PB0681 - Pharmacovigilance study of Drug associated Evans syndrome: Analysis of FAERS database

Background: Evans syndrome is a rare and potentially fatal autoimmune condition presenting with two or more cytopenias, that commonly includes Autoimmune Hemolytic Anemia, Immune Thrombocytopenia, with or without Immune Neutropenia. Various drugs have been implicated in Evans syndrome but their association remains poorly studied.

Aims: To study the association of drugs with Evans syndrome

Methods: A retrospective pharmacovigilance study using data from FDA Adverse Event Reporting System database was conducted to identify drugs associated with Evans syndrome. The top 20 drugs ranked by number of cases were documented and disproportionality signal analysis was employed to calculate the reporting odds ratio (ROR) with a 95% confidence interval (CI).

Results: Within the FAERS database that contains more than 2.7 million adverse events, a total of 335 events of Evans syndrome were found between the years 2003 and 2023. The distribution was 46.2% in males and 39.7% in females. 18.2% patients were below 18 years of age, 57.9% were adults, and 23.8% patients had age not defined. Death was reported in 13% cases. The top five drug associations were Oxaliplatin (39 cases), Tacrolimus (35 cases), Cyclosporine (30 cases), Romiplostim (28 cases), and Rituximab (27 cases). The top drugs ranked by signal strength were Romiplostim (ROR 128.1, 95%CI 86.9-188.9), Busulfan (ROR 54.5, 95%CI 31.9-93.3), T-lymphocyte immune-globulin (ROR 48.6 95% CI 21.9-109.2), Alemtuzumab (ROR 48.3 95%CI 28.8-81.2), Fludarabine Phosphate (ROR 40.4 95%CI 25.9-62.9), and Oxaliplatin (ROR 30.4 95%CI 20.6-44.9).

Conclusion(s): This study helps to identify the drugs most commonly associated with Evans syndrome. Compared to Evans syndrome in general that has pediatric predilection, drug associated Evans syndrome seems to predominantly affect adults. Most of the cases were found to be associated with the commonly used chemotherapy drugs. Pre-existing cancerous condition could be one of the confounders. Further studies are needed to identify the mechanism and establish a causal relationship.