Haploidentical Stem Cell Transplantation for Refractory/Relapsed Neuroblastoma

Area of Science:

• Pediatric Oncology
• Hematology
• Immunology

Background:

• Pediatric neuroblastoma (NBL) with refractory or relapsed metastatic disease has a poor prognosis, even after autologous stem cell transplantation (SCT).
• Allogeneic SCT from haploidentical donors demonstrates significant alloreactive effects in leukemia treatment, suggesting potential for other high-risk pediatric cancers.

Purpose of the Study:

• To evaluate the efficacy and safety of haploidentical allogeneic SCT in pediatric patients with very high-risk neuroblastoma (NBL).
• To assess engraftment, survival rates, and graft-versus-host disease (GVHD) incidence in this patient cohort.

Main Methods:

• Analysis of data from 2 prospective phase I/II trials involving 26 pediatric patients with refractory, relapsed metastatic, or locally relapsed MYCN-positive NBL.
• Patients received T/B cell-depleted CD34+ stem cells from a haploidentical donor, along with a specific conditioning regimen and post-transplantation immunosuppression.

Main Results:

• Successful engraftment was achieved in 96% of patients.
• Five-year event-free survival (EFS) and overall survival (OS) were 19% and 23%, respectively.
• No transplantation-related mortality was observed; Grade II/III acute GVHD occurred in 43% and chronic GVHD in 38% of patients.

Conclusions:

• Haploidentical SCT is a feasible treatment for pediatric neuroblastoma (NBL) with refractory or relapsed disease, offering a potential for long-term remission and manageable side effects.
• Patients achieving complete remission before SCT had a significantly better prognosis.
• This approach may facilitate the development of novel post-transplantation immunotherapies leveraging the donor immune system.