Evaluating Efficacy of B7-H3-CAR T Cells Administered at the End of Upfront Map Chemotherapy in Patients With Newly Diagnosed High-Risk Osteosarcoma

May 18, 2026 updated by: St. Jude Children's Research Hospital

A Phase II Study Evaluating Efficacy of B7-H3-CAR T Cells Administered at the End of Upfront Map Chemotherapy in Patients With Newly Diagnosed High-Risk Osteosarcoma

The purpose of this study is to assess the safety, feasibility, and effectiveness of a consolidative B7-H3 CAR T cell therapy in patients with newly diagnosed high-risk osteosarcoma who have undergone upfront standard chemotherapy.

Primary Objectives:

- To evaluate 1-year RFS from the time of SJCARB7H3_41BBL infusion for patients with newly diagnosed metastatic osteosarcoma who received standard chemotherapy.

Secondary Objectives:

  • To evaluate the OS from time of SJCARB7H3_41BBL infusion for patients with newly diagnosed metastatic osteosarcoma who received standard chemotherapy.
  • To evaluate the feasibility of delivering SJCARB7H3_41BBL at the end of standard therapy in patients with newly diagnosed metastatic osteosarcoma.
  • To describe the safety of autologous SJCARB7H3_41BBL therapy when delivered at the end of standard therapy in patients with newly diagnosed metastatic osteosarcoma.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a phase 2 study of SJCARB7H3_41BBL for participants with newly diagnosed high-risk metastatic osteosarcoma who received standard chemotherapy.

All participants will receive standard chemotherapy (for example methotrexate, anthracycline, platinum), local control surgery, and pulmonary metastasectomy if applicable, and this is not considered part of protocol therapy. Participants will undergo apheresis prior to standard local control surgery (about 12 weeks after diagnosis) for SJCARB7H3_41BBL manufacture and then resume standard consolidation therapy. A safety run will initiate with Regimen A. For Regimen A, eligible participants with available SJCARB7H3_41BBL product will receive lymphodepletion chemotherapy 14-28 days after the completion of standard chemotherapy (31 weeks after diagnosis), followed by SJCARB7H3_41BBL infusion. If Regimen A is not cleared, then Regimen B will be evaluated, where lymphodepletion and SJCARB7H3_41BBL infusion occur post pulmonary metastasectomy. Following successful clearance of either regimen A or, if necessary, regimen B, then the efficacy cohort will be initiated. Participants will be followed with serial disease evaluations for 2 years from SJCARB7H3_41BBL infusion prior to transfer to our institutional long-term follow-up (LTFU) protocol. The total duration from completion of standard therapy, including experimental therapy and follow-up on 3CAR4OS, is approximately 2 years.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
41

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Tennessee
      • Memphis, Tennessee, United States, 38105-2794
        • Recruiting
        • St. Jude Children's Research Hospital
        • Principal Investigator:
          • Julie Park, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Participant and/or legally authorized representative has signed the Informed Consent Form for this study

  2. Prior cancer therapy:

    • Regimen A only: Completed all planned cycles of consolidation therapy between 14-28 days prior.
    • Regimen B only: has completed all planned cycles of consolidation chemotherapy at least 14 days prior and if clinically indicated, participant has undergone pulmonary metastasectomy. They must have recovered from any surgical complications with no ongoing sequelae of category 2 or higher by the Clavien-Dindo classification system and less than 6 weeks must have passed from time of pulmonary metastasectomy.
  3. No evidence of progressive disease since enrolled on study
  4. Lansky performance status score of ≥ 50 for participants <16 years of age or Karnofsky score ≥ 50 for participants ≥ 16 years. Participants who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for purposes of assessing performance status

  5. Adequate organ function as indicated by:

    • Renal: Serum creatinine ≤ 1.5 X the upper limit of normal (ULN) based on enrollment eligibility table.
    • Hepatic: Total bilirubin ≤ 3 times ULN for age OR conjugated bilirubin ≤ 2 mg/dL AND ALT (SGPT) ≤ 5 times ULN
    • Cardiac: Shortening fraction ≥ 28% OR ejection fraction ≥ 50% as measured by echocardiogram
    • Respiratory: Oxygen saturation ≥ 90% on room air without supplemental oxygen or mechanical ventilation

  6. Laboratory values meet the following criteria:

    • Absolute Neutrophil Count (ANC) ≥ 750 cells/uL
    • Platelet Count of ≥ 75,000 (can be transfused)
    • Hemoglobin ≥ 7 g/dL (can be transfused)
  7. Participant is ≥ 7 days from receiving supra-physiologic dosing of systemic (IV or PO) corticosteroids. Glucocorticosteroid physiologic replacement therapy for management of adrenal insufficiency is allowed.
  8. Participant and/or legally authorized representative has signed the Informed Consent Form for the treatment phase of this study.

