IgA nephropathy is a progressive disease, with up to 50% of IgA nephropathy patients developing end-stage kidney disease within 20 years, requiring dialysis or kidney transplant for survival.

Typically, proteinuria (protein in the urine) and/or hematuria (blood in the urine) are the first symptoms seen in patients with IgA nephropathy.  The proteinuria might cause the urine to be foamy or turn dark brown. As the disease progresses, kidney function declines and can lead to an accumulation of waste products as measured by creatinine. Creatinine levels in the blood are used to calculate an estimate of the glomerular filtration rate (eGFR), which is a measure of the kidneys’ capacity to filter and clear waste from blood.

The disease is often detected through routine health checks during which protein is found in the urine, or by the patient going to a physician because of bloody or foamy urine. Following elimination of other reasons for these symptoms, patients may be referred to a nephrologist (kidney specialist) for further examination including urine tests, blood tests, and a kidney tissue sampling (kidney biopsy). Show Less

Management of the disease currently consists primarily of drugs to control blood pressure and, occasionally, may include use of corticosteroids in an attempt to reduce the inflammation in the kidneys. Show less

In IgA nephropathy, the IgA-containing antibody complexes that become trapped in the kidneys’ tufts of capillaries (called “glomeruli”) trigger activation of the complement system. This complement activation results in further deposition of proteins in the kidney, creating more inflammation and kidney damage, which leads to a vicious cycle of even greater activation of the complement system. Complement activation is considered by many experts to be the key to IgA nephropathy and the kidney damage that it causes. Blocking activation of the complement system – specifically, complement’s lectin pathway – represents a novel approach to treating IgA nephropathy and to preventing further damage to the kidney. Show Less

Narsoplimab is being evaluated across a wide range of disorders, including IgA nephropathy in Omeros’ ARTEMIS-IGAN clinical trial. Narsoplimab, a fully human therapeutic antibody, specifically targets an enzyme known as mannan-associated, lectin-binding serine protease 2 (MASP-2). MASP-2 is the enzyme critical to the function of the lectin pathway – the pathway whose activation is thought to be largely responsible for IgA nephropathy. By binding to MASP-2, narsoplimab blocks the activation of the lectin pathway. Show less