3-year experience of the Belgian multidisciplinary immunotoxicity board (BITOX)

With the increasing use of immune-checkpoint inhibitors (ICIs), immune-related adverse events (irAEs) are increasingly prevalent. The common exclusion of patients with dysimmune comorbidities from clinical trials with these agents as well as a lack of long-term data on the management of irAEs, make multidisciplinary collaboration essential. In this light, BITOX, a biweekly virtual meeting between Belgian oncologists and organ specialists, was founded in 2021 to share experiences and identify clinically relevant research questions related to the management of irAEs. During ESMO 2024, Dr Marthe Verhaert (University Hospital Brussels, Brussels, Belgium) presented a retrospective analysis of the cases discussed during the first three years of BITOX. 

From March 2021 to March 2024, a total of 246 submissions from 131 physicians have been discussed. Surprisingly, rare irAEs such as neurological (14,4%) and rheumatological toxicity (13,2%) were the most frequent irAEs that were discussed during BITOX meetings. Regarding irAE management, escalation of immunosuppression was recommended in 26% of cases, whereas de-escalation was suggested in 51,8% of cases that were on multiple immunosuppressants prior to referral. To extend the reach of BITOX, multiple presentations were done, resulting in quarterly rises in submissions from physicians across all Belgian regions. 

In conclusion, these results show that setting up a national, virtual, multidisciplinary immunotoxicity board is feasible and enhances the multidisciplinary discussion of ICI-related problems. Furthermore, discussions during these meeting can identify relevant research questions, such as the lingering uncertainties regarding neurological and rheumatological irAEs.