# End-of-Induction Response and Tolerability of High-Risk Neuroblastoma Treated with Chemoimmunotherapy—Modified N7 Regimen with Dinutuximab Beta

## TL;DR

This study shows that combining chemotherapy with dinutuximab beta is effective and safe for treating high-risk neuroblastoma in children.

## Contribution

The study introduces a modified chemoimmunotherapy regimen with dinutuximab beta during induction treatment for high-risk neuroblastoma.

## Key findings

- 78% of patients achieved tumor response at the primary site and 100% at metastatic sites.
- Grade 3 or higher toxicities were observed but manageable in all patients.
- 78% of patients achieved a modified Curie score of ≤2 on MIBG scan.

## Abstract

High-risk neuroblastoma is an aggressive childhood cancer where intensive induction chemotherapy is a cornerstone of treatment. This study evaluated a novel strategy of integrating a targeted immunotherapy agent, dinutuximab beta, concurrently with a modified induction chemotherapy backbone. The primary aims were to assess the preliminary efficacy of this combination in achieving tumour response and to evaluate its safety and tolerability in a clinical setting. The findings demonstrate a high rate of tumour regression with a manageable adverse event profile, supporting the feasibility of this chemoimmunotherapy approach. This research provides a foundational clinical evidence base that may influence future treatment protocols and justifies larger, confirmatory trials to establish its role in improving survival outcomes for paediatric neuroblastoma patients.

Background: The integration of anti-disialoganglioside GD2 (anti-GD2) immunotherapy during induction chemotherapy has emerged as a promising strategy to improve outcomes in high-risk neuroblastoma (HR-NB). This study evaluated the end-of-induction (EOI) response and tolerability of a modified N7 induction regimen combined with dinutuximab beta in a Hong Kong paediatric cohort. Methods: A retrospective territory-wide analysis was conducted on nine HR-NB patients treated from 2022 to 2025. They received a modified N7 chemotherapy backbone with dinutuximab beta (17.5 mg/m2/day for 4 days per cycle), alongside granulocyte–macrophage colony-stimulating factor (GM-CSF) and low-dose interleukin-2. Response was assessed using the Revised International Neuroblastoma Response Criteria (INRC), and toxicity was graded according to the Common Terminology Criteria for adverse events (CTCAE). Results: The EOI objective response rate was 78% (7/9 patients) for the primary tumour site and 100% at metastatic sites. No patient exhibited progressive disease. A modified Curie score of ≤2 on MIBG scan was achieved in 78% of patients. Grade 3 or higher toxicities, including neutropenic fever, enterocolitis, and capillary leak syndrome, were observed in eight patients but were manageable. Conclusions: The incorporation of dinutuximab beta into a modified N7 induction regimen demonstrates a satisfactory EOI response rate and a manageable safety profile in children with HR-NB. These preliminary results support the feasibility of this chemoimmunotherapy approach and warrant further investigation in larger cohorts to confirm its efficacy in long-term survival outcomes.