D3.342 - Adverse Events of Biologic Therapies: A One-Year Retrospective Study

Biologic therapies are widely used for the management of rheumatic and inflammatory diseases.  Although thought to have lower toxicity than traditional systemic treatments due to their high specificity, they may be associated with severe adverse events (AEs).  The commonly reported AEs include infusion and injection site reactions. However, as the prescription of biologic medications is rapidly expanded; immune-related hypersensitivity reactions are increasingly reported. This study aims to describe the profile of AEs associated with biologics.

A retrospective analysis was conducted on all reported cases to the Pharmacovigilance Center of Sousse between January 2025 and January 2026. Data included demographic characteristics, clinical indications, incriminated agents, and the nature of the reactions.

A total of 30 cases were collected. The mean age was 41.2 years (range 16–64 years) , with a female predominance (18 F / 12 M; sex ratio 1.5). The use of biologics was for inflammatory bowel diseases in 13 cases, for rheumatoid arthritis in 8 cases and spondyloarthritis in 5 cases. Other indications were multiple sclerosis and Juvenile arthritis (2 cases for each indication). Incriminated biologics were mainly Infliximab (24 cases (80 %), Rituximab (3 cases),  Adalimumab  (2 cases) and Ocrelizumab (1 case). Reported AE were immediate hypersensitivity reactions in 20 cases. Infusion-related reactions were reported in 10 cases.

High grade anaphylactic reaction contraindicated the use of the biological therapy. Reintroduction was considered at higher risk in these patients. Several patients (N=2) experienced anaphylactic reactions during repeated doses, highlighting the importance of continuous monitoring, even if the initial doses were well tolerated. In our serial case, predisposing factors seems to be IBD and Infliximab therapy. However, these results should be considered with cautions as the collected sample is limited.

Clinical symptoms and signs of per perfusion reactions are usually due to the cytokine release. In these cases, the reintroduction was allowed. Essential steps include immediate cessation of the perfusion and monitoring of vital signs, administering IV fluids, antihistamines, or corticosteroid. Anaphylactic reaction should be ruled out to determine if the transfusion can be reintroduced.  

Biologic therapies are considered as a significant therapeutic option for many conditions. In some cases, AE may be lifethreatening and management may be challenging. More multicentre studies should be conducted to identify the frequency of severe immune-allergic reactions.