Kidney Week

Abstract: TH-PO647

Real-World Time to Diagnosis in C3 Glomerulopathy (C3G)

Session Information

• Glomerular Diseases: Epidemiology and Case Reports
  November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

• Lafayette, Richard A., Stanford University, Stanford, California, United States

Richard A. Lafayette,

• Pannagl, Katharina, Novartis Pharmaceuticals UK Ltd, London, United Kingdom

Katharina Pannagl,

• Ndife, Briana C., Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, United States

Briana C. Ndife,

• Smeets, Serge, Novartis Pharma AG, Basel, Basel-Stadt, Switzerland

Serge Smeets,

• Murphy, Kathleen, Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, United States

Kathleen Murphy,

• de Courcy, Jonathan, Adelphi Real World, Bollington, Cheshire East, United Kingdom

Jonathan de Courcy,

• Libby, Susanna, Adelphi Real World, Bollington, Cheshire East, United Kingdom

Susanna Libby,

• Proudfoot, Clare, Novartis Pharma AG, Basel, Basel-Stadt, Switzerland

Clare Proudfoot,

Background

Complement 3 glomerulopathy (C3G) is a rare kidney disease, with an estimated incidence of 1-2/million/year. C3G is associated with a high risk of disease progression, approximately 50% of patients reach kidney failure within 10 years of diagnosis (Dx). Delayed dx may lead to poor prognosis. This analysis aims to better understand the diagnostic pathway in C3G.

Methods

Data were drawn from the Adelphi C3G Disease Specific Programme, a cross-sectional survey of C3G-treating nephrologists in US, France, Germany, Italy, Spain, UK (EU5), China and Japan between August 2022 and April 2023. Nephrologists completed forms for consecutive patients presenting with C3G. The forms included demographics, clinical information and reasons for diagnostic delay.

Results

111 nephrologists completed records for 385 C3G patients (EU5 189, US 100, CN 60, JP 36). Median patient age at time of Dx was 38.8, and 59% were male.
Median time from symptom onset to the patient’s first physician consultation was reported for 78% of patients. In the EU5 (n=150) this was 4.1 weeks (IQR: 0.3-8.7), in the US (n=63) and China (n=59) this was 4.4 weeks (IQR US: 1.3-6.4, IQR CN: 1.3-12.4), and Japan (n=30) 6.8 weeks (IQR: 4.1-17.6).
Median time from first physician consultation to confirmed C3G Dx was reported for 85% of patients. Half of the patients received Dx within 4.6 weeks, 10% experienced a much longer period (table 1).
Reasons for a delay >4 weeks between first consultation and Dx were reported for 54% of patients (n=206). Waiting to conduct biopsy (39% EU5, 38% US, 27% China and 45% Japan) and waiting for biopsy results (33% EU5, 20% US, 38% China and 32% Japan) were the most common causes.
When (e)GFR was recorded at Dx (84%), 43% of patients were at CKD stages 3b-5 (GFR <45 mL/min/1.73 m2).

Conclusion

While half of patients with C3G receive a diagnosis within 4-6 weeks of presentation, 1 in 10 wait over 21 weeks. During this time patients may progress to later stages of CKD. Accelerating Dx may improve prognosis for some patients.

Table 1: C3G Dx delay and (e)GFR

Funding

• Commercial Support – Novartis Pharmaceuticals Corporation