This clinical trial is focused on studying a type of cancer called high-risk neuroblastoma. Neuroblastoma is a cancer that most often affects children and develops from immature nerve cells found in several areas of the body. The study is specifically looking at patients who have a form of the disease that is either resistant to initial treatment or has not fully responded to additional treatments targeting the bone or bone marrow.

The trial will test a combination of two treatments: naxitamab and granulocyte-macrophage colony-stimulating factor (GM-CSF). Naxitamab is a type of medication known as a monoclonal antibody, which is designed to target and attach to specific cancer cells, helping the immune system to destroy them. GM-CSF is a protein that helps stimulate the growth of white blood cells, which are important for fighting infections and may help the body respond better to cancer treatment. Naxitamab is given as a solution for infusion, meaning it is administered directly into the bloodstream through a vein, while GM-CSF is given as a solution for injection under the skin.

The purpose of the study is to evaluate how well the combination of naxitamab and GM-CSF works in treating high-risk neuroblastoma. Participants in the study will receive these treatments over a period of time, and their response to the treatment will be closely monitored. Some participants may receive a placebo, which is a substance with no active medication, to compare the effects of the actual treatment. The study will also look at the safety of the treatment by monitoring any side effects that occur. The trial aims to provide valuable information on the effectiveness and safety of this treatment combination for patients with high-risk neuroblastoma.