Partial Response to Naxitamab for Brain Metastasis in Neuroblastoma.

Neuroblastoma (NBL) is a common pediatric tumor arising from sympathetic ganglion cells. High-risk NBL is based on age, stage, histology, and MYCN amplification, and is associated with a high mortality rate. The combination of naxitamab (NAX) and granulocyte-macrophage (cerebrospinal fluid) is a new treatment for high-risk and relapsed NBL approved for bone or bone marrow disease. NAX is a monoclonal antibody directed against anti-disialoganglioside, which is overexpressed in neuroblastoma. Under normal circumstances, monoclonal antibodies, such as NAX, cannot cross the blood-brain barrier due to size. We present the case of a patient with high-risk NBL treated with NAX for multiple bony relapses. Unexpectedly, her brain metastasis responded clinically, histologically, and by imaging to the treatment. We believe this is the first documented case of NBL of the brain responding to NAX.