Biologically-Adapted, Dose-Escalated Radiotherapy for the Treatment of Ewing Sarcoma, BEAR Trial

NCT07188532 | Recruiting DMC FDA Device

• 4 other identifiers: GMROR2411NCI-2025-0650724-004837BEAR
• Study Type: interventional
• Target: 141
• Locations: 1 country
• Sites: 1

Brief Summary

This clinical trial evaluates the effect of radiotherapy doses based on tumor size and tumor-specific characteristics (biologically-adapted) in treating patients with Ewing sarcoma. Radiotherapy uses high energy x-rays, particles, or radioactive seeds to kill tumor cells and shrink tumors. Conventional radiotherapy uses minimal imaging support to determine the positioning of radiotherapy. Hypofractionated radiotherapy delivers higher doses of radiotherapy over a shorter period of time and may kill more tumor cells and have fewer side effects. Dose-escalated radiotherapy uses doses that are higher than those used in conventional radiotherapy. Larger tumor sizes and other tumor-specific characteristics have been shown to be related to poorer outcomes. In addition, after dose-escalated radiotherapy, patients with larger tumors have demonstrated improved control of the disease at the primary tumor site. Giving biologically-adapted, dose-escalated radiotherapy may reduce the return of the cancer at the primary tumor site in patients with Ewing sarcoma with large tumors and other unfavorable characteristics. This clinical trial also evaluates the role of biomarkers in patients with Ewing sarcoma. Studying samples of blood and tumor tissue from patients with Ewing sarcoma in the laboratory may help doctors learn more about predicting the amount of disease and the likelihood of the cancer coming back.

Conditions

Ewing Sarcoma; Round Cell Sarcoma With EWSR1-non-ETS Fusion

Outcome Measures

Primary Outcomes (1)

• Reduction in local failure for patients with large tumors (Cohort A)

  Large tumors defined as ≥ 8cm. Will be compared to the historical control of 14.3%. Local failure will be defined per the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.

  Up to 2 years

Secondary Outcomes (4)

• Incidence of targeted, late grade 3 or greater adverse events (Cohort A)

  Up to 1 year after completion of local therapy

• Event-free survival (Cohort A)

  Up to 1 year after completion of local therapy

• Time to progression (Cohort A)

  Up to 1 year after completion of local therapy

• Overall survival (Cohort A)

  Up to 1 year after completion of local therapy

Study Arms (4)

Cohort A Group 1 (dose-escalated radiotherapy)

EXPERIMENTAL

Patients may receive SOC chemotherapy every 2 weeks for at least 3 cycles prior to radiotherapy. Patients then undergo hypofractionated or conventional dose-escalated radiotherapy daily, excluding weekends and holidays, for 25-36 treatment fractions in the absence of disease progression or unacceptable toxicity. Patients may also receive consolidation chemotherapy after completion of radiotherapy and/or surgical resection. Patients also undergo blood sample collection throughout the study. Additionally, patients may also undergo CT, PET/CT, and MRI with or without CT throughout the study at treating clinician's discretion.

Procedure: Biospecimen Collection; Drug: Chemotherapy; Procedure: Computed Tomography; Procedure: Conventional Radiotherapy; Procedure: Definitive Surgical Resection; Radiation: Dose-escalated Radiation Therapy; Other: Electronic Health Record Review; Radiation: Hypofractionated Radiation Therapy; Procedure: Magnetic Resonance Imaging; Procedure: Positron Emission Tomography; Other: Questionnaire Administration

Cohort A Group 2 (standard dose radiotherapy)

EXPERIMENTAL

Patients may receive SOC chemotherapy every 2 weeks for at least 3 cycles prior to radiotherapy. Patients then undergo hypofractionated or conventional standard dose radiotherapy daily, excluding weekends and holidays, for 25-31 treatment fractions in the absence of disease progression or unacceptable toxicity. Patients may also receive consolidation chemotherapy after completion of radiotherapy and/or surgical resection. Patients also undergo blood sample collection throughout the study. Additionally, patients may also undergo CT, PET/CT, and MRI with or without CT throughout the study at treating clinician's discretion.

