Case Report: Early introduction of anti-GD2 immunotherapy during induction chemotherapy in high-risk neuroblastoma: two pediatric cases.

Anti-Ganglioside (GD)2 monoclonal antibodies are widely used as maintenance therapy for high-risk neuroblastoma (HR-NB). However, the potential benefit of introducing immunotherapy during induction chemotherapy remains unclear. We report two pediatric patients with newly diagnosed HR-NB who received naxitamab in combination with chemotherapy starting from the second cycle of induction. Clinical characteristics, treatment regimens, and outcomes were retrospectively reviewed. Both patients achieved complete remission (CR) per International Neuroblastoma Response Criteria at the end of induction. Treatment-related adverse events, including hypotension, pain, and rash, capillary leak syndrome, and chemotherapy-related myelosuppression, were transient and manageable with supportive care and infusion adjustments. No treatment discontinuation due to toxicity occurred. While these preliminary findings demonstrate the feasibility and tolerability of early naxitamab introduction, the limited sample size precludes definitive conclusions regarding efficacy. This report provides exploratory data to support future prospective studies on optimizing the timing of anti-GD2 immunotherapy in HR-NB.