Exclusion Criteria:

  1. Major surgical adverse event related to the primary tumor local control defined as Clavien-Dindo category 3 requiring ongoing wound care.
  2. Evidence of clinically significant encephalopathy/new focal neurologic deficits.

  3. Presence of active severe infection, defined as:

    • positive blood culture within 48 hours of enrollment, OR
    • fever above 38.2° C, AND clinical signs of infection within 48 hours of enrollment

  4. Participant has received prior disease-directed therapy other than 1st line therapy with methotrexate, an anthracycline, and a platinum and local control surgery

    • Regimen B only - okay to have undergone initial pulmonary metastasectomy

  5. Pregnant or breastfeeding
  6. Presence of any condition that, in the opinion of the investigator, would prohibit the participant from undergoing treatment under this protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: 3CAR4OS Treatment
All patients will receive standard of care chemotherapy, which is not considered part of protocol therapy. Eligible patients will undergo apheresis prior to standard local control surgery for CAR T cell manufacture and then resume standard therapy. In the absence of progressive disease, eligible patients with available SJCARB7H3_41BBL product will receive lymphodepletion chemotherapy (fludarabine/cyclophosphamide) after the completion of standard chemotherapy, followed by SJCARB7H3_41BBL infusion. Pulmonary metastasectomy will be performed as indicated according to the standard of care and will be timed after (Regimen A) or before (Regimen B) lymphodepletion and SJCARB7H3_41BBL infusion. Following successful clearance of either regimen A or, if necessary, regimen B, the efficacy cohort will be initiated.
Drug: Cyclophosphamide
IV
Drug: Fludarabine
IV
Drug: Mesna
IV prior to and again at 3, 6, and 9 hours following each dose of cyclophosphamide.
Procedure: Apheresis
IV collection
Procedure: SJCARB7H3_41BBL infusion
1X107 CAR+ T cells/kg

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Event-free survival (EFS), defined as time from SJCARB7H3_41BBL infusion to disease relapse, progressive disease, new systemic therapy, secondary malignancy or death
Time Frame: Time from SJCARB7H3_41BBL infusion to time of first event, followed up to 24-months post-infusion
Event-free participants will be censored at the time of last follow-up. This analysis will report the Kaplan-Meier (KM) curve, along with the 12-month EFS estimate and its 80% confidence interval using the arcsine-square root transformation. Evaluable participants are those who complete standard chemotherapy, receive SJCARB7H3_41BBL and are treated on the regimen used for the Efficacy phase.
Time from SJCARB7H3_41BBL infusion to time of first event, followed up to 24-months post-infusion

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Overall survival (OS), defined as time from SJCARB7H3_41BBL cell infusion to all-cause mortality.
Time Frame: Time from SJCARB7H3_41BBL infusion to time of death from any cause, followed up to 24-months post-infusion
Event-free participants will be censored at the time of last follow-up. OS will be reported similarly to the EFS endpoint on the same participant subset.
Time from SJCARB7H3_41BBL infusion to time of death from any cause, followed up to 24-months post-infusion
Number of participants experiencing protocol-specified regimen-related toxicities.
Time Frame: Time from SJCARB7H3_41BBL infusion up to 28 days post-infusion.
This outcome measure will be descriptively summarized for the overall participant group and by regimen (if more than 1 regimen is evaluated) for each regimen-related toxicity. Evaluable participants include those who receive SJCARB7H3_41BBL and remain on protocol therapy through at least 28 days post-infusion or experience a related unacceptable toxicity.
Time from SJCARB7H3_41BBL infusion up to 28 days post-infusion.
Number of participants with successful manufacture of SJCARB7H3_41BBL cells of sufficient dose and planned product administration
Time Frame: Time of SJCARB7H3_41BBL infusion
This outcome measure will be descriptively summarized for the overall participant group and by regimen (if more than 1 regimen is evaluated) for participants who undergo apheresis and remain on protocol therapy through the end of standard therapy.
Time of SJCARB7H3_41BBL infusion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
St. Jude Children's Research Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Julie Park, MD, St. Jude Children's Research Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2034

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2035

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 5, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 17, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 24, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 18, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 3CAR4OS

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant de-identified datasets containing the variables analyzed in the published article will be made available (related to the study primary or secondary objectives contained in the publication). Supporting documents such as the protocol, statistical analyses plan, and informed consent are available through the CTG website for the specific study. Data used to generate the published article will be made available at the time of article publication. Investigators who seek access to individual level de-identified data will contact the computing team in the Department of Biostatistics (ClinTrialDataRequest@stjude.org) who will respond to the data request.

IPD Sharing Time Frame

Data will be made available at the time of article publication.

IPD Sharing Access Criteria

Data will be provided to researchers following a formal request with the following information: full name of requestor, affiliation, data set requested, and timing of when data is needed. As an informational point, the lead statistician and study principal investigator will be informed that primary results datasets have been requested.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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