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Active, not recruitingNCT06068075Updated May 5, 2026

Liquid Biopsy in Ewing Sarcoma and Osteosarcoma as a Prognostic And Response Diagnostic: LEOPARD

An interventional study of FoundationOne Liquid CDx in Ewing Sarcoma, Ewing Sarcoma of Bone and Ewing Sarcoma of Soft Tissue, sponsored by Dana-Farber Cancer Institute. Active, not recruiting at 15 sites in United States. Open to participants aged 12 Months to 50 Years. Per ClinicalTrials.gov, last updated 2026-05-05.

Sponsored by Dana-Farber Cancer Institute · Not applicable, Interventional, and Diagnostic

From the registry’s dates

  • Registered 5 years 4 months after the study started (first participant enrolled May 2018, registered Sep 2023).
Phase
Not applicable
Study type
Interventional
Enrollment
340
Allocation
Non-randomized
Ages
12 Months to 50 Years
Sex
All
01

Study summary

This is a prospective multicenter biomarker study evaluating the prognostic impact of ctDNA detection at diagnosis in patients with Ewing sarcoma or osteosarcoma.

Read the detailed description

The purpose of this study is to evaluate whether ctDNA in the blood can provide information about the chances of Ewing sarcoma or osteosarcoma coming back after treatment. This research study is evaluating a new advanced laboratory test to detect small pieces of tumor genes in the peripheral blood known as circulating tumor DNA (ctDNA).

Part A : During this part of the research study (Part A) participants will be asked to provide blood samples at pre-defined times. These blood samples may help find specific genetic alterations commonly seen in Ewing sarcoma or osteosarcoma that may allow investigators to learn more about the uses of ctDNA. The results of the ctDNA analysis will not be returned to participants.

Approximately 90 patients will take part in this study across multiple centers.

Part B: This research study is evaluating new advanced laboratory tests to detect small pieces of tumor genes in the peripheral blood known as circulating tumor DNA (ctDNA). Part B of the research study, which focuses on ctDNA tests that can be returned to providers and patients with Ewing sarcoma. This part of the study will allow comparison of commercial ctDNA testing from Foundation Medicine to our research testing. It is expected that about 60 people with Ewing sarcoma will take part in Part B of this research study.

The sponsor of this protocol is Dana-Farber Cancer Institute and is providing funding for the study. Additional funding for this study is provided by the Conquer Cancer Foundation of the American Society of Clinical Oncology, Alex's Lemonade Stand Foundation, Boston Children's Hospital Office of Faculty Development, the Friends of Dana-Farber Cancer Institute, The Harvard Catalyst Program, and the Spada Pediatric Sarcoma Foundation

02

Conditions studied

  • Ewing Sarcoma
  • Ewing Sarcoma of Bone
  • Ewing Sarcoma of Soft Tissue
  • Peripheral Primitive Neuroectodermal Tumor
  • Peripheral Primitive Neuroectodermal Tumor of Bone
  • Peripheral Primitive Neuroectodermal Tumor of Soft Tissue
  • High-grade Osteosarcoma

Keywords

  • Ewing Sarcoma
  • Ewing Sarcoma of Bone
  • Ewing Sarcoma of Soft Tissue
  • Peripheral Primitive Neuroectodermal Tumor
  • Peripheral Primitive Neuroectodermal Tumor of Bone
  • Peripheral Primitive Neuroectodermal Tumor of Soft Tissue
  • High-grade osteosarcoma
03

In context

Sarcoma, Ewing

250 studies on the registry are indexed under Sarcoma, Ewing; 69 are open to participants now.

This study's planned enrollment of 340 is above the median of 36 across 204 interventional studies indexed under Sarcoma, Ewing.

Browse Sarcoma, Ewing studies →

Lead sponsor

Dana-Farber Cancer Institute is the lead sponsor of 834 studies on the registry; 122 are open to participants now.

Of its 114 completed or terminated interventional studies of FDA-regulated products, 78 (68%) have results posted.

Browse Dana-Farber Cancer Institute studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
12 Months to 50 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • For Part A, subjects must meet all of the following eligibility criteria.
  • Age: ≥ 12 months of age at time of study enrollment to 50 years of age
  • Diagnosis: Patients with histologic diagnosis (by institutional pathologist) of newly diagnosed, localized or regionally disseminated Ewing sarcoma or peripheral primitive neuroectodermal tumor (PNET) of bone or soft tissue or; Patients with histologic diagnosis (by institutional pathologist) of newly diagnosed, non-pelvic, localized or regionally disseminated high-grade osteosarcoma. NOTE: Staging will be assessed according to standard of care at the treating center.

  • Prior Therapy:

    • Patients should have only previously had a , and not had prior attempt at tumor resection.
    • Not yet started chemotherapy or radiation therapy OR patient has started chemotherapy or radiation therapy, but an appropriate pre-treatment baseline sample was collected and processed for ctDNA under a local banking study in DFCI Pediatrics and is available to use for this study.

  • Planned to receive chemotherapy as follows:

    -- VDC/IE as per COG protocols AEWS0031, AEWS1031 or AEWS1221 (for patients with Ewing sarcoma or PNET); or MAP as per COG protocol AOST0331 (for patients with osteosarcoma).

