P527 A review of adverse events associated with immunosuppressive treatments in inflammatory bowel disease patients
D. Tassone1, N. Ding2
1St Vincent’s Clinical School, University of Melbourne, Fitzroy, Australia, 2Department of Gastroenterology, St Vincent’s Hospital Melbourne, Fitzroy, Australia
Background
Medical therapies that suppress various pathways involved in inflammation comprise the mainstay of inflammatory bowel disease (IBD) treatment. Adverse events, including the development of serious infection and malignancy, have been associated with these therapies. This study evaluates the current evidence regarding serious adverse events associated with immunosuppressive agents in the IBD patient population.
Methods
A systematic search was conducted in September 2019 by combining three key research themes: inflammatory bowel disease, immunosuppression, and adverse events. For this systematic review, adverse events are defined as either the development or recurrence of malignancy or the development of serious infection necessitating hospital admission.
Results
There is a demonstrated association between thiopurine use and increased risk of both nonmelanoma skin cancer (NMSC) or lymphoma. The length of thiopurine exposure required to increase NMSC risk is, however, unclear. Of the papers reporting on exposure length and NMSC risk, the thiopurine exposure duration required to result in a statistically significant increase in NMSC risk varied from 6 months to 5 years. Among the studies retrieved, there is a lack of consensus on malignancy risk associated with the use of anti-TNF agents. From 5 studies on malignancy risk associated with the use of anti-TNF agents, one concluded that malignancy risk is increased while three concluded that risk is unchanged from baseline. The fifth study is inconclusive on any possible association. Confounding by past or concurrent thiopurine exposure remains an issue. There is a clear association between combination therapy with both thiopurines and anti-TNF agents and increased malignancy risk when compared with exposure to either thiopurine or anti-TNF therapy alone. Anti-integrin agents were not found to be associated with an increase in adverse effects when compared with placebo, while nil studies on ustekinumab were retrieved. Individual studies on infection risk do not consistently stratify infections according to severity, limiting any analysis.
Conclusion
An established association between thiopurine use and increased risk of both lymphoma or NMSC exists. However, the duration of thiopurine exposure necessary to increase NMSC risk is uncertain. There is a lack of consensus on whether anti-TNF agents increase malignancy risk due to confounding from past or concurrent thiopurine exposure. Combination therapy increases malignancy risk when compared with exposure to either thiopurine or anti-TNF therapy alone. Limited studies on the newer biologic therapies were retrieved. Finally, evidence which stratifies infections according to severity is lacking.