A Study of 177Lu-DTPA-Omburtamab in Children and Adolescents With Brain Cancer or Cancer That Has Spread to the Central Nervous System (CNS)

A Phase I Dose Escalation Trial of Compartmental Radioimmunotherapy (cRIT) Using 177Lu-DTPA-omburtamab in Pediatric and Adolescent Patients With Recurrent or Refractory B7H3 Expressing Primary or Metastatic CNS Tumors

The purpose of this study is to find out whether 177Lu-DPTA-omburtamab is a safe treatment for children and adolescents with recurrent/refractory medulloblastoma or another type of cancer with CNS metastases.

Study Overview

• Status: Recruiting
• Conditions: Recurrent Medulloblastoma; Refractory Medulloblastoma; CNS Metastases; Central Nervous System Metastasis
• Intervention / Treatment: Biological: 25 mCi 177Lu- DTPA-omburtamab

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Ravinder Grewal, MD; Phone Number: 212-639-2872; Email: grewalr@MSKCC.ORG
• Study Contact Backup: Name: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153; Email: faroukss@mskcc.org

Study Locations

• United States
  • New Jersey
    • Basking Ridge, New Jersey, United States, 07920
      • Recruiting
      • Memorial Sloan Kettering Cancer Center Basking Ridge (Limited Protocol Activities)
      • Contact: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153
    • Middletown, New Jersey, United States, 07748
      • Recruiting
      • Memorial Sloan Kettering at Monmouth (Limited Protocol Activities)
      • Contact: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153
    • Montvale, New Jersey, United States, 07645
      • Recruiting
      • Memorial Sloan Kettering at Bergen (Limited Protocol Activities)
      • Contact: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153
  • New York
    • Commack, New York, United States, 11725
      • Recruiting
      • Memorial Sloan Kettering at Suffolk-Commack (Limited Protocol Activities)
      • Contact: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153
    • Harrison, New York, United States, 10604
      • Recruiting
      • Memorial Sloan Kettering at Westchester (Limited Protocol Activities)
      • Contact: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153
    • New York, New York, United States, 10065
      • Recruiting
      • Memorial Sloan Kettering Cancer Center (All Protocol Activities)
      • Contact: Sameer Farouk Sait, MD; Phone Number: 212-639-2153
    • Uniondale, New York, United States, 11553
      • Recruiting
      • Memorial Sloan Kettering at Nassau (Limited Protocol Activities)
      • Contact: Sameer Farouk Sait, MBBS; Phone Number: 212-639-2153

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

- Disease type:

• Histologically confirmed diagnosis of a tumor that is known to express B7-H3 including but not limited to neuroblastoma, medulloblastoma, rhabdoid tumors, pineoblastoma, retinoblastoma, CNS embryonal tumor, rhabdomyosarcoma, Ewing's sarcoma and ependymoma.

  • Disease status:

• Patients must have recurrent or refractory disease with CNS parenchymal and/or leptomeningeal disease which has been treated with conventional therapies or for which no conventional therapy exists. Measurable or evaluable disease is not required at time of enrollment.

  - Age: Patients must be ≥ 3 and < 22 years of age at the time of enrollment.

  • Prior Therapy: The participant must have recovered from acute toxic effects of prior anti-cancer therapies with the following minimum duration from prior therapy:
• Chemotherapy: Patients must have received their last dose of known myelosuppressive anticancertherapy at least 21 days (3 weeks) prior to enrollment or at least 42 days (6 weeks) if prior nitrosourea.
• Anti-GD2 monoclonal antibody (neuroblastoma patients): Patients must have received their last dose of anti-GD2 mAb at least 14 days (2 weeks) before enrollment.

• Radiation: Patients must have had their last fraction of:

  • Craniospinal irradiation, whole brain radiation, or total body irradiation at least 21 days (3 weeks) prior to study enrollment.
  • Focal radiation to areas of symptomatic metastatic disease at least 14 days (2 weeks) prior to study enrollment.
• Stem Cell Transplant (SCT): For autologous SCT, 60 days (≥ 2 months) must have elapsed before study enrollment. Patients who have received an autologous hematopoietic stem cell injection to support non- myeloablative therapy (such as 131 I-MIBG) are eligible at any time as long as they meet the other criteria for eligibility. 131
• I-MIBG therapy or treatment with other radiopharmaceuticals (neuroblastoma 131 patients): A minimum of 42 days (6 weeks) must have elapsed after I-MIBG therapy before start of protocol therapy.
• Investigational/Biologic Agent (anti-neoplastic): Patient must have recovered from any acute toxicity potentially related to the agent and received their last dose of the investigational or biologic agent ≥ 7 days (1 week) prior to study enrollment.

• Molecular targeted therapies: Patients must complete a washout period from last therapy that is either 7 days (1 week) or 3 half-lives, whichever is longer.

  • Patients with neurological deficits should have deficits that are stable for a minimum of 7 days (1 week) prior to enrollment.
  • Patients with seizure disorders may be enrolled if seizures are controlled.
  • Karnofsky Performance Scale (KPS for > 16 years of age) or Lansky Performance Score (LPS for ≤ 16 years of age) assessed within 14 days (2 weeks) prior to study enrollment must be ≥ 50%.

• Patients who are unable to walk because of neurologic deficits, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.

  • Peripheral absolute neutrophil count (ANC) ≥ 0.5x 109/ L (must not have received G-CSF within 7 days (1 week) prior to enrollment or pegfilgrastim within 14 days (2 weeks) prior to enrollment.
  • Platelet count ≥ 75 x 109/ L. Growth factor support (romiplostim or biosimilar) is permitted both prior to and during therapy.

• For patients with neuroblastoma (regardless of marrow disease status) and other solid tumors known bone marrow infiltration from disease: platelet count ≥ 50 x 109/ L (with no platelet transfusion within 7 days prior to study enrollment).

  - Adequate Renal Function Defined as:

  - A creatinine based on age/gender as follows: Age; Maximum Serum Creatinine (mg/dL) Male and Female

  1 month to < 6 months; 0.4, 0.4 6 months to < 1 year; 0.5, 0.5

  1. to < 2 years; 0.6, 0.6
  2. to < 6 years; 0.8, 0.8

  6 to < 10 years; 1, 1 10 to < 13 years; 1.2. 1.2 13 to < 16 years; 1.5, 1.4

  ≥ 16 years; 1.7, 1.4

  • The threshold creatinine values in this Table were derived from the Schwartz formula for estimating GFR utilizing child length and stature data published by the CDC.
  • Adequate Liver Function Defined as: - Bilirubin ≤ 1.5 x upper limit of normal (ULN) for age (or ≤ 3 x ULN if Gilbert's syndrome) - SGPT (ALT) < 135 U/L. For the purpose of this study, the ULN for SGPT is 45 U/L.
  • Presence of an appropriate intraventricular access device (e.g., programmable ventriculoperitoneal [VP] shunt or Ommaya reservoir). Patients are not required to have an existing programmable VP shunt or Ommaya at the time of study enrollment but must be willing and able to undergo a surgical procedure to have one placed prior to cRIT.

• Note: Patients with an existing intraventricular VP shunt without a programmable component must be willing and able to undergo modification of the shunt.

  • Patients may have active malignancy outside the central nervous system but do not immediately require treatment for systemic disease. Neuroblastoma patients with CNS and systemic disease will only receive 1 dose of cRIT 177Lu- omburtamab while patients with CNS metastases in the absence of systemic disease can receive 2 doses of cRIT 177Lu-omburtamab.
  • Patients may be on standing steroids, as long as the dosage is either stable or decreasing for at least 7 days (1 week) prior to enrollment.
  • Human Anti-Mouse Antibody (HAMA) testing will be performed prior to 177Lu-DTPAomburtamab.

Exclusion Criteria:

• Patients with obstructive or symptomatic communicating hydrocephalus.
• Patients with an uncontrolled life-threatening infection.

• Patients who are pregnant:

  o A negative pregnancy test is required for all women of childbearing age, and appropriate contraception for 3 months after the last dose of 177Lu-DTPAomburtamab is required during the study period.

• Severe major organ toxicity:

  • Cardiac, pulmonary, and gastrointestinal system toxicity should all be < grade 2
  • Patients with grade 4 hearing loss are excluded

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dose Level 1: 25 mCi; 25 mCi 177Lu- DTPA-omburtamab	Biological: 25 mCi 177Lu- DTPA-omburtamab; The dose of DTPA-omburtamab will be decided by the dose escalation design
Experimental: Dose Level 2: 50 mCi; 50 mCi 177Lu- DTPA-omburtamab	Biological: 25 mCi 177Lu- DTPA-omburtamab; The dose of DTPA-omburtamab will be decided by the dose escalation design
Experimental: Dose Level 3: 75 mCi; 75 mCi 177Lu- DTPA-omburtamab	Biological: 25 mCi 177Lu- DTPA-omburtamab; The dose of DTPA-omburtamab will be decided by the dose escalation design
Experimental: Dose Level 4: 100 mCi; 100 mCi 177Lu- DTPA-omburtamab	Biological: 25 mCi 177Lu- DTPA-omburtamab; The dose of DTPA-omburtamab will be decided by the dose escalation design

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with toxicities	To determine safety of up to 2 cycles of cRIT with 177Lu-DTPA-omburtamab treatment in pediatric patients graded according to CTCAE version 5	Up to 2 cycles (each cycle is 28 days)
Maximum Tolerated Dose/MTD	To determine the maximum tolerated dose (MTD) and/or the recommended Phase 2 dose (RP2D) of a single injection of cRIT with 177Lu-DTPA-omburtamab in pediatric patients.	Up to 2 cycles (each cycle is 28 days)

Collaborators and Investigators

• Sponsor: Memorial Sloan Kettering Cancer Center
• Collaborators: Y-mAbs Therapeutics
• Investigators: Principal Investigator: Sameer Farouk Sait, MBBS, Memorial Sloan Kettering Cancer Center

Publications and helpful links

Helpful Links

• Memorial Sloan Kettering Cancer Center

Study record dates

Study Major Dates

• Study Start (Actual): July 2, 2026
• Primary Completion (Estimated): June 2, 2030
• Study Completion (Estimated): July 2, 2030

Study Registration Dates

• First Submitted: July 6, 2026
• First Submitted That Met QC Criteria: July 9, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): July 13, 2026
• Last Update Submitted That Met QC Criteria: July 9, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Memorial Sloan Kettering Cancer Center; Recurrent Medulloblastoma; CNS Metastases; Refractory Medulloblastoma; Central Nervous System Metastasis; 26-097; 177Lu-DTPA-Omburtamab
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Glioma; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Neuroectodermal Tumors, Primitive; Medulloblastoma
• Other Study ID Numbers: 26-097

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made following one year after publication and for up to 36 months later. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No