Navin Pinto

Risk-based treatment approaches for neuroblastoma have been ongoing for decades. However, the criteria used to define risk in various institutional and cooperative groups were disparate, limiting the ability to compare clinical trial results. To mitigate this problem and enhance collaborative research, homogenous pretreatment patient cohorts have been defined by the International Neuroblastoma Risk Group classification system. During the past 30 years, increasingly intensive, multimodality approaches have been developed to treat patients who are classified as high risk, whereas patients with low- or intermediate-risk neuroblastoma have received reduced therapy. This treatment approach has resulted in improved outcome, although survival for high-risk patients remains poor, emphasizing the need for more effective treatments. Increased knowledge regarding the biology and genetic basis of neuroblastoma has led to the discovery of druggable targets and promising, new therapeutic approaches. Collaborative efforts of institutions and international cooperative groups have led to advances in our understanding of neuroblastoma biology, refinements in risk classification, and stratified treatment strategies, resulting in improved outcome. International collaboration will be even more critical when evaluating therapies designed to treat small cohorts of patients with rare actionable mutations.

Diffuse intrinsic pontine glioma (DIPG) remains a fatal brainstem tumor demanding innovative therapies. As B7-H3 (CD276) is expressed on central nervous system (CNS) tumors, we designed B7-H3-specific chimeric antigen receptor (CAR) T cells, confirmed their preclinical efficacy, and opened BrainChild-03 (NCT04185038), a first-in-human phase I trial administering repeated locoregional B7-H3 CAR T cells to children with recurrent/refractory CNS tumors and DIPG. Here, we report the results of the first three evaluable patients with DIPG (including two who enrolled after progression), who received 40 infusions with no dose-limiting toxicities. One patient had sustained clinical and radiographic improvement through 12 months on study. Patients exhibited correlative evidence of local immune activation and persistent cerebrospinal fluid (CSF) B7-H3 CAR T cells. Targeted mass spectrometry of CSF biospecimens revealed modulation of B7-H3 and critical immune analytes (CD14, CD163, CSF-1, CXCL13, and VCAM-1). Our data suggest the feasibility of repeated intracranial B7-H3 CAR T-cell dosing and that intracranial delivery may induce local immune activation. SIGNIFICANCE: This is the first report of repeatedly dosed intracranial B7-H3 CAR T cells for patients with DIPG and includes preliminary tolerability, the detection of CAR T cells in the CSF, CSF cytokine elevations supporting locoregional immune activation, and the feasibility of serial mass spectrometry from both serum and CSF. This article is highlighted in the In This Issue feature, p. 1.

PURPOSE: Case reports and small prospective trials suggest that administering targeted therapies to patients with advanced cancer and an identified genomic target may be associated with clinical benefit. The TAPUR Study, a phase II, prospective, non-randomized, multi-basket, pragmatic clinical trial aims to identify signals of drug activity when Food and Drug Administration (FDA) approved drugs are matched to pre-specified genomic targets in patients with advanced cancer, outside of approved indications. METHODS: Patients eligible to participate in TAPUR are ages 12 years and older, with advanced, measurable or evaluable solid tumors, multiple myeloma or B cell non-Hodgkin lymphoma. Eligible participants are matched to any of the sixteen FDA approved study drugs based on protocol specified genomic inclusion and exclusion criteria. Genomic profiling from any Clinical Laboratory Improvement Amendments certified, College of American Pathologists accredited laboratory is acceptable. The treating physician selects the treatment from the available study therapies, or consults with the TAPUR Molecular Tumor Board. Participants are placed into multiple parallel cohorts defined by tumor type, genomic alteration and drug. The primary study endpoint within each cohort is objective response or stable disease of at least 16 weeks duration. Secondary endpoints include safety, progression-free survival and overall survival. RESULTS: More than 1000 participants have thus far been registered and more than 800 treated with a TAPUR study drug. Two study cohorts have permanently closed to enrollment due to lack of anti-tumor activity and 12 have expanded to the second stage of enrollment due to promising preliminary activity. CONCLUSION: The TAPUR Study will describe the efficacy and toxicity of the targeted drugs used outside of their approved indications when matched to a somatic genomic variant.