Evaluation of the safety of intravesical BCG therapy in France: analysis of serious adverse events notified over a three-year period.

Objectives: Intravesical BCG therapy remains the first-line prophylactic tr eatment for recurrences of superficial bladder tumours. However necessary t he safety, of this medicinal product, for which a potential risk of complic ations was demonstrated during development, needs to be evaluated. Material and Methods: Based on spontaneous notifications of adverse events reported according to good pharmacovigilance practice and in the context of a survey conducted jointly with Health Authorities, the authors present an analysis of adverse event notifications received by the manufacturer over a three-year period. A summary of serious adverse events (SAE) was establis hed and hypotheses concerning factors predisposing to these adverse events were discussed. Finally, practice guidelines were formulated. Results: During this period, 97 SAEs were reported spontaneously, including 12 local SAEs, 12 regional SAEs and 73 systemic SAEs. 46 of the 73 systemi c SAEs were suspected to be due to BCG infection, 18 were related to immune disorders and the cause of 9 SAEs could not be determined. Several hypothe ses are formulated concerning the circumstances leading to the onset of the se SAEs and practice guidelines are proposed. Conclusion: Pharmacovigilance has allowed a better understanding of the qua litative and quantitative safety of BCG-IT in France. Hypotheses concerning factors predisposing to adverse effects were formulated and practice guide lines were proposed. It is essential to continue this collaboration between practitioners, Health Authorities and the manufacturer to ensure optimal u se of this medicinal product.