Sponsor: St. Jude Children's Research Hospital (other)
Phase: 1
Start date: July 6, 2022
Planned enrollment: 32
B7-H3 CAR-T therapies are autologous or allogeneic chimeric antigen receptor T cells engineered to recognize B7-H3 (CD276), a checkpoint-like immunomodulatory molecule overexpressed across many solid tumors and associated with poor outcomes. Clinical-stage programs include TX103 for recurrent glioblastoma (rGBM) and a fourth‑generation construct 4SCAR‑276 being studied in B7‑H3–positive solid tumors. Interim human data have been presented for TX103 in rGBM; other programs (e.g., 4SCAR‑276) remain in early-phase evaluation without published response outcomes to date. (aacrjournals.org)
TX103 (autologous B7‑H3 CAR‑T; rGBM) - Study: Phase 1, single‑arm, dose‑escalation with intracavitary and/or intraventricular administration via Ommaya; NCT05241392. Interim ASCO 2024 abstract reported 13 treated patients between March 2022 and January 2024. (ascopubs.org) - Outcomes (interim): Among six patients from dose levels 1–2 evaluable for 12‑month survival as of January 2024, 12‑month OS was 83.3% (95% CI 58.3–100); median OS 20.3 months (95% CI 20.3–not reached). In dose level 2, two of three patients achieved partial and complete responses, respectively. CSF cytokines (e.g., IL‑6, IFN‑γ) and CAR transgene copies increased post‑infusion, with minimal peripheral changes. (ascopubs.org)
Allogeneic B7‑H3 CAR‑T in recurrent high‑grade glioma (for context; different product) - MT027 UCAR‑T IIT (ChiCTR2100047968): ASCO 2023/2024 abstracts reported favorable tolerability with no grade ≥3 toxicities; 12‑month OS 85.7% (95% CI 48.7–97.4) in one analysis; PK/PD showed CSF persistence and cytokine increases. These are single‑center, early‑phase data. (ascopubs.org)
4SCAR‑276 (B7‑H3 CAR‑T; fourth‑generation) - Multicenter Phase I/II trial in B7‑H3–positive solid tumors (NCT04432649) is listed; as of the latest registry snapshots, no results are posted. (cdek.pharmacy.purdue.edu)
TX103 (NCT05241392; interim)
- No dose‑limiting toxicities or treatment‑related deaths reported among 13 patients.
- Treatment‑related adverse events included cytokine release syndrome, increased intracranial pressure, headache, seizures, decreased consciousness, vomiting, and fever; most were grade 1–2. Three grade‑3 events occurred (increased intracranial pressure at dose level 2; seizure and decreased level of consciousness at dose level 3). (ascopubs.org)
Allogeneic B7‑H3 UCAR‑T (context) - Early reports noted no grade ≥3 toxicities, with most common events being fever and headache; no CRS/ICANS/GvHD observed in the presented dataset. (ascopubs.org)
Notes: Published evidence to date is primarily from conference abstracts and trial registries; peer‑reviewed, full clinical manuscripts for these specific products were not identified as of October 7, 2025.
Last updated: Oct 2025
Goal: Determine the safety profile and maximum tolerated dose of a single intravenous infusion of autologous B7-H3–directed CAR T cells following lymphodepleting chemotherapy in pediatric and young adult patients with relapsed/refractory B7-H3–positive solid tumors, and to explore preliminary antitumor activity and biologic correlates.
Patients: Children, adolescents, and young adults aged 21 years or younger with measurable, relapsed or refractory B7-H3–positive solid tumors confirmed by IHC (H-score ≥100), adequate organ function, performance status ≥50, and an estimated life expectancy >8–12 weeks depending on stage. Key exclusions include primary immunodeficiency, HIV infection, severe uncontrolled infections (including active hepatitis B/C), hypersensitivity to murine proteins, rapidly progressive disease, and recent/high-dose systemic steroids or therapies expected to interfere with CAR T activity.
Design: Single-center, phase 1, nonrandomized, dose-escalation study using a standard 3+3 design with a 6-week DLT evaluation window to define the maximum tolerated dose. Total study duration is 1 year, after which patients transition to a long-term follow-up protocol for recipients of gene-modified cell products.
Treatments: Lymphodepleting chemotherapy with fludarabine and cyclophosphamide with MESNA support followed by a single intravenous infusion of autologous B7-H3 CAR T cells. B7-H3 CAR T cells are engineered autologous T cells expressing a CAR against CD276 (B7-H3), a checkpoint-like antigen broadly overexpressed across pediatric solid and CNS tumors with limited normal tissue expression. Second-generation B7-H3 CAR constructs have shown preclinical potency and emerging clinical activity, particularly in locoregional CNS delivery settings; early phase studies in pediatric DIPG and recurrent glioblastoma have reported feasible administration, manageable toxicity, and signals of antitumor activity. Safety profiles to date are consistent with CAR T–related inflammatory toxicities, with variable rates of neuroinflammatory events depending on route and disease context.
