Effect and Tolerance of N5 and N6 Chemotherapy Cycles in Combination with Dinutuximab Beta in Relapsed High-Risk Neuroblastoma Patients Who Failed at Least One Second-Line Therapy

SIMPLE SUMMARY: Dinutuximab beta is an antibody approved for the maintenance treatment of patients with high-risk neuroblastoma. It is being investigated in combination with different established chemotherapy regimens in various clinical settings. We reviewed the clinical charts of 25 patients with relapsed/refractory neuroblastoma who had failed one or more second-line treatments and were given compassionate use treatment with dinutuximab beta long-term infusion combined with two induction chemotherapy regimens (N5 and N6), recommended by German guidelines. We found no unexpected severe toxicities. Grade 3/4 pain was reported in treatment cycle 1 by four patients, which was reduced to no patients by cycles 3 and 4. Almost half (48%) of patients had a complete, partial or minor response to treatment, despite previous treatment failures. Therefore, combining long-term infusion of dinutuximab beta with these chemotherapy regimens during earlier treatment phases may be beneficial for patients with relapsed/refractory neuroblastoma and should be further evaluated in clinical trials. ABSTRACT: The anti-disialoganglioside (GD2) monoclonal antibody dinutuximab beta is approved for the maintenance treatment of high-risk neuroblastoma. Dinutuximab beta combined with different chemotherapy regimens is being investigated in various clinical settings. We conducted a retrospective clinical chart review of 25 patients with relapsed/refractory neuroblastoma who had failed ≥1 second-line therapy and received compassionate use treatment with dinutuximab beta long-term infusion combined with the induction chemotherapy regimens N5 (cisplatin, etoposide, vindesine) and N6 (vincristine, dacarbazine, ifosfamide, doxorubicin) recommended by the German Pediatric Oncology and Hematology Group [GPOH] guidelines. The treatment did not result in any unexpected severe toxicities or in any major treatment delays. Grade 3/4 pain was reported by 4/25 patients in cycle 1, decreasing to 0/9 patients in cycles 3 and 4. The median follow-up was 0.6 years. The best response in this group was 48% (12/25 patients), which included three patients with minor responses. At 1 year, the estimated event-free survival was 27% (95% confidence interval [CI] 8–47) and overall survival was 44% (95% CI 24–65). Combining long-term infusion of dinutuximab beta with N5 and N6 chemotherapy demonstrated an acceptable safety profile and encouraging objective response rates in heavily pretreated patients with high-risk neuroblastoma, warranting further evaluation in clinical trials.