  • For Part B subjects must meet all of the following eligibility criteria.
  • Age: ≥ 12 months of age at time of study enrollment
  • Diagnosis: Patients with histologic diagnosis (by institutional pathologist) of newly diagnosed Ewing sarcoma or peripheral primitive neuroectodermal tumor (PNET) of bone or soft tissue

  • Prior Therapy:

    • Patients should have had only frontline therapy as per institutional standard, and maintenance therapy if given (no relapse therapy).
    • If frontline systemic therapy already completed (not including maintenance or site radiation), therapy completed within 6 months of enrollment to Part B.
    • Subjects must have a willing physician provider supporting their participation in Part B.
  • For Part B, providers are eligible to receive the provider survey if they are listed as the primary provider for the patient at the study site.

Exclusion criteria

Exclusion Criteria:

  • For Part A, subjects must not meet any of the following exclusion criteria.
  • Patients with distant disease.
  • Patients with known Ewing-like sarcoma (e.g., BCOR-CCNB3 or CIC-DUX4 translocated small round cell sarcomas) are not eligible.
  • Patients who are enrolled with an initial diagnosis of Ewing sarcoma and subsequently found to have Ewing-like sarcoma will be replaced. Samples obtained prior to removal from study will be analyzed and reported descriptively. Patients with Ewing-like tumors may continue to provide samples and clinical data until they meet off-study criteria per protocol.
  • Patients weighing \< 5 kg at time of diagnosis
  • Patients with a second malignant neoplasm
  • Patients without detectable tumor at the time of study enrollment (ie, complete tumor resection prior to study enrollment)
  • Patients already receiving tumor-directed therapy at the time of study enrollment except when a pre-treatment baseline sample has already been obtained under a local banking study in DFCI Pediatrics that would be eligible for analysis under this study.
  • Patients with osteosarcoma with a pelvic primary tumor site Pregnancy
  • For Part B, subjects must not meet any of the following exclusion criteria.
  • Patients with known Ewing-like sarcoma (e.g., BCOR-CCNB3 or CIC-DUX4 translocated small round cell sarcomas) are not eligible.
  • Samples obtained prior to removal from study will be analyzed and reported descriptively. Patients with Ewing-like tumors may continue to provide samples and clinical data until they meet off-study criteria per protocol
  • Patients weighing \< 5 kg at time of enrollment
  • Patients diagnosed with disease and/or having started therapy directed at disease relapse
  • Pregnancy
  • Resides outside of the United States
  • For Part B, providers at non-study centers will not be eligible to receive the provider survey.
Terms in these criteria, in plain language(3)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Relapsed and refractory

Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.

05

Study design

Phase
Not applicable
Primary purpose
Diagnostic
Allocation
Non-randomized
Intervention model
Single group
Masking
None (open label)
Enrollment
340 participants (estimated)

Study arms

  • No intervention
    REG EWING or OSTEO: ctDNA EVALUATION

    This study involves collection of blood samples at pre-specified time points as well as collection of information about this disease. For each timepoint, submit two tubes of blood (17 mL total or a little more than 3 teaspoons) per standard ctDNA workflow

  • Experimental
    EWING ctDNA RETURN OF RESULTS

    This study involves collection of blood samples at pre-specified time points as well as collection of information about this disease. For each timepoint, submit two tubes of blood (17 mL total or a little more than 3 teaspoons) to a commercial testing laboratory called Foundation Medicine and one tube of blood (10 mL or 2 teaspoons) to standard ctDNA workflow

    Other: FoundationOne Liquid CDx

Interventions

  • OtherFoundationOne Liquid CDx

    a FoundationOne liquid biopsy test kit will be sent to the laboratory of the subject's treating center, in addition to the paired cell stabilizing tube from the primary center

    Also known as: Liquid Biopsy

06

What researchers measure

Primary outcomes

  1. Event-free survival rate

    Proportion of patient without an event by baseline detection of ctDNA

    Time frame: 2 years

Secondary outcomes

  1. Event-free survival rate

    Proportion of patient without an event by ctDNA burden at baseline

    Time frame: 2 years

07

Study locations

15 sites
08

References and documents

Individual participant data

Plan to share: Yes — The Dana-Farber / Harvard Cancer Center encourages and supports the responsible and ethical sharing of data from clinical trials. De-identified participant data from the final research dataset used in the published manuscript may only be shared under the terms of a Data Use Agreement. Requests may be directed to Sponsor Investigator or designee. The protocol and statistical analysis plan will be made available on Clinicaltrials.gov only as required by federal regulation or as a condition of awards and agreements supporting the research.

Supporting information: Study protocol, Statistical analysis plan

Time frame: Data can be shared no earlier than 1 year following the date of publication

Access criteria: Contact the Belfer Office for Dana-Farber Innovations (BODFI) at innovation@dfci.harvard.edu

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started May 2018 (actual). Primary completion is estimated for Jan 2027, 103 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 28, 2023
First posted
Oct 5, 2023
StartActual
May 8, 2018
Primary completionEst.
Jan 1, 2027
CompletionEst.
Jan 1, 2027
Last update
May 5, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on May 5, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06068075
Lead sponsor
Dana-Farber Cancer Institute
Collaborators
Alex's Lemonade Stand Foundation, Conquer Cancer Foundation, Harvard University, Sam Day Foundation
Responsible party
David S Shulman, MD (Principal Investigator, Dana-Farber Cancer Institute) — Principal investigator
First posted
Oct 5, 2023
Start date
May 8, 2018
Primary completion
Jan 1, 2027 (estimated)
Completion
Jan 1, 2027 (estimated)
Last update
May 5, 2026

Study contacts

David S Shulman, MD
principal investigator · Dana-Farber Cancer Institute

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.

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