LEOPARD Study: Liquid Biopsy for Ewing Sarcoma and Osteosarcoma
This study, called LEOPARD, is looking at a new way to understand Ewing sarcoma and osteosarcoma. Researchers are using a "liquid biopsy" (a blood test) called FoundationOne Liquid CDx to detect tiny pieces of tumor DNA (ctDNA) in your blood. The goal is to see if finding ctDNA at the time of diagnosis can help predict if the cancer will return after treatment. This study is for people aged 12 months to 50 years who have been newly diagnosed with Ewing sarcoma or a related tumor. The main way they will measure success is by looking at how long people live without the cancer coming back, measured at 2 years. The current status of this study is unclear, and it plans to enroll 340 participants.
- Study design
- This is an interventional study planning to enroll 340 participants. It is a multicenter biomarker study.
- What's involved
- If you join Part A, you will provide blood samples at specific times. Part B involves comparing commercial ctDNA testing with research testing.
- Compensation
- Not stated in the trial record.
- Follow-up
- The study measures event-free survival at 2 years, which suggests a follow-up period of at least that long.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
NCT06068075
Liquid Biopsy in Ewing Sarcoma and Osteosarcoma as a Prognostic And Response Diagnostic: LEOPARD
Active, Not Recruiting
NAAges 12–50InterventionalDiagnosticDana-Farber Cancer InstituteInvestigator-initiated
~340 participants
Updated 2026-05-05 on ClinicalTrials.gov
What's tested:FoundationOne Liquid CDx
At a glance
Recruiting sites
0 of 15 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Event-free survival rate
Measured over 2 years
Conditions
Where it's being run
15 sites across 11 statesMassachusetts4
Ohio2
California1
Georgia1
Minnesota1
Pennsylvania1
Rhode Island1
Tennessee1
Study leadership
- David S Shulman, MD · PRINCIPAL_INVESTIGATOR · Dana-Farber Cancer Institute
Who to contact
This trial hasn't published a contact. View it on ClinicalTrials.gov
Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
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 biopsy, 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:
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 metastatic 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
Patients with distant metastatic 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
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 relapsed 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.
What this trial measures
- Event-free survival rate2 years
Proportion of patient without an event by baseline detection of ctDNA