Provided are methods for preventing or ameliorating toxicity caused by or due to a therapy, such as an immunotherapy or a cell therapy, by pre-emptive or early administration toxicity-targeting agent(s). In some embodiments, the therapy is a cell therapy in which the cells generally express recombinant receptors such as chimeric receptors, e.g., chimeric antigen receptors (CARs) or other transgenic receptors such as T cell receptors (TCRs). Features of the methods, including the timing of the administration of the agents or treatments for toxicity, provide various advantages, such as lower toxicity while maintaining persistence and efficacy of the administered cells.