Cost-Effectiveness Analysis of Nefecon versus Best Supportive Care for People with Immunoglobulin A Nephropathy (IgAN) in the United States

Exploring Novel Adverse Events of Nefecon

Introduction

Nefecon, the first innovative drug approved by both the US Food and Drug Administration (FDA) and European Medicines Agency for IgA nephropathy (IgAN), lacked comprehensive real-world assessments of its adverse events (AEs).

Methods

We leveraged postmarketing data of Nefecon from the US FDA Adverse Event Reporting System (FAERS), employing disproportionate analysis (DPA) to detect positive signals at the system organ class (SOC) and preferred terms (PTs) levels. Duplicate AEs related to budesonide and those previously reported in studies were excluded through the use of the Medical Dictionary of Regulatory Activities (MedDRA). Our analysis encompassed time-to-onset (TTO), Weibull shape parameter (WSP) evaluation, cumulative incidence, clinical prioritization evaluation, and subgroup analysis based on gender and age.

Results

A total of 1515 individuals with IgAN were included. Five positive SOC signals and 23 positive PT signals were identified, including 4 PTs (asthenia, malaise, product dose omission issue, and anxiety) representing novel AEs newly identified in this study. None of the positive PTs were classified as high clinical priority, with only acne, hypertension, swelling face, and weight increased considered as moderate clinical priority events. The median time to TTO was 31 days. All WSP test results indicated an early failure type profile. Lastly, subgroup analysis provided further insights into the relative risk of specific AEs.

Conclusion

Nefecon demonstrates a favorable safety profile, with no high-priority clinical events identified. The identification of novel AEs and subgroup-specific relative high-risk events fills a gap in existing studies and offers valuable insights for early clinical vigilance.

Diagnosing and Treating IgAN: Steroids, Budesonide, or Maybe Both?

IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, is characterized by a mesangial IgA deposit and a variety of histological lesions, as described by the Oxford classification system. Despite the well-described "four-hit hypothesis", there are still plenty of less or undescribed mechanisms that participate in the disease pathogenesis, such as B-cell priming, which seems to be initiated by different antigens in the intestinal microbiota. Diagnosis of the disease is currently based on kidney biopsy findings, as the sensitivity and specificity of the many serum and urinary biomarkers described so far do not seem to have diagnostic accuracy. Therapeutic strategies consist of the initial step of non-immune medication, aiming to reduce both the intraglomerular pressure and proteinuria to below 0.5 g/day, followed by systemic corticosteroid administration in patients who remain at high risk for progressive chronic kidney disease despite the maximum non-immune treatment. The 6-month systemic corticosteroid treatment reduces proteinuria levels; however, the increased possibility of adverse events and increased relapse rate after treatment raises the need for a new therapeutic approach. Targeted-release budesonide is a therapeutic modality that aims to inhibit disease pathogenetic pathways at early stages; it has minor systemic absorption and proven beneficial effects on renal function and proteinuria. In the present systemic review, the benefits and adverse events of steroids and budesonide are described, and the possibility of combined treatment is questioned in selected cases with active histologic lesions.

Treatment of IgA Nephropathy: A Rapidly Evolving Field

The pivotal event in the pathophysiology of IgA nephropathy is the binding of circulating IgA-containing immune complexes to mesangial cells, with secondary glomerular and tubulointerstitial inflammation and fibrosis. The paramount difficulty in the management of IgA nephropathy is the heterogeneity in its clinical presentation and prognosis, requiring an individualized treatment approach. Goal-directed supportive care remains the bedrock of therapy for all patients, regardless of risk of progression. Sodium-glucose transporter 2 inhibitors and sparsentan should be integral to contemporary supportive care, particularly in patients with chronic kidney damage. Pending the development of reliable biomarkers, it remains a challenge to identify patients prone to progression due to active disease and most likely to derive a net benefit from immunosuppression. The use of clinical parameters, including the degree of proteinuria, the presence of persistent microscopic hematuria, and the rate of eGFR loss, combined with the mesangial hypercellularity, endocapillary hypercellularity, segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis, crescents score, is currently the best approach. Systemic glucocorticoids are indicated in high-risk patients, but the beneficial effects wane after withdrawal and come at the price of substantial treatment-associated toxicity. Therapies with direct effect on disease pathogenesis are increasingly becoming available. While targeted-release budesonide has garnered the most attention, anti-B-cell strategies and selective complement inhibition will most likely prove their added value. We propose a comprehensive approach that tackles the different targets in the pathophysiology of IgA nephropathy according to their relevance in the individual patient.