Fluorescence-Guided Surgery of Rhabdomyosarcoma Using a B7-H3 Targeted Antibody-Fluorophore Conjugate.
Ritika Gupta1, Evie G Ehrhorn2,3, Ashruti Pant1
1Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986120 Nebraska Medical Center, Omaha, Nebraska 68198-6858, United States of America.
Molecular Pharmaceutics
|June 11, 2026
Summary
This study developed MGA271-IRDye800, a novel imaging agent targeting B7-H3 for sarcoma surgery. It significantly improves tumor visualization and margin delineation, aiding in reducing residual disease for better patient outcomes.
Area of Science:
- Oncology
- Medical Imaging
- Molecular Biology
Background:
- Sarcoma resection is challenged by infiltrative growth and residual disease.
- Effective intraoperative imaging is crucial for complete tumor removal.
- B7-H3 is a potential target for sarcoma-specific imaging.
Purpose of the Study:
- To develop and evaluate MGA271-IRDye800, a near-infrared fluorescent imaging agent targeting B7-H3 for sarcoma.
- To assess its efficacy in visualizing primary and metastatic sarcoma lesions intraoperatively.
Main Methods:
- Conjugation of anti-B7-H3 antibody (MGA271) to IRDye800CW.
- In vitro studies using B7-H3-expressing and negative sarcoma cell lines.
- In vivo near-infrared fluorescent imaging (NIRF) in an orthotopic rhabdomyosarcoma xenograft model.
Main Results:
- MGA271-IRDye800 showed specific binding and strong fluorescence in vitro.
- In vivo NIRF imaging demonstrated significantly improved tumor visualization and higher tumor-to-background ratios (TBRs) compared to controls.
- The agent enabled clear delineation of tumor margins and detection of micrometastases during fluorescence-guided surgery.
Conclusions:
- B7-H3-targeted NIRF imaging with MGA271-IRDye800 provides sensitive and specific intraoperative visualization of sarcoma.
- This probe has strong potential for clinical translation to guide surgical resection and improve patient outcomes.