Outcomes: Primary: safety and maximum tolerated dose based on dose-limiting toxicities within 6 weeks; dose levels include 3×10^5/kg, 1×10^6/kg, 3×10^6/kg, and 1×10^7/kg CAR+ T cells. Secondary: objective response rate per RECIST v1.1 at 6 weeks. Exploratory: changes in tumor microenvironment; immunophenotype, clonal structure, and repertoire of CAR and non-CAR T cells; and peripheral blood cytokine profiling after infusion.
Burden on patient: High. Participants undergo leukapheresis for cell manufacture (if not previously collected), lymphodepleting chemotherapy requiring inpatient or intensive outpatient monitoring, and a single CAR T infusion followed by close observation during a 6-week DLT window with frequent clinic visits, labs, and potential cytokine/immune monitoring. Additional imaging for response assessment at 6 weeks and research blood draws for correlative studies are expected. Management of potential acute toxicities such as cytokine release syndrome or neurotoxicity may necessitate hospitalization, adding travel and time demands. Transition to long-term follow-up for gene-modified cell recipients increases duration of monitoring beyond the primary study year.
Last updated: Oct 2025
Inclusion Criteria:
Procurement and T-cell production eligibility\*
\*a previously collected, autologous leukapheresis product can be used for T-cell production
* Age ≤21 years old
* B7-H3+ solid tumor with measurable disease; B7-H3 expression will be evaluated by standard immunohistochemistry (IHC) using a previously obtained biopsy; a tumor is considered B7-H3 positive with an H-score ≥100
* Estimated life expectancy of \>12 weeks
* Karnofsky or Lansky (age-dependent) performance score ≥50
* For females of child bearing age:
* Not pregnant with negative serum pregnancy test within 7 days prior to enrollment
* Not lactating with intent to breastfeed
* Meets eligibility criteria to undergo autologous apheresis, or have previously undergone autologous apheresis
Exclusion Criteria:
* Known primary immunodeficiency
* Known HIV positivity
* Severe intercurrent bacterial, viral or fungal infection (e.g. active hepatitis B or C infection or adenovirus infection)
* History of hypersensitivity reactions to murine protein-containing products
* Rapidly progressive disease (in the opinion of the study PIs)
Inclusion criteria
Treatment eligibility
* Age ≤21 years old
* B7-H3+ solid tumor with measurable disease
* Evidence of relapsed or refractory disease after standard first-line therapy
* Estimated life expectancy of \>8 weeks
* Karnofsky or Lansky (age-dependent) performance score≥50
* Echocardiogram with a ventricular ejection fraction
* \>40%; or shortening fraction ≥25%
* Adequate renal function defined as creatinine clearance or radioisotope GFR 50 ml/min/1.73m2 (GFR 40 ml/min/1.73m2 if \< 2 years of age)
* Adequate pulmonary function defined as pulse oximetry ≥92% on room air or forced vital capacity (FVC) ≥50% of predicted value
* Total Bilirubin ≤3 times the upper limit of normal for age, except in subjects with Gilbert's syndrome
* Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤5 times the upper limit of normal for age
* Hemoglobin≥ 7g/dL (can be transfused)
* Platelet count \>50,000/uL (can be transfused)
* Absolute neutrophil count (ANC) ≥ 1000/uL
* Has recovered from all NCI CTAE grade III-IV, non-hematologic acute toxicities from prior therapy
* For females of child bearing age:
* Not pregnant with negative serum pregnancy test within 7 days prior to enrollment
* Not lactating with intent to breastfeed
* If sexually active, agreement to use birth control until 3 months after T-cell infusion. Male partners should use a condom.
* Available autologous transduced T-cell product that has met GMP release criteria
* Agreement to participate in long-term follow-up protocol for patients, who have received genetically modified cell products
Exclusion criteria
* Known primary immunodeficiency
* History of HIV infection
* Severe, uncontrolled intercurrent bacterial, viral or fungal infection
* History of hypersensitivity reactions to murine protein-containing products
* Receiving systemic steroid therapy exceeding the equivalent of 0.5 mg/kg/day of methylprednisolone, in the 7 days prior to B7-H3-CAR T-cell infusion
* Receiving systemic therapy in the 14 days prior to CAR T-cell infusion, which will interfere with the activity of the B7-H3-CAR product (in the opinion of the study PIs).
* Rapidly progressing disease (in the opinion of the study PIs)
Memphis, Tennessee, 38105, United States
[email protected] / 866-278-5833
Status: Recruiting