Analysis of immune-related adverse events caused by immune checkpoint inhibitors using the Japanese Adverse Drug Event Report database.

Purpose: The aim of our study was to characterize the clinical features of immune-related adverse events (irAEs) associated with immune checkpoint inhibitors (ICIs) in a real-world setting using the Japanese Adverse Drug Event Report (JADER) database.

Methods: The irAEs were defined using the preferred terms of the Medical Dictionary for Regulatory Activities. irAEs were categorized as follows: adrenal insufficiency, colitis, eye diseases, hematological disorder, hepatitis, hyperthyroidism, hypopituitarism, hypothyroidism, myasthenia gravis, myocarditis, nephritis/renal dysfunction, pneumonitis, rash, and type 1 diabetes mellitus. We used several indices such as reporting odds ratio (ROR) to assess disproportionality in pharmacovigilance data, time-to-onset analysis using Weibull shape parameters, and the association rule mining technique to evaluate possible risk factors between variables in the spontaneous reporting system database.

Results: The JADER database contained 534 688 reports from April 2004 to June 2018. The RORs of pneumonitis including interstitial lung disease for nivolumab, pembrolizumab, and ipilimumab were 7.02 (95% confidence interval: 6.55-7.52), 9.08 (8.28-9.97), and 1.74 (1.27-2.38), respectively. The median onsets (quartiles, 25-75%) of myocarditis caused by nivolumab and pembrolizumab were 28.0 (15.5-60.5) and 18.0 (13.0-44.5) days, respectively. Co-therapy with nivolumab and ipilimumab may be associated with irAEs in several categories as per the association rule mining analysis.

Conclusion: Our results demonstrated a potential risk of irAEs associated with ICIs, based on RORs and time-to-onset analysis. Furthermore, our findings indicated that patients receiving nivolumab and ipilimumab as co-therapy should be carefully monitored.