the University of Copenhagen, was detailed at the ASN Annual Meeting in a poster entitled "Reduction of Urinary Levels of Lectin Pathway Complement Components in an IgA Vasculitis Patient after MASP-2 Inhibition with Narsoplimab".

The patient, a 21-year-old woman, presented with a rapidly progressive glomerulonephritis. The objective was to stabilize her rapidly deteriorating kidney function to allow for renal transplantation. Her clinical course and response to the MASP-2 inhibitor narsoplimab are detailed in a publication by Selvaskandan et al.1 In brief, kidney biopsy revealed marked vascular damage with significant interstitial fibrosis, tubular atrophy and evidence of complement involvement. Diagnosed with IgA vasculitis, she developed rapidly worsening kidney function with highly elevated creatinine levels, hypertension, proteinuria, and hematuria despite treatment with systemic corticosteroids. She began treatment with narsoplimab. After one course of 12 weekly doses of narsoplimab, her kidney function stabilized and she was able to undergo successful renal transplantation without the need for dialysis.

As reported in yesterday's ASN Annual Meeting presentation, complement levels assessed in urinary samples collected during the patient's clinical course demonstrated substantial reduction in local complement activation associated with narsoplimab treatment-related lectin-pathway inhibition and stabilization of kidney function. Specifically, C4c/creatinine ratio, ficolin-3/creatinine ratio and C3bc/creatinine ratio levels were decreased 75%, 58% and 29%, respectively, from baseline to the end of the treatment. Levels of MBL and CL-11 remained stable during treatment. Further studies are ongoing to evaluate the use of urine as a non-invasive and readily accessible resource to monitor responses to narsoplimab treatment.

A second presentation directed to narsoplimab in IgA-related disease -- Long-Term Phase 2 Efficacy of the MASP-2 Inhibitor Narsoplimab for Treatment of Severe IgA Nephropathy -- was also included in yesterday's program at the ASN Annual Meeting.

1Selvaskandan H, Kay Cheung C, Dormer J, Wimbury D, Martinez M, Xu G, Barratt J. Inhibition of the lectin pathway of the complement system as a novel approach in the management of IgA vasculitis-associated nephritis. Nephron. 2020;144(9):453-458. doi: 10.1159/000508841.