A Phase II Study of 131I-Omburtamab plus Radiotherapy in People with Desmoplastic Small Round Cell Tumors and Other Solid Tumors in the Peritoneum


Full Title

Phase II Combination of 131I-Omburtamab Radioimmunotherapy and External Beam Radiotherapy for Desmoplastic Small Round Cell Tumor


The purpose of this study is to assess the safety and effectiveness of the investigational drug omburtamab when combined with radiotherapy in patients with desmoplastic small round cell tumors (DSRCT) and other solid tumors of the peritoneum (lining of the abdomen) that have a protein called B7H3, the target of omburtamab. Omburtamab can attach to many kinds of cancer cells, including DSRCT cells and other cancers of the peritoneum that express B7H3. Linking omburtamab to radioactive iodine (131I) makes it more effective for killing tumor cells. 131I-Omburtamab carries radiation directly to cancer cells and kills them.

Patients whose DSRCT was previously removed completely through surgery will also receive radiation therapy to the entire abdominal cavity in addition to omburtamab. Omburtamab is given as one dose via injection directly into the abdominal lining, where the tumor is.

Who Can Join

To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have DSRCT or a peritoneal tumor that has the B7H3 protein.
  • At least 4 weeks must pass between the completion of prior therapies and entry into the study.
  • This study is for patients age 1 year and older.

For more information about this study and to inquire about eligibility, please contact 1-833-MSK-KIDS.




Phase II (phase 2)


ClinicalTrials.gov ID