**4. Principles of immunotherapy rechallenge post occurrence of immune-related adverse events**

Caution should be considered upon resumption of immunotherapy especially after a severe irAE. After rechallenging with ICI, close follow-up should be performed to monitor for symptoms recurrence [23]. Permanent discontinuation of the ICI is warranted if the ICI is re-challenged and toxicity recur [5, 24, 25]. Prior to re-challenge, patient's tumor status should be assessed. Due to risk of toxicity recurrence following the resumption of the ICI, re-challenge can be considered if the response was partially or fully achieved [26]. A consultation with the irAEs designated specialists might be appropriate before immunotherapy re-challenge.
