#5478 Real-World Signs and Symptoms at Diagnosis in Patients With C3 Glomerulopathy - Interim Results From a Multi-Country Study

Abstract

Background and Aims C3 glomerulopathy (C3G) is a rare form of glomerulonephritis, with an estimated incidence of 1 – 2 per million per year. C3G is associated with a high risk of disease progression with approximately 50% of patients reaching kidney failure within 10 years of diagnosis. Common signs and symptoms include proteinuria, hematuria, edema and hypertension. The aim of this analysis was to better understand the clinical characteristics of C3G patients from the US, Europe and Asia, at the time of diagnosis. Method An analysis was conducted using interim data from the Adelphi C3G Disease Specific Programme (DSP), a cross-sectional survey of C3G-treating nephrologists in US, EU5 (France, Germany, Italy, Spain, UK), China and Japan (study ongoing since August 2022; interim analysis based on data until November). Nephrologists completed structured forms administered via online links for consecutive patients presenting with C3G. The forms included demographic and clinical information including signs, symptoms, and lab values amongst others. Results In this interim analysis, 88 nephrologists had completed records for 277 patients in this survey, including 95 in US, 120 in EU5, 39 in China and 23 in Japan. Median patient age at diagnosis was 40.9, and 60% were male. 80% had C3 glomerulonephritis (C3GN) and 19% had dense deposit disease (DDD). Median proteinuria at diagnosis was 2.9 g/day, and was ≥1 g/day in 82% of patients. Median eGFR at diagnosis was 50 ml/min/1.73m2 (Table 1). In addition to proteinuria, the main clinical signs and symptoms at diagnosis were hematuria, edema, hypertension and fatigue. Pain, appetite loss and sleep problems were also reported. Physicians described disease severity at diagnosis as moderate in 53% and severe in 31% of patients. Conclusion This study allows evaluation of a rare disease across geographies. C3G patients experience substantial symptomatic and clinical burden at diagnosis. This symptom burden, high proteinuria, and relatively low eGFR is consistent with physician assessment that the disease is moderate or severe by the time of diagnosis. Facilitating early diagnosis of C3G and rapid initiation of treatment could be beneficial for patients in slowing disease progression.