A single-centre, non-randomised, open label Phase I clinical trial of an Advanced Therapy Investigational Medicinal Product (ATIMP) in children and teenagers aged 1-16 years with relapsed or refractory neuroblastoma. The study will assess the feasibility of generating the ATIMP (GD2 CAR T cells) and the safety of administering the ATIMP in participants with relapsed or refractory neuroblastoma. A total of 12 participants will be treated at 1 participating site.

Participants will undergo an unstimulated leucapheresis for the generation of the ATIMP which will take approximately 15 days to generate. Participants will receive lymphodepleting (LD) chemotherapy with fludarabine administered over 4 days(Day -6 to Day -3) and cyclophosphamide administered over 2 days (Day -4 and Day-3). This will be followed by CAR T cells infusion administered on Day 0. Participants will be followed up regularly until 1-year post-ATIMP infusion.  After 1 year, participants will continue to be followed up annually until 15 years post ATIMP infusion.

Key inclusion criteria:

• Age between 1 and 16 years;
• Tissue diagnosis of neuroblastoma;
• Disease which has relapsed after or is refractory to at least one line of salvage combination chemotherapy;
• Measurable/evaluable disease by imaging;
• Absolute lymphocyte count ≥ 0.25 x 109/L;
• Creatinine needs to be less than 1.5 of upper limit of normality for age (if higher, an estimated (calculated) creatinine clearance must be ≥ 60 ml/min/1.73 m2).

• Patients with only bone marrow detectable disease (in the absence of measurable disease by imaging);
• Active, inoperative CNS disease including leptomeningeal disease;
• Active HepB, HepC or HIV infection