Provided are methods, kits and compositions for ameliorating toxicity, such as cytokine release syndrome or neurotoxicity, suspected or being induced by or associated with, administration of a therapeutic agent, such as a immunotherapeutic agent targeting T cells and/or genetically engineered T cells, e.g. chimeric antigen receptor (CAR)-expressing T cells. The methods involve administering an additional agent, such as an agent having anti-oxidant or anti-inflammatory properties, that modulates immune cells such as by preventing or reducing the production of pro-inflammatory cytokines or stress cytokines and/or promoting differentiation to a neuroprotective phenotype, and/or capable of preventing, blocking or reducing microglial cell activation or function and/or capable of modulating, such as promoting, the activity of NRF2 or a component of an NRF2-regulated pathway, and/or one or more components involved in an antioxidant response element (ARE). The provided methods can be used in connection with or for methods of treating a disease or condition.