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.