4SCAR-T Therapy Targeting GD2, PSMA and CD276 for Treating Neuroblastoma

Neuroblastoma is one of the most aggressive childhood tumors arising from neural crest cells. Nearly 50% of patients with high risk disease have poor long-term survival even after multimodal treatments. Novel immunotherapy targeting tumor-specific antigens has been developed to meet the desperate need.

Disialoganglioside (GD2) is a well-studied tumor associated antigen which is expressed uniformly in NB but restrictedly in normal tissue. Over the past few years, CAR-T therapy against GD2 in NB has achieved encouraging but modest outcomes. Only a fraction of patients achieved measurable responses. Like for many other solid tumors, CAR-T therapy for NB is not as effective as for hematologic malignancies.

In this study, the investigators use "multiple targeting" approach as the strategy to overcome the challenge in treating NB. Prostate-specific membrane antigen (PSMA) is expressed in normal prostate but is upregulated in prostate tumor. However, PSMA expression is not restricted to prostate cancer. By immunohistochemistry (IHC) staining, the investigators confirmed that PSMA is expressed in a variety of solid tumors, including brain tumor, neuroblastoma and some lymphoma tumor tissues. Therefore, PSMA could potentially serve as a promising target for antigen-specific immunotherapy in patients with NB. In addition, CD276 (B7-H3) is an immune checkpoint molecule highly expressed on many solid tumors including NB. CD276 has been characterized to be involved in tumor evasion and thus its expression is correlated with poor prognosis. These characteristics make CD276 an attractive candidate for immunotherapy. Given the significant variation of tumor antigen expression among patients, the investigators aim to examine GD2, PSMA and CD276 expression in each patient's tumor sections by IHC staining, and combine two or three highly-expressed targets for the 4SCAR-T therapy. This individualized and multi-antigen-targeted approach is a new strategy to overcome the limited clinical outcome in the 4SCAR-T therapy against NB.

The purpose of this clinical study is to assess the feasibility, safety and efficacy of the combinational GD2, PSMA and CD276 4SCAR-T cell therapy against NB. Another goal of the study is to learn more about the function of the multi-4SCAR-T cells and their persistency in the patients.

Inclusion criteria

• Patients with tumors have received standard first-line therapy and been judged to be non-resectable, metastatic, progressive or recurrent.
• The expression status of GD2, PSMA and CD276 antigens of the tumor will be determined for eligibility. Positive expression is defined by GD2, PMSA and CD276 antibody staining results based on immunohistochemistry or flow cytometry analyses.
• Body weight greater than or equal to 10 kg.
• Age: ≥1 year and ≤ 65 years of age at the time of enrollment.
• Life expectancy: at least 8 weeks.
• Prior Therapy:

• There is no limit to the number of prior treatment regimens. Any grade 3 or 4 non-hematologic toxicity of any previous therapy must have resolved to grade 2 or less.
• Participant must not have received hematopoietic growth factors for at least 1 week prior to mononuclear cells collection.
• At least 7 days must have elapsed since the completion of therapy with a biologic agent, targeted agent, tyrosine kinase inhibitor or a metronomic non-myelosuppressive regimen.
• At least 4 weeks must have elapsed since prior therapy that included a monoclonal antibody.
• At least 1 week since any radiation therapy at the time of study entry.
• Karnofsky/jansky score of 60% or greater.
• Cardiac function: Left ventricular ejection fraction greater than or equal to 40/55 percent.
• Pulse Ox greater than or equal to 90% on room air.
• Liver function: defined as alanine transaminase (ALT) <3x upper limit of normal (ULN), aspartate aminotransferase (AST) <3x ULN; serum bilirubin and alkaline phosphatase <2x ULN.
• Renal function: Patients must have serum creatinine less than 3 times upper limit of normal.
• Marrow function: White blood cell count ≥1000/ul, Absolute neutrophil count ≥500/ul, Absolute lymphocyte count ≥500/ul, Platelet count ≥25,000/ul (not achieved by transfusion).
• Patients with known bone marrow metastatic disease will be eligible for study as long as they meet hematologic function criteria, and the marrow disease not evaluable for hematologic toxicity.
• For all patients enrolled in this study, their parents or legal guardians must sign an informed consent and assent.

Exclusion criteria

• Existing severe illness (e.g. significant cardiac, pulmonary, hepatic diseases, etc.) or major organ dysfunction, with the exception of grade 3 hematologic toxicity.
• Untreated central nervous system (CNS) metastasis: Patients with previous CNS tumor involvement that has been treated and is stable for at least 6 weeks following completion of therapy are eligible.
• Previous treatment with other genetically engineered GD2, PSMA and CD276 CART cells.
• Active HIV, Hepatitis B virus (HBV), Hepatitis C virus (HCV) infection or uncontrolled infection.
• Patients who require systemic corticosteroid or other immunosuppressive therapy.
• Evidence of tumor potentially causing airway obstruction.
• Inability to comply with protocol requirements.
• Insufficient CART cells availability.