GPC3-targeted CAR T cells armored with IL-15 and IL-21 for pediatric non‑CNS solid tumors

Immunotherapy for Solid Tumor Malignancies in Pediatrics Using Interleukin-15 and -21 Armored Glypican-3-specific Chimeric Antigen Receptor T Cells

Phase 1 Interventional Seattle Children's Hospital · NCT07148050

This treatment will try personalized CAR T cells that target GPC3 and are engineered to make IL‑15 and IL‑21 in children and young adults with relapsed or refractory non‑CNS solid tumors that express GPC3.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment21 (estimated)
Ages1 Year to 26 Years
SexAll
SponsorSeattle Children's Hospital Academic / other
Drugs / interventionsCAR T, chemotherapy, prednisone, chimeric antigen receptor, cyclophosphamide, fludarabine
Locations1 site (Seattle, Washington)
Trial IDNCT07148050 on ClinicalTrials.gov

What this trial studies

This Phase 1, open-label, non-randomized protocol enrolls pediatric and young adult patients with relapsed or refractory non‑CNS solid tumors that express glypican‑3 (GPC3). A blood sample is collected from each eligible patient and peripheral blood mononuclear cells are genetically modified to co‑express a GPC3‑specific CAR, interleukin‑15, interleukin‑21, and an inducible caspase‑9 safety switch (SC‑CAR.GPC3xIL15.21). The manufactured CAR T cells are infused and patients are monitored closely for safety, feasibility of manufacturing/delivery, and early signs of anti‑tumor activity. Preclinical comparisons showed that CAR T cells with IL‑15 and IL‑21 had improved tumor killing versus CAR T cells without those cytokines, and the product is investigational and not FDA approved.

Who should consider this trial

Good fit: Children and young adults with relapsed or refractory non‑CNS solid tumors that test positive for GPC3, with Lansky/Karnofsky ≥60% and life expectancy >16 weeks, are the intended participants.

Not a fit: Patients whose tumors do not express GPC3, those with active serious infections, prior organ transplantation, known HIV, or significant hypersensitivity to murine proteins are unlikely to be eligible or to benefit from this approach.

Why it matters

Potential benefit: If successful, these armored CAR T cells could persist longer and be more potent against GPC3‑positive tumors, potentially shrinking or controlling disease in some patients.

How similar studies have performed: CAR T therapies have been highly successful in blood cancers but have shown limited success in solid tumors; GPC3‑targeted CARs and cytokine 'armoring' have encouraging preclinical results and limited early clinical signals but remain largely experimental.

Eligibility criteria

Show full inclusion / exclusion criteria
1. Procurement Eligibility

   Inclusion Criteria:
   * Diagnosis of a solid tumor expressing GPC3
   * Lansky or Karnofsky score of \>=60%
   * Life expectancy of \>16 weeks
   * Informed consent explained to, understood by and signed by patient/guardian.

   For patients with hepatocellular carcinoma only:
   * Barcelona Liver Cancer Stage A, B or C
   * Child-Pugh Turcotte Score \<7

   Exclusion Criteria:
   * History of hypersensitivity reactions to murine protein-containing products OR presence of human anti-mouse antibody (HAMA) prior to enrollment for patients who have received prior therapy with murine antibodies.

     * History of organ transplantation
     * Known HIV positivity
     * Active bacterial, fungal, or viral infection (except Hepatitis B or Hepatitis C virus infections)
2. Treatment eligibility

Inclusion Criteria:

* Lansky or Karnofsky score of \>=60%
* Life expectancy of \>16 weeks
* Informed consent explained to, understood by and signed by patient/guardian.
* Adequate organ function
* Adequate laboratory values
* Refractory or relapsed disease after treatment with up- front therapy and at least one salvage treatment cycle
* Recovered from acute toxic effects of all prior chemotherapy and investigational agents before entering this study
* Sexually active patients must be willing to utilize one of the more effective birth control methods for 12 months after the T-cell infusion.
* Informed consent explained to, understood by and signed by patient/guardian.

For patients with hepatocellular carcinoma only:

* Barcelona Liver Cancer Stage A, B or C
* Child-Pugh Turcotte Score \<7

Exclusion Criteria:

* History of hypersensitivity reactions to murine protein-containing products OR presence of human anti-mouse antibody (HAMA) prior to enrollment for patients who have received prior therapy with murine antibodies.

  * History of organ transplantation
  * Known HIV positivity
* Active autoimmune or inflammatory disorder
* Live vaccines within 30 days prior to enrollment

  • Active bacterial, fungal, or viral infection (except Hepatitis B or Hepatitis C virus infections)
* Pregnancy or lactation
* Uncontrolled infection
* Systemic steroid treatment (≥ 0.5 mg prednisone equivalent/kg/day, dose adjustment or discontinuation of medication must occur at least 24hrs prior to CAR T cell infusion)
* Congestive heart failure (as defined by New York Heart Association Functional Classification III or IV), unstable angina, serious uncontrolled cardiac arrhythmia, a myocardial infarction within 6 months prior to study entry or a history of myocarditis.

Where this trial is running

Seattle, Washington

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Solid TumorLiver Cell CarcinomaMalignant Rhabdoid TumorYolk Sac TumorLiposarcomaRhabdomyosarcomaEmbryonal Sarcoma of LiverWilms Tumor
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.