Dual-Target GD2/B7-H3 CAR-NK Cells for Pediatric Relapsed or Refractory Neuroblastoma

The investigational product in this example is a cord blood-derived allogeneic NK-cell therapy engineered to express a dual-target CAR recognizing GD2 and B7-H3, supported by IL-15 to improve short-term persistence and equipped with an inducible safety switch. The study is designed as a multicenter Phase 1/Phase 2 protocol: Part A uses a standard 3+3 dose-escalation approach across predefined dose levels, and Part B expands at the RP2D in a biomarker-characterized population. All participants undergo central review of tumor tissue or marrow for GD2 and B7-H3 expression before treatment. Patients receive protocol-defined lymphodepletion followed by CAR-NK infusion on Day 0, with optional additional infusions on Days 7 and 14 if there is no dose-limiting toxicity (DLT), uncontrolled cytokine release syndrome (CRS), or rapid progression. Formal disease assessment uses revised International Neuroblastoma Response Criteria (rINRC). Correlative studies assess CAR-NK expansion and persistence, cytokine kinetics, tumor-response associations with antigen density, and whether future development should remain dualtarget or shift toward a GD2-dominant or B7-H3-enriched strategy. Long-term follow-up for gene-modified cellular therapy is planned per local regulatory requirements.

• EB-DTNB-NK (Biological), also known as Dual-target GD2/B7-H3 CAR-NK: Allogeneic, cord blood-derived NK cells engineered with a dual-target CAR recognizing GD2 and B7-H3 (CD276), with IL-15 support and an inducible safety switch; administered intravenously on Day 0 with optional repeat dosing on Days 7 and 14 if tolerated.
• Fludarabine (Drug), also known as Flu: Lymphodepleting chemotherapy administered before CAR-NK infusion according to the protocol-defined conditioning regimen.
• Cyclophosphamide (Drug), also known as Cy: Lymphodepleting chemotherapy administered before CAR-NK infusion according to the protocol-definedb conditioning regimen.

Primary outcomes

• Incidence of dose-limiting toxicities (DLTs) after first CARNK infusion, using protocol-defined DLT criteria. [28 days]
• Incidence and severity of treatment-emergent adverse events [12 months]: Incidence and severity of treatment-emergent adverse events, including CRS and ICANS, graded using CTCAE v5.0 and ASTCT consensus criteria.

Secondary outcomes

• Objective response rate by revised International Neuroblastoma Response Criteria (rINRC). [12 months]
• Duration of response among responders [24 months]
• Progression-free survival [12 months]
• Overall survival [24 months]

Sex: All, ages: 12 Months to 21 Years

Inclusion Criteria:

* Age 12 months to 21 years at consent/assent.
* Histologically confirmed neuroblastoma or ganglioneuroblastoma with relapsed, refractory, progressive, or persistent high-risk disease for which no curative standard option is available.
* Measurable or evaluable disease according to revised International Neuroblastoma Response Criteria (rINRC), including MIBG-avid disease, CT/MRI-evaluable soft-tissue disease, and/or bone marrow disease.
* Tumor material available for central assessment of GD2 and B7-H3 expression; at least one target must be positive.

GD2 is treated as the core target and B7-H3 as the complementary target for correlative target-prioritization analyses.

* Prior exposure to standard neuroblastoma therapy, including anti-GD2-based therapy, unless contraindicated, unavailable, or declined for a documented medical reason.
* Lansky or Karnofsky performance score >= 50.
* Life expectancy >= 8 weeks.
* Recovery from clinically significant acute toxicities of prior therapy and protocol-defined washout from chemotherapy, biologics, radiation, and prior cell therapy.
* Adequate organ function: hematologic, renal, hepatic, cardiac, and pulmonary function considered sufficient by protocoldefined laboratory and clinical thresholds.
* Negative pregnancy test for patients of childbearing potential and agreement to use effective contraception during the protocol-defined period.
* Written informed consent from parent/legal guardian and assent from the participant when appropriate.

Exclusion Criteria:

* Active uncontrolled infection, including bacteremia, uncontrolled viral infection, or invasive fungal disease.
* Pregnancy or breastfeeding.
* Active grade >= 2 graft-versus-host disease, or systemic immunosuppression for treatment/prevention of graft-versushost disease within the protocol-defined washout period after prior allogeneic transplant.
* Symptomatic or unstable central nervous system disease requiring urgent medical intervention.
* Prior genetically modified cellular therapy within the protocol-defined washout window, or unresolved clinically significant toxicity from prior cell therapy.
* Active autoimmune disease requiring systemic immunosuppressive therapy.
* Clinically significant uncontrolled cardiovascular, pulmonary, hepatic, renal, or neurologic disorder that would increase study risk.
* Known hypersensitivity to fludarabine, cyclophosphamide, study-product components, or supportive-care medications required by the protocol.
* Known uncontrolled HIV infection or uncontrolled hepatitis B or C.
* Any medical, psychosocial, or logistical condition that, in the investigator's judgment, would make study participation unsafe or would impair protocol adherence.