Procedure: Biospecimen Collection; Drug: Chemotherapy; Procedure: Computed Tomography; Procedure: Conventional Radiotherapy; Procedure: Definitive Surgical Resection; Other: Electronic Health Record Review; Radiation: Hypofractionated Radiation Therapy; Procedure: Magnetic Resonance Imaging; Procedure: Positron Emission Tomography; Other: Questionnaire Administration; Radiation: Radiation Therapy

Cohort B (definitive radiotherapy, surgical resection)

EXPERIMENTAL

Patients may receive SOC chemotherapy every 2 weeks for at least 3 cycles prior to radiotherapy. Patients with tumor size \< 8cm at diagnosis undergo definitive radiotherapy or surgical resection. Patients may also receive consolidation chemotherapy after completion of definitive radiotherapy or surgical resection. Patients also undergo blood sample collection throughout the study. Additionally, patients may also undergo CT, PET/CT, and MRI with or without CT throughout the study at treating clinician's discretion.

Procedure: Biospecimen Collection; Drug: Chemotherapy; Procedure: Computed Tomography; Procedure: Definitive Surgical Resection; Other: Electronic Health Record Review; Radiation: External Beam Radiation Therapy; Procedure: Magnetic Resonance Imaging; Procedure: Positron Emission Tomography; Other: Questionnaire Administration

Cohort C (radiotherapy, surgical resection)

EXPERIMENTAL

Patients may receive SOC chemotherapy every 2 weeks for at least 3 cycles prior to radiotherapy. Patients undergo radiotherapy before or after undergoing definitive surgical resection. Patients may also receive consolidation chemotherapy after completion of definitive radiotherapy and surgical resection. Patients also undergo blood sample collection throughout the study. Additionally, patients may also undergo CT, PET/CT, and MRI with or without CT throughout the study at treating clinician's discretion.

Procedure: Biospecimen Collection; Drug: Chemotherapy; Procedure: Computed Tomography; Procedure: Conventional Radiotherapy; Procedure: Definitive Surgical Resection; Other: Electronic Health Record Review; Radiation: External Beam Radiation Therapy; Radiation: Hypofractionated Radiation Therapy; Procedure: Magnetic Resonance Imaging; Procedure: Positron Emission Tomography; Other: Questionnaire Administration; Radiation: Radiation Therapy

Interventions

Chemotherapy DRUG

Given chemotherapy

Also known as: Chemo, Chemotherapy (NOS), Chemotherapy, Cancer, General

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Computed Tomography PROCEDURE

Undergo CT or PET/CT

Also known as: CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized axial tomography (procedure), Computerized Tomography, Computerized Tomography (CT) scan, CT, CT Scan, Diagnostic CAT Scan, Diagnostic CAT Scan Service Type, tomography

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Conventional Radiotherapy PROCEDURE

Undergo conventional radiotherapy

Also known as: 2-Dimensional Conventional Radiation Therapy, 2D Conventional Radiotherapy, 2D Radiotherapy, 2D-RT, Radiation, 2D Conventional

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort C (radiotherapy, surgical resection)

Definitive Surgical Resection PROCEDURE

Undergo definitive surgical resection

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Dose-escalated Radiation Therapy RADIATION

Undergo hypofractionated or conventional radiotherapy

Also known as: Dose-escalated RT

Cohort A Group 1 (dose-escalated radiotherapy)

Electronic Health Record Review OTHER

Ancillary studies

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

External Beam Radiation Therapy RADIATION

Undergo definitive radiotherapy

Also known as: Definitive Radiation Therapy, EBRT, External Beam Radiation, External Beam Radiotherapy, External Beam Radiotherapy (conventional), External Beam RT, external radiation, External Radiation Therapy, external-beam radiation, Radiation, External Beam, Teleradiotherapy, Teletherapy, Teletherapy Radiation

Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Hypofractionated Radiation Therapy RADIATION

Undergo hypofractionated radiation therapy

Also known as: Hypofractionated, Hypofractionated Radiotherapy, hypofractionation, Radiation, Hypofractionated

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort C (radiotherapy, surgical resection)

Magnetic Resonance Imaging PROCEDURE

Undergo MRI

Also known as: Magnetic Resonance, Magnetic Resonance Imaging (MRI), Magnetic resonance imaging (procedure), Magnetic Resonance Imaging Scan, Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance, MR, MR Imaging, MRI, MRI Scan, MRIs, NMR Imaging, NMRI, Nuclear Magnetic Resonance Imaging, sMRI, Structural MRI

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Positron Emission Tomography PROCEDURE

Undergo PET/CT

Also known as: Medical Imaging, Positron Emission Tomography, PET, PET Scan, Positron emission tomography (procedure), Positron Emission Tomography Scan, Positron-Emission Tomography, PT

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Questionnaire Administration OTHER

Ancillary studies

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Radiation Therapy RADIATION

Undergo hypofractionated or conventional standard radiotherapy

Also known as: Cancer Radiotherapy, Energy Type, ENERGY_TYPE, Irradiate, Irradiated, Irradiation, Radiation, Radiation Therapy, NOS, Radiotherapeutics, Radiotherapy, RT, Therapy, Radiation

Cohort A Group 2 (standard dose radiotherapy); Cohort C (radiotherapy, surgical resection)

Biospecimen Collection PROCEDURE

Undergo blood sample collection

Also known as: Biological Sample Collection, Biospecimen Collected, Specimen Collection

Cohort A Group 1 (dose-escalated radiotherapy); Cohort A Group 2 (standard dose radiotherapy); Cohort B (definitive radiotherapy, surgical resection); Cohort C (radiotherapy, surgical resection)

Eligibility Criteria

• Age: 2 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients of age ≥ 2 years are eligible for the study
• Lansky or Karnofsky performance status ≥ 70
• Ability to provide written informed consent and complete questionnaire(s) by themselves or with assistance
• Willing to provide blood samples for correlative research purposes
• COHORT A ONLY: Willing to provide biopsy sample to run Mayo Complete Solid Tumor Panel

You may not qualify if:

• Prior chemotherapy or radiotherapy that, in the opinion of the treating medical oncologist or radiation oncologist, is considered to interfere with the current treatment or measurement of outcomes
• Receiving any investigational agent which would be considered as a treatment for the primary neoplasm that is considered by the investigator to interfere with the current treatment or measurement of outcomes
• Note: Co-enrollment on another clinical trial is allowed per the treating radiation oncologist's discretion
• Other active malignancy ≤ 1 year prior to registration that is considered by the investigator to interfere with the current treatment or measurement of outcomes
• Patients that have severe co-morbid systemic illness or other disease which would interfere significantly with the current treatment or measurement of outcomes
• Patients that have active uncontrolled systemic infection, symptomatic congestive heart failure, unstable angina, cardiac arrhythmia, or psychiatric illness or social situation that would limit study adherence
• Any of the following:
• Pregnant patients
• Nursing patients

Sponsors & Collaborators

• Mayo Clinic: lead

Study Sites (1)

Mayo Clinic in Rochester

Rochester, Minnesota, 55905, United States

RECRUITING

Related Links

• Mayo Clinic Clinical Trials

MeSH Terms

Conditions

Sarcoma, Ewing

Interventions

Specimen Handling; Drug Therapy; Radiation; Congresses as Topic; Radiation Dose Hypofractionation; Magnetic Resonance Spectroscopy; Radiotherapy

Condition Hierarchy (Ancestors)

Osteosarcoma; Neoplasms, Bone Tissue; Neoplasms, Connective Tissue; Neoplasms, Connective and Soft Tissue; Neoplasms by Histologic Type; Neoplasms; Sarcoma

Intervention Hierarchy (Ancestors)

Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Investigative Techniques; Therapeutics; Physical Phenomena; Organizations; Health Care Economics and Organizations; Dose Fractionation, Radiation; Radiotherapy Dosage; Spectrum Analysis; Chemistry Techniques, Analytical

Study Officials

• Roman O. Kowalchuk, MD

  Mayo Clinic in Rochester

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Clinical Trials Referral Office

CONTACT

855-776-0015; mayocliniccancerstudies@mayo.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 16, 2025
• First Posted: September 23, 2025
• Study Start: November 24, 2025
• Primary Completion (Estimated): December 31, 2029
• Study Completion (Estimated): December 31, 2029
• Last Updated: January 23, 2026

Record last verified: 2026-01

Locations

US (1)