Intrathecal hydrocortisone for treatment of children and young adults with CAR T-cell immune-effector cell-associated neurotoxicity syndrome.

Immune-effector cell-associated neurotoxicity syndrome (ICANS) is a significant toxicity occurring with chimeric antigen receptor (CAR) T-cell therapy, with first-line treatment options including supportive care and systemic corticosteroids. Sparse data exist on how to approach progressive/refractory cases of ICANS. We present five pediatric and young adult patients with relapsed/refractory B-cell acute lymphoblastic leukemia (ALL) who had progressively worsening ICANS despite systemic steroids, and received intrathecal hydrocortisone with rapid reversal of ICANS. Therapeutic lumbar punctures are routinely used in upfront ALL therapy in pediatrics, with a demonstrable safety profile, thus use of intrathecal hydrocortisone merits further prospective studies in patients with severe ICANS.