A pretty good read for the very first pediatric patient being...

A pretty good read for the very first pediatric patient being treated with CAR-T: https://journals.lww.com/oncology-times/Fulltext/2022/03200/The_Incredible_Story_of_Emily_Whitehead___CAR.1.aspx

She was treated in 2012 and is still alive and healthy to this day. They also explain her and the investigator's journey through the Cytokine Release Syndrome when first infused with CAR-T. They used tocilizumab as CRS is mostly triggered in CAR-T Cell therapy by interleukin-6 (IL-6) and tocilizumab is a monoclonal antibody that blocks IL-6 from binding to the IL-6R, which then prevents the cytokine storm (very simplified explanation).

This rescue treatment was so effective the FDA approved Tocilizumab in CAR-T patients experiencing CRS: https://www.gene.com/media/press-releases/14679/2017-08-30/fda-approves-genentechs-actemra-tocilizu

CRS is not the be-all and end-all of the CAR-T clinical trial journey. There is a treatment option for it and every clinical trial protocol is designed to have a mitigation plan for when it does happen. It's expected and planned for.