Real-world evidence of incidence and outcomes of aplastic anaemia following administration of immune checkpoint inhibitors.

Aplastic anaemia (AA) is a rare immune-related adverse events (irAEs) after immune checkpoint inhibitors (ICIs) administration with poorly understood incidence and outcomes. We analysed an electronic health record database of 52 303 ICI-treated patients and found 77 (0.15%) cases of AA, with a median onset of 126 days (interquartile range, 58-363 days). The most used treatment for AA was systemic glucocorticoids 60 (77.9%) and 32 (41.6%) patients were able to resume ICI within 1 year. Patients diagnosed with AA had a steep decline in overall survival (OS) within the first 120 days; when compared to propensity score-matched patients without AA, they had a significantly worse OS (hazard ratio 1.72, 95% confidence interval 1.19-2.50; p = 0.003).