Immunotherapy rechallenge after significant toxicity - can it be done successfully?

Aim: We describe a single-center burden of admissions for irAE management and rechallenge feasibility. Methods: A retrospective single-center study of patients receiving immunotherapy between 2015–2018 assessing irAE and immunotherapy rechallenge outcomes. Results: 69 of 307 patients (22%) required 124 hospitalizations for irAEs. 8 required ICU admission (2.6%). 6 (1.9%) died from irAEs. Corticosteroids were used in 96% of admissions. Additional immunosuppression was required in 26 admissions (21%). 47 of 69 patients were rechallenged (68%). The median duration between toxicity and rechallenge was 49 days (range 17–994 days). 19 of 47 rechallenged patients (40%) were admitted for subsequent irAE. 19 patients of the rechallenged group (40%) were alive at last follow-up. Conclusion: Immunotherapy rechallenge following prior irAE hospitalization is feasible but carries significant toxicity